ESE's works engine tuner

[TZ350]

284354

I just love these bikes and the clever work that goes into them.

[F5 Dave]

trailing axle forks. reduces the wheelbase I guess. I'll have to draw a picture to think about how it affect the trail

[Moooools]

trailing axle forks. reduces the wheelbase I guess. I'll have to draw a picture to think about how it affect the trail

Increases mechanical trail.

I suppose that means you can run less caster and maintain your trail. I don't really know why you would want to do this though. The steering angles any bike sees is pretty damn minimal so you aren't going to see any sort of camber through caster.

I do wonder about the purpose of caster at initial tun in though. I suppose because the wheel contact patch moves upwards (relative to COG) on turn in the normal load decreases momentarily on the front tyre. Which could lead to a front end slide. I don't know if the steering rates are great enough to make this a significant change in normal force at the contact patch.

Any thoughts on this. I know it comes up now and again that caster isn't necessary, but is it better to have no caster or perhaps even negative caster (a nightmare to package) so that normal load increases on turn in when the front tyre is doing the most work. All while maintaing adequate trail.

[TZ350]

284436

I have been playing with EngMod simulating the Ball Valve and trying different scenarios.

284438

I have been looking at how the 24mm throttle body will go with the Ball Valve.

284440

And found that the Ball Valve on its own was likely to be better than with the plenum.


284439

Then I had the bright idea to simulate the Ball Valve 24mm throttle body combo with a Boost Bottle.

284437

Red Line is the Ball Valve and 24mm throttle body, Blue line is with a Boost Bottle. It looks like something worth checking out in real life on the dyno.

[TZ350]

284444

Something else to think about, water injection, could it work on a 2-stroke for detonation suppression... :scratch:

284445

http://www.rbracing-rsr.com/waterinjection.html

That was an interesting read.

Husa, what do you think, should I try puffing some water mist into the bell-mouth at peak torque for detonation suppresion.

[fatbastd]

Impressive graphs. Keen to see a 125 AC bucket with 43hp. I'll be banging on your door!

[TZ350]

Keen to see a 125 AC bucket with 43hp.

Me too, but the simulated graph is crank hp, so you have to drop a bit for rear wheel hp.

284448 31 rear wheel hp, at a guess is more or less 35-36 crank hp.

I have previously made 34-36 crank hp so maybe 40ish is not that impossible.

284449

I wouldn't get to hung up on the hp numbers, the real thing to take notice of, is that EngMod2T is pointing out that a Boost Bottle with the Ball Valve is a worthwhile direction to explore.

[Flettner]

Here is ball valve and EFI at work. Interesting how the variable rotary valve housing needed to be controlled differently to get rid of the unwanted torque dip around 4 to 5 thousand. Thanks to Rob for sorting this out, I thought I knew a bit about rotary valve engines but after this run at ESE under Robs guidance, I am definitely the apprentice.


http://youtu.be/ifSEql1X4R0

[TZ350]

284480

The piston skirt was exposing the bottom of the exhaust port at TDC so as an experiment I am screwing and gluing a piece of alloy into the exhaust port floor. With any luck this will let the piston seal the crankcase and I have made the wall a little higher than the piston at BDC.

I remember (hopefully correctly) Frits talking about Jan experimenting with this and that it made more power by reducing short circuiting.

But they had not found the upper limits of how high the wall could be. If I can make the wall high enough it might not be to far fetched to add another transfer port there, after all once exhaust blow down is complete there is little point to the lower 1/3 or so of the exhaust port.

[TZ350]

When I made the triple exhaust port cylinder I was aiming for the maximum blow down STA possible. 200 deg worked well for me on the single exhaust port cylinder so I figured it would be even better with side exhaust port windows.

I wish I had of had the EngMod2T simulation package before I made the triple port cylinder.

284491

EngMod simulation of the 200 deg duration triple exhaust port.

284493

And the shape was pretty much what EngMod said it would be.

The difference in outright power is due to the fact EngMod simulates crank hp, and I can only measure rear wheel hp.

I had also overstated the combustion efficiency of the head I was using and I guess the workmanship is less than what EngMod was expecting too.

284492

The Blue line is the triple exhaust and the Red line is the single exhaust port cylinder, both have 200 deg duration, all other ports and timings are the same.

284494

The Blue line is the triple exhaust with 188 deg duration and the Red, the single at 200.

284490

I guess I may need to also think about attaching something to the exhaust port roof to change the exhaust timing from opening at 80 deg ATDC to 86.

When I have proved the cylinder layout on the dyno I will make another one that incorporates all the good bits.

[RomeuPT]

Here, Have my like TZ. Great Project, Great Dedication.

Waiting for the results of having that piece of alloy in the exhaust floor :)

[fatbastd]

me too. Stock 1970's TZ exhaust ports usually have a little 'ramp' too. It's subtle and many people grind it out...and make less power. Years ago, a mate in the Uk sold a TZ cylinder to someone drag racing an RD engine, quite successfully. The buyer noted that the ramp had been removed - he wasn't bothered, saying that he'd soon put it back in (and a bit more)..

[TZ350]

me too. Stock 1970's TZ exhaust ports usually have a little 'ramp' too. It's subtle and many people grind it out...and make less power....

