ESE's works engine tuner

[nick gill]

That low-conductive duct would pass less exhaust gas heat on to the the cylinder, so the cylinder would stay cooler while the heat would stay on the inside surface of the duct. It would then neatly raise the temperature of the washed-through fresh mixture before this would get shoved back into the cylinder, ready to create the mother of all detonations.

Hi Frits. So I guess I've misinterpreted this part of my 2T education :facepalm:
This may also kill off my other two deto interventions, namely 1) Putting a Thermal Barrier Coating on the smooth surfaced ex port duct (easily removed, phew) 2) Fabricating a Ti header section.
Am I following your logic correctly? Or would I have been better to put the TBC on the textured transfers and keep the ex duct as a heatsink for the gas column?
A thousand thanks as always for your teachings.

[jonny quest]

I'm surprised there hasn't been a HP vs TQ debate here yet.

Did you just start one TZ350?

Wouldn't the RPM spread between HP and TQ be more important?

TQ is a static measurement. HP is not. Why isn't HP just the ultimate goal?

[jonny quest]

Re connecting rods

Hot Rods switched manufacturing to the USA recently.

I typically only use OEM, PROX, Carrillo. A few instances lately I had no choice but to use Hot Rods. These were on 250F's mind you, but basically stock rebuilds. Guess what happened. Blamo, through the cases. Not cheap fix. Not saying all their rods are faulty. ... but be careful

[husaberg]

I'm surprised there hasn't been a HP vs TQ debate here yet.

Did you just start one TZ350?

Wouldn't the RPM spread between HP and TQ be more important?

TQ is a static measurement. HP is not. Why isn't HP just the ultimate goal?


HP is merely the rate at which an engine performs TQ.

[jonny quest]

HP is merely the rate at which an engine performs TQ.

Ok, great. Our motors move the bike and us. Tq is a static measurement, not moving us yet until you enter time into the equation. Hp moves us. Rate is the time then, correct?

[husaberg]

Ok, great. Our motors move the bike and us. Tq is a static measurement, not moving us yet until you enter time into the equation. Hp moves us. Rate is the time then, correct?

I understand you guys threw them out a couple of hundred years ago, but English please?:bleh:
Torque is work, HP is the rate at which this work is performed.
Remember the horse and the bucket.
318543

[Sketchy_Racer]

Ok, great. Our motors move the bike and us. Tq is a static measurement, not moving us yet until you enter time into the equation. Hp moves us. Rate is the time then, correct?

Yes, Hp (which i hate, as we use Torque in Nm (metric) and power in HP?? I prefer kW but i digress...) Is the "power" we have available to move us. The faster we move the more work is done the more power is required.

But in terms of looking at how the motor is best performing then torque shows where the motor is working the most efficiently irrespective of the power output (which is a product of the torque.rpm) Eg: Peak torque will be where cylinder filling and combustion is the best.

[husaberg]

Yes, Hp (which i hate, as we use Torque in Nm (metric) and power in HP?? I prefer kW but i digress...) Is the "power" we have available to move us. The faster we move the more work is done the more power is required.

But in terms of looking at how the motor is best performing then torque shows where the motor is working the most efficiently irrespective of the power output (which is a product of the torque.rpm) Eg: Peak torque will be where cylinder filling and combustion is the best.

BMEP is I think the best measure of an engines efficiency (but I have been wrong more times than I care to count)
But lap times and race wins are what actually counts.

[paul gane]

This is my first post, I've been following this fantastic thread for over a year now, and have learned so much, many thanks to you all.
I have been building a TZ350 with a 58mm banshee crankshaft. We're now at the stage where I need to weld a plate to top surface of the cylinder. I see Wobbly has already done this on the Frepin TZ350, with great success. I am planning on keeping the standard bore size 64mm, I need advice on what is the best grade of aluminium plate for the welding, and any tips on minimising bore distortion during the process. Many thanks in advance.
PS can't wait for the Ryger technology to be posted.

[TZ350]

BMEP is I think the best measure of an engines efficiency. But lap times and race wins are what actually counts.

Race wins for sure but BMEP has the benefit of allowing you to compare one engine to another of the same type. Whether it is an industrial engine being compared to a lawn mower or something more racy. BMEP is a yardstick for comparing engine performance and can also give you an indication whether the stated claims for an engine are probable or not.

BMEP is just a number and is defined something like the mean average pressure that if applied uniformly to the top of a piston throughout the full stroke would produce the same torque as measured for that engine.

[Frits Overmars]

Hi Frits. So I guess I've misinterpreted this part of my 2T education :facepalm:. This may also kill off my other two deto interventions, namely 1) Putting a Thermal Barrier Coating on the smooth surfaced ex port duct (easily removed, phew) 2) Fabricating a Ti header section. Am I following your logic correctly? Or would I have been better to put the TBC on the textured transfers and keep the ex duct as a heatsink for the gas column?I'd say you've grasped it Nick. A thermal barrier coating will do a good job any place where the fresh mixture comes into contact with hotter surfaces, excepting surfaces that also come into contact with even hotter spent gases.
These latter surfaces are all surfaces of the combustion chamber, including the top of the piston, and the first part of the exhaust duct.
As a rule of thumb I'd say that the length of this first part of the duct should be such that it can contain a volume equal to one cylinder capacity.
Isolating the remainder of the exhaust system, where fresh mixture does not come, is fine. So you can build your titanium header section, and the whole rest of the pipe, from that distance on.


The faster we move the more work is done the more power is required. But in terms of looking at how the motor is best performing then torque shows where the motor is working the most efficiently irrespective of the power output (which is a product of the torque x rpm) Eg: Peak torque will be where cylinder filling and combustion is the best.
BMEP is I think the best measure of an engines efficiency (but I have been wrong more times than I care to count)Not this time Husa; you're quite right. A BMEP-curve and a torque curve are identical, just with different values along the Y-axis.
Torque curve values are also dependent on cylinder capacity; BMEP-values are not. So like TZ350 says, BMEP-curves are the best means of comparing engines.


Sure did Frits, and I agree completely that we should be using the blowdown as a basis for all this, as it has a direct relationship to the power capability available. Now that we are seeing the real possibilities surrounding lifting the port floor, this is again making the port window area even more irrelevant so I need to start generating a data point set to indicate the numbers we need to be looking at based on blowdown STA. Add to this the duct length factors I detailed before and then real gains can be made with ease.
Neels has done an update to the EngMod RSW sim using the above numbers that will make your socks roll up and down.Yes, I had an exciting email-exchange with Neels; I think we should permit ourselves a wee single malt, Wob :drinknsin.

[nick gill]

As a rule of thumb I'd say that the length of this first part of the duct should be such that it can contain a volume equal to one cylinder capacity.

Thank you Frits. Excellent information as usual.

[ief]

Perhaps related.. In engmod you see possible outcome in the STA and then one sees exhaust port say 5 hp and blowdown 6 hp. That seems weird since the blowdown is part of that same exhaust port or... not?

[Vannik]

I thought it would make for interesting results doing a Wobbly exhaust port duct on a very high performance engine - something much better than the best HRC could do. So what better to use an Aprillia RSW125 as developed by Jan Thiel?

It makes for interesting results:

318565

[AndreasL]

I thought it would make for interesting results doing a Wobbly exhaust port duct on a very high performance engine - something much better than the best HRC could do. So what better to use an Aprillia RSW125 as developed by Jan Thiel?


Nice work Neels (and Wobs)!

Is this new theories something that can be "included to the code" in the future? "Wobbly exhaust design radio button" ;)
The homework to understand whats happening is ofcorse every end users responsibility.

[AndreasL]

Moving on with the Mach numbers in EngMod.

I'm still stuck with my crap transfers. Straight (tapered) walls, no inner radius etc etc.
I'm aware of the "non importance" of the "entry to exit area ratio", but any way...

I like to try some sort of inner radius but since theres limited material in the outside wall, that can't be altered much.

As PtrMach only gives the port mach numbers I'm not sure if this tells us anything usefull for what I like to find out.

Any approach to determine if transfer port cross sectional area is sufficient is welcomed.

Or when thinking about it some more...make it as constant as possible, don't change more then one direction at the time...all related to the sufficient transfer STA already present.

Asking questions is good...it makes you think! :niceone:

[wobbly]

EngMod gives you the Ex Port STA as well as the Blowdown for that same port.
The blowdown number is only related to the configuration above the transfers, and as we are coming to realize what goes on below that point
is becoming increasingly redundant.
Blowdown sets the actual power capability of the port,how good the duct geometry is will help to bump up power for free in effect.

Lifting the port floor and filling in the bottom corner rads is what Jan was doing in stages at Aprilia, and now TeeZee and his ESE gang are off on a new tangent
that will give us all some pointers as to how important the A port short circuiting factor is Vs the port window area.
Neels has already included a radio button to set the duct exit area at 75% that we know is a good start point for a T or 3 port,but the 1.5 * bore for the smallest nozzle area length
and the 2* bore for the start of the header is usually limited by the physical layout of your cylinder/spigot.
So I think its best to leave this as a user input,related to what can actually be done with the project engine you are working on.

The results of a small change to Jans RSW 125 duct layout shows what can be achieved by applying a scientific approach to any engine, no matter how good/bad it may be, and I hope this
silences the few shortsighted critics that have their heads sarcastically buried in HRC quicksand.

[wobbly]

I think you have a good part of the answer already Andreas.
Where you have crap duct geometry the only real way of ensuring some sort of equality of Cd with the Blowdown STA is as you say
to ensure singular directional changes,but more importantly just increase the Transfer STA to compensate.

This was done sort of in reverse with the RSA 125.
The Blowdown Cd was VERY good in this engine due to the big Aux and the big radius on the opening edge of the Ex ports.
Thus the transfer STA had to be made larger in relation to the Ex, even though the transfer duct geometry in Jans opinion was as good as could be
achieved within the stud limitations that were fixed.

Remember the sim is a single dimensional analysis tool, and within the limitations of the scavenging models Neels has applied,the model has no way of predicting
the inlet/outlet Cd ratios that are set by the duct geometries of the ports.

[AndreasL]

Thanks Wobbly (2x),

A great summery of "what we know".
Its good to have it in print though.

Think I will cut/measure my transfer molds to find out what is doable within limits.

Starting to get really exiting.

Edit: Realize that I have a 55mm exhaust duct length. 39mm bore x 1.5 = 58.5. Close enough I say!
Finally ONE positive thing with this engine. ;)

[ief]

Moving on with the Mach numbers in EngMod.

I'm aware of the "non importance" of the "entry to exit area ratio", but any way...

Asking questions is good...it makes you think! :niceone:

I think it's not totally unimportend since engmod uses it to calculate duct volume to calculate CCR?

[AndreasL]

I think it's not totally unimportend since engmod uses it to calculate duct volume to calculate CCR?

No, not totally. That's why I put it in "".

But sims and dynoruns (made by wobbly I think) have confirmed that the transfer entry:exit ratio has very little impact on power. So it was somewhat a "isolated" comment from my side.

[Haufen]

I thought it would make for interesting results doing a Wobbly exhaust port duct on a very high performance engine - something much better than the best HRC could do. So what better to use an Aprillia RSW125 as developed by Jan Thiel?

It makes for interesting results:

318565

Thanks for the graph, Neels. Could you tell us the nozzle % on these both curves? I guess it's 75 on the red one, but what is it on your RSW model?
With my model (which is built entirely on internet information, as I have never gotten my hands on a real RSW or RSA engine), I get the following:

as a start, I put the minimum diameter in the middle of the exhaust port and varied the nozzle diameter in % of the actual exhaust port area
318567
Quite an improvement, but I guess most of us were already aware of that potential.

Next, I varied the position of the nozzle. I also found that the best value was 1,5 times the bore diameter, with 1,25 times about equal.
Interesting about my results is that the position of the nozzle does not so much add more hp, but fills the midrange dip quite remarkably instead.
318568

In combination this gives a really nice improvement.
318569

[AndreasL]

Haufen, great results and presentation.

Have done something similar in the past, but "by accident", so wasn't looking for the right things and details.

With the "1.5 x bore" duct length we have one more rule of thumb to add to our toolbox trying to improve our different types of machinery.

[speedpro]

I thought it would make for interesting results doing a Wobbly exhaust port duct on a very high performance engine - something much better than the best HRC could do. So what better to use an Aprillia RSW125 as developed by Jan Thiel?

It makes for interesting results:

318565

Impressive improvement on what was probably the pinnacle of 2T development. Awesome software Vannik, and Wobbly - well done

[wobbly]

The plate added to the 3G3 TZ350 cylinder to accommodate the long stroke crank was in 6061 alloy.
This is needed to be compatible with the plating process - but you need to tell your plater this is the material/weld used.

Of significance though is the fact that the plate is thicker than needed, and that it is thru bolted at all 11 stud holes whilst welding around the bore
and the water jacket.
I also took the opportunity to completely change the water flow.
The plate has only 4 - 12mm water exit holes above the Ex ports.
With the water inlet from the pump into the top back of the cylinder, all the cold flow is forced over the transfers,around the bore,then over the Ex duct and up into the head.
Then it travels back ,over the inserts, to the rear again and out at the highest point.
A small 3mm hole in the plate at the highest point of the cylinder allows trapped air to get out, into the head water jacket above.

Put large chamfers on the plate/bore faces, so the weld has good deep penetration, then the bore can be re cut without removing any of the existing bore face
and the top can be cut before plating, to give the correct deck position.

[paul gane]

Many thanks Wobbly for all the info about plate and water jacket mods. I've be following your posts on the TZ400 with great interest. I was going to fit the head the standard way around, but I'll be checking to see if it will fit on the G chassis with the thermostat housing towards the rear now. Thanks for your help, it's much appreciated.

[wobbly]

I cut the thermostat housing off and welded a thin plate over the top.
The std Yamaha thermostat is junk - it opens at way too high temperature, and from memory the head isnt symmetrical so wont go on backward.
Now I use a proper bypass thermostat that starts to open at 42*C and with the larger pump impeller the 400 sits on 50*C all day.
The water outlet to the radiator on the back of the head, is the original inlet fitting.

[husaberg]

Frepin Replica TZ400
Most if not all the links


http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130563280#post1130563280

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130559561#post1130559561

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130920986#post1130920986

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130639230#post1130639230

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130930712#post1130930712

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130540263#post1130540263

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130346957#post1130346957

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130708802#post1130708802

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130930046#post1130930046

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410366#post1130410366

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130411359#post1130411359

One I missed
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130929996#post1130929996
Bypass
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410293#post1130410293
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410828#post1130410828

[TZ350]

Pictures of the Exhaust dam.


This is a model of the exhaust port dam.


TeeZee, the Mach numbers are telling you exactly what you need to know. The port layout as it stands with the huge width above the transfers is operating like a T or 3 port, thus the Mach numbers for ExMach 1 are too low as I have found most ducts taken down to 75% area at the flange will approach 0.8Mach - and this seems to be the best compromise for power.


EngMod2T simulation and engine performance analysis.

Back story covering the development of the dam and using Engmod2T to analyse how to develop it.

318593

After analyzing the mach numbers in the exhaust duct using Engmod2T we had a plan for the new exhaust duct.

318592 318591

The new exhaust duct requires boring the existing over size duct out and pressing in a new smaller nozzle shaped duct. Chambers made a fly cutter and using Team ESE's rattly old mill drill with a bit of careful work he manged to make quite a neat job of boring the old duct out.

[paul gane]

Thanks Husaberg for the links, only problem is that I should be getting up now, but haven't slept for the last few hours reading and digesting. All for a good cause though.
Wobbly, looking at the rear of the cylinder water entry, how do you get the water to flow around the outside of the water jacket ? It looks like it would flow straight between the the barrels to the exhaust side. Is there a baffle or restrictor. I really like the cnc water pump impeller, that must almost double the flow rate, nice. Thanks again gentlemen.

[husaberg]

Thanks Husaberg for the links, only problem is that I should be getting up now, but haven't slept for the last few hours reading and digesting. All for a good cause though.
Wobbly, looking at the rear of the cylinder water entry, how do you get the water to flow around the outside of the water jacket ? It looks like it would flow straight between the the barrels to the exhaust side. Is there a baffle or restrictor. I really like the cnc water pump impeller, that must almost double the flow rate, nice. Thanks again gentlemen.

I missed one
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130929996#post1130929996

[F5 Dave]

Thanks Husaberg for the links, only problem is that I should be getting up now, but haven't slept for the last few hours reading and digesting. All for a good cause though.
Wobbly, looking at the rear of the cylinder water entry, how do you get the water to flow around the outside of the water jacket ? It looks like it would flow straight between the the barrels to the exhaust side. Is there a baffle or restrictor. I really like the cnc water pump impeller, that must almost double the flow rate, nice. Thanks again gentlemen.
Anything has got to be better than std Yamaha which is like putting a flat plate on a bucket with an outlet on one side and squirting a low powered hose in another hole.

[breezy]

Ryger production is running in high gear in order to meet the CIK regulations.
314432314433

Frits,isnt there something missing off the first picture, which sits under the carb on the front of the casings with water pipe type connections?:sherlock:

[wobbly]

Yes, the std TZ350 cylinder has a thick wall between the cylinders that has a hold down stud tapped into it from above.
There is only a small water flow gap down low over the inner transfers, so water is forced to flow around the outsides as well.

[Jvenni]

What you don't see is the cover the crankcase ventilation which was a separate part of the engine. This original design was not approved by the CIK/FIA. Ryger had to adjust this design. The crankshaft ventilation has now become an integral part of the crankcase.

The Ryger concept is completely accepted by the CIK/FIA and the engine seems to be homologated.

[TZ350]

page 1420 links list to go here when I have compiled them..... :bleh:

The Frepan TZ400 ... you will have click through to the original post to see the pictures.


Previously I said I would post pics of the mods done to the TZ400 that won at the Shorai Challenge, so here are some of the modified head and new water circuit.

From the pump water enters the rear of the cylinder below the welded on top plate, this forces flow around over the transfers then up into the front of the head via holes on each side of the Ex duct. This water is then forced to flow around the inserted head, and out at the highest point, with an auto air bleed back to the top of the cross flow rad.

The 3G3 - 6 port cylinder has an intake bridge added with a boost port cut on each side and ported to suit the Banshee 58mm stroker crank and special single ring Wossner 66mm Blaster pistons. After plating the 6mm welded on plate was reduced 2.8mm so that all the squish is in the cylinder with no step on the insert face.

It runs 16.2 :1 com on Avgas with 40mm Lectron HV carbs that are period legal- running into CR125 Reedblocks from VeeForce.
This makes the cylinder the same configuration as the TZ500 factory engine as run by Roberts - pre 82


I got one of the carbs off Ebay and it just happened to be an FBG, nothing special about it, they just jet them to suit. Make sure you get the HV version with the venturi behind the slide.

The only thing to correct or set is the float needle size for gravity or pump feed, the main needle and the powerjet size. Thing is they flow alot more air size for size than a Mik or Keihin, and the venturi then gives way better part throttle response than what you would expect from the carb size.

Looking at the Lambda on the dyno they have a really linear A/F ratio, a Mik or Keihin is all over the place as the circuits overlap. On the TZ400 I started out with a 4-2 needle and a 75 powerjet, this was too lean on top, and needed a 95 powerjet to settle at 650C at full noise.

This is too big, so I went up to a 6-2 needle and the powerjet dropped into the 60 range - that gave a spot on fuel curve to suit that engine. Only problem I had is that the Frepin frame has the tank very low and close to the carbs, thus the fuel head is minimal above the bowls unless the tank was near full.

The stock gravity needle and seat is a 3mm, so I got the special option 3.6 and this stopped it leaning out as the fuel level in the tank became low.
They do an add on air bell as well that dramatically improves air flow.


One last point about the Lectron is that as it has no idle circuit in front of the slide, it can be run at a very steep downdraft angle to straighten out the flow into the reedblock. This is worth plenty of Hp.