Yep ... been there done that .... :facepalm:


Here, Have my like TZ. Great Project, Great Dedication. Waiting for the results of having that piece of alloy in the exhaust floor http://www.kiwibiker.co.nz/forums/images/smilies/smile.gif


... noted that the ramp had been removed - he wasn't bothered, saying that he'd soon put it back in (and a bit more)..

Thanks guys, hopefully get it sorted for the weekend.

[Flettner]

Yes, TZ I too am considering placing a small transfer port in that front area below the exhaust port. In the new piece of " realestate" opened up by raising the bottom of the exhaust port. First need to confirm how high this " dam " can be? This could be very useful for helping to cool the front exhaust edge of the piston each cycle, the most dangerous area.

[F5 Dave]

ok I understand the gluing bit, (although devcon in direct contact blows out of an ex, maybe the ally will shield that). . . -but how the heck do you 'screw' it in?

[wobbly]

Finally off the meds enough to say something and be reasonably sure of not making myself a bigger dick.
The trailing axle as seen is also used with a huge amount of offset on the tripples.
Thus rake and trail are " normal " as we would define them, the actual position of the leg centre line is irrelevant - its the axle position in relation
to the steering axis that forms the trail number.
You could have a leading axle and very little offset - same geometry.

Re RS125 squish, 0.65mm is the number with around 50% SAR, a sharp bowl edge and toroidal chamber for a flat top, or bathtub for a domed piston.

[TZ350]

Good to see your back Wob.

[TZ350]

ok I understand the gluing bit, . . . -but how the heck do you 'screw' it in?

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The stuffer plate is held down by screws through the exhaust port floor, the glue is only there to seal it.

[RomeuPT]

Welcome Back Wob.

My question got lost, not in a hurry but I really need to get the proper clearance.


Wob, I need your help.

I have a 9.7cc Honda RS head that I am not using, and now I have got some VHM domes, I am thinking in milling the 9.7cc head and fit the domes.

What tolerance should I use between the head and the outer diameter of the domes?

Thanks

[F5 Dave]

Ah, fairly thick plate Rob, well interesting.

Good to see you back Wob, hope Op went well.

[teriks]

Yes, TZ I too am considering placing a small transfer port in that front area below the exhaust port. In the new piece of " realestate" opened up by raising the bottom of the exhaust port. First need to confirm how high this " dam " can be? This could be very useful for helping to cool the front exhaust edge of the piston each cycle, the most dangerous area.

Here's an example, something on raised exhaust port floors from Jan Thiel on that same page too.
It seems that one have to click the link (arrow thingy to the right of "Frits Overmars") to see the picture..

Here it is: the MB40-6port. What is your link with MB40 engines, Teriks? Do you take part in F3D competition? If so, under which name?
Now, piston rings might not like that export witdth.

[FastFred]

Originally Posted by Jan Thiel
So that you might be able to raise the exhaust's 'floor'.This helps improve blowdown flow, as seen on a flowbench.In 2007 we started to raise the underside of the exhaust port.The first results were very promising!But at the end of 2007 I retired, so I could not finish what I started.The idea was to raise the exhaust underside as much as possible until power dropped.And then, with a smaller exhaust port underside it might have been possible to widen the A-ports more
without losing the fresh charge into the exhaust.
Even more radical things were tested I have been told, like an additional transfer port below the export floor.

284552


Here it is: the MB40-6port.

Is this what TeeZee is up to and Jan was talking about, raising the exhaust port floor and maybe fitting an extra transfer there too?

[wobbly]

The inserts are a neat sliding fit into the head skull, the actual clearance is not important.
What is important is ensure the the insert face projects at least 0.05mm, so it is clamped onto the head face by the stud pressure.
I also make the skull face around the spark plug 0.1mm low, so that the top of the dome is pushed down by the head cover, and then the studs also pull the cover down over the inserts
outer flange as above.
Not all covers can be machined to do this, but it works well in adding strength to the insert at its weakest point - the middle of the chamber.

[TZ350]

I would be very interested in the roof angle of the 6th transfer port thats under exhaust.


284552



Is this what TeeZee is up to and Jan was talking about, raising the exhaust port floor and maybe fitting an extra transfer there too?

This is where I have got to tonight, cylinder prepped and ready to go.

284574

The floor of the exhaust port is higher than BDC. I have no idea how high the exhaust port floor could be and I would dearly love to know more about it and what sort of angle a 6th transfer port there should be.

284575284576

The alloy stuffer plate and Belzona glue.

284573

All assembled, and compression tested OK so ready for a run up on the dyno, hopefully tomorrow night.

I want to get a good base run with the carb setup then switch to fuel injection. I have no idea how long the stuffer plate and Belzona will last, I guess we will find out soon enough.

[wobbly]

To make the raised floor work as part of an overall plan that was seen all the way thru by Jan at Aprilia, the area reduction at the port should be extended all the
way to the flange.
Making this oval, and reducing the duct volume all the way to the exit then works with the 75% area guideline for T or tripple port duct exit geometry.

[Flettner]

How interesting is this, leading edge.
The real key is to get rid of the exhaust port altogether and just have transfers only around the cylinder. Exhaust needs to be in the roof, Uniflow scavenge. Tell me I'm wrong.

[teriks]

284552



Is this what TeeZee is up to and Jan was talking about, raising the exhaust port floor and maybe fitting an extra transfer there too?
If you look at the original post, you'll see that the extra transfer port was mentioned only in the context of MB40 cylinders.
I.e. I have no idea if an additional port was tested at Aprilia.
I read what Jan wrote as his intention was to widen the existing transfers, not add another one.

[Yow Ling]

How interesting is this, leading edge.
The real key is to get rid of the exhaust port altogether and just have transfers only around the cylinder. Exhaust needs to be in the roof, Uniflow scavenge. Tell me I'm wrong.

Ahh Anton, kinda like this
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130229157#post1130229157

but dont have to get all complicated like the uniflow, transfers for africa and a few exhausts as well

[Flettner]

So, how did it go? There must be some results by now? Casting the cylinder is not a problem. Transfer arrangement is not quite as simple as you might think. In my uniflow cylinder there are two transfer types one set after the other arranged around the cylinder wall, so they don't all eject ( I do mean this in a non pornographic way ) into each others stream.
I was thinking more along the lines of the Rolls Royce Crecy.

http://youtu.be/zPEbv3DlGh0

[Farmaken]

And a little boy waits .......

[bucketracer]

And a little boy waits .......

284754

I understand TeeZee has had all sorts of trouble trying to get his first triple port effort to run properly with a carb before he can try it with EFI, and it looks like he will flag it and start again.

Apparently taking a perfectly good 200 deg duration single exhaust port cylinder and adding side ports has not worked out very well. Looks like you can have to much exhaust blow down STA or at least get out of balance with the other aspects of the cylinder.

The word is that he is going to prepare a proven single exhaust port cylinder that has worked well with before for EFI and try again. Then have another go at making another triple port, with about 188 deg duration and only slightly more blow down STA than the 200 duration single port had.

[wobbly]

I dont get it - take a perfectly good single port with 200* and add triples - of course its going to have idiot blowdown STA.
Then drop a triple port to 188*, and of course it wont have enough, I thought we were using EngMod to stop all the guessing bullshit.

[TZ350]

I dont get it - take a perfectly good single port with 200* and add triples - of course its going to have idiot blowdown STA.

I had cut the side ports into the 200 when blow down was all the rage and before I had my own copy of EngMod2T.


When I made the triple exhaust port cylinder I was aiming for the maximum blow down STA possible. 200 deg worked well for me on the single exhaust port cylinder so I figured it would be even better with side exhaust port windows. I wish I had of had the EngMod2T simulation package before I made the triple port cylinder.

You will have to go to the original post to see the simulated and dyno graphs.


Then drop a triple port to 188*, and of course it wont have enough, I thought we were using EngMod to stop all the guessing bullshit.

As if I would have just guessed at 188 and not simulated some options. ... :facepalm:

Still, I will post pictures of the STA's and Graphs later as there is something I dont understand. Matched STA's did not give the best graph, I got the graph I liked best with 188.

[FastFred]

I dont get it - I thought we were using EngMod to stop all the guessing bullshit.

Bit silly suggesting TZ just flounders around guessing. Sure he often gets it wrong but he probably does more research than most and is indisputably at the pointy end of the Bucket horse power stakes.

[F5 Dave]

So how big do you think you can make these aux without encroaching the wrist pin yet have transfer area for revs you're turning? I don't have engmod but you're suggesting quite a lot less degrees than say the RSA

[2T Institute]

I had cut the side ports into the 200 when blow down was all the rage and before I had my own copy of EngMod2T.



You will have to go to the original post to see the simulated and dyno graphs.



As if I would have just guessed at 188 and not simulated some options. ... :facepalm:

Still, I will post pictures of the STA's and Graphs later as there is something I dont understand. Matched STA's did not give the best graph, I got the graph I liked best with 188.

Your possibly looking at even more basic issues, I still see the rear transfers pointing at the exhaust duct and square subs. The subs should be triangular with a dead straight top edge extending to just before the centreline of the crank/bore. That works better than anything else.

[husaberg]

Your possibly looking at even more basic issues, I still see the rear transfers pointing at the exhaust duct and square subs. The subs should be triangular with a dead straight top edge extending to just before the centreline of the crank/bore. That works better than anything else.

I guess you mean something like this?
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282323&d=1367565858" width="340px"/>

[wobbly]

The issue you are up against TeeZee is that EngMod has no way of knowing how bad your transfer duct ans scavenging pattern really are.
The ducts you have and the port geometry ( mains too big ) means the transfers as modelled are not, and cant, perform anything like the simple one dimensional numbers suggest.
Thus you have to use the blowdown to shoot for the actual power you need, and the transfers MUST be way bigger in STA than the calculations suggest.
And in doing this, the Ex port STA number is basically irrelevant.
But in any case of trying to extract any worthwhile power out of a race engine worthy of being called one, it is near on impossible to generate sufficient REAL transfer STA, then add the correct Blow STA on top of this
- with a limiting total height at 188*.
It just cant be done.
The ONLY thing 188 has going for it is strong port/pipe resonance over a wider band, but no matter what you do the power achieved will always be severely limited, even with the best developed ducts and ports known to man,
completely what you havnt got due to the inherent design limitations of the base engine.
Not arseholing your efforts at all - just pointing out hard learned basics of the physics,gained from fucking it up myself.