If you sat a Mik or Kehin at those angles they would spew fuel from the bowl directly thru the idle circuit ( not having it drawn up thru the jet well by vacuum ) especially with the fuel surging to the front of the bowl under brakes.


I met all the USA guys at the Island last year, a great bunch of really enthusiastic racers and tuners.

The TZ400 we took was easily fastest in practice, but the brand new Nova special ratio set shat 3rd gear in the morning warmup and threw Discombe down the road on his head. He had concussion so wasnt allowed back on the bike.

Dennis Charlett is racing the Nationals at Timaru the weekend of the Island this year,so we will have to wait. He is entered on the TZ for the last round at Hampton in early March,in the support Post Classic class, hope the new track is all done for that.

We wanted to run the Pre 82 in Superlight,as with a speedshifter working and stickys the TZ would easily cut lap times to be at the front, but the classes are too close together for the Grandfather to be comfortable racing the SV650 as well.

Master plan is to build another Frepin with a 4 cylinder version of the TZ400, as Paul Mclachlan rode one configured like that at Puke with a std TZ500 back in the day. If I put the same attention to detail into that bike it will for sure easily smoke the usual 750s as well as the big 4T pigs at the Island, we will see.

Here is another small item in the TZ400 - a double sized CNC waterpump impeller,it sits on 50*C all day.


The same point about material advances applies to forgings - they are now run at the same clearances as top notch Jap cast pistons..

The only way to go in my opinion is Wossner - to many horror stories from Wiseco.

I can get direct into the CAD side of Wossner and organise any piston you want. And have been using a 60mm design for ages in various engines and have a few ready to go into the NSR300s I am building.

This is based on Wossners HRC RS125 design, but if you stick with that you will have to bore the cylinders for the oversize and replate ( but that's also a good time to port them properly ).

It has a single ring pinned on centre so you can grind on the B ports and has gas ports in the ring groove.

The deck height is 29.5 and with 113 rods from Samarin no deck machining is needed ( good as the case is too small anyway ).
Im about to order some more - and could ask if they could adapt the design in 59.5 size ( don't know if the have that ring ).


With my experience of kart carb setup, the only way to go is "pump around ".

This eliminates the fuel height changes in the bowl due to float bounce or any issues from centripetal acceleration forces.

If you dont know about this,its simple. The carb float is removed and fuel is pumped ( from the usual round Mikuni pulse pump ) into the carb via the open needle valve hole.

Another fitting or tube is added at the correct fuel height, and this is plumbed to the suction side of another pulse pump ).
This sends the excess fuel back to the tank.

In your case where the fuel always sloshes to one side, then that would be the side to draw from. The bowls are filled with tank foam to reduce the fuel swirling about at the main jet height.

Works perfectly.

Here is a shot of the system on a KTM 250 for road racing. The two pumps are secured to a plate back to back with the pulse line fitted into that with a cross hole to operate both diaphrams. And in the case shown the suction side is the original fuel entry, as it just happened to be the right level.

Re the Lectrons, one style of bowl has individual floats that slide on rods, so any variation in fuel height side to side is taken care of by this system.
But even then I would dump the floats and use pumparound.


Technically, it's a weir arrangement. Yes, very old, particularly in rivers...Rex McCandless played around with weir type "float bowls" on works Nortons in the 50's. He had a hatred of floats or as he called them, cisterns. Quoted as saying his toilet wouldn't stop flooding so why use the same setup on a bike....


I never had heard of putting a suction pump on the fuel-out side, but in the days when a lot of guys were converting the Carter N carbs from old Mercurys to alcohol, floatless arrangements were very common. I even built a set of three floatless carbs from billet on my little Sears Craftsman lathe. 2'" 6061 bar stock, one piece for the throttle body, the other for the bowl and end caps, and a funnel of Delrin for the overflow. Beautiful, if functionally crude.

H-berg, I remember seeing ads for the Lakes injector. At one point I believe the rights to it were bought by somebody in the light aircraft industry, even got FAA approval. The office was supposed to at Renton (Washington State) Airport where I was learning to fly; I looked for it one day, but don't recall now whether I found it or talked to anybody. The aircraft version might have been larger than the original Lakes Injector, which I recall being made primariy for karters, with a bore of around 25mm. I'll look at your inks again, fun old stuff.

I suppose there must be a "tank foam" that stands up to methanol and the other fractions.

Do any of the kart classes run alcohol these days, as they did long ago? The only motorcycles I remember running alcohol, besides the drag bikes, were the "speedway" dirt track bikes, an interesting in-crowd sport mostly in southern California, IIRC. Oops, just did a quick google, and I see there is speedway racing Down Under. Serious racing, but looks sort of like drift-cars but with bikes.

Well, also it might be that the pari-mutuel gambling motorcycle racers in Japan run alcohol. I never saw them when I was living in Japan in 1970, but I did spend an afternoon at the gambling boat races. Twenty four marine stadiums built for the purpose, tons of money involved. I've often thought if amateur outboard racers in the US could work out arrangements to where people could gamble on our races, there would finally be money in the sport, and a guy could make a living at the thing he loved.

http://www.aeroconversions.com/products/aerocarb/index.html
http://www.ellison-fluid-systems.com/


318089
I have posted some stuff on all of them including the mouse trap.
I will dig it up latter.
Gardner made a set of carbs for the Dual valve Exactaweld (whoops it was the Armstrong)
A few used to gun them on the early clasics including from memory Bill Swallow of the 3 bearing Velo modified Norton into a near Seeley thing he used to race.
https://c1.staticflickr.com/3/2810/10042872034_880e6ccb21_b.jpg
I am not sure if the Gardner had a conventional needle or funny shape like the posa, lake,EI, Bluestreak, lectron, Quiksilver Edlebrock, Smart family


318083318084


Merry Xmas to all and thanks again for all the amazing information shared on this Thread. I am sure It's made a massive difference to anyone racing a 2 stroke in NZ or anywhere across our small planet for that matter. Well done Rob!

We will be flying the 2 stroke flag again this year at the cemeterycircuit on boxing day. ( www.cemeterycircuit.co.nz (http://www.cemeterycircuit.co.nz/) ) This time with 3 bikes. 3 x NSR300's There is live streaming if you want to take a look. F3 is where we will be.

Live timing. http://www.livetiming.co.nz/Live_Timing.aspx


The issue you are up against is that the traditional layout dictates that the idle jet ( and its supply well ) are in front of the slide ( engine side ).

The Lectron has no idle circuit at all, with all the fuel entering the venturi up the main ( emulsion tube - but not ) needle well. With this old school setup the fuel level for this circuit becomes progressively closer to the exit hole in the floor of the venturi, as the carb is tipped upward.

If you go too high, fuel will simply run straight up the well and dribble into the venturi in front of the slide, with no air flow needed. To make matters worse this fuel level rises in the front side of the bowl under brakes, again fuel spews out the idle circuit without any vacuum.

Best example of this is a TZ350, where plenty of power gain is to be had by shaving off the rubber manifold face to straighten out the intake by
re angling up the old VM38mm carbs. Go greater than about 5* and its impossible to stop the flooding under brakes, no matter how low you drop the fuel level by shutting off the float valves early.

The only way I know to get around this is to use the OEM carbs made by Keihin on things like NSR400 etc where the bowl is kept horizontal,and the venturi is angled.People on here can tell you several other models that had the downdraft carbs from the factory - for exactly the reasons above.
The other example is an FCR as was designed for the heavily downdrafted ports on big 4T engines.

There are quite a few sizes availble in the OEM carbs used by Honda with a D shaped venturi, and the FCR is made in plenty of sizes as well, but jets for this are a nightmare to size for a 2T.

Dellorto have made some carbs with the idle jet ( and its fuel well ) on the intake trumpet side , with drillings down the side of the emulsion tube and around in front of the slide.They usually have a fuel adjuster screw on the side, not an idle air screw.

These could easily be modified to run seriously downdraft, as the greater the angle the lower the fuel gets in relation to the actual idle jet height.


Most of the Dellortos made since the intro of the PHF series have the idle jet on the intake side and can be easily run at up to 45 degrees inclination. The downdrafts pictured earlier would appear to be based on the basic PHF style bodies. Anyone got any pics of them without the bowls fitted ?

Amusingly enough, the AMAL concentric series, both 1 & 2, have the same setup and are quite good at steep downdrafts.


But I feel I must add here, that my whole perception of dyno testing was changed by Jan stating that a lot of the pipe testing that was originally done was invalidated in that the jetting wasn't optimised for each change of dimensions.

What he was saying is that if a pipe affected the egt due to its design, then the power change was due to the egt change - not the actual efficiency ( or not ) of the actual pipe.

I have taken this on board and for some time EVERY run I do I aim to jet for exactly the same peak power egt. A small change in reed stiffness will absolutely change the egt number, and if you dont then rejet to achieve the target, then the temp change is causing the power difference - not the reed change.

I shoot for 650*C on a KZ2 for example as this is what we see for best power. Now I am starting to use Lambda, to achieve a target A/F ratio.
Both methods, are in effect approximating what should really be done to do this properly, that is measuring air and fuel flow to generate a max power BSFC number.

But anyway, what I am saying is that just doing a dyno run, making a change and then not rejetting - is a waste of effort.


The Lambda I use is from Innovate Motorsports with a Bosch heated wideband, and it can read out in various formats. It will convert directly to A/F ratio, Lambda Number, or 0-5V, I use the A/F ratio as an input direct to the dyno datalogger so as to see
the power overlayed with A/F as well as deto etc.

The probe is in the front of the muffler,with a threaded insert that sits right on top of the perf tube. It has a gauge reading out A/F, but you for sure havnt time to watch that when doing a dyno run.

One take on the dam idea affecting the top end so much, is that is exactly the effect you see by putting a 75% nozzle in the duct exit when running a sim. This is why I thought the next step should be to extend the floor right out the flange face.

Gaining all that top end means you have an option to redesign the pipe for better mid, or use the overev capability and use the pipe to make even more power up top. The Ryger homologation is due to be published publicly by the CIK on the 1st Jan.
I will be onto the site all day looking for the info we all are screaming for.


Thats what I alluded to re tracking EGT with a really fast response probe ( open tip, Stinger from EGT Industries - guaranteed for 2 years ) and datalogging it against power.

If the egt has dropped from say 650 to 600, then it would need at least 2 jets leaner to get back to your baseline. 2 jets is night and day power wise, and peak power rpm wise. And as you well know, if the mid has gone rich in relation to the top,then you will need to adjust the air correction to skew the fuel curve as well.

This is the controller I use for the Lambda,and this sends the A/F corrected numbers to the dyno datalogger - 12.8:1 makes alot more sense to me than 0.9 Lambda ever did.

http://www.innovatemotorsports.com/products/lc2.php


This is my first post, I've been following this fantastic thread for over a year now, and have learned so much, many thanks to you all.

I have been building a TZ350 with a 58mm banshee crankshaft. We're now at the stage where I need to weld a plate to top surface of the cylinder.

I see Wobbly has already done this on the Frepin TZ350, with great success. I am planning on keeping the standard bore size 64mm, I need advice on what is the best grade of aluminium plate for the welding, and any tips on minimising bore distortion during the process. Many thanks in advance.


The plate added to the 3G3 TZ350 cylinder to accommodate the long stroke crank was in 6061 alloy. This is needed to be compatible with the plating process - but you need to tell your plater this is the material/weld used.

Of significance though is the fact that the plate is thicker than needed, and that it is thru bolted at all 11 stud holes whilst welding around the bore
and the water jacket. I also took the opportunity to completely change the water flow.

The plate has only 4 - 12mm water exit holes above the Ex ports. With the water inlet from the pump into the top back of the cylinder, all the cold flow is forced over the transfers,around the bore,then over the Ex duct and up into the head.

Then it travels back ,over the inserts, to the rear again and out at the highest point. A small 3mm hole in the plate at the highest point of the cylinder allows trapped air to get out, into the head water jacket above.

Put large chamfers on the plate/bore faces, so the weld has good deep penetration, then the bore can be re cut without removing any of the existing bore face and the top can be cut before plating, to give the correct deck position.


Many thanks Wobbly for all the info about plate and water jacket mods. I've be following your posts on the TZ400 with great interest. I was going to fit the head the standard way around, but I'll be checking to see if it will fit on the G chassis with the thermostat housing towards the rear now. Thanks for your help, it's much appreciated.


I cut the thermostat housing off and welded a thin plate over the top.

The std Yamaha thermostat is junk - it opens at way too high temperature, and from memory the head isnt symmetrical so wont go on backward.

Now I use a proper bypass thermostat that starts to open at 42*C and with the larger pump impeller the 400 sits on 50*C all day.
The water outlet to the radiator on the back of the head, is the original inlet fitting.


Frepin Replica TZ400 Most if not all the links

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130563280#post1130563280

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130559561#post1130559561

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130920986#post1130920986

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130639230#post1130639230

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130930712#post1130930712

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130540263#post1130540263

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130346957#post1130346957

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130708802#post1130708802

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130930046#post1130930046

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410366#post1130410366

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130411359#post1130411359

One I missed

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130929996#post1130929996

Bypass

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410293#post1130410293 (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410293#post1130410293)

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410828#post1130410828 (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410828#post1130410828)

[breezy]

What you don't see is the cover the crankcase ventilation which was a separate part of the engine. This original design was not approved by the CIK/FIA. Ryger had to adjust this design. The crankshaft ventilation has now become an integral part of the crankcase.

The Ryger concept is completely accepted by the CIK/FIA and the engine seems to be homologated.

Ok... thanks for that.:2thumbsup

[wobbly]

The Ryger homologation hasnt been posted on the CIK site - so no one can say for sure yet it has been approved ( without inside info of course ).

[MotleyCrue]

The Ryger homologation hasnt been posted on the CIK site - so no one can say for sure yet it has been approved ( without inside info of course ).

Is there any sort of deadline date for CIK to post it, so the Ryger can actually be used in 2016 ? I imagine they won't post it until the absolute last second that it can be posted, whenever that is. Is it conceivable the Ryger could enter as late as mid season with enough arm twisting applied, you know being revolutionary and all ?

[jonny quest]

Anyone help with the link to connecting rod chart? I need a 78mm c to c, 22mm dia, 14mm dia

[TZ350]

Anyone help with the link to connecting rod chart? I need a 78mm c to c, 22mm dia, 14mm dia

Page 1370 has a posts list with a lot of Husaburgs links to pistons, rods and other useful stuff. ... http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1370

[paul gane]

Many thanks for all the sharing of knowledge. This weekend will be a busy one.

[wobbly]

The date was officially supposed to be 1st Jan.
But so far none of the new homologations have been issued - even though we have the interim numbers for all of them.

[ken seeber]

Checking back, it wasn't til 18th Feb 2013 that they published the engines, carbs and ignitions for the 2013 to 2016 period. The first CIK KZ event appears to be around the 4th month of the year.
So, don't hold your breath unless you have BIG lungs.

318603

[G Jones]

This is my first post, I've been following this fantastic thread for over a year now, and have learned so much, many thanks to you all.
I have been building a TZ350 with a 58mm banshee crankshaft. We're now at the stage where I need to weld a plate to top surface of the cylinder. I see Wobbly has already done this on the Frepin TZ350, with great success. I am planning on keeping the standard bore size 64mm, I need advice on what is the best grade of aluminium plate for the welding, and any tips on minimising bore distortion during the process. Many thanks in advance.
PS can't wait for the Ryger technology to be posted.Just curious - are you also converting the TZ cylinder to Reed Valve ?

[paul gane]

No Gordon, staying with piston port. I've got a ignitech P2 race ignition fitted, 26j carbs
, and a Mestre inserted head. I want to set up Wobbly's cooling system layout next, and would like to do the duct reducing mod to the exhaust port. There's life in the old dog yet, just not enough time.

[G Jones]

No Gordon, staying with piston port. I've got a ignitech P2 race ignition fitted, 26j carbs
, and a Mestre inserted head. I want to set up Wobbly's cooling system layout next, and would like to do the duct reducing mod to the exhaust port. There's life in the old dog yet, just not enough time.I thought I recognized the name...OK - sounds like you're heading in the right direction - we use a very similar setup - any mods with the carbs ? (you know I have new slides for those ? don't look at the eb*y price though) - the reduction on exh port is worth doing - we did one 22 years ago...although probably a little more basic than the things being done now...

I too am looking very closely at the cooling - we are now running at a very acceptable level in the rad - but I'm sure there are benefits in getting the cylinder / head temperature improved (reduced) in the right places.

We use a Pro-digital ignition - very happy with it - but looking for an alternative as it's no longer available - still sitting on the fence regarding the ignitech - have seen some comments that it may be a bit low on Spark energy - although - what that means in practice - not really sure - just know if I fit another ignition - it must be at least as good as the Pro-digital.

I've tried most of the TZ ignitions over the years - most of them no longer available - not really keen on any of the currently available self generating systems - so we're back to the Ignitech & RTD....just have to decide which is best...
Life in the old dog ? - tend to agree - not bad for an engine that's getting on for 40 years old...

PS - I had a friend asking the other day if I had a copy of the old TSR software - I did have it years ago - but can't find it - so - anyone know if there's anything available anywhere ? (no - I don't know why he wants it...)

[paul gane]

Hi Gordon, I've no mods to carbs other than all new parts, slides needles float valves emulsion tubes.
Is it you selling the Metor pistons ?
Re ignitech, the coils supplied could be bettered by the rgv coil as Wobbly recommend, the standard spark does look a little weak.
I really like the simplicity of these old tz's, so many replica parts made now, just need Yamaha to start re- casting crankcases and could have a new engine.

[G Jones]

Hi Gordon, I've no mods to carbs other than all new parts, slides needles float valves emulsion tubes
6FBY44
247 - O0
We use Viton tipped float needles - as our system uses a vac pump.

Is it you selling the Metor pistons ?Yes


Re ignitech, the coils supplied could be bettered by the rgv coil as Wobbly recommend, the standard spark does look a little weak.We use RGV coil - or a clone of it - massive spark even at zero RPM - by that I mean you can move the magnet past the coil & produce a fat spark...

I really like the simplicity of these old tz's, so many replica parts made now, just need Yamaha to start re- casting crankcases and could have a new engine.
That might not be necessary.....

[crbbt]

whilst driving around this vast country. thinking about all aspects of life...

has anyone put a power valve on the bottom of the of the exhaust port?

I've assumed that the short circuiting from the A port to the exhaust port mostly happens in the lower rev range?

If not, then, nevermind

[J.A.W.]

whilst driving around this vast country. thinking about all aspects of life...

has anyone put a power valve on the bottom of the of the exhaust port?

I've assumed that the short circuiting from the A port to the exhaust port mostly happens in the lower rev range?

If not, then, nevermind

Yeah, funnily enough crbbt, I did raise the notion of such a device back in post# 21005..

Dunno if its been tried, since in general PV's concern themselves with the top/opening of the exhaust,
perhaps some H. Ricardo sleeve-valve work considered the lower port issues in the past, if not variable nozzle ducts..

[TZ350]

We use RGV coil - or a clone of it - massive spark even at zero RPM

If possible could you please post a photo and some pointers of where we could get RGV or Clone RGV coils, many thanks TeeZee. Team ESE would like to use them with their Ignitecs too.

[cotswold]

If possible could you please post a photo and some pointers of where we could get RGV or Clone RGV coils, many thanks TeeZee. Team ESE would like to use them with their Ignitecs too.

http://www.nology.com/

http://www.thetuningworks.co.uk/store/product_info.php?cPath=21_125&products_id=683&osCsid=f6ef18edc42f207c1b7af1b7e6ff50fe

[Bert]

If possible could you please post a photo and some pointers of where we could get RGV or Clone RGV coils, many thanks TeeZee. Team ESE would like to use them with their Ignitecs too.


http://www.nology.com/

http://www.thetuningworks.co.uk/store/product_info.php?cPath=21_125&products_id=683&osCsid=f6ef18edc42f207c1b7af1b7e6ff50fe

Talk to Liam Venter @ fastbikegear. He has the Nology coils in stock.