[Frits Overmars]

I agree 100% ,Wob.

[TZ350]

So a little guessing really is involved .... http://www.kiwibiker.co.nz/forums/images/smilies/laugh.gif


The issue you are up against TeeZee is that EngMod has no way of knowing how bad your transfer duct ans scavenging pattern really are. The ducts you have and the port geometry ( mains too big ) means the transfers as modeled are not, and cant, perform anything like the simple one dimensional numbers suggest.

I also used the worst transfer duct option available.


Thus you have to use the blow down to shoot for the actual power you need, and the transfers MUST be way bigger in STA than the calculations suggest. And in doing this, the Ex port STA number is basically irrelevant.

Wob, I suspected this, and its nice to have it confirmed as its the way I had already approached it.

284799284800284801284803

With the spread of the STA's for the 188 duration triple Ex port are pretty much the way you outlined they should be.

But, after what you have said, maybe I need to go even bigger on the transfers STA, so your input here with some concrete numbers would be welcome.


The ONLY thing 188 has going for it is strong port/pipe resonance over a wider band,

A wider spread is what I was looking for and the approach was pretty much the way you outlined it should be.

So your best guess's at how much I should favor the transfer ports and any of the other compromises needed for EngMod2T to better model my motor would be welcome, what do you think?

[TZ350]

I still see the rear transfers pointing at the exhaust duct and square subs.

Its the same cylinder re cycled for the EFI experiment.


The subs should be triangular with a dead straight top edge extending to just before the centreline of the crank/bore. That works better than anything else.

Thanks for the tip, its the shape I will aim for on the next cylinder.

[speedpro]

With talk of building up the exhaust port floor I thought it interesting that the transfer ports have a figure that can be entered for when they are fully open in crankshaft degrees from TDC. There would obviously be flow benefits having the port fully open and unobscured for the maximum number of crankshaft degrees but I wonder what the effect of reducing the ultimate port area would be.

[TZ350]

So how big do you think you can make these aux without encroaching the wrist pin yet have transfer area for revs you're turning? I don't have engmod but you're suggesting quite a lot less degrees than say the RSA

After quite a bit of work, I have just figured out, that I can plan, simulate and maybe even cut ports the size of the RSA but with constipated transfers and other real life short comings, having blow down like an RSA won't do me any good.

Something less that the rest of the motor can keep up with will suit me better. Pretty obvious really....:blank:

[tdc211]

My 31.8hp graph back around page 682 is all about transfer and scavenging . I have more transfer timing than most and is a triple ex setup.
Engine did not have any bmep in the mid range until this was done. Also it is the reason it makes pk power at 11000 with higher ports than 188, as I sacrificed some blowdown time/area . I built another one and am at 33.3hp at 12000rpm. I am working on more hp at higher rpm with the same bmep. I lost a little bmep, but not terrible. Working on getting that back now. Wob is correct as always.

[FastFred]

284804


I have been following this thread. Here is my output shaft steel wheel dyno chart of my mx piped engine, a few ccs over 100.

Save looking for it.

BMEP close to 12 Bar, not a bad effort.

[TZ350]

284826284827284825284828

About ready to try the EFI thing again, this time on the single exhaust port cylinder.

[bucketracer]

Is that injector going to spit straight through the transfer port? is that a good idea? .... :scratch:

[RAW]

Is that injector going to spit straight through the transfer port? is that a good idea? .... :scratch:

Interesting question that one,
nitros injectors & all 32 injectors in top fuel drag race engines face against the direction of flow, this is to enable a more thorough homogenous mixture for combustion, given the comments of Frits I would envisage that as having such a short time frame for the fuel and air to mix sufficiently that this placement of the injectors angle may be appropriate

[bucketracer]

... given the comments of Frits I would envisage that as having such a short time frame for the fuel and air to mix sufficiently that this placement of the injectors angle may be appropriate

Sorry I don't recall Frits's comments, are you saying against the flow or like TZ has it, would be appropriate?

[TZ350]

I am picking some of the raw fuel will help cool the piston crown. The injection timing will be setup to end at transfer port closing with the start point progressively advancing as more fuel is required. But I have no real idea about what is best here, this is truly a case of suck it and see.

284830

I have a RD400 rod kit coming that is 115mm between centers, 10mm longer than the current 105mm RGV250 rod and 15mm longer than the original GP rod.

284831

My preference for the next engine is to have the injectors in a 15mm spacer plate between the cylinder and crankcase and firing across the direction of transfer flow.

And I like the idea of the extra 60cc of crankcase volume that I will be getting with the longer rod too.

[Flettner]

injectors don't spit, they produce more of a fog. Aiming against the flow is not a bad thing.

http://i1056.photobucket.com/albums/t380/uniflow/IMG_0868_zps6f424fcc.jpg

Or across the catchment of the port.

http://i1056.photobucket.com/albums/t380/uniflow/1f6c55fd.jpg

[Haufen]

I am picking some of the raw fuel will help cool the piston crown. The injection timing will be setup to end at transfer port closing with the start point progressively advancing as more fuel is required. But I have no real idea about what is best here, this is truly a case of suck it and see.

284830

I have a RD400 rod kit coming that is 115mm between centers, 10mm longer than the current 105mm RGV250 rod and 15mm longer than the original GP rod.

284831

My preference for the next engine is to have the injectors in a 15mm spacer plate between the cylinder and crankcase and firing across the direction of transfer flow.

And I like the idea of the extra 60cc of crankcase volume that I will be getting with the longer rod too.

Looks like you're spraying a great amount of fuel directly onto the back of the liner? To allow for best possible atomization and mixing, would it not be best to avoid hitting anything else but air with the injected fuel?

[wobbly]

TeeZee, send me your current file pack for the 3 port and i will have a play whilst im lying down recovering.

[2T Institute]

I have a RD400 rod kit coming that is 115mm between centers, 10mm longer than the current 105mm RGV250 rod and 15mm longer than the original GP rod.



I would not reccommend doing that in conjuction with the EFI, long rods seem to throw any prior fueling baseline out the window.
115mm to a 50mm stroke is 2.3:1 110mm is a better option

[TZ350]

Looks like you're spraying a great amount of fuel directly onto the back of the liner?

Nothing about this setup is ideal, it just gets me started on the 2-Stroke EFI learning curve, things will get better.

They tell me nothing worthwhile gets done without making a few mistakes and if you want to get some where faster, then make more mistakes quicker.

I hope they are right.

[TZ350]

I would not reccommend doing that in conjuction with the EFI, long rods seem to throw any prior fueling baseline out the window.

Thanks for the tip, with the long rod I was looking for extra crankcase volume for the new engine.

[TZ350]

TeeZee, send me your current file pack for the 3 port and i will have a play whilst im lying down recovering.

Thanks Wob, will do.

[TZ350]

Posted because I was asked what sort of ignition would be good for a TF/TS125.

284894284895

These early KX80 ignitions with the triangle shaped stator and small CDI black box have a straight line ignition curve. The flywheel taper fits the Suzuki 100/125 crank shafts, the timing marks line up for a perfect setup every time, and the stator is easy to fit to the cases. I think the KX80 is a realy good ignition if you want something simple.

There are several different lookalike versions of this KX80 ignition, so it pays to get a complete unit as parts from the different versions are not interchangeable. Ebay is a good source for these ignitions, its where we got ours from.

[Rick 52]

I am please to say I am now riding for the ESE team with a satellite ride, this has already produced 1.5 extra HP and much better curve through some fantastic advice and set up on the Dyno from Teezee.
Improved pipe design, new carb and a little porting and we now have 22.8 HP from the TF
Teezee has started to design a new engine for me to build with the intentions of getting the very most we can get from a TS 125 engine, this will take some time but would be aiming for the middle of the NI rounds or GP .

[speedpro]

this will take some time but would be aiming for the middle of the NI rounds or GP .

this year??

[Haufen]

Nothing about this setup is ideal, it just gets me started on the 2-Stroke EFI learning curve, things will get better.

They tell me nothing worthwhile gets done without making a few mistakes and if you want to get some where faster, then make more mistakes quicker.

I hope they are right.

I understand, and I totally agree. But wouldn't it be better to avoid things which might be not so ideal in the first place? Dealing with EFI alone will be challenging enough, I guess. On the other hand, I understand that you are looking forward to trying it out, finally.

[FastFred]

... wouldn't it be better to avoid things which might be not so ideal in the first place?

I am sure TZ would if he could see a better practical way of doing it.

[TZ350]

The issue you are up against TeeZee is that EngMod has no way of knowing how bad your transfer duct ans scavenging pattern really are.

The ducts you have and the port geometry ( mains too big ) means the transfers as modeled are not, and cant, perform anything like the simple one dimensional numbers suggest.

Thus you have to use the blow down to shoot for the actual power you need, and the transfers MUST be way bigger in STA than the calculations suggest.

And in doing this, the Ex port STA number is basically irrelevant.

But in any case of trying to extract any worthwhile power out of a race engine worthy of being called one, it is near on impossible to generate sufficient REAL transfer STA, then add the correct Blow STA on top of this - with a limiting total height at 188*, It just cant be done.

The ONLY thing 188 has going for it is strong port/pipe resonance over a wider band, but no matter what you do the power achieved (with 188 Ex duration) will always be severely limited. Just pointing out hard learned basics of the physics,gained from fucking it up myself.

Wob had a look at my original 188 ex duration file and made a few changes for me. Starting by getting the blow down STA in the right area for the power we want, and that meant the exhaust now has 194 degrees duration, a bit up from my original 188.

284928

Wobes notes he sent me with the updated EngMode file.

TZ
Here is the new pack with a little work.
Biggest issue I found was 15.5 com with 17.5* spark would be instant death to an air cooled piston.
So way more power now with much less com and timing - adding com and timing would bump up sim a heap, but isn't reality.
A - transfer angle is corrected to 25* as well as heights. Ex is 194 with nozzle, and rear cone is way shallower.
Original power band would be say 8200 to 12200 = 4000, new setup would be 9000 to 1300 = 4000 with a ton more area under the curve.

cheers
wob

ps - the pipe wall temp i changed to 50 - from 450, not on the money at all for accurate pipe length behavior, Neels recommends 50 to 150

284927

And an EngMod graph comparison.