[paul gane]

Gordon, yes using that needle and tube combination.
In the photos of Meteor Pistons, the ring groove looks to lower than a Yamaha G piston, is this the case ?
Are all the piston dimensions the same as std Yamaha ?
I'm interested in the RGV 'clone' coils, where can I source them in UK ?
When you said 'might not be necessary' , did you mean new crankcases are still available, or someone has plans to make billet sets ??? Sorry for all the questions. Just curious. ..

[Jvenni]

Well, DEA has decided to do something different

318631318632

Why opening the C port at the bore ?

[breezy]

Well, DEA has decided to do something different

318631318632

Why opening the C port at the bore ?

looks like a wind up mate:2thumbsup

[Frits Overmars]

Why opening the C port at the bore ?My guess: so the ends of the piston ring will have less of a torture when passing the C-port floor (if there is no floor, you can't hit it).

[F5 Dave]

I haven't seen a triple boost port before, or indeed inlet of that splayed size, presumably towards the transfers.

but the boost is interesting if modifying an old cylinder if it were effective.

[Grumph]

Piston life would surely become an issue with that gaping hole ?

And you just know that the first thing anyone's going to do is radius the transfers/bore edge...

[F5 Dave]

Yeah it's got boysen ports as well, presumably with the studs partially obscuring the flow.

[Tim Ey]

I haven't seen a triple boost port before,

It is no triple boostport, it is a divided B-Port like in Suzuki GT250 or old Suzuki RM125 Cylinders.

Triple boostports have been used by Malossi on their MHR Team Bigbore because of the limited space for the B-Port (studpatern).

[wobbly]

Why would DEA make a cylinder reed for KZ2 when they already have a case reed KZ2 engine ?

[Tim Ey]

The pictures added by Jvenni show a cylinder for Vespa Smallframe.

[F5 Dave]

It is no triple boostport, it is a divided B-Port like in Suzuki GT250 or old Suzuki RM125 Cylinders.

Triple boostports have been used by Malossi on their MHR Team Bigbore because of the limited space for the B-Port (studpatern).
Ahh yes the first picture makes that more clear.

[Jvenni]

I just copy past it from the dea kz announcement focussing not understanding why an open c port. In the case of an reed valve on the cylinder quite clear.

Should have seen that one, sorry for posting.

[AndreasL]

Anyone with ideas how to create at least SOME inner radius to some straight and very narrow transfers? (Approx 15x15mm at the case-to-cylinder entry.) :facepalm:

First thought was to add epoxy and then try to shape it with a curved file...but I don't really see me having success doing so.

Make some inserts and epoxy them to the inner wall?
Maybe not to bad except no uniform surface in any direction...but the epoxy will take care of that I guess.

Any input and crazy ideas is more than welcomed.
Cold (-19 yesterday) greetings from the other side of the globe. :cold:

[Muciek]

Try to carve something with aluminium and glue it, I have used piece of round pipe with ID of OD of the liner and epoxy it's easier to make 2 same inserts and glue them after shaping.

[AndreasL]

Thanks Muciek,

Thats probably my biggest concern, to get two equally shaped inserts/ducts.

Have been so focused at keeping as much of the original wall as possible but realize now how much it complicates things. This approach really needs to be investigated some more.

You don't suppose to have any pictures of your work?

[F5 Dave]

I've done this with ally inserts on my mb100 bucket.
Here's what I have learnt; yeah its easy enough to make shaped inserts and devcon them in securely, but applying the devcon to fill the gaps took multiple applications.
Then you run some vinamould into it to check if you did a good job.
Then you redo it as what looked good initially was crap.
Repeat six more times.

The results didn't show any improvement. Although the outer walls looked curved OK in hindsight, I'll hog them out some more one day. I think what I gained in better control, I lost in transfer volume, and as we now know needs to be there to fill the cylinder.

Had a pic but can't drag and drop on tablet.

Hmm this might work. Clearly this was not even cleaned up first attempt.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=306988&d=1419366485

[kel]

Anyone with ideas how to create at least SOME inner radius to some straight and very narrow transfers?

You can use the putty type epoxy. Make yourself a forming tool which has the inner duct profile cut into it (from memory I used a piece of 5mm ali). Apply the epoxy putty to the duct and then mash into shape using the forming tool. There will be finishing required, but the formed epoxy should be pretty close.
318638 318637

[TZ350]

Back story covering the development of the dam and using Engmod2T to analyse how to develop it.

318591

The new exhaust duct requires boring the existing over size duct out and pressing in a new smaller nozzle shaped duct.

318646

Cylinder exhaust duct nicely bored out.

318648318649318650

Chambers made an exhaust duct, oval to round and pressed it into the cylinder with final porting to match it to the cylinder.

318647

Finished product, narrowest part of the duct is 1.5 times the bore diameter from the exhaust port window, it looks the business.

Now for a bit of dyno time and glory.

318645

Blue = ex dam and no nozzle, Red = ex dam plus nozzle.

Well that didn't go so well ... again :facepalm: .... so one more in a long list of things that didn't go well.

Chambers recons my scientific and analytical approach is Horse Shit Hocus Pocus, I think he is loosing the faith.

If there was any beer left in the fridge we would have both gone and got drunk .... :drinknsin

If we can't think of anything better the next move is to remove the dam or at least lower it a bit.

[AndreasL]

Great to see that many ideas.
Really appreciate it.

Now I have to decide what's the best option for me...

More input and pictures are welcomed since my black belt in Googling failed me for once. :(

[AndreasL]

That was a surprise TZ. It really looks good to me...but my knowledge is limited.

Wonder what's wrong?
Interesting none the less.

[adegnes]

318646

Cylinder exhaust duct nicely bored out.

318648318649318650

Chambers made an exhaust duct, oval to round and pressed into the cylinder with final porting to match it to the cylinder.

318647

Finished product, narrowest part of the duct is 1.5 times the bore diameter from the exhaust port window, it looks the business.

Now for a bit of dyno time and glory.

318645

Blue = ex dam and no nozzle, Red = ex dam plus nozzle.

Well that didn't go so well ... again :facepalm: .... so one more in a long list of things that didn't go well.

Chambers recons my scientific and analytical approach is Horse Shit Hocus Pocus, I think he is loosing the faith.

If there was any beer left in the fridge we would have both gone and got drunk .... :drinknsin

If we can't think of anything better the next move is to remove the dam or at least lower it a bit.


Great work! Don't feel to bad about it not producing results yet, thats the way it is with bleeding edge r&d!
Btw, I'm real happy this thread is back on track with awesome bucket developement!


"Success consists of going from failure to failure without loss of enthusiasm." - Winston Churchill

[teriks]

If there was any beer left in the fridge we would have both gone and got drunk .... :drinknsin

If we can't think of anything better the next move is to remove the dam or at least lower it a bit.
Beer is seldom wrong :)

I think its a great idea, but thought that you were going to replace the previous "dam" with the nozzle, or at least replacing a decent chunk of the dam with the pressed in nozzle.
That way you could better replicate what you model in Engmod, i.e a linear change of duct area, instead of, as I interpret the pictures anyway, a big area increase along the dam.

[F5 Dave]

It looks nice but does it reduce to 75%. Assuming the port being so wide is a triple impersonator. That dam still looks like a brick wall. Couldn't the insert have met the floor?

[Frits Overmars]

It looks nice but does it reduce to 75%. Assuming the port being so wide is a triple impersonator. That dam still looks like a brick wall. Couldn't the insert have met the floor?My thoughts exactly
(I was just going to write '+1' but the forum insists on at least 10 characters so I was forced to make it sound pompous :p).

[SwePatrick]

SwePat,a free Xmas gift for you, may I suggest you polish that piston in a lathe to a mirror finish.
The dark, crater surface will be absorbing a huge amount of combustion heat ( like having fins all over the surface ) that should be heating the gas
and pushing the piston down - not making it bigger.
This was done at Aprilia, and I have been doing it for years on all race engines.

Re the ignition noise - use a resistor plug and cap, this will remove most of the RF in the ignition lead.

And,,, confirmed!
I did 9 pulls 3 without polished crown, three with polished, and three again without.
Average gain 0.8hp (peak 1.3hp)
All was done with new piston and rings.

Also did an equal test with overfilling the gearbox with 2dl oil extra.
Average loss: 0.5hp (dip 0.6)
Then tested to add a 1dl GL5 hypoidoil into the dexron VI i´m running.
Averege gain: 0.3hp (peak 0.4)

Have reached total peak at 26.78hp at 12200rpm with 10% VP116 octane mixed into ordinary premium fuel from station.

[teriks]

It looks nice but does it reduce to 75%. Assuming the port being so wide is a triple impersonator.
With the "dam" in place and all (if I remember correctly) of the remaining port area in the blowdown region I don't think you'd want much of a reduction at all.
75% of the original port area, or perhaps equal to or sligtly larger than the remaining area could be good starting points for some work in Engmod.

Couldn't the insert have met the floor?
Thats basically what I tried to say earlier, only tip-toeing in a foreign language ;)

[AndreasL]

With the "dam" in place and all (if I remember correctly) of the remaining port area in the blowdown region I don't think you'd want much of a reduction at all.
75% of the original port area, or perhaps equal to or sligtly larger than the remaining area could be good starting points for some work in Engmod.

Thats what came to my mind during lunch as well.
My interpretation of Wobblys guidelines has always been for % of TOTAL ex port area.
The last days we have learned that a "more accurate way" may be to base the spigot min area on blowdown numbers alone. Hopefully we will get to know how some day in the future.

But I'm sure TZ will tell us what area % used.

Great to see the thread getting back to DIY Works Tuning. ;)

[Frits Overmars]

First we have the blowdown area. I relate all other exhaust system areas to it; then I don't need to differentiate between 75% for a triple port, 90% for a single malt port, and so on.



I agree completely that we should be using the blowdown as a basis for all this, as it has a direct relationship to the power capability available. Now that we are seeing the real possibilities surrounding lifting the port floor, this is again making the port window area even more irrelevant so I need to start generating a data point set to indicate the numbers we need to be looking at based on blowdown STA. Add to this the duct length factors I detailed before and then real gains can be made with ease.
Neels has done an update to the EngMod RSW sim using the above numbers that will make your socks roll up and down. We will see soon what he has come up with.



With the "dam" in place and all of the remaining port area in the blowdown region I don't think you'd want much of a reduction at all. 75% of the original port area, or perhaps equal to or sligtly larger than the remaining area could be good starting points for some work in Engmod.



My interpretation of Wobblys guidelines has always been for % of TOTAL ex port area. The last days we have learned that a "more accurate way" may be to base the spigot min area on blowdown numbers alone. Hopefully we will get to know how some day in the future.Like Teriks suggests, after the blowdown area we probably do not want a further cross flow area reduction down the exhaust duct. Wobbly and Neels are already pondering on new promising duct shapes.
My experience is somewhat biased because the Aprilia-research was cut short by the two-stroke ban in GP racing, so I concentrated on my FOS cylinder layout with blowdown area to spare, even with my mild 192° exhaust timing. The exhaust floor timing was 160°; well above the 130° transfers, so this layout may not be directly comparable with a bucket-situation. But for what it's worth, the FOS exhaust ducts expand at a 3° included angle right from the blowdown area.
I guess, and until it has been tested, it is no more than a guess, that for a bucket the exhaust duct should expand between 0° and 3°, starting at the blowdown area.
With that I mean that all cross flow areas, when converted into circles, should form a cone with a 0° to 3° included angle.

[Frits Overmars]

One more word about that exhaust floor. Looking at TZ350s picture I get the impression that his situation is not very different from mine: for the most part his floor is well above the transfers too; only the middle part of the exhaust window, where the dam is, extends a little further down.
But the blowdown flow should make use of all available time and area between exhaust opening and transfer opening, so the exhaust window should extend down to the effective transfer opening timing. Having the exhaust floor higher than that is giving away valuable real estate.
Yes, I do it too in the FOS system, but for me there is no other way. And what's more, I have about twice his total exhaust port width and my ports do not suffer from the area loss caused by the large corner radii that TZ has to use in order to keep the piston ring alive in his very wide single exhaust port.
All in all I am not surprised that TZ's dam-cylinder has trouble reaching the power level of the dam-less cylinder, and that any flow-aiding radius at the dam helped.

318670 318669

[peewee]

Anyone with ideas how to create at least SOME inner radius to some straight and very narrow transfers? (Approx 15x15mm at the case-to-cylinder entry.) :facepalm:

First thought was to add epoxy and then try to shape it with a curved file...but I don't really see me having success doing so.

Make some inserts and epoxy them to the inner wall?
Maybe not to bad except no uniform surface in any direction...but the epoxy will take care of that I guess.

Any input and crazy ideas is more than welcomed.
Cold (-19 yesterday) greetings from the other side of the globe. :cold:

this is how I decided to do it. first I made 2D drawing then I can print this on paper. then I can cut it out and trace than onto a thin piece of flat alloy plate and cut out that. then I can use that as my template when I put in the epoxy. after that I just grind down the epoxy to the indentation that my tamplate has left when it was pressed into the uncured epoxy. its hard to explain but maybe you understand

[Frits Overmars]

I like your port drawing Peewee; it has a nice gradual narrowing. How did you establish the inner and outer duct radii and their center positions?

[AndreasL]

I like your port drawing Peewee; it has a nice gradual narrowing. How did you establish the inner and outer duct radii and their center positions?

Finally it might be the right time to ask a little about what numbers goes where in your drawing Frits?
I'm a bit stuck trying to get the position of every dot etc sorted when scaling it for my own engine. :weird:

318673

[MotleyCrue]

One quick question, how long should the ring locator pin be (I will be making a pin and relocating to the 6 o'clock position)? Never had a locator pin out before to see how long it is.

[peewee]

I like your port drawing Peewee; it has a nice gradual narrowing. How did you establish the inner and outer duct radii and their center positions?


frits theres some free 3D programs like solidworks but obviously with less functionality but for simple stuff the free ones work great. what I did was just take a few quick measurements from the cylinder, like how tall the inner wall is, how big the transfer entrance is, then you can draw what you want with the program. you can make the radius what ever you want, the walls what ever length you want, the roof angle into the cylinder what ever you want, etc.

[ief]

Curious to see if it turns out to be true that starting the exhaust header dia at the x % of the export will be the way to go. Somehow those anti step solutions never agreed with me. (and up to now haven't figured out why the header had to start with a big(ger) dia in the first place, didn't look very hard as well tho...)

But could well be wrong, as allways ....

[TZ350]

And,,, confirmed!
I did 9 pulls 3 without polished crown, three with polished, and three again without.
Average gain 0.8hp (peak 1.3hp)
All was done with new piston and rings.

Also did an equal test with overfilling the gearbox with 2dl oil extra.
Average loss: 0.5hp (dip 0.6)
Then tested to add a 1dl GL5 hypoidoil into the dexron VI i´m running.
Averege gain: 0.3hp (peak 0.4)

Have reached total peak at 26.78hp at 12200rpm with 10% VP116 octane mixed into ordinary premium fuel from station.

Very interesting results. ... Thanks.


My interpretation of Wobblys guidelines has always been for % of TOTAL ex port area.

But I'm sure TZ will tell us what area % used.

There have been a lot of good comments about the exhaust duct. I will have to sit down with Chambers and carefully review the recent posts and our work. There must be some miss match with what we have done, been fun though, maybe we will find success next time ... :2thumbsup

[Frits Overmars]

I like your port drawing Peewee; it has a nice gradual narrowing. How did you establish the inner and outer duct radii and their center positions?


frits theres some free 3D programs like solidworks but obviously with less functionality but for simple stuff the free ones work great. what I did was just take a few quick measurements from the cylinder, like how tall the inner wall is, how big the transfer entrance is, then you can draw what you want with the program. you can make the radius what ever you want, the walls what ever length you want, the roof angle into the cylinder what ever you want, etc.


Finally it might be the right time to ask a little about what numbers goes where in your drawing Frits?
I'm a bit stuck trying to get the position of every dot etc sorted when scaling it for my own engine. Scaling that drawing down only makes sense if various other dimensions from your cylinder and mine will also fit the same scale, which usually won't be the case.
I can recommend Peewees approach.

[AndreasL]

Thanks Frits and, of course, you right.
Scaling might not be the correct word, but for sure your drawing is the inspiration.

I already have several sketches in Catia for transfers and more.
A bit all over the place with to many ideas at the same time though.
Need to sit down and try to make something like peewee.
KISS...my hardest part.

Hope to have something to show of what can be done within the limited space of an old cylinder.
Don't expect anything fantastic, but I better start contributing to the thread and not just lurk around.

[wobbly]

Well at the moment what we know "works" is to make the header inlet 100% of the Ex port effective window area and place this at 2* bore diameter
from the port.
Then a nozzle of 75% effective area at 1.25* to 1.5* bore from the piston that has a smooth transition from oval to round ( steps DONT work as well ).
And the floor of the transition should be co-linear with the duct entry angle.
These are the numbers that Neels used to make near on 10% more power in his very accurate RSW125 sim - I challenge anyone to find any other way of improving Jan Thiels RSA/RSW by
that sort of gain in power.
And exactly the same numbers I have dyno and sim proven in dozens of project engines.

Just yesterday I measured up an 04 Honda CR125, and it has a much smaller duct exit than its predecessors,the area % and the spigot transition shape are dead on the money.
It even has reverse staggered transfers like an Aprilia, so as this model was the only cable driven servo PV they made, its a no brainer that
a couple of these will be going onto an MC21 to make a 80Hp road rocket.

The next step is to construct a point graph of all the proven results and to mathematically relate the Blowdown to duct exit and header entry areas - Frits request is my command.

[ief]

Well at the moment what we know "works" is to make the header inlet 100% of the Ex port effective window area and place this at 2* bore diameter
from the port.
Then a nozzle of 75% effective area at 1.25* to 1.5* bore from the piston that has a smooth transition from oval to round ( steps DONT work as well ).
And the floor of the transition should be co-linear with the duct entry angle.
These are the numbers that Neels used to make near on 10% more power in his very accurate RSW125 sim - I challenge anyone to find any other way of improving Jan Thiels RSA/RSW by
that sort of gain in power.
And exactly the same numbers I have dyno and sim proven in dozens of project engines.



100 % is fine as well :) Didn't know it was common knowledge allready, gutfeeling was kinda right for a change, yeaaay. My english is not up to the task of understanding what you mean with the green colored sentence and it seems importend.

[Frits Overmars]

The next step is to construct a point graph of all the proven results and to mathematically relate the Blowdown to duct exit and header entry areas - Frits request is my command.Yeah right Mr Wright; pull the other one. You're as curious as I am, Wob :D.

I think we should look at the upper edge of the exhaust port first. The turbulence caused by a sharp edge there will destroy a lot of exhaust gas energy before we can even start harnessing it in an efficient duct & pipe. A generous radius there will not only improve the flow coefficient, it will also leave more energy available (De Laval nozzle) although that port edge radius will only create half a nozzle; radiusing the piston edge too would make it complete; it would also help in the return of washed-through fresh mixture.
Too bad these phenomenons can't be incorporated in EngMod, so we will have to experiment the hard way: on the dyno.

[wobbly]

" And the floor of the transition should be co-linear with the duct entry angle. "

Here is the layout, showing the floor of the transition continues out to the header round diameter at the same exit angle as the duct.
All of the transition angle is in the roof of the usually CNC generated spigot.

Yea well Frits, at the time I was so big headed about myself finding a relationship that worked with the full port exit area, I would never have
even thought that the Blowdown was the real determining factor.
As I said before - we are finding more and more so that the area of the duct below the transfers is becoming less and less ( in size and importance ),in that
the "power" numbers attributed to the Ex port area in various papers from Nomura/Blair/TSR etal , and now still present in EngMod, are basically irrelevant.

[ief]

A picture...

Tnx Wob.