284933 284934

The exhaust and transfer port details.

Thanks Wob, it looks good, I will use your new layout when I make the next triple port cylinder.

[F5 Dave]

Well had a good talk to Neil at the epic ride today. Good to see the Bighorn in the flesh and the YZ. Bit sodding wet though.

[TZ350]

284936

That fuel injected Kawasaki Big Horn is impressive.

[2T Institute]

With a decent pipe would be about 50HP as well.

[Flettner]

Good to see you there F5 Dave, I didn't fire the Kawasaki up in the end, we just concentrated on testing the two YZ's. Then went home cold and wet! The EFI YZ goes real nice, smooth power output. I think I might like mine EFI as well now.

[TZ350]

Ok, making a bit of progress with setting up the EFI systems throttle body.

284965

The original idea was to run the 32mm Ball Valve inside a plenum feed by a 24mm carb equivalent, but things change and now I am going to try it with a 24mm insert first.

284966284967284969

The 24mm venture insert is going hard up behind the Ball Valve. I am not sure exactly where reversion will accour but it looks like it will be a reasonably short inlet tract.

The insert has an aerofoil shaped leading edge and the trailing edge is a 14 degree (included angle) divergent cone, in fact it diverges at 14 deg more or less all the way out to the rotary valve face.

284968

32mm Ball Valve with 24mm carburetor equivalent throttle body venture behind it.

[Rick 52]

I am please to say I am now riding for the ESE team with a satellite ride, this has already produced 1.5 extra HP and much better curve through some fantastic advice and set up on the Dyno from Teezee.
Improved pipe design, new carb and a little porting and we now have 22.8 HP from the TF
Teezee has started to design a new engine for me to build with the intentions of getting the very most we can get from a TS 125 engine, this will take some time but would be aiming for the middle of the NI rounds or GP .

Thanks Teezee, the bike was a missile today, had a little trouble learning to ride it again, qualified 2nd behind the currant lap record holder Garry Cunningham in the dry but cold track conditions, hole shot both points races but locked the front in the rain in the first race and went very wide, finishing 4th and finished 3rd in the second race struggling with the extra power in the pouring rain, the dyno curve showed the biggest increase in power on the overrun, over 4hp extra! Looking forward to a dry race to show what we can do .

[F5 Dave]

Good to see you there F5 Dave, I didn't fire the Kawasaki up in the end, we just concentrated on testing the two YZ's. Then went home cold and wet! The EFI YZ goes real nice, smooth power output. I think I might like mine EFI as well now.
Today the track was unbelievably well drained. Even got the sun out.

[G Jones]

I also make the skull face around the spark plug 0.1mm low, so that the top of the dome is pushed down by the head cover, and then the studs also pull the cover down over the inserts
outer flange as above.Hi - I know the amount is not much - but could that 0.1mm cause any problems with the outer O ring leaking ? (I'm thinking of this on a TZ350 head)
Thanks...

[TZ350]

Thanks Teezee, the bike was a missile today, qualified 2nd behind the currant lap record holder Garry Cunningham.

I am glad to hear you enjoyed it.

[wobbly]

The head studs are outside the diameter of the skull flange, and usually they pull the cover down hard enough to keep the crush on the insert as well as " bend " the
cover enough to keep the outer O ring seal intact.
A 2mm head O ring should have around 0.3mm crush, so the 0.1 would not cause any issue.The outer water O ring has virtually no pressure
on it - well it shouldnt , anyway.
I have done many TZ350 heads with the 0.1mm protrusion with no issues.

[G Jones]

I have done many TZ350 heads with the 0.1mm protrusion with no issues.Thanks - very much appreciate you taking the time to explain...
I've been machining some new inserts earlier today - and was basing the measurements on those taken from a head I had "inserted" by someone else a couple of years ago - I'm guessing those inserts / head have probably "settled" a bit in use - so wasn't sure how valid those measurements would be - your figures seemed to make sense - I was just a bit unsure how the outer o ring would cope...
Thanks again - just got to machine the chambers & squish now...:eek:

[Flettner]

http://i854.photobucket.com/albums/ab102/GerbilGronk/Random%20Shots/IMG_8927_zps94d576b6.jpg

http://i854.photobucket.com/albums/ab102/GerbilGronk/Random%20Shots/IMG_8924_zpsb83289f1.jpg

F5 Dave, just knew we should have gone on Sunday! Had a good time anyway. Proved our point, 2T EFI works in the real world. Out of the four bikes we took only two had carburetors.

[TZ350]

284978284979284980

Chambers is getting his RG50 ready and fitting the new 24mm Tillotson HL360A carb.

[F5 Dave]

The head studs are outside the diameter of the skull flange, and usually they pull the cover down hard enough to keep the crush on the insert as well as " bend " the
cover enough to keep the outer O ring seal intact.
A 2mm head O ring should have around 0.3mm crush, so the 0.1 would not cause any issue.The outer water O ring has virtually no pressure
on it - well it shouldnt , anyway.
I have done many TZ350 heads with the 0.1mm protrusion with no issues.
While we're talking heads & leaking; I have an aircooled head I've converted to LC. I've porpoisely avoided welding in the chamber (or anywhere if I've been able to avoid it). Sadly there are a couple of pinholes exposed in the original casting once its been skimmed & reshaped. They lead through to the water chamber & pressurising the head in a bucket of water shows some tiny bubbles. Just on the edge of squish & just in the chamber.