[peewee]

did you guys notice engmod has new stuff added like sharp or bullnose trans entrance and straight or tea cup :Punk: oh ya and it shows a image of the boyesen ports now

[wobbly]

That was added by Neels as following Mr Thiel ( as usual ) the flow regime of the Aprilia was made so much better by adding a BIG ball nose radius to
the edge formed by the inner transfer duct walls and the bottom of the bore.
Doing this does changes the flow for the better and is proven to make power whenever its done.

[AndreasL]

If the Master (Frits) say you need to do things...you do! :yes:

Played a bit within my cramped space for transfers.
What we see is a cross section taken "in the flow direction". (60° from exhaust port as per Wobblys guidelines.)
Not to bad after all considering everything is small in this engine.

The approach, if any one else like to try it, was the following:

- Hights for deck plane (xy = 0), port floor/roof (19 and 29mm) and skirt (-2mm) was set.
- Radial (x) limits set. Liner thickness (~2.5mm) and outer wall limit (16mm).
- Help lines at the port entry. (30° as per Wobblys recommendations.)
- Fit a inner arc, tangential to above mentioned (lower) help line/liner intersection at the top and intersecting the port entry point at the base of the cylinder...or what ever point one think is best.
- Add a radius between the upper, angled, help line and the vertical outer limit line.
- Adjust the outer radius untill you have the min distance between the inner and outer radii just before the outer radius meets (tan) the "roof line".

Any one left reading?
Was it understandable?
Is it even a valid approach?

I think the result is fairly similar to peewees?

Please criticize and add ideas of your own.

318684

In 2D it's not to bad as I said. The problem starts when trying to implement the profile to the 3D world of the cylinder.
For simplicity it would have been nice to keep the need of adding material to a minimum. At least for this one cylinder.

Thanks Frits and peewee for kicking me in the but to take a look at this matter for real. ;)

EDIT: A better picture including as big a ball nose radius as possible as well as the liner thickness.

[JanBros]

a question about the washers next to the rod on the big end :

I'm turning a Honda Sky (SGX50) into a proper MX-moped and welded plates on top of the crankcase to have a bigger intake. I thought I had found the proper conrod (8mm longer) and bought it some time ago, but now it turns out the bloke hadn't put the correct sizes with the add : the big end is 26 and not 24mm :facepalm:

so I need another one and have been looking everywhere but one that would be perfect doesn't excist.
closest would be one that is 13 thick at the big end . The Sky's rod is 12mm thick and has 2 1mm washers next to it. would it be ok to use a 13mm thick rod with only 1 washer ?

[breezy]

If the Master (Frits) say you need to do things...you do! :yes:

Played a bit within my cramped space for transfers.
What we see is a cross section taken "in the flow direction". (60° from exhaust port as per Wobblys guidelines.)
Not to bad after all considering everything is small in this engine.

The approach, if any one else like to try it, was the following:

- Hights for deck plane (xy = 0), port floor/roof (19 and 29mm) and skirt (-2mm) was set.
- Radial (x) limits set. Liner thickness (~2.5mm) and outer wall limit (16mm).
- Help lines at the port entry. (30° as per Wobblys recommendations.)
- Fit a inner arc, tangential to above mentioned (lower) help line/liner intersection at the top and intersecting the port entry point at the base of the cylinder...or what ever point one think is best.
- Add a radius between the upper, angled, help line and the vertical outer limit line.
- Adjust the outer radius untill you have the min distance between the inner and outer radii just before the outer radius meets (tan) the "roof line".

Any one left reading?
Was it understandable?
Is it even a valid approach?

I think the result is fairly similar to peewees?

Please criticize and add ideas of your own.

318684

In 2D it's not to bad as I said. The problem starts when trying to implement the profile to the 3D world of the cylinder.
For simplicity it would have been nice to keep the need of adding material to a minimum. At least for this one cylinder.

Thanks Frits and peewee for kicking me in the but to take a look at this matter for real. ;)

EDIT: A better picture including as big a ball nose radius as possible as well as the liner thickness.


makes you wonder how big the bull nose profile could be before it became no longer relative/ and could it be helped by being started inside the piston skirt? (profile inside piston skirt the same as what you have shown in the transfer port....)

[AndreasL]

The Sky's rod is 12mm thick and has 2 1mm washers next to it. would it be ok to use a 13mm thick rod with only 1 washer ?

Why not use 2 0.5mm washers together with the 13mm rod?

[AndreasL]

makes you wonder how big the bull nose profile could be before it became no longer relative/ and could it be helped by being started inside the piston skirt? (profile inside piston skirt the same as what you have shown in the transfer port....)

Think I get what you mean. Interesting thought.
My take on it though is that the piston only spend a very small portion of the stroke at BDC.
So, at BDC it might be a benefit, but overall I would go for the traditional chamfered/radiused piston skirt to promote lubrication.

Do I know for sure?
Absolutely not!

[JanBros]

Why not use 2 0.5mm washers together with the 13mm rod?

where can I buy seperate washers ?
the washers I suppose prevent the rod from wearing into the web, but how come some rods/cranks come without the washers (like the 13mm one I'd like to use) ?

[wobbly]

Jan reported that the Aprilia made no more power by radiusing the piston skirt cutaway area once the bore had the ball nose added.
Ken S has experimented with a heap of piston radiusing, but not I believe in concert with a ball nosed bore as well.
The ball nosed bore has an effect on flow as soon as the transfers are open, so I can see why that is a major influence on power.

[peewee]

frits you can see here how easy it is to make the 2D image. I didn't enter any particular lengths, radius etc because I had to hold the camera but you get the idea. after its finished you can print the image on paper and transfer that to a thin piece of aluminum for the template. if you enlarge the video to full screen you can see better


https://www.youtube.com/watch?v=aCSczcgyRXw

[peewee]

wob you know how the override transmissions work ? just picked up a 2-5 with N in the down position and billet 2nd gear. ive never seen one before but it doesn't have the same arrangement of gears as a normal trans when I was comparing them

[husaberg]

where can I buy seperate washers ?
the washers I suppose prevent the rod from wearing into the web, but how come some rods/cranks come without the washers (like the 13mm one I'd like to use) ?

Samarin sell them.
http://www.samarin.net/?productos

As do Pro X

Try barikit as well

Some bikes use top guided rods, ie washers at the top, a modernish example is a RGV250

[Frits Overmars]

frits you can see here how easy it is to make the 2D image. I didn't enter any particular lengths, radius etc because I had to hold the camera but you get the idea. after its finished you can print the image on paper and transfer that to a thin piece of aluminum for the template.It's even easier for me Peewee, because I wrote a dedicated program ages ago. Too bad I wrote it for my own use exclusively, so it's not user-friendly; otherwise I would have made it available here. But your method will do fine.

[bjorn.clauw.1]

I was wondering if anybody had any pictures from a cilinder made up of several modular pieces. (for dyno testing purposes). I believe Jan (or Frits) posted pictures a while back, but I can't find them anymore. If memory serves me correct the transfer ports and exhaust duct were seperate blocks that could be exchanged.

For testing purposes I would like to use a pressed in cast iron sleeve because it is easy (and cheap) to modify. I know these are not ideal in a watercooled cilinder. I was wondering if this could be improved by milling away the aluminum above the exhaust port (full curcumference) so the top 20mm of the liner under the head is exposed to the cooling fluid.

[JanBros]

For testing purposes I would like to use a pressed in cast iron sleeve because it is easy (and cheap) to modify. I know these are not ideal in a watercooled cilinder. I was wondering if this could be improved by milling away the aluminum above the exhaust port (full curcumference) so the top 20mm of the liner under the head is exposed to the cooling fluid.

wouldn't that nescesitate the use of a seal between sleeve and cylinder ?

[bjorn.clauw.1]

wouldn't that nescesitate the use of a seal between sleeve and cylinder ?

I also think the remaining press fit would not be up to the task of holding the cooling fluid out of the engine (or exhaust gas out of the cooling fluid). I have had some good experiences with ekraz o-rings (working temp of 300°c). So it would probably be neccesary to put an oring groove on the outside of the liner so it seals the cooling water from the rest of the engine (much like a detroit diesel liner).

[Frits Overmars]

I was wondering if anybody had any pictures from a cilinder made up of several modular pieces. (for dyno testing purposes). I believe Jan (or Frits) posted pictures a while back, but I can't find them anymore. If memory serves me correct the transfer ports and exhaust duct were seperate blocks that could be exchanged.Here you are Bjorn. These modular pieces started life as normal cylinders (Garelli 250 cc V-twin, about 1984) that were modified so they could easily be fitted one into the other and taken apart again for modification. They were not meant to be used on a running engine on the dyno, but for flow testing on a flow bench.
318699 318700 318701

[Muciek]

I was wondering if anybody had any pictures from a cilinder made up of several modular pieces. (for dyno testing purposes). I believe Jan (or Frits) posted pictures a while back, but I can't find them anymore. If memory serves me correct the transfer ports and exhaust duct were seperate blocks that could be exchanged.

For testing purposes I would like to use a pressed in cast iron sleeve because it is easy (and cheap) to modify. I know these are not ideal in a watercooled cilinder. I was wondering if this could be improved by milling away the aluminum above the exhaust port (full curcumference) so the top 20mm of the liner under the head is exposed to the cooling fluid.


Here it is


Found on net, Billet 3 piece cylinder block for RD400 for land speed record racing ,
315111315112315113315114315115315116

Edit: Text that was under pictures


"I am also going back to iron sleeves. Nikasil is more of a pain than I think it is worth. I may prove myself wrong, but I am going with it.

The problem with Nikasil is if you seize it ruins it which is expensive and takes a month to have re-done. But the worst part is every time it has to be replated, the nitric acid eats all of the alloying elements out of the aluminum. Last years engine is toast. The threads are all gone. Anything that used to be a press fit is now loose. It may make more power not to have the residual heat from the iron heating up the intake, but it comes at a way too high of cost...for me.

The bike is all ready to go for this year. It makes more power than I ever dreamed. But the salt may be a thing of the past. Speed week was canceled and the Bonneville Motorcycle Speed Trials right after. World of Speed has not been canceled as of yet, but all reports make it look not promising. I will be there if it is a go.

[bjorn.clauw.1]

Thanks for the replies. Some food for thought this week.
When I arrive at something tangible I will post some pics here.

Frits, you talked in the past about a structurally thermal sound engine being watercooled with onepiece cilinder (nikasil) and a high flow waterpump. Do you believe exposing a cast iron liner as much as possible to the cooling fluid would help, or will it be the proverbial (in Dutch anyways) 'droplet on a hot plate'?

[Frits Overmars]

Frits, you talked in the past about a structurally thermal sound engine being watercooled with onepiece cilinder (nikasil) and a high flow waterpump. Do you believe exposing a cast iron liner as much as possible to the cooling fluid would help, or will it be the proverbial (in Dutch anyways) 'droplet on a hot plate'?It will certainly help, compared to a conventional shrunk-in or pressed-in liner but I think it will not be good enough once your engine starts making real power.
Heat transport through the iron is not nearly as good as through aluminium, only a small part of the iron liner will be in direct contact with the water, and the transition to the surrounding aluminium will be a thermal barrier for the remainder of the liner, you'll need O-ring sealing above and below the wet part of the liner, a cylinder with any shrunk-in or pressed-in liner, even if it is a light-alloy liner, is structurally weaker than an integral cylinder, the cut-away volume of aluminium will weaken the cylinder even more, and a hard-chrome plated piston ring in an iron liner will cause rapid wear unless you give that liner a nikasil surface; but then why opt for a liner at all?

[bjorn.clauw.1]

It will certainly help, compared to a conventional shrunk-in or pressed-in liner but I think it will not be good enough once your engine starts making real power.
Heat transport through the iron is not nearly as good as through aluminium, only a small part of the iron liner will be in direct contact with the water, and the transition to the surrounding aluminium will be a thermal barrier for the remainder of the liner, you'll need O-ring sealing above and below the wet part of the liner, a cylinder with any shrunk-in or pressed-in liner, even if it is a light-alloy liner, is structurally weaker than an integral cylinder, the cut-away volume of aluminium will weaken the cylinder even more, and a hard-chrome plated piston ring in an iron liner will cause rapid wear unless you give that liner a nikasil surface; but then why opt for a liner at all?

Hi Frits, I am having great difficulties formulating a reply when you answer a question. :)

Bottom line for me would be costs. I can machine everything at home, make changes and test it the same day on an engine dyno. (It would be nice for testing purposes if you can bolt on a different exhaust duct.) Afterwards the best design can then be transfered to a nikasil cilinder.


This brings me to another question :)
I am in the proces of building an engine dyno/test stand. The dyno brake is a hydraulic pump suspended on bearings with a reaction arm connected to a load cell. Did anyone here build their own dyno/have any experiences with this matter?

[wobbly]

That modular CNC machined RD400 cylinder was analysed /designed in EngMod and was beautiful work.
The good thing about optimizing everything in a well constructed sim first, was that it made exactly the power as predicted, no experimental changes were needed at all.
He solved all the issues with sealing the liner and it ran very hard as you can see from the dyno graph.
If you are serious about doing the huge amount of machine work then PM me and I can put you in touch.
It hasnt run on the salt yet to my knowledge due to water issues ruining the speed week.

[TZ350]

Back story so far:- Finished product, narrowest part of the duct is 1.5 times the bore diameter from the exhaust port window, it looks the business.

318719

Blue = 75% nozzle of total port window, but with a dam blocking part of it. So basically 100% of the blowdown. Tonight's efforts, Red line = 75% nozzle of the open part of the exhaust port. Or basically 75% of the blowdown. The 75% restriction is 1.5 times the bore diameter downstream from the piston.

It is looking like the nozzle should be 75% of the total exhaust port window without the dam.

318712

At 13.6 rwhp this is Team ESE's best RG50 powered bike. It was prepared by Chambers for Av. The engine development is fairly conventional and its performance is good by New Zealands F5 standards. The best F5 bike I have heard talk of, is a Derbi with mid 14 rwhp.

318715 318717318714

The Team went to a lot of trouble to build a better RG50 engine, full reed inlet system, toridal head insert and exhaust port dam with exhaust port duct nozzle, bigger A transfers and Boost ports.

318718

Top Blue line is Chambers best cylinder, currently in bike 21.

Green is the new cylinder we had high hopes for with big case reeds, toridal head, but with no exhaust port dam or exhaust duct nozzle yet.

Middle Blue line is the new cylinder with exhaust port dam added and a 90% of blowdown nozzle.

Red, our latest effort, 75% of blowdown nozzle.

We recon that if we keep working diligently by the end of the week we will have halved the power we started with.

And by the end of the year, will possibly have disappeared into a black hole. ... :laugh:

Next move is to remove the dam and start working backwards undoing all those good ideas.

[F5 Dave]

I found a std head under some stuff the other day if you have an actual need for it its yours.

[Grumph]

Sit down with a nice wine and contemplate "the first concept of superior principle is always defeated by the perfected example of established practice"

[TZ350]

I found a std head under some stuff the other day if you have an actual need for it its yours.

Thanks but I think the problem is not going to be the head, I suspect the reed valve setup myself.


Sit down with a nice wine and contemplate "the first concept of superior principle is always defeated by the perfected example of established practice"

That seems to be so true ...... :yes:

[Frits Overmars]

I am in the proces of building an engine dyno/test stand. The dyno brake is a hydraulic pump suspended on bearings with a reaction arm connected to a load cell. Did anyone here build their own dyno/have any experiences with this matter?That sounds a lot like a water brake. My first dyno was a Heenan & Froude water brake. In its original form it was totally unsuitable for two-stroke development.
The torque curve of the engines was much steeper than the brake's torque curve so either the engine torque was lower than the brake's and the engine would stall,
or the engine torque was higher than the brake's and the revs would shoot right up to the engine's maximum rpm.
I more or less solved that by doubling the brake's revs and tripling the water pressure in the system. But the high pressure led to the next problem: the hoses that connected the brake body to the feed pump, tried to straighten themselves, exerting an unknown amount of extra torque on the brake body and hence on the scales (no load cells in those days).

Another consideration: building an inertia dyno is always simpler and cheaper than building a braked dyno and an inertia dyno is much more useful for competition engine development because you can choose the gearing such that the rate of engine acceleration on the dyno equals that of the same engine on the race track.
This way the all-important temperature rise of the exhaust pipe will match the real circumstances; that is impossible to achieve with a brake.
And before someone tells you it can be done with a step-test: no it can't. A step-test requires a brake with a sophisticated controller and all it can do is register a certain rpm and a certain torque value, and then let the engine accelerate to the next rpm-step in a pre-set amount of time. If the engine happens to pass through a torque dip, the controller will ease off some braking in order to get to that next rpm within the pre-set time.
Reality is not so kind: if an engine on the track goes through a torque dip, the rate of acceleration will drop, it will take more time to get through the dip, and sometimes carburation behaves so bad that the engine won't climb out of the dip at all. An inertia dyno will relentlessly reveal this; a brake won't.

[Frits Overmars]

318728Very true Grumph. It means that each time the result of a modification is bad, you will have to fight the general opinion that the modification itself was bad.
And as the general usually holds the purse, this can be lethal for research. I've experienced it more times than I care to remember.

[ief]

Searched the thread on this but not to much came up (perhaps because it's a none issue to most if not all but still)

I understand one should have the proper heatgrade plug with the proper gap, the right octane fuel, ignition etc. etc.

But...

If one is restricted to a given ignition is there a way to play with these variables and what would the relations be and how would they influence things?

Reason I ask is simple, thought I try a ngk 6 instead of 7 and it felt leaner. And if the picture below is right it's still to cold (burnplace of electrode) but it now seems I have to jet up for the hotter plug. Also using ron 98 instead of 95, not sure if necessary but to be on the safe side so it made me wonder about above.

+ I seem to have an awesome fuel ecconemy as is :)

[teriks]

(It would be nice for testing purposes if you can bolt on a different exhaust duct.
How about a wet exhaust insert/nozzle inspired by what TeeZee have shown instead of a partially wet liner?
Should be possible to achieve id think, but ignorance is bliss, I have never cut apart a water cooled cylinder..

[Frits Overmars]

thought I try a ngk 6 instead of 7 and it felt leaner. And if the picture below is right it's still to cold.What engine are you working on Ief? A Solex? :p
Sure, if the plug gets hotter, the insulator will become cleaner. That is why determining jet sizes by plug-reading only works if the plug has the correct heat range.
Using RON 98 instead of RON 95 is a waste of money, unless you are plagued by detonation. But then you'd better solve that problem first (less ignition advance, less compression, better cooling, more petrol).

[ief]

Lol, a TOMOS Frits :banana:

Fine way to experiment to my hearts intent (finally) on a practical level without braking the bank and just as much room for learning and discovering (for me, at this point anyway)

If only, getting a model in engmod within 95% (90 maybe, don't know what is possible) accuracy is a challange of it's own so loads of stuff to figure out and do.

[adegnes]

Lol, a TOMOS Frits :banana:

Fine way to experiment to my hearts intent (finally) on a practical level without braking the bank and just as much room for learning and discovering (for me, at this point anyway)

If only, getting a model in engmod within 95% (90 maybe, don't know what is possible) accuracy is a challange of it's own so loads of stuff to figure out and do.

What model Tomos is it?
I've got an a35 engine in pieces, and could help with measurements for your sim.

[ief]

That's the one :)

I allready bought an extra engine for exactly that reason but tnx for the offer. If only Neels and I can get on the same page I can continue (lol, just a joke Neels :cool:)

Na, I need to remeasure the ducts to get the proper CCR. More complicated stuff seems to be ignition and temps etc. mostly the revs below say 2500 rpm seem way off...

No hurry.

[adegnes]

That's the one :)

I allready bought an extra engine for exactly that reason but tnx for the offer. If only Neels and I can get on the same page I can continue (lol, just a joke Neels :cool:)

Na, I need to remeasure the ducts to get the proper CCR. More complicated stuff seems to be ignition and temps etc. mostly the revs below say 2500 rpm seem way off...

No hurry.

Ok! Check out mopedarmy for info if you haven't yet, lot's of it there.

[peewee]

frits you might be happy to know I made a mistake and after some thought I revised these cylinders so water can go fully around the exh port. sometimes you have to look at something a few times before you see a better way :laugh:

[wobbly]

I agree with everything Frits has to say on the dyno issue.
Ive been thru the water brake drama with a Land and Sea, just way more drama than its worth and was only
useful when a large inertia wheel was added as the brake control simply could not keep up with the rate of change of torque
in a 2T.

Re the sim accuracy,Neels code is so refined now that it is easily capable of predicting spot on accuracy within the powerband.
The only real unknown variable now is being able to assign correct values to the transfer and Ex Cd.
A good example is the RSW where we see that the raw STA numbers are skewed in favor of the transfers.
This is because as Jan alluded to, the transfer ducts and the sharp edge port exits are as good as he thought they could be.
The Ex Blowdown STA is low by comparison, but the Cd of the Ex ports is hugely affected by the big radius on the timing edge
and the port is capable of far more efficient flow than the simple timing/area numbers would indicate.
This is sort of the same but opposite to what we see in engines with crap straight transfer ducts with a right angle bend into the port.
We have to skew those transfer ports STA upwards in relation to the Blowdown, as they simply cant/wont flow anything like the plain numbers would indicate.

And in relation to the idea of a wet nozzle and or flange spigot.
Many engines with a bolt on spigot,can have slots cut in the spigot face to allow water access right around the Ex duct, and the slots also allow
water to cool the spigot back face.
Works a treat, but I can tell you now when it does work well, the egt drops significantly, and you HAVE to be tracking this and rejet on the dyno to see the real effect working.

[Larry Wiechman]

Re the sim accuracy,Neels code is so refined now that it is easily capable of predicting spot on accuracy within the powerband.
The only real unknown variable now is being able to assign correct values to the transfer and Ex Cd.
A good example is the RSW where we see that the raw STA numbers are skewed in favor of the transfers.
This is because as Jan alluded to, the transfer ducts and the sharp edge port exits are as good as he thought they could be.
The Ex Blowdown STA is low by comparison, but the Cd of the Ex ports is hugely affected by the big radius on the timing edge
and the port is capable of far more efficient flow than the simple timing/area numbers would indicate.
This is sort of the same but opposite to what we see in engines with crap straight transfer ducts with a right angle bend into the port.
We have to skew those transfer ports STA upwards in relation to the Blowdown, as they simply cant/wont flow anything like the plain numbers would indicate.




Is there a way to utilize flowbench data in the simulation?

[Makr]

I was wondering if anybody had any pictures from a cilinder made up of several modular pieces. (for dyno testing purposes). I believe Jan (or Frits) posted pictures a while back, but I can't find them anymore. If memory serves me correct the transfer ports and exhaust duct were seperate blocks that could be exchanged.

For testing purposes I would like to use a pressed in cast iron sleeve because it is easy (and cheap) to modify. I know these are not ideal in a watercooled cilinder. I was wondering if this could be improved by milling away the aluminum above the exhaust port (full curcumference) so the top 20mm of the liner under the head is exposed to the cooling fluid.



Found on net, Billet 3 piece cylinder block for RD400 for land speed record racing ,
Attachment 315111Attachment 315112Attachment 315113Attachment 315114Attachment 315115Attachment 315116

Edit: Text that was under pictures

"I am also going back to iron sleeves. Nikasil is more of a pain than I think it is worth. I may prove myself wrong, but I am going with it.

The problem with Nikasil is if you seize it ruins it which is expensive and takes a month to have re-done. But the worst part is every time it has to be replated, the nitric acid eats all of the alloying elements out of the aluminum. Last years engine is toast. The threads are all gone. Anything that used to be a press fit is now loose. It may make more power not to have the residual heat from the iron heating up the intake, but it comes at a way too high of cost...for me.

The bike is all ready to go for this year. It makes more power than I ever dreamed. But the salt may be a thing of the past. Speed week was canceled and the Bonneville Motorcycle Speed Trials right after. World of Speed has not been canceled as of yet, but all reports make it look not promising. I will be there if it is a go.


I just lurk on this forum, but I am here. :D

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

[ken seeber]

RYGER time ?

"Re: The Ryger engine.
«Reply # 128 Posted on: January 10th, 2016, 22:29:43»
Quote from: lvenni on January 10, 2016, 20:48:38
After a fantastic visit to the magnificent work, and with Mr. ryger talking to.

Conclussion, answered many questions, and I can not log else ....


It MUST work, what a wonderful piece of engineering is that .....

Hugely impressed!

Later this week we know it, and a deep bow to Mr. ryger ....... "

Seeing this is from a Dutch forum, it's gotta be right, hey. :2thumbsup

[jonny quest]

TZ350, have you tried a boost bottle on the intake boot? Wobbly or Frits? I have never dyno'ed a with and without boost bottle.

[wobbly]

Boost bottles do "work" but do need serious rejetting to optimize the effect.
The engines that have them simply wont respond at all if they are removed.
But at the end of the day, exhaust tuning is vastly superior in a 2T,due to the much greater wave action energy compared to a 4T
and thus has hugely more energy easily used in an ATAC setup.
We saw close to 30% more power in the BSL500 at the bottom of the powerband when utilizing an effective servo driven ATAC, whereas
an optimized boost bottle was struggling to crack 5%.

[jonny quest]

Do you typically lean the mixture with boost bottles?
I have a CR 125 that needs help on the low end.

[TZ350]

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

I would love to see much more posted of your work. ... :yes:

[seymour14]

I just lurk on this forum, but I am here. :D

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

Had a good read on your two stroke forum. Really excellent work, lovely machining. Shame about the cancellation of speed week, patience is a virtue!

Here's a picture of the race bike we have just finished with a three piece CNC barrel and CNC air cooled head, it pulls outrageous hp and torque figures for its bucket racing restrictions. Will post up more pictures tomorrow.

[husaberg]

Do you typically lean the mixture with boost bottles?
I have a CR 125 that needs help on the low end.

www.eric-gorr.com/images/documents/HondaCRModelTuningTips.pdf

[bjorn.clauw.1]

I just lurk on this forum, but I am here. :D

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

Hello Makr, read your thread on 2strokeworld and am amazed by the amount of work and detail you have put into this project. The powercurve is impressive to say the least. I believe a lot of people would like to know more about your project.

[Frits Overmars]

frits you might be happy to know I made a mistake and after some thought I revised these cylinders so water can go fully around the exh port.
sometimes you have to look at something a few times before you see a better way :laugh:.I'd say you improved the aesthetics as well as the cooling :2thumbsup.


Is there a way to utilize flowbench data in the simulation?In theory we could collect flowbench data per crank degree of port opening for each port and then use these data to create angle.flow tables instead of angle.area tables for the sim to work with. But getting the proper flowbench data is far from simple.
Let's take a look at the blowdown phase. The cylinder pressure at the start of the blowdown phase can be as high as 12 bar, creating sonic outflow. A flowbench may be able to generate a pressure differential of say 200 mbar; it's no comparison.
The second factor is inertia. The mass of gas in an exhaust duct is accelerated to Mach 1 within a couple of crank degrees. A regular flow bench generates a nice constant flow - no acceleration at all.
True, we could build a pulsating flowbench. But we would also have to operate it with a gas at 12 bar and 1800°C...
Luckily such devices exist. They run on petrol; we call them engines :p .


I just lurk on this forum, but I am here :D.
This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.Hey Mark, welcome. Good to have you with us.


Do you typically lean the mixture with boost bottles? I have a CR 125 that needs help on the low end.A boost bottle causes a somewhat more constant flow through the carb, with weaker suction pulses, so less fuel gets added to the air. In short: yes, it weakens the mixture. I think I wrote a bit more on boost bottles here in the past but I can't find it right now.
One more important aspect to watch: unless you mount the boost bottle with the connecting hose at the lowest point, fuel tends to collect in the bottle, upsetting the mixture strength at certain revs.

[41juergen]

I played a bit more with the ExDuct and "stinger" design as Wob recommended. That's the Mach numbers which gave the best power. Are these data close to what is reasonable?
BTW: Yes, I collect all comments from you guys having much more know how than I have to learn more about these tricky machines... :) Thank's a lot!

[1948rod]

hi would a water cooled first section of the ex. header be a help to cool returning ex gases after transfer closing. a fabricated header with inlet from around ex. port like wobbly post with outlet on top of header. a seperate inlet and outlet using the water out of top of head before it returns to the rad. could be used. this would be easy to do on 100cc kart engines and also incorporate the nozzle if required. love your forum.

[Frits Overmars]

hi would a water cooled first section of the ex. header be a help to cool returning ex gases after transfer closing. a fabricated header with inlet from around ex. port like wobbly post with outlet on top of header. a seperate inlet and outlet using the water out of top of head before it returns to the rad. could be used. this would be easy to do on 100cc kart engines and also incorporate the nozzle if required. love your forum.The idea is sound, 1948rod (my year of birth). But in a well-designed engine the washed-through fresh mixture doesn't make it all the way into the header; it stays in the exhaust duct of the cylinder. Water cooling the first section of the header would withdraw energy from the spent gases at the expense of pulse strength.
Maybe your scheme could work in those 100 cc kart engines because I seem to remember that those had extremely short exhaust ducts.

[peewee]

frits did you say the volume of water in the cooling system should be small and move fast ? is it like a small pot of water on the stove could absorb the heat a lot faster than a large pot of water ?

[Frits Overmars]

frits did you say the volume of water in the cooling system should be small and move fast ? is it like a small pot of water on the stove could absorb the heat a lot faster than a large pot of water ?A small pot of water will absorb heat slower than a large pot. Moreover the water in that small pot will heat up quicker, so the temperature difference between water and stove drops, slowing heat transfer down even more.

I didn't say the volume should be small. I said that a large volume of slow-moving, almost stationary water is not effective. Water passages should be narrow so that most of the water is in contact with the walls instead of flowing down the middle without touching the hot metal surfaces. Narrow passages will also keep the flow velocity up, which helps heat transfer from those surfaces to the water.

[Makr]

I would love to see much more posted of your work. ... :yes:

:D

Had a good read on your two stroke forum. Really excellent work, lovely machining. Shame about the cancellation of speed week, patience is a virtue!

Here's a picture of the race bike we have just finished with a three piece CNC barrel and CNC air cooled head, it pulls outrageous hp and torque figures for its bucket racing restrictions. Will post up more pictures tomorrow.

Thank you. Yes, it is a shame. My family's first year out there was '74, so most of my life has been landspeed racing. The state of things makes my heart hurt.

Cool bike.


Hello Makr, read your thread on 2strokeworld and am amazed by the amount of work and detail you have put into this project. The powercurve is impressive to say the least. I believe a lot of people would like to know more about your project.

Thanks. I give a huge amount of credit for the power it makes to wobbly. That guy is a genius, and feel honored he helps me.



Hey Mark, welcome. Good to have you with us.



Thanks Frits.


Not really sure where to start. Wob and Frits have seen most of it, and it seems the TSW thread has been viewed.

I run a Yamaha RD400 on the salt flats with a RZ case and transmission. The rest is mine. I have to keep the stock case to keep in the class I am running.

http://img.photobucket.com/albums/v283/superr5/2015/11219107_10153518251098006_6567724929155651015_n_z psk64lxdsi.jpg (http://smg.photobucket.com/user/superr5/media/2015/11219107_10153518251098006_6567724929155651015_n_z psk64lxdsi.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-03-26%2019.29.16_zpsbuox6tvn.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-03-26%2019.29.16_zpsbuox6tvn.jpg.html)

So from my 2014 engine to 2015 I went back to iron liners, made the transfers much bigger, went to larger reed, and carbs. I also ran coolant under the crankcase, which I hope was worth something because it was a pain in the ass to do. Partially because I am a fair-at-best welder. :)

http://img.photobucket.com/albums/v283/superr5/2015/2015-01-26%2017.07.41_zpsbuzcljxj.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-01-26%2017.07.41_zpsbuzcljxj.jpg.html)

I connected the webbed pockets as a maze and then capped the pockets.


http://img.photobucket.com/albums/v283/superr5/2015/2015-01-23%2015.04.31_zpswunr3vj7.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-01-23%2015.04.31_zpswunr3vj7.jpg.html)

[seymour14]

Hope you don't mind TZ, will pop some of the old work on your site for posterity, it seems to get some great viewing internationally and is a pool for all time...

Here is that CNC billet build, will show some of the end stuff first so that it can be followed easier. Essentially it was a two piece barrel, head, and sleeve, all CNC'ed.

Good to know I am not the only sadist on this planet, it's a lot of hard work to knock up that first one...:niceone:

Air cooled 125cc Two stroke, based on a KR150 bottom end for bucket racing.

First photo is very early on, barrel is barely machined, the lower part in the photo gets spigotted inside the barrel and forms the "swept" intake, sleeve is second photo, head barrel and exhaust stub in the last.

[peewee]

A small pot of water will absorb heat slower than a large pot. Moreover the water in that small pot will heat up quicker, so the temperature difference between water and stove drops, slowing heat transfer down even more.

I didn't say the volume should be small. I said that a large volume of slow-moving, almost stationary water is not effective. Water passages should be narrow so that most of the water is in contact with the walls instead of flowing down the middle without touching the hot metal surfaces. Narrow passages will also keep the flow velocity up, which helps heat transfer from those surfaces to the water.

I think I get it. with less temperature difference there will be less heat transfer to the water ? ive got to either buy a radiator or have one made (either larger or smaller than whats currently available, based on what ever advice you could give me). this is a methanol drag racing bike remember. to reduce weight ive seen some guys use just a very small rectangle aluminum tank, so water can still be pumped through the cylinders and head but there is no fins or tubes on the tank, basically just a rectangle alloy box. other guys use a radiator but its very small, to reduce weight I suppose.

i guess those methods would work for one run and shut the engine off but i need a system that offers good cooling for continuos multiple runs. from what ive seen, the water temp is lower with methanol but eventually it starts to creep up near that of what you would expect from a average 2t gas engine. do you have any rule of thumb for radiator size ?

[peewee]

http://img.photobucket.com/albums/v283/superr5/2015/2015-03-26%2019.29.16_zpsbuox6tvn.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-03-26%2019.29.16_zpsbuox6tvn.jpg.html)


those look like mikunis ? im looking for some carbs around 40mm that will still function halfway normal while slanted forward at a fairly steep angle. i was thinking of lectrons unless theres something better thats readily available . do you have any advice on this ?

[41juergen]

:D


Thank you. Yes, it is a shame. My family's first year out there was '74, so most of my life has been landspeed racing. The state of things makes my heart hurt.

Cool bike.



Thanks. I give a huge amount of credit for the power it makes to wobbly. That guy is a genius, and feel honored he helps me.



Thanks Frits.


Not really sure where to start. Wob and Frits have seen most of it, and it seems the TSW thread has been viewed.

I run a Yamaha RD400 on the salt flats with a RZ case and transmission. The rest is mine. I have to keep the stock case to keep in the class I am running.

http://img.photobucket.com/albums/v283/superr5/2015/11219107_10153518251098006_6567724929155651015_n_z psk64lxdsi.jpg (http://smg.photobucket.com/user/superr5/media/2015/11219107_10153518251098006_6567724929155651015_n_z psk64lxdsi.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-03-26%2019.29.16_zpsbuox6tvn.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-03-26%2019.29.16_zpsbuox6tvn.jpg.html)

So from my 2014 engine to 2015 I went back to iron liners, made the transfers much bigger, went to larger reed, and carbs. I also ran coolant under the crankcase, which I hope was worth something because it was a pain in the ass to do. Partially because I am a fair-at-best welder. :)

http://img.photobucket.com/albums/v283/superr5/2015/2015-01-26%2017.07.41_zpsbuzcljxj.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-01-26%2017.07.41_zpsbuzcljxj.jpg.html)

I connected the webbed pockets as a maze and then capped the pockets.


http://img.photobucket.com/albums/v283/superr5/2015/2015-01-23%2015.04.31_zpswunr3vj7.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-01-23%2015.04.31_zpswunr3vj7.jpg.html)

That is an interesting setup how you cool the case. I'm working on the same idea on my RZ with taking a smaller amount of water coming from the pump leading through the case and than back to the radiator... Have you already run the engine with that case cooling, did you found significant gains?
Juergen

[wobbly]

The basic rule is that you cant have a radiator thats too big.
But running Methanol will basically turn an air cooled motor into an efficient an engine, as a normal watercooled.
This basically means that the aircooled wont go off due to thermal overload like it will do naturally on petrol.
But running a watercooled on meth means it will be hard initially to get any temp into the water, so my advise is to use a small rad but plumb it with a bypass
thermostat.
This will naturally reduce the water cooling effect early in the passes, but when the temp starts to rise it will then use the water to do its job.

[bjorn.clauw.1]

That sounds a lot like a water brake. My first dyno was a Heenan & Froude water brake. In its original form it was totally unsuitable for two-stroke development.
The torque curve of the engines was much steeper than the brake's torque curve so either the engine torque was lower than the brake's and the engine would stall,
or the engine torque was higher than the brake's and the revs would shoot right up to the engine's maximum rpm.
I more or less solved that by doubling the brake's revs and tripling the water pressure in the system. But the high pressure led to the next problem: the hoses that connected the brake body to the feed pump, tried to straighten themselves, exerting an unknown amount of extra torque on the brake body and hence on the scales (no load cells in those days).

Another consideration: building an inertia dyno is always simpler and cheaper than building a braked dyno and an inertia dyno is much more useful for competition engine development because you can choose the gearing such that the rate of engine acceleration on the dyno equals that of the same engine on the race track.
This way the all-important temperature rise of the exhaust pipe will match the real circumstances; that is impossible to achieve with a brake.
And before someone tells you it can be done with a step-test: no it can't. A step-test requires a brake with a sophisticated controller and all it can do is register a certain rpm and a certain torque value, and then let the engine accelerate to the next rpm-step in a pre-set amount of time. If the engine happens to pass through a torque dip, the controller will ease off some braking in order to get to that next rpm within the pre-set time.
Reality is not so kind: if an engine on the track goes through a torque dip, the rate of acceleration will drop, it will take more time to get through the dip, and sometimes carburation behaves so bad that the engine won't climb out of the dip at all. An inertia dyno will relentlessly reveal this; a brake won't.


Tanks for the input Frits and Wobbly. Will put my hydraulic brake + load cell in storage. There has gone some work in modifying and machining the hydraulic pump but this does not compare to the amount of work that still had to be done on electronics. So thank you both for the extra 2 months I saved by not pursuing this. ;)

I have a burnt out electric 3 phase motor 22kw 900rpm. Digging through some datasheets the inertia af the rotor is 11.4kg/m2. In the ballpark of others systems I found. Will give this a try instead.

[bjorn.clauw.1]

Not really sure where to start. Wob and Frits have seen most of it, and it seems the TSW thread has been viewed.



Hi Makr. I was wondering if you still use a slipfit to install your liner? You o ring the 'levels' of your cilinder so water, ports and crankcase are seperated but is there a barrier between the transfer ports and the exhaust ports? (In other words, could the exhaust blow (/creep) around the liner to where the transfers enter the outside of the liner?

[Frits Overmars]

this is a methanol drag racing bike remember. to reduce weight ive seen some guys use just a very small rectangle aluminum tank, so water can still be pumped through the cylinders and head but there is no fins or tubes on the tank, basically just a rectangle alloy box.If you don't cool the water it's a different situation. The more water you carry, the slower it will heat up and the longer it will take before your engine power collapses.


do you have any rule of thumb for radiator size ?Yes: bigger!


I have a burnt out electric 3 phase motor 22kw 900rpm. Digging through some datasheets the inertia af the rotor is 11.4kg/m2. In the ballpark of others systems I found. Will give this a try instead.That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

You may want to play a little with this program: 318780 It has attained the age of majority so I'm not sure if it will run on your computer. Just let me know.