Do you think they will block with carbon? I can't see much volume escaping through such a tiny passage, but the pressure is considerably more than my testing pressure. That said, ring gap is vast by comparison.

[Ocean1]

While we're talking heads & leaking; I have an aircooled head I've converted to LC. I've porpoisely avoided welding in the chamber (or anywhere if I've been able to avoid it). Sadly there are a couple of pinholes exposed in the original casting

There's a process involving a sodium silicate resin and an autoclave that works well, but I don't know who might be doing it in NZ now.

[husaberg]

There's a process involving a sodium silicate resin and an autoclave that works well, but I don't know who might be doing it in NZ now.

Sodium silicate "Water glass" is used to make sand casting cores solid, available cheap from pottery suppliers about $7:50 for 500mm $20 for 2 liters (http://www.nelsonpottery.co.nz/downloads/SouthStreetGallery2013.pdf) (also used to preserve eggs i think) add co2 and sets like concrete, baking in a dirty oven i understand does the same, don't know about the process of sealing heads though .......

http://www.youtube.com/watch?v=hCBRfrPV8BY&feature=player_detailpage#t=127s
2m:11s for the impatient.

You can use other catalysts to set it off FERROSILICON etc

Edit i think they also use sodium silicate to render engines totally useless at recycling.

Often called liquid glass, sodium-silicate solution has been better known for being used to save motors rather than killing them: It is used to stop leaks in the gaskets that seal cylinder heads to engine blocks.

At dealerships across America, mechanics accustomed to fixing engines are battling for the chance to ruin them. "Everybody wants to go first, so I'm probably going to have to make them draw straws," says Jim Burton of Randy Curnow Buick Pontiac GMC in Kansas City, Kan. As service manager, however, he might reserve that thrill for himself. "I can't wait," he says.

Over the weekend, half a dozen mechanics gathered around three clunkers marked for death at Jim Clark Motors in Lawrence, Kan. As Loris Brubeck Jr., the dealership's president, held a stopwatch, the sodium-silicate solution took two minutes flat to kill a 2002 Ford Windstar, and just a few seconds more to kill a 1999 Jeep. But a 1988 Dodge van lasted more than six minutes.

"Sometimes those old engines, they're the hardest to kill," says Mr. Brubeck.
reading this (http://online.wsj.com/article/SB124934376942503053.html) i guess that is what a lot of the commercial sealers are made from

[F5 Dave]

Actually I have some block sealer left over I used to treat my 496 as a precaution (as my original CPI block leaked), I heated it up in some water on the stove with solution inside & pressurised it with a hand pump.

I do wonder if a pinhole would leak at all? But might do this as a matter of course. Thanks for the ideas guys.

[TZ350]

Are on Mylaps thanks to Tim

http://www.mylaps.com/en/events/928592

284998

AMCC round 1 results courtesy of David Diprose.

[TZ350]

285000

I just love these Arrows.

And Husa put me onto this Ariel Arrow tune up article

[jasonu]

Actually I have some block sealer left over I used to treat my 496 as a precaution (as my original CPI block leaked), I heated it up in some water on the stove with solution inside & pressurised it with a hand pump.

I do wonder if a pinhole would leak at all? But might do this as a matter of course. Thanks for the ideas guys.

Why don't you just get it welded and re machined?

[Drew]

Why don't you just get it welded and re machined?Surely you don't mean using anything but composits in his motor?

[F5 Dave]

Why don't you just get it welded and re machined?

Because I've seen Honda metal turn to bubbles when I've tried that before. Casting metal is a pig but more so 70/80s Honda metal.

[bucketracer]

285027T

Took a sneaky peak at TeeZee's special inlet, just to see if it was actually 24mm.

It will be interesting to see how he fits a boost bottle in there, looks a bit tight.

[Grumph]

Actually I have some block sealer left over I used to treat my 496 as a precaution (as my original CPI block leaked), I heated it up in some water on the stove with solution inside & pressurised it with a hand pump.

I do wonder if a pinhole would leak at all? But might do this as a matter of course. Thanks for the ideas guys.

Dave - you shouldn't be overly worried about a pressure leak outward from the cylinder...Though it will blow all the water out....You should be bloody worried about finding the cylinder full of water after leaving it standing for a week. If it's still accessible from outside you could tap and fit a brass screw.

It's only a matter of time before a bucket racer here in NZ makes a complete devcon barrel. This obsession with avoiding welding is a mystery to me.

[husaberg]

285016

Took a sneaky peak at TeeZee's special inlet, just to see if it was actually 24mm.

It will be interesting to see how he fits a boost bottle in there, looks a bit tight.

I am no engineer, but isn't that 24.1mm lol..................<_<:innocent:
Not that it matters, i hope she works well as expected.
I just noticed the GP125 makes 30 hp vs the yz250's 47hp ish.


285000

I just love these Arrows.

And Husa put me onto this Ariel Arrow tune up article

I read the other day that Herman Meiers Ariel 250 that i posted ages ago used lab crank seals supposedly they were worth a couple of HP on a 20 ish hp bike then he borrowed the idea from DKW. i will see if i can find the pic.