[bjorn.clauw.1]

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

You may want to play a little with this program: 318780 It has attained the age of majority so I'm not sure if it will run on your computer. Just let me know.

Forgot to mention the overspeed (safe max speed) is 2400 rpm. Will do some numbercrunching this evening. Let you know what I come up with.
(Offtopic: had a rotor that exploded once, hydro electric setup with screw of archimedes. Fault in electric braking circuit and motor 120kw revved to about 8000rpm.
It was the gearbox thar failed first (20:1) but motor followed shortly after. They had quitte a bit of work repairing the walls/ceiling afterwards.

Makes you wonder what the flywheel would take with him when your engine seizes during the max rev part of the run on. (One way clutch would not hurt here)

[adegnes]

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.


The rotor in my dyno is a feeble 2.17kgm2, 317mm diameter, also from an old ac motor (ABB). Seems to work fine up to at least 60whp, it's spinning uncomfortably fast when selecting a high enough gearing to get good runs with that kind of power though... I've touched 4000rpm! Nothing I would encourage anyone to duplicate.

[Frits Overmars]

Makes you wonder what the flywheel would take with him when your engine seizes during the max rev part of the run on. (One way clutch would not hurt here)If you're lucky the chain will snap without hitting you on the back; a bit less lucky and the engine will be ground to smithereens. If the chain and the engine can withstand all the violence, the flywheel may turn the whole test bench over and over. You don't want to be in the same time zone when that happens.

Warning! this may also happen when you just brake too hard after a successfull dyno run. Therefore it's wise to put a spring and an end stop under the dyno brake pedal. Another nice solution is to operate the brake caliper with compressed air instead of hydraulic pressure. The air pressure can than be regulated thus that there is no risk of overbraking.

[wobbly]

In my opinion you must run an intermediate shaft ( like a kart axle behind the engine ) that has an overun clutch
that then drives to the flywheel.
You can make a very easy/small/cheap overun clutch from the ones they use on a tractor PTO shaft, for when driving mowers etc.
If they dont use one the mower inertia is so great, it keeps driving the tractor forward with no engine power.
Having said that I have never seized an engine on my dynos in 30 years.
If you watch the power curve,or egt, or deto level on screen as the run up progresses, you can see if something is seriously wrong.
But just seems comfortable to me that when you are doing a run up, you can shut down the engine instantly at any time,and then brake the flywheel
independently ( slowly or fast, it makes no odds ).
I have several different sprockets permanently fixed onto the axle shaft that can be moved into line for any engine.
An 80 tooth 100cc kart one and 428/520/525 ones for 125 and 250/400 kart/bike engines.

[AndreasL]

Hmm, a lot of people "active" in this thread right now.

Might it be the news that the Ryger engine has passed homologation that drives people here...

Congratulations Harry! :2thumbsup

[wobbly]

The Ryger may have been passed but the homologation papers are still not posted on the CIK site.

[Makr]

those look like mikunis ? im looking for some carbs around 40mm that will still function halfway normal while slanted forward at a fairly steep angle. i was thinking of lectrons unless theres something better thats readily available . do you have any advice on this ?

44 mm round slide Mikunis. These would be 15 degrees from parallel. They work fine. I have very little experience performance tuning anything else. I seem to be able to tune the round slide so as adventurous as I am in some areas there are some I try to keep consistent.


That is an interesting setup how you cool the case. I'm working on the same idea on my RZ with taking a smaller amount of water coming from the pump leading through the case and than back to the radiator... Have you already run the engine with that case cooling, did you found significant gains?
Juergen

I have no idea if there are any gains because this is a completely new engine. I run all of the coolant through the base and then up through the port in the center that goes up through the intake manifold and into the cylinder. I will plumb it different next time to just go straight into the cylinder. Frits pointed out it was heating up the intake after I had it all done. Doh!


http://img.photobucket.com/albums/v283/superr5/2015/2015-03-25%2019.14.31_zpswhxcngkv.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-03-25%2019.14.31_zpswhxcngkv.jpg.html)


Hi Makr. I was wondering if you still use a slipfit to install your liner? You o ring the 'levels' of your cilinder so water, ports and crankcase are seperated but is there a barrier between the transfer ports and the exhaust ports? (In other words, could the exhaust blow (/creep) around the liner to where the transfers enter the outside of the liner?

Yes it is a snug slip fit. Yes it absolutely can leak and probably does. I see it as a small compromise.

http://img.photobucket.com/albums/v283/superr5/2015/2015-02-14%2017.38.15_zpsed1hvzs7.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-02-14%2017.38.15_zpsed1hvzs7.jpg.html)


I welded a plate onto the top of the case to accept the much larger transfers. It pulled itself apart several times before I had to fix it for good.

Plus it was a leaky mess anyway.
http://img.photobucket.com/albums/v283/superr5/2015/2015-05-30%2018.39.09-1_zpsnzwzkbrc.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-30%2018.39.09-1_zpsnzwzkbrc.jpg.html)

I cut off the front of another case and machined a piece to replace it.

http://img.photobucket.com/albums/v283/superr5/2015/2015-07-16%2016.58.40_zpspxlbgsg9.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-07-16%2016.58.40_zpspxlbgsg9.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-07-16%2011.53.02_zpsskmeskpz.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-07-16%2011.53.02_zpsskmeskpz.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-07-17%2006.29.23_zpsa9qqtitw.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-07-17%2006.29.23_zpsa9qqtitw.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-07-29%2014.51.29_zps9akcaug0.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-07-29%2014.51.29_zps9akcaug0.jpg.html)

This is a picture of the setup part but you get the idea.

http://img.photobucket.com/albums/v283/superr5/2015/2015-02-07%2011.45.00_zpszspqenxs.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-02-07%2011.45.00_zpszspqenxs.jpg.html)


I haven't pulled it apart since.
http://img.photobucket.com/albums/v283/superr5/2015/2016-01-13%2019.33.47_zpshh71uwrh.jpg (http://smg.photobucket.com/user/superr5/media/2015/2016-01-13%2019.33.47_zpshh71uwrh.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2016-01-13%2019.33.55_zpsathv1xrz.jpg (http://smg.photobucket.com/user/superr5/media/2015/2016-01-13%2019.33.55_zpsathv1xrz.jpg.html)

[wobbly]

If you want to tip carbs up steep then Lectrons are the go.
They flow way more air than any round slide, are easy to tune and are period legal for Pre 82 Post Classic if thats important, and were used by King Kenny
on TZ750/500 in the early 70s..
As long as you keep the powerjets reasonably small ( 60 ) the fuel curve is much better than any normal carb where the fuel circuits and air correction
overlap, that cause dips and bumps in the A/F readings.

[husaberg]

In my opinion you must run an intermediate shaft ( like a kart axle behind the engine ) that has an overun clutch
that then drives to the flywheel.
You can make a very easy/small/cheap overun clutch from the ones they use on a tractor PTO shaft, for when driving mowers etc.
If they dont use one the mower inertia is so great, it keeps driving the tractor forward with no engine power.
.
Pretty much any tractor made after 1960 now is non live drive, but anyone who has driven a mower on a fergie will know the but clenching that occurs when the mower starts and continues to drive the tractor even though the clutch is pressed in.
Many a fence has been driven through when this occurs.
I am suprised how easy it is to still get the over running clutch it might pay to buy a few, because they will stop making them someday.
<iframe width="420" height="315" src="https://www.youtube.com/embed/voYfpkQyPQ0" frameborder="0" allowfullscreen></iframe>

[Flettner]

I cut off the front of another case and machined a piece to replace it.


Didn't you say you had to use the original cases? Is there some percetage rule?:laugh:

[adegnes]

Didn't you say you had to use the original cases? Is there some percetage rule?:laugh:

Small repairs are allowed:laugh:

[richban]

Anyone know anything about the 2 stroke engine in these. They must have plenty of power.

http://www.jet-surf.com/en/machines.php

318802

[bjorn.clauw.1]

Anyone know anything about the 2 stroke engine in these. They must have plenty of power.

http://www.jet-surf.com/en/machines.php

318802

http://ing.jetsurfmexico.com/docs/manuals.pdf
~17hp 100cc, interesting location for the intake (overall size vs hp compromise I believe)

http://www.msrengines.eu/vyvoj.htm

[Brett S]

The official CIK list is out, Ryger is on it.
All we need now is the homologation papers...

[Makr]

Didn't you say you had to use the original cases? Is there some percetage rule?:laugh:

I thought a lot about that when I did it.

This only became an issue when someone complained that an S&S powered Harley with no actual Harley parts in the engine really wasn't the rule. There are many records on the books with that combination.

Mine is still 75% Yamaha!


Small repairs are allowed:laugh:

Right! :thumbsup

[richban]

http://ing.jetsurfmexico.com/docs/manuals.pdf
~17hp 100cc, interesting location for the intake (overall size vs hp compromise I believe)

http://www.msrengines.eu/vyvoj.htm

Cheers thanks for that. I would have guessed it had more power to push the thing through water with someone standing on it. An interesting toy.

[wobbly]

Here is the sim power graph and the Mach numbers for a race RZ400, to show how to interpret the traces.
The approach with this engine was to maximize power spread, rather than outright max power.
This makes a racebike with good suspension and sticky slicks faster, with plenty of off corner power,plus the RZ has very
compromised transfer ducts due to the bore centers,thus high peak power is hard to generate without badly narrowing the powerband.
Add to this the fact that the gear ratios available are not particularly close, and a good spread of power is essential.

If you look at the Mach numbers for both the stinger and the duct nozzle, they are both a little under Mach 0.8.
Having a slightly bigger nozzle and stinger restrictor favors mid power, over outright peak production, so the Mach numbers tell me, as did the power
output that I was choosing the right approach.For peak power the stinger would have gone sonic then been close to/above Mach 0.8
and the duct exit would be on 0.8 for much longer.
It made 96Hp on a load controlled Dynojet with no power fade at all, and has tons of mid torque - job done.
The other thing of note is how accurate the sim represents the power.
Take off around 12% from the crank power and you get real close to the Dynojet rear wheel power output.
And the real engine has a 2 stage PV blade that works way better than that simulated, so the mid power is even better than expected in reality.

[MotleyCrue]

Were there specifics given out already about the port timing and exhaust dimensions for this RZ400 engine or is that guarded info?

[AndreasL]

Thanks wobbly.

This is great info and very helpful.

[wobbly]

The RZ400 cost the customer plenty, but the real issue is that this is very much a 1 off special synergy of parts.
It has a CPI Cheetah cylinder on a long rod 58 crank, and the cylinder was a special with large Ex spigot diameter to enable the duct to be CNC machined
to make a nozzle.
It also had a curved 2 stage PV blade driven with the Ignitech and a servo, not the complete shit Rotax style pneumatic bellows type.
The cylinder was dropped to enable reverse stagger transfers to be ground, and the Aux were welded to make them triangular right at bore center.
The Ex port floor was lifted 4mm, and the corner rads filled.
It also has 60mm CR125 VF3 reeds in there on bore center with side stuffer plates.
As it was found that the big 68mm CR250 reeds, positioned off center, gave asymmetric inlet flow and lost 5 Hp, despite the better flow characteristics.
I am happy to give out the port and pipe specs, but they are useless information unless the whole engine is recreated in every detail.
Where else do you find a race 2T with peak torque and Hp near 3000 rpm apart.
To get this sort of project right,you gotta pay to get it done completely, even if only in sim form.

[jfn2]

wobbly:
What did you use for piston pin plugs?

[wobbly]

Torlon plugs

[bjorn.clauw.1]

Is it possible to elaborate a bit more on the last graph. (Mach numbers) I never thought 2 stroke software was this close to real world results.
Is this software available/affordable for the enthusiastic amateur?

I noticed the A-transfer inlet is lower than the B-transfer inlet. Also no boyesen ports in the inlet duct. Both a result of space limitations or is there a design philosophy behind it?

[FastFred]

I never thought 2 stroke software was this close to real world results. Is this software available/affordable for the enthusiastic amateur?

The last time I looked, Engmod2T was $400 USD ...

To put it in prospective, Engmod2T is cheaper than a good set of porting tools:- http://www.ccspecialtytoolstore.com/

[FastFred]

Were there specifics given out already about the port timing and exhaust dimensions for this RZ400 engine or is that guarded info?

This whole thread is like a University course where you learn the principles so you can successfully apply them yourself.

[jfn2]

Thank you wobbly.
Is it the #4203 or the #4301?
Did you machine as per Fritz's drawings? Can/will you sell them or does someone sell them?

[wobbly]

The software is scary good, and for whatever reason ( I simply dont care ) the crank power if estimated with all good inputs to the sim
will translate to close to 12% reduction needed to account for gear/chain/tyre losses on a Dynojet.
Contact Neels the code man at vannik@mweb.co.za pay your money and you are away.

Dont get confused,the RZ400 ( for F3 or Superlight ) info I just posted, isnt the same engine I detailed a bit further back - that was a TZ400 using a 6 port 3G3 cylinder for pre 82 Post Classic racing.
In the TZ400 the A duct being shorter than the B/C is from dyno testing done many ( MANY ) years ago by Helmut Fath ( my Hero ) who tuned for John Eckerold among others ( Freddie ).
There is no room in the TZ350 cylinder for more inlet area, the sides are 1mm away from the stud holes as it stands.
It is possible to make larger screw in studs with cutaways in them and 3 port the Exhaust, but as the rod angularity pushes the piston against the inlet wall
I dont think anyone has ever put boyesens into an RD/TZ/LC - I never considered it, maybe it is possible.
The inlet area is the big mechanical issue in the older Yamaha design as the studs are so close together, but by fitting an inlet divider to help the piston wear issue
( just as a 250G killed them also ) and adding twin boost ports, the power is respectable.

The RZ400 is a different story altogether.

[TZ350]

Page 1430 links list .....



I have tuned it a bit now, runs smoother on idle, but as there is no venturi in this carb i figure it will work better on a engine with bigger displacement.
An engine that pulls more air before getting into the pipe so to speak.
I still have this HUGE gap in power when giving it full throttle, it just dies, no fuel is drawn into airstream, until i hit ~11000rpm(when the pipe is pulling hard)

I feel it´s the drawback on this model of carb, it´s a 'slide' model.

Rgds.SwePatric...

Provided that there are NO air leaks anywhere with in the carb and fuel lines, and the carb is mounted with the pump assembly to the top... The first thing in getting rid of the throttle lag, is to increase the volume of fuel in the chamber located above the fulcrum arm. This makes more fuel quickly available to reach the venturi when the throttle is snapped open. To do this simply raise the fulcrum arm height. Be aware if the fulcrum is raised to far, the back side of the metering diaphragm will make contact with the pump body and prevent the fuel inlet seat from completely closing. To check for this.... After setting the fulcrum arm height, with the pump assembly removed, re-set the pop-off back to the original setting. Then remove the needles put the pump assembly back on and re-check the pop-off through the fuel inlet. It should be with-in less than 1 psi to the same reading as when the pump is removed. Usually the fulcrum height dimension is measured from the gasket surface to the top of the fulcrum arm. With .010" increments being a common adjustment. Lower pop-off settings will also help get rid of this lag, but as you have already seen lower pop-off will have other detrimental effects. If you have the diaphragm start hitting the pump, but still want more volume. An additional gasket can be placed between the metering diaphragm and the pump body. When set at the same pop-off, lighter rate springs also slightly richen up the throttle opening. Hope this helps.... Kermit Buller


What sort of pop off pressure is being used in the pumper now ?
I did a 100cc air cooled shifter engine years ago for a restricted kart class, that used a Tillotson 26mm slide carb.
The factory setting for this was 12 psi, but to get enough fuel into the low end transition circuit I had to eventually go to 1/2 this at 6 psi
with the lever height raised 0.5mm higher than stock as well.
The other "trick " is reverse jetting,with something like 2.5 turns on the L jet and 0.25 on the H, but this then needs a higher pop off.
This works well, as the L circuit is air corrected late in the fuel curve and it leans out past peak power, just whats needed.

319150 Tillotson HL360A 24mm carb on TeeZees 28rwhp 1978 Suzuki GP125 engine. 319173


The Keihin that came off the Honda RS125/250 has a PJ solenoid with a Viton tip.
It is the same as was used by the later Aprilia - it had pwm control,the Honda just used an on/off from the ECU.
The part is the same as is used I believe in a Fiat Uno and several other carbs as an idle air controller.

And re the PVL ignitions.
The analogue black box stator and coils are used by the thousand in KZ2 kart engines, so most are a straight line as mandated by the CIK.
Other stators have higher resistance ie more,thinner wire, and this gives a little more retard curve with no electronics involved.
You can buy stators for a Banshee that have the max amount of wire in the coils, so they will start with only minimal kickstart turns.
These are cloth covered coils ( called 5000 wind ), but even they only retard about 10* from 2000 to 10,000 - again pretty useless compared to the amounts of retard
and the curve shape we use now in a cheap Ignitech setup.
PVL make digital, red coils,and there are a few good versions of these, but 15 years ago you paid E500 to have one programmed for you - yea right,no thanks.


Wobbly, the power jet on the Keihin ? Is that an on / off or a pulsed type pj


Pumper carbs are alot more complex than you would think.
The 3 main tuning variables are pop off pressure, diaphragm lever height, and needle positions.
What are these variables at the moment - if you dont know, and or cant change all these,then you cant tune one.
If you can tune the top end OK with the H needle, but need the L out too far to get response off idle then you need to drop
the pop off a couple of psi.
This will then allow much less L needle but still be rich enough to accelerate off idle.
But then the H needle will need to go in some to lean off the top end.

The other issue I can see is PVL.
What is the stator coil resistance - as most of these ignitions are useless on a racing 2T as they have almost no retard at all.
If its 50 ohms you have a straight line ignition off a KZ2, useless - if its 200 ohms then you have around 7* retard, still useless.


Was surprised how bad my transfers were. I took my time measuring them using all kinds of tools, but the Vinamold told the truth.


The mechanical PV mechanism is almost always set by the tension of a spring resisting the movement of balls up a ramp.
Its easy to shim the spring to make it open later ( looks like the KR is opening way too soon ).
But the issue then is that it may be fully open at a later rpm, but the more you shim it, the faster it opens.
This is usually not whats needed.

Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position.
Overlay the graphs and the 3 points are then easy to plot.
This will be impossible to replicate with a mechanical servo.
But using the EXUP motor off an R1 its cheap and easy to add an electronic setup driven by an Ignitech.
When people put pipes on an R1 they always dump the EXUP, so they are available off Ebay for chips.
Honda also did a cable servo PV in 2004 on the CR125, so those bits will work as well.
Here is the setup on a KTM250.


That looks like a nice job on the RZ cylinders.
But possibly not needed nowdays as VF have a new reed for the Banshee that is a big step ahead of the VF3.
The RZ needs plenty of inlet capability when tuned really hard, but the CPI Cheetah cylinder had CR250 size reeds ( 68mm wide )
that needed to be offset outward to make them fit.
Calvin and I had a major disagreement about this, until I fitted the smaller 60mm CR125 VF3 ( looks the same as your NSR reed )
and offset them back onto the cylinder center, with a 6mm stuffer plate down one side to equalise the flow.
This change made +5Hp, and the CR125 reed is capable of even more than the engine could mangage.
So bigger in this case for shure wasnt better.


Yeah, toluene used to be advertised as 'methyl benzine' as used in Shell 'super' petrol ( along with tetra ethyl lead).

Here are some recipes for home blending.. www.gnttype.org/techarea/misc/octanebooster.html (http://www.gnttype.org/techarea/misc/octanebooster.html)

& the TEL is still available as an additive 'Octane Supreme 130' www.hi-flow.com/hp016os.html (http://www.hi-flow.com/hp016os.html) - the lead works
- as a lubricant for highly stressed 2T parts, look how much power/reliability was lost from G.P. 2Ts - when it was banned..


The software is scary good, and for whatever reason ( I simply dont care ) the crank power if estimated with all good inputs to the sim
will translate to close to 12% reduction needed to account for gear/chain/tyre losses on a Dynojet.
Contact Neels the code man at vannik@mweb.co.za pay your money and you are away.

Dont get confused,the RZ400 ( for F3 or Superlight ) info I just posted, isnt the same engine I detailed a bit further back - that was a TZ400 using a 6 port 3G3 cylinder for pre 82 Post Classic racing.
In the TZ400 the A duct being shorter than the B/C is from dyno testing done many ( MANY ) years ago by Helmut Fath ( my Hero ) who tuned for John Eckerold among others ( Freddie ).
There is no room in the TZ350 cylinder for more inlet area, the sides are 1mm away from the stud holes as it stands.
It is possible to make larger screw in studs with cutaways in them and 3 port the Exhaust, but as the rod angularity pushes the piston against the inlet wall
I dont think anyone has ever put boyesens into an RD/TZ/LC - I never considered it, maybe it is possible.
The inlet area is the big mechanical issue in the older Yamaha design as the studs are so close together, but by fitting an inlet divider to help the piston wear issue
( just as a 250G killed them also ) and adding twin boost ports, the power is respectable.

The RZ400 is a different story altogether.


And as I have said a dozen times on here, its only in lawnmowers that the dropping piston has anything to do with promoting flow
from the conventional case - thru the transfers,as there is more pressure above than there is below the piston at TPO.
The Ryger is using a very small trapped volume, that is compressed substantially by the larger diameter piston portion.
Thus it simply doesnt need a ton of blowdown to reduce the combustion pressure above the transfers, and as well it doesnt need the big negative pressure
ratio created by the diffuser to pull mixture into the cylinder when the piston is at BDC.
So a single Ex port seems entirely reasonable and expected.
The top end workings I believe we have pretty much guessed the trickery, as for the 30,000 rpm capable bottom end - darkness and guessing are really confusing
and we are not even close to reality yet.


It almost looks like a return to the origins of the 2 stroke where the piston was assumed to do all the pumping work. Still trying to visualise whether the under piston pumping setup is more efficient than the usual crankcase volume. Certainly plenty of transfer volume to provide mixture and as dave notes, it's provided with plenty of inlet area too. If it's a more efficient pump, it may not need the usual triple exhaust to generate flow...
At least we can now see why it's a short rod. I'd been assuming a trunk piston as it does seem to be a wet bottom end, well it is and it isn't a trunk piston..



We are waiting on the delivery of a decent porting tool so we can shape the "A" port properly as we suspect our previous efforts have only made them prone to short circuiting.
get some vinamold while your at it. I thought I had my A pretty good until I made some molds with the vina and seen they weren't as good as I thought
+1

Can't stress enough how right you are peewee!
Was surprised how bad my transfers were. I took my time measuring them using all kinds of tools, but the Vinamold told the truth.


Yeah, toluene used to be advertised as 'methyl benzine' as used in Shell 'super' petrol ( along with tetra ethyl lead).

Here are some recipes for home blending.. www.gnttype.org/techarea/misc/octanebooster.html (http://www.gnttype.org/techarea/misc/octanebooster.html)

& the TEL is still available as an additive 'Octane Supreme 130' www.hi-flow.com/hp016os.html (http://www.hi-flow.com/hp016os.html) - the lead works
- as a lubricant for highly stressed 2T parts, look how much power/reliability was lost from G.P. 2Ts - when it was banned..


If you want to tip carbs up steep then Lectrons are the go.
They flow way more air than any round slide, are easy to tune and are period legal for Pre 82 Post Classic if thats important, and were used by King Kenny
on TZ750/500 in the early 70s..
As long as you keep the powerjets reasonably small ( 60 ) the fuel curve is much better than any normal carb where the fuel circuits and air correction
overlap, that cause dips and bumps in the A/F readings.


The basic rule is that you cant have a radiator thats too big.
But running Methanol will basically turn an air cooled motor into an efficient an engine, as a normal watercooled.
This basically means that the aircooled wont go off due to thermal overload like it will do naturally on petrol.
But running a watercooled on meth means it will be hard initially to get any temp into the water, so my advise is to use a small rad but plumb it with a bypass
thermostat.
This will naturally reduce the water cooling effect early in the passes, but when the temp starts to rise it will then use the water to do its job.


I think I get it. with less temperature difference there will be less heat transfer to the water ? ive got to either buy a radiator or have one made (either larger or smaller than whats currently available, based on what ever advice you could give me). this is a methanol drag racing bike remember. to reduce weight ive seen some guys use just a very small rectangle aluminum tank, so water can still be pumped through the cylinders and head but there is no fins or tubes on the tank, basically just a rectangle alloy box. other guys use a radiator but its very small, to reduce weight I suppose.

i guess those methods would work for one run and shut the engine off but i need a system that offers good cooling for continuos multiple runs. from what ive seen, the water temp is lower with methanol but eventually it starts to creep up near that of what you would expect from a average 2t gas engine. do you have any rule of thumb for radiator size ?


A small pot of water will absorb heat slower than a large pot. Moreover the water in that small pot will heat up quicker, so the temperature difference between water and stove drops, slowing heat transfer down even more.

I didn't say the volume should be small. I said that a large volume of slow-moving, almost stationary water is not effective. Water passages should be narrow so that most of the water is in contact with the walls instead of flowing down the middle without touching the hot metal surfaces. Narrow passages will also keep the flow velocity up, which helps heat transfer from those surfaces to the water.


frits did you say the volume of water in the cooling system should be small and move fast ? is it like a small pot of water on the stove could absorb the heat a lot faster than a large pot of water ?

[MotleyCrue]

At what rpm would the exhaust valve be fully open on the RZ ?

[wobbly]

RZ400 powervalve timing

[adegnes]

Anyone know exactly what fuels the various options in engmod is based on?

Avgas, methanol etc. is self explanatory, but what exactly is "regular", "premium", "unleaded 95", "unleaded 100"?

I've used "unleaded 100" in my simulations, and need to get the same or preferably a higher octane rated fuel in real life - Simulations show massive detonation with "regular", "premium" and "unleaded 95".
"unleaded 100" is marginally ok.

Wish avgas wasn't so restricted in Norway.

Btw; my bike is up and running! Needs a longer belt + some minor fixes and dialing in the carb.


http://youtu.be/V73dVEfDjNA

[ief]

I presume unleaded 95 is what is sold in the netherlands standard fuel, 100 what is sold in Germany (or is that 101?) Regular and premium no idea as well. (you did read the chasing detonation paper from Neels?)

See you have the powerspark, do you like it, what was the price?

[TZ350]

My bike is up and running! Needs a longer belt + some minor fixes and dialing in the carb. https://youtu.be/V73dVEfDjNA

Great job, I see there are lots of Spx video clips on Youtube, those bikes look like great fun. Please keep posting your progress.

[adegnes]

I presume unleaded 95 is what is sold in the netherlands standard fuel, 100 what is sold in Germany (or is that 101?) Regular and premium no idea as well. (you did read the chasing detonation paper from Neels?)

See you have the powerspark, do you like it, what was the price?

yep, read the paper. I'm perfectly fine with having to run high octane fuel(read: I'm eager to see the results of what I've built and don't want to tear down the engine for further modication yet)
Anyone have experience with mixing in some toulene in pump fuel? I've mixed 20/80 toulene/98 pump before with no ill effects. My test engine didn't need the higher octane and thereby it didn't prove anything other than that it wasn't short time damaging to the engine though.

[adegnes]

Great job, I see there are lots of Spx video clips on Youtube, those bikes look like great fun. Please keep posting your progress.

Thanks! I will!

[adegnes]

re Power-spark.
It's worked great for me so far, but I can't really say anything about it yet.
Sorry, can't remember what I paid, do a search, I think I did a post on it.

[TZ350]

It does not matter what your into, just get out there and do it:-

https://youtu.be/GEOiNjYIN7c

https://youtu.be/qFFVcyqBcl0

https://youtu.be/pu_LHxC3hB0

https://youtu.be/iI2xCACU_j8

So much one could do so little time ...

[AndreasL]

Which trick from the movies do you plan for your self TZ? :corn:

[TZ350]

Which trick from the movies do you plan for your self TZ? :corn:

There is just so much great stuff one could do .... :) ... but it takes me about a year to just build a new bike.

[J.A.W.]

yep, read the paper. I'm perfectly fine with having to run high octane fuel(read: I'm eager to see the results of what I've built and don't want to tear down the engine for further modication yet)
Anyone have experience with mixing in some toulene in pump fuel? I've mixed 20/80 toulene/98 pump before with no ill effects. My test engine didn't need the higher octane and thereby it didn't prove anything other than that it wasn't short time damaging to the engine though.


Yeah, toluene used to be advertised as 'methyl benzine' as used in Shell 'super' petrol ( along with tetra ethyl lead).

Here are some recipes for home blending.. www.gnttype.org/techarea/misc/octanebooster.html

& the TEL is still available as an additive 'Octane Supreme 130' www.hi-flow.com/hp016os.html - the lead works
- as a lubricant for highly stressed 2T parts, look how much power/reliability was lost from G.P. 2Ts - when it was banned..

[RAW]

If you don't cool the water it's a different situation. The more water you carry, the slower it will heat up and the longer it will take before your engine power collapses.

Yes: bigger!

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

You may want to play a little with this program: 318780 It has attained the age of majority so I'm not sure if it will run on your computer. Just let me know.

Frits would you PLEASE upload a version that can run on Windows 7, 64 bit :msn-wink:

[adegnes]

Frits would you PLEASE upload a version that can run on Windows 7, 64 bit :msn-wink:

Maybe some useful info here:
http://dtec.net.au/Tech%20Articles.htm

[marsheng]

How to you time a power valve when working from scratch ?

This is the plot from a KR150

The next question is, I don't think there is any adjustments to be made on the motor?

http://www.marshland.co.nz/ftp/Misc/Brad_Dyno.JPG

Thanks Wallace

[Yow Ling]

How to you time a power valve when working from scratch ?

This is the plot from a KR150

The next question is, I don't think there is any adjustments to be made on the motor?

http://www.marshland.co.nz/ftp/Misc/Brad_Dyno.JPG

Thanks Wallace

Its a mechanical powervalve, all you can change is the weights or the spring, I guess you could get a PV servo and make it electronic
Why does your plot only go to 8800, my KR revs to 12,000

[F5 Dave]

An RG150 should touch 30hp, presumably the KR should be close yeah?

[gamma500]

Frits would you PLEASE upload a version that can run on Windows 7, 64 bit :msn-wink:

You can run it with program called dosbox, check youtube for tutorials.

[Frits Overmars]

Frits would you PLEASE upload a version that can run on Windows 7, 64 bit :msn-wink:I would love to, Raw. All I need is a 64 bit laptop. Do you want my bank account number?
Or all you'd need is a Windows 98 emulator. I can recommend VMware Player. I use it on my 32bit Windows7 machine. It's free. Last time I checked, laptops weren't.


You can run it with program called dosbox, check youtube for tutorials.Better check Dosbox itself, Gamma. That is one emulator I can not recommend. It's a fleeced version of MS-DOS 5 and it won't run most of my programs.

[marsheng]

Its a mechanical powervalve, all you can change is the weights or the spring, I guess you could get a PV servo and make it electronic
Why does your plot only go to 8800, my KR revs to 12,000

I need to update the software, it reads under by 1000 rpm and the final HP depends on the accuracy of calibration. PS I'm only plotting the problem point. Interestingly with a Trail Tech rev counter, it tops out at 10500.

My guess would be to remove the mechanical advance and do a plot. Wherever the max HP is, is the point where the mechanical advance should start.

This is an interesting motor. We stripped out the excess wiring today and we were left with very little. A wire from the magneto to the coil and nothing else. No CDI box no regulator no battery.

[gamma500]

I would love to, Raw. All I need is a 64 bit laptop. Do you want my bank account number?
Or all you'd need is a Windows 98 emulator. I can recommend VMware Player. I use it on my 32bit Windows7 machine; it's free. Last time I checked, laptops weren't.

Better check Dosbox itself, Gamma. That is one emulator I can not recommend. It's a fleeced version of MS-DOS 5 and it won't run my programs.

I have ran your flywheel program with dosbox, it seems to work for me :drinknsin Never used vmware,but it is most probably a lot better

[Frits Overmars]

I have ran your flywheel program with dosbox, it seems to work for me :drinknsin Never used vmware,but it is most probably a lot betterFLYWHEEL.EXE will run directly under Windows 7, no emulation required, mainly because it does not call any graphics functions, but most of my other programs won't.

When I started writing my programs, I used Algol (ancient Greek for computers). Those programs would not even run on home computers, because these did not yet exist. Later, when I got my own PC, I had to rewrite everything for the MS-DOS operating system. And when that was succeeded by Windows 95/98 I had the same pleasure again.
The sad thing about it is that this repeated labour did not contribute a thing to the functionality of the programs; it only served to keep them alive under ever more Microsoft-belches.

The programs in their present form run under all Microsoft operating systems from DOS 6.2 to Windows 98SE. Depending on the graphics card in a particular computer they may also function with Windows 2000 and XP. Under Vista and Windows 7 they can be used via an emulator. But the recent Microsoft operating systems are so preoccupied with virus control that real-time communication between my electronic equipment and the computer suffers. Of course there is a solution: rewrite all programs and have new measuring equipment built, at appreciable financial consequences. And then, when everything functions again, Microsoft will introduce something even newer, even better, and I can start all over again. I am not young enough anymore to waste my time with such nonsense.

[adegnes]

FLYWHEEL.EXE will run directly under Windows 7, no emulation required, mainly because it does not call any graphics functions, but most of my other programs won't.

When I started writing my programs, I used Algol (ancient Greek for computers). Those programs would not even run on home computers, because these did not yet exist. Later, when I got my own PC, I had to rewrite everything for the MS-DOS operating system. And when that was succeeded by Windows 95/98 I had the same pleasure again.
The sad thing about it is that this repeated labour did not contribute a thing to the functionality of the programs; it only served to keep them alive under ever more Microsoft-belches.

The programs in their present form run under all Microsoft operating systems from DOS 6.2 to Windows 98SE. Depending on the graphics card in a particular computer they may also function with Windows 2000 and XP. Under Vista and Windows 7 they can be used via an emulator. But the recent Microsoft operating systems are so preoccupied with virus control that real-time communication between my electronic equipment and the computer suffers. Of course there is a solution: rewrite all programs and have new measuring equipment built, at appreciable financial consequences. And then, when everything functions again, Microsoft will introduce something even newer, even better, and I can start all over again. I am not young enough anymore to waste my time with such nonsense.


https://upload.wikimedia.org/wikipedia/commons/thumb/a/af/Tux.png/220px-Tux.png

[tjbw]

https://upload.wikimedia.org/wikipedia/commons/thumb/a/af/Tux.png/220px-Tux.png

That made me smile :)

[Muciek]

Does it miss anything Frits? 318875

[Frits Overmars]

That made me smile :)I bet it did. It sounds like a Linux commercial, doesn't it?
If it were up to me, I would have switched to Linux ages ago. I believe in the idea of open source; that is what I'm trying to accomplish in the two-stroke field too.
But it is not up to me; practically all users of my software run Windows, so I was compelled to develop my programs using that same operating system.


Does it miss anything Frits?If you mean the graphics: no, it doesn't seem to miss anything. Dosbox must have bettered its life.
If you mean the functionality of the program: you tell me. It depends on what is needed to develop two-stroke HCCI; that is largely unknown territory yet.

EDIT: I just tested your Dosbox version 0.74. It still is a fleeced version of Dos 5.00 and it does not recognize a lot of functions that were used in my programs.
Some programs may run; most of them won't.

[lohring]

Maybe some useful info here:
http://dtec.net.au/Tech%20Articles.htm

And Here:
http://performancetrends.com/tdkmotorsports/index.html

Lohring Miller

[MotleyCrue]

Later, when I got my own PC, I had to rewrite everything for the MS-DOS operating system. And when that was succeeded by Windows 95/98 I had the same pleasure again.


Doesnt matter much now but there was a dead simple GUI setting in WIN95/98 that would allow WIN95/98 to run real DOS, not the fake DOS that WIN95/98 ran by default. Used it many times back in the day. Someone posted it on the internet way back when, :sweatdrop.

[41juergen]

The software is scary good, and for whatever reason ( I simply dont care ) the crank power if estimated with all good inputs to the sim
will translate to close to 12% reduction needed to account for gear/chain/tyre losses on a Dynojet.
Contact Neels the code man at vannik@mweb.co.za pay your money and you are away.

Dont get confused,the RZ400 ( for F3 or Superlight ) info I just posted, isnt the same engine I detailed a bit further back - that was a TZ400 using a 6 port 3G3 cylinder for pre 82 Post Classic racing.
In the TZ400 the A duct being shorter than the B/C is from dyno testing done many ( MANY ) years ago by Helmut Fath ( my Hero ) who tuned for John Eckerold among others ( Freddie ).
There is no room in the TZ350 cylinder for more inlet area, the sides are 1mm away from the stud holes as it stands.
It is possible to make larger screw in studs with cutaways in them and 3 port the Exhaust, but as the rod angularity pushes the piston against the inlet wall
I dont think anyone has ever put boyesens into an RD/TZ/LC - I never considered it, maybe it is possible.
The inlet area is the big mechanical issue in the older Yamaha design as the studs are so close together, but by fitting an inlet divider to help the piston wear issue
( just as a 250G killed them also ) and adding twin boost ports, the power is respectable.

The RZ400 is a different story altogether.

This is how I did some longer time ago the boost ports into my RZ. Also I widened up the reed case to fit the bigger NSR125 VForce 3 cages (with the stuffers and an other inlet rubber replaced nowadays)... Of course not as good as your setup with the CPI barrels...

[wobbly]

That looks like a nice job on the RZ cylinders.
But possibly not needed nowdays as VF have a new reed for the Banshee that is a big step ahead of the VF3.
The RZ needs plenty of inlet capability when tuned really hard, but the CPI Cheetah cylinder had CR250 size reeds ( 68mm wide )
that needed to be offset outward to make them fit.
Calvin and I had a major disagreement about this, until I fitted the smaller 60mm CR125 VF3 ( looks the same as your NSR reed )
and offset them back onto the cylinder center, with a 6mm stuffer plate down one side to equalise the flow.
This change made +5Hp, and the CR125 reed is capable of even more than the engine could mangage.
So bigger in this case for shure wasnt better.

[Yow Ling]

How to you time a power valve when working from scratch ?

This is the plot from a KR150

The next question is, I don't think there is any adjustments to be made on the motor?

http://www.marshland.co.nz/ftp/Misc/Brad_Dyno.JPG

Thanks Wallace

Ok so you dont want to set the powervalve you want to set the ignition timing, my understanding was the early krs had 2 steps and needed a battery which you have removed, is this a development class bike or a Cams150 bike if it is a development class bike then you should only run stock timing.
There is no mechanical advance on the ignition , the powervalve is mechanicaly operated

[wobbly]

The mechanical PV mechanism is almost always set by the tension of a spring resisting the movement of balls up a ramp.
Its easy to shim the spring to make it open later ( looks like the KR is opening way too soon ).
But the issue then is that it may be fully open at a later rpm, but the more you shim it, the faster it opens.
This is usually not whats needed.

Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position.
Overlay the graphs and the 3 points are then easy to plot.
This will be impossible to replicate with a mechanical servo.
But using the EXUP motor off an R1 its cheap and easy to add an electronic setup driven by an Ignitech.
When people put pipes on an R1 they always dump the EXUP, so they are available off Ebay for chips.
Honda also did a cable servo PV in 2004 on the CR125, so those bits will work as well.
Here is the setup on a KTM250.

[TZ350]

Ok, another RG50 run on the dyno.

318905

Blue line = exhaust dam plus a nozzle that was 90% of the open part of the exhaust port window. Red line = no dam and nozzle that is 90% of the total exhaust port window.

318906

Green line, our original best with an 85% Ex, no dam and no nozzle but since then we tried to improve the flow direction of the "A" transfer port windows. We are waiting on the delivery of a decent porting tool so we can shape the "A" port properly as we suspect our previous efforts have only made them prone to short circuiting.

[speedpro]

I'm giving you another week to get to 6hp.

[TZ350]

I'm giving you another week to get to 6hp.

We are working on it, and well on schedule thanks :facepalm: ..... :laugh:

[ief]

If the lesser result was due to (more) shortcutting wouldn't the revs go down instead of up TZ?

[RAW]

I would love to, Raw. All I need is a 64 bit laptop. Do you want my bank account number?
Or all you'd need is a Windows 98 emulator. I can recommend VMware Player. I use it on my 32bit Windows7 machine. It's free. Last time I checked, laptops weren't.

Better check Dosbox itself, Gamma. That is one emulator I can not recommend. It's a fleeced version of MS-DOS 5 and it won't run most of my programs.

Haha Frits, your bank account details or your money is of no interest to me, thought provoking information, knowledge is all I wish for, teach me how to & I may just be able to do you proud

[TZ350]

318906

Green line, our original best with an 85% Ex, no dam and no nozzle but since then we tried to improve the flow direction of the "A" transfer port windows. We suspect our efforts with the "A" ports have only made them prone to short circuiting.


If the lesser result was due to (more) shortcutting wouldn't the revs go down instead of up TZ?

I am not a 100% sure about this, but I think the effective short circuiting decreases as the rpm goes up, less time maybe?

[peewee]

We are waiting on the delivery of a decent porting tool so we can shape the "A" port properly as we suspect our previous efforts have only made them prone to short circuiting.

get some vinamold while your at it. I thought I had my A pretty good until I made some molds with the vina and seen they weren't as good as I thought

[marsheng]

Ok so you dont want to set the powervalve you want to set the ignition timing, my understanding was the early krs had 2 steps and needed a battery which you have removed, is this a development class bike or a Cams150 bike if it is a development class bike then you should only run stock timing.
There is no mechanical advance on the ignition , the powervalve is mechanicaly operated

CAMS bike. I have no idea where the battery would be connected. One wire comes from the magneto and goes straight into the coil. There is no CDI box or rectifier. The only possibility is the CDI (which must be very small) is built into the coil itself. Only one space lug to the coil and an earth.

The bike as a Tyga Performance exhaust so I'm guessing the pipe and the mechanical advance are not quite synchronised.

Cheers Wallace

[marsheng]

Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position.
Overlay the graphs and the 3 points are then easy to plot.


Thanks Wobbly, I will try this and see what it gives. I don't need the full power range, just enough to keep it between gear changes.

Cheers Wallace

[AndreasL]

get some vinamold while your at it. I thought I had my A pretty good until I made some molds with the vina and seen they weren't as good as I thought

+1

Can't stress enough how right you are peewee!
Was surprised how bad my transfers were. I took my time measuring them using all kinds of tools, but the Vinamold told the truth.

[Frits Overmars]

The mechanical PV mechanism is almost always set by the tension of a spring resisting the movement of balls up a ramp. Its easy to shim the spring to make it open later.. But the issue then is that it may be fully open at a later rpm, but the more you shim it, the faster it opens. This is usually not whats needed. Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position. Overlay the graphs and the 3 points are then easy to plot. This will be impossible to replicate with a mechanical servo. But using the EXUP motor off an R1 its cheap and easy to add an electronic setup driven by an Ignitech..Of course an electronic power valve governor is preferable to a centrifugal one (and let's not even mention a pneumatic one). But if you are compelled to use a centrifugal setup, a highly progressive spring could help. Space permitting you can approach that with a second, shorter spring, floating inside the original spring, which will give you a two-step spring constant.


Thanks Wobbly... I don't need the full power range, just enough to keep it between gear changes.Reality is going to kick you in the face, Wallace. No matter how good a rider you are, one day someone will block your line and you'll lose one second getting back into the power band. And in racing one second is like a week...

[RAFFY]

on the rg50 dyno graphs the rpm peak has moved approx 750 rpm to the right and large loss on way up as a result of the dam and insert ,be worth a try lengthening the header as a quick test ,also the dam looks to be ? opposite to the cotton bobbin duct shape your trying to achieve if you do a quick cross section sketch to check,a small ball ended cutter on a straight porting tool will get you into the a transfers to put some hooks into them if the 90 tool is late arriving

[Peter1962]

The mechanical PV mechanism is almost always set by the tension of a spring resisting the movement of balls up a ramp.
Its easy to shim the spring to make it open later ( looks like the KR is opening way too soon ).
But the issue then is that it may be fully open at a later rpm, but the more you shim it, the faster it opens.
This is usually not whats needed.

Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position.
Overlay the graphs and the 3 points are then easy to plot.
This will be impossible to replicate with a mechanical servo.
But using the EXUP motor off an R1 its cheap and easy to add an electronic setup driven by an Ignitech.
When people put pipes on an R1 they always dump the EXUP, so they are available off Ebay for chips.
Honda also did a cable servo PV in 2004 on the CR125, so those bits will work as well.
Here is the setup on a KTM250.

Beautiful work ! Is it for a karting project ? What is the device that is mounted behind the cilinder ?

[husaberg]

Beautiful work ! Is it for a karting project ? What is the device that is mounted behind the cilinder ?
A diaphragm fuel pump
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130927084#post1130927084
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130930915#post1130930915
318918318919

[JanBros]

FLYWHEEL.EXE will run directly under Windows 7, no emulation required, mainly because it does not call any graphics functions, but most of my other programs won't.

When I started writing my programs, I used Algol (ancient Greek for computers). Those programs would not even run on home computers, because these did not yet exist. Later, when I got my own PC, I had to rewrite everything for the MS-DOS operating system. And when that was succeeded by Windows 95/98 I had the same pleasure again.
The sad thing about it is that this repeated labour did not contribute a thing to the functionality of the programs; it only served to keep them alive under ever more Microsoft-belches.

The programs in their present form run under all Microsoft operating systems from DOS 6.2 to Windows 98SE. Depending on the graphics card in a particular computer they may also function with Windows 2000 and XP. Under Vista and Windows 7 they can be used via an emulator. But the recent Microsoft operating systems are so preoccupied with virus control that real-time communication between my electronic equipment and the computer suffers. Of course there is a solution: rewrite all programs and have new measuring equipment built, at appreciable financial consequences. And then, when everything functions again, Microsoft will introduce something even newer, even better, and I can start all over again. I am not young enough anymore to waste my time with such nonsense.


people throw away old laptops/computers because they are worth absolutly nothing.
my advice to people would be to simply find an old computer , put win98 or even only dos on it and run the software on that one.

[Makr]

I design the cylinder as a solid model before I start machining. I think I was working out how the upper part of the aux exhaust ports would come out. I think this is pretty close to what they are. The sleeve is the only bridge (this doesn't have the sleeve installed). I was pretty worried about that, but it seems to be a non issue.

You can see the coolant passage around the exhaust port.

http://img.photobucket.com/albums/v283/superr5/2015/EXTENDEDAUX_zps9faf9b83.jpg (http://smg.photobucket.com/user/superr5/media/2015/EXTENDEDAUX_zps9faf9b83.jpg.html)

Liner in, but aux ports unfinished..

http://img.photobucket.com/albums/v283/superr5/2015/MODLINER_zpsd4fa8823.jpg (http://smg.photobucket.com/user/superr5/media/2015/MODLINER_zpsd4fa8823.jpg.html)

This is after a bunch of dyno pulls.

http://img.photobucket.com/albums/v283/superr5/2015/2015-05-02%2018.34.07_zpstzpl3czm.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-02%2018.34.07_zpstzpl3czm.jpg.html)

[Makr]

The other thing I have been using the past couple of years is a two piece piston. I tried plugging the wristpin and had plugs come out, and really unless you use a drag racing type of pin boss the completely plugs the pin bore you are always going to have a passage from one port to the next. I initially designed this to get rid of the wristpin hole, but because I could make this round instead of cam shaped, it has worked out mechanically better. I don't really have rattly pistons they seem to seal really well. I can run them pretty tight even though the ones I have been using are not a high silicon alloy. I think using 4032 grade alloy would make them even better.

http://img.photobucket.com/albums/v283/superr5/2015/2015-05-16%2011.56.59_zpshqqy7bif.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-16%2011.56.59_zpshqqy7bif.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-05-30%2017.45.24_zpso61vrded.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-30%2017.45.24_zpso61vrded.jpg.html)

The pin boss connects to the connecting rod like normal, and the the boss threads into the piston itself. It keeps from unscrewing by the threaded bolts. and the bolts have c-clips to keep them in place.

http://img.photobucket.com/albums/v283/superr5/2015/2014-10-21165409_zps4e819c40.jpg (http://smg.photobucket.com/user/superr5/media/2015/2014-10-21165409_zps4e819c40.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2014-10-21165220_zps39ad02d4.jpg (http://smg.photobucket.com/user/superr5/media/2015/2014-10-21165220_zps39ad02d4.jpg.html)

the one on the left was run for quite a while so you can see how uniform the wear is all around. Or maybe not the picture is a cell phone pic.

http://img.photobucket.com/albums/v283/superr5/2015/2014-10-20175552_zpsfc89e516.jpg (http://smg.photobucket.com/user/superr5/media/2015/2014-10-20175552_zpsfc89e516.jpg.html)

The only issue I have had is the the boss to piston joint starts to get loose after 40 or 50 dyno pulls. Not very loose, but enough I swap them out. I think plenty of longevity for my application. I have been working on a ACME thread version, as I think deeper and more perpendicular surface area will extend the life. I haven't machined new ones yet as I like what I have, and like all of you, waiting for the Ryger thing that may make all of this outdated anyway.

You are welcome to make your own just give me credit. :D

[Peter1962]

A diaphragm fuel pump
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130927084#post1130927084
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130930915#post1130930915
318918318919

Thank you, husaberg. I overlooked those obviously. That engine is a work of art.

[adegnes]

The other thing I have been using the past couple of years is a two piece piston. I tried plugging the wristpin and had plugs come out, and really unless you use a drag racing type of pin boss the completely plugs the pin bore you are always going to have a passage from one port to the next. I initially designed this to get rid of the wristpin hole, but because I could make this round instead of cam shaped, it has worked out mechanically better. I don't really have rattly pistons they seem to seal really well. I can run them pretty tight even though the ones I have been using are not a high silicon alloy. I think using 4032 grade alloy would make them even better.

http://img.photobucket.com/albums/v283/superr5/2015/2015-05-16%2011.56.59_zpshqqy7bif.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-16%2011.56.59_zpshqqy7bif.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2015-05-30%2017.45.24_zpso61vrded.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-30%2017.45.24_zpso61vrded.jpg.html)

The pin boss connects to the connecting rod like normal, and the the boss threads into the piston itself. It keeps from unscrewing by the threaded bolts. and the bolts have c-clips to keep them in place.

http://img.photobucket.com/albums/v283/superr5/2015/2014-10-21165409_zps4e819c40.jpg (http://smg.photobucket.com/user/superr5/media/2015/2014-10-21165409_zps4e819c40.jpg.html)

http://img.photobucket.com/albums/v283/superr5/2015/2014-10-21165220_zps39ad02d4.jpg (http://smg.photobucket.com/user/superr5/media/2015/2014-10-21165220_zps39ad02d4.jpg.html)

the one on the left was run for quite a while so you can see how uniform the wear is all around. Or maybe not the picture is a cell phone pic.

http://img.photobucket.com/albums/v283/superr5/2015/2014-10-20175552_zpsfc89e516.jpg (http://smg.photobucket.com/user/superr5/media/2015/2014-10-20175552_zpsfc89e516.jpg.html)

The only issue I have had is the the boss to piston joint starts to get loose after 40 or 50 dyno pulls. Not very loose, but enough I swap them out. I think plenty of longevity for my application. I have been working on a ACME thread version, as I think deeper and more perpendicular surface area will extend the life. I haven't machined new ones yet as I like what I have, and like all of you, waiting for the Ryger thing that may make all of this outdated anyway.

You are welcome to make your own just give me credit. :D

wow! That's awesome, thanks for sharing!

[41juergen]

That looks like a nice job on the RZ cylinders.
But possibly not needed nowdays as VF have a new reed for the Banshee that is a big step ahead of the VF3.
The RZ needs plenty of inlet capability when tuned really hard, but the CPI Cheetah cylinder had CR250 size reeds ( 68mm wide )
that needed to be offset outward to make them fit.
Calvin and I had a major disagreement about this, until I fitted the smaller 60mm CR125 VF3 ( looks the same as your NSR reed )
and offset them back onto the cylinder center, with a 6mm stuffer plate down one side to equalise the flow.
This change made +5Hp, and the CR125 reed is capable of even more than the engine could mangage.
So bigger in this case for shure wasnt better.

Yeah, I saw your comments earlier. Before I got EngMod I used the try end error method to see what's an improvement. I also modified the WSM pistons to bigger inlet windows. This happened after only a few hundred kilometers on the street (not so hard riding.....) :shit:

After lessons learned I asked Woessner to make these for me.... Later then when feeding all data then into EngMod I found them to be more or less ok for my desired setup. Now the Ex port incl. aux ports needs to be adapted (not my picture, but that's how I will try and of course with a bit more triangular window). I also got new head inserts based on your recommendations with a CNC made radius following the piston dome. Finally the pipe needs changes...

BTW. if interested here is the link on the American RZ forum I posted my stuff longer time ago.
http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=3918

[2005bully]

MAKR...
Really impressive work from concept to completion!!!

You mention that 4032 alloy may be a better choice of material for the 2 pc pistons, What alloy are you currently using?

Your pictures are like eye candy

[wobbly]

Great work on the RZ.
I also got Nova to do a new input shaft setup,as the TZ first gear is way too tall,but for the RZ it is possible to
use a Banshee 1st shaft that is taller then the stock ratio - its not long enough for the dry clutch though.
One thing I would suggest on the insert design.
Change the O ring seal to the top face, so you are using the strength of the head cover to support the insert around the plug.
Then machine above the bowl to allow water to cool the plug threads.

[peewee]

Yeah, I saw your comments earlier. Before I got EngMod I used the try end error method to see what's an improvement. I also modified the WSM pistons to bigger inlet windows. This happened after only a few hundred kilometers on the street (not so hard riding.....) :shit:

After lessons learned I asked Woessner to make these for me.... Later then when feeding all data then into EngMod I found them to be more or less ok for my desired setup. Now the Ex port incl. aux ports needs to be adapted (not my picture, but that's how I will try and of course with a bit more triangular window). I also got new head inserts based on your recommendations with a CNC made radius following the piston dome. Finally the pipe needs changes...

BTW. if interested here is the link on the American RZ forum I posted my stuff longer time ago.
http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=3918

you might look into the wiseco. they seem to hold up well and don't have those huge cutouts around the wristpin area. then again if your aux ports don't extend into the cutout area I guess that's a non issue.

[Makr]

MAKR...
Really impressive work from concept to completion!!!

You mention that 4032 alloy may be a better choice of material for the 2 pc pistons, What alloy are you currently using?

Your pictures are like eye candy

Thank you. The inside is 6061 and the outside is 2024.

I have made them out of a bunch of different alloys. You know, just to see.haha!

These were 7068, I think. They didn't last one hard pull.


http://img.photobucket.com/albums/v283/superr5/2015/2015-05-28%2020.21.25-1_zpswxwt5xni.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-28%2020.21.25-1_zpswxwt5xni.jpg.html)

I spent all day with the bike at a car show. Terry Nish's 412 mph streamliner in the background.



http://img.photobucket.com/albums/v283/superr5/2015/2016-01-14%2014.53.56_zps64kykvzi.jpg (http://smg.photobucket.com/user/superr5/media/2015/2016-01-14%2014.53.56_zps64kykvzi.jpg.html)

[seymour14]

Thank you. The inside is 6061 and the outside is 2024.

I have made them out of a bunch of different alloys. You know, just to see.haha!

These were 7068, I think. They didn't last one hard pull.


http://img.photobucket.com/albums/v283/superr5/2015/2015-05-28%2020.21.25-1_zpswxwt5xni.jpg (http://smg.photobucket.com/user/superr5/media/2015/2015-05-28%2020.21.25-1_zpswxwt5xni.jpg.html)

I spent all day with the bike at a car show. Terry Nish's 412 mph streamliner in the background.



http://img.photobucket.com/albums/v283/superr5/2015/2016-01-14%2014.53.56_zps64kykvzi.jpg (http://smg.photobucket.com/user/superr5/media/2015/2016-01-14%2014.53.56_zps64kykvzi.jpg.html)

Are there other events you can participate in before speed week? You would seem to be a very patient man if you had to wait so long between outings.

Used 6061 on our sleeves, having been told they were good with nicosil coatings, the F4 GP will prove or disprove that theory. That 7068 sure does not look like a winner at all...

[2005bully]

Makr...
Thanks... I often wondered if 2024 might work. Kermit Buller

[F5 Dave]

Taken a while to get my head around the 2 piece pistons.
So what is the weight comparison?
Did you have to experiment with shape of outer piston as no connected boss perhaps just conical which would be easier to machine?
Did you have notable gains from removal of the holes?

Make your own pistons? Are you crazy? It's a brave man to ignore the norms and tread his own path. Outstanding, even if it wasn't a sustainable solution it would still be cool.

Instead of a thread, why not a machined groove and a large wire circlip. Bore would have to be tight for heat transfer.

[speedpro]

Those pistons are clever. Round is OK as the piston without the pin boss will expand a lot more evenly than a regular piston. I would have been real nervous first time out on them.

[RAW]

Hello Frits,
I dug out an old laptop & guess what, it will run your Flywheel Zip file. WooHoooo
Question - Velocity at maximum rpm. Would you explain this please. 318935

[lodgernz]

Instead of a thread, why not a machined groove and a large wire circlip.

Need to prevent rotation of the outer piston, so would have to retain the two-lock-bolt system or something similar.
The thread arrangement probably gives quite good heat conduction from outer to inner, especially at the top.

[Makr]

Are there other events you can participate in before speed week? You would seem to be a very patient man if you had to wait so long between outings.

Used 6061 on our sleeves, having been told they were good with nicosil coatings, the F4 GP will prove or disprove that theory. That 7068 sure does not look like a winner at all...

There is Elmirage dry lake bed in California, and that is maybe the future for me. There are some events run on air strips, but they are about the same time as salt events.

The reason those records on the salt flats are so cherished is you have one tiny window of opportunity and everything has to go perfect. It very rarely does...

Two years ago I used aluminum sleeves that were 6061. They worked fine.


Makr...
Thanks... I often wondered if 2024 might work. Kermit Buller

That seems to be the best commercially available grade. 4032 I can only find in forgings from a piston forging house, and there is a minimum buy in for plain slugs. I think it was $1500 for 20.


Taken a while to get my head around the 2 piece pistons.
So what is the weight comparison?
Did you have to experiment with shape of outer piston as no connected boss perhaps just conical which would be easier to machine?
Did you have notable gains from removal of the holes?

Make your own pistons? Are you crazy? It's a brave man to ignore the norms and tread his own path. Outstanding, even if it wasn't a sustainable solution it would still be cool.

Instead of a thread, why not a machined groove and a large wire circlip. Bore would have to be tight for heat transfer.

I machined them round and used about the same taper as the pistons I have run in the past. It came out about right. I have never done a back to back test between other pistons and these. I will at some point. They are way lighter than any other comparable forged piston. Off the top of my head these were 215 grams and Wossners were 340.

Thanks. I thought about every union possible for about a year. I always came back to a thread. Even at 215 grams the piston is 1400 lbs inertial weight at 11,000 RPM. The threads hold to way over ten thousand pounds and that was when the wrist pin breaks out of the boss it is in. The threads never failed.


Those pistons are clever. Round is OK as the piston without the pin boss will expand a lot more evenly than a regular piston. I would have been real nervous first time out on them.

I was. haha I have run them enough now, I don't think about it any more. Thanks