Well I be buggered.

[Drew]

It's only a matter of time before a bucket racer here in NZ makes a complete devcon barrel. This obsession with avoiding welding is a mystery to me.You reckon it'd work? I would like to make a reed/crank ported GT125.

[bucketracer]

I am no engineer, but isn't that 24.1mm lol..................<_<:innocent:

Wooops ... TeeZee wont thank me for that. :laugh: . ... parallax error maybe.

[jasonu]

Because I've seen Honda metal turn to bubbles when I've tried that before. Casting metal is a pig but more so 70/80s Honda metal.

A GOOD welder who knows what he is doing should be able to handle it OK.

[Forgi]

I would be very interested in the roof angle of the 6th transfer port thats under exhaust.

This is where I have got to tonight, cylinder prepped and ready to go.

The floor of the exhaust port is higher than BDC. I have no idea how high the exhaust port floor could be and I would dearly love to know more about it and what sort of angle a 6th transfer port there should be.

The alloy stuffer plate and Belzona glue.

All assembled, and compression tested OK so ready for a run up on the dyno, hopefully tomorrow night.

I want to get a good base run with the carb setup then switch to fuel injection. I have no idea how long the stuffer plate and Belzona will last, I guess we will find out soon enough.

Hello Teezee!

How about the running on dyno? I'd be interested what are the results?

And hi everybody!

Is there anyone especially Frits or Wob who has Engmod file pack about GP Van Veen (15-20 Ps) from the 70's-80's? Regretfully in Hungary there is no such old GP 50cc cylinders. I'd be gratefull for that pack as on the net there are a lots of pics and explanations, but they are not so usefull.

Thanks in advance!

[wobbly]

We , anyone,can only construct an EngMod sim by having the complete engine sitting on the bench.
I seriously doubt anyone that has access to a stripped Van Veen, would also have the software to model it correctly.

[Neal]

[QUOTE=I read the other day that Herman Meiers Ariel 250 that i posted ages ago used lab crank seals supposedly they were worth a couple of HP on a 20 ish hp bike then he borrowed the idea from DKW. i will see if i can find the pic.[/QUOTE]


I remember a story from an old racer/tuner I know , he was testing with Herman Meiers before the TT . Every session Herman would walk to the end of the pits and watch the opposition on their bike as 1 other team were testing at the track . He would be playing his harmonica , when my friend walked over to ask him what he was doing , he explained that he had tuned his harmonica to peak revs and he could work out if the opposition were hitting peak revs down the straight when he played the same tune as them .

[TZ350]

The floor of the exhaust port is higher than BDC. I have no idea how high the exhaust port floor could be.

284575284576

The alloy stuffer plate and Belzona glue.
Hello Teezee!

How about the running on dyno? I'd be interested what are the results?

The glued and screwed in port floor dam held up OK and the dyno results were better.

285043285044285045

Raised port floor Blue line.

285042

But I wouldn't read to much into it as this triple exhaust port cylinder made much better power before I "improved" it.

285046

All I did was tidy up around the inside of the main exhaust port area where the side ports converge and after I had finished that I found that some of the horses had bolted.

What was a stable of 29 became less than 20 ??????? ... :scratch:

Originally the the exhaust timing was 203 degrees duration, lowering the cylinder to 200 exposed the bottom of the exhaust port, the floor dam fixed that.

I was also going to try a power valve like piece in the top of the port but in the end a glued solution was not going to be satisfactory in the long run.

Messing with this has held me up so I have switched to working on fuel injecting a known good single exhaust port cylinder. I will try making another triple exhaust later.

[TZ350]

I remember a story from an old racer/tuner I know , he was testing with Herman Meiers before the TT . Every session Herman would walk to the end of the pits and watch the opposition on their bike as 1 other team were testing at the track . He would be playing his harmonica , when my friend walked over to ask him what he was doing , he explained that he had tuned his harmonica to peak revs and he could work out if the opposition were hitting peak revs down the straight when he played the same tune as them .

Thats very clever.

285062

12,000 rpm 2-Stroke Single is 200 Hz (12,000rpm/60sec=200Hz), I guess the sound of a Twin firing twice a revolution would be 400 Hz.

Someones water cooled Ariel Arrow Racer.

[F5 Dave]

A GOOD welder who knows what he is doing should be able to handle it OK.
Seriously it's pin hole that you couldn't get a pin in

[Yow Ling]

Seriously it's pin hole that you couldn't get a pin in

A folicle maybe?

[twotempi]

TZ350 - According to your musical instrument frequency chart Mr Herman Meir could have been better using a piano rather than a mouth organ , but it probably would have been a bit too obvious !!

[F5 Dave]

I think you could have passed it off as eccentrically mad:wacko:

[wobbly]

The Arrow race engine I did with pipes for a guy here in Tauranga, had pin hole casting inclusions all over the place.
I ground the holes out and re welded each one in turn, the re machined the squish area 3 times I think before it cleaned up and didnt leak.
It had a horrible tall coned chamber originally with the plug some 30mm away from the piston.
I turned it into a " normal " hemispherical shape to run Methanol at 17:1.
A hateful job I wouldn't do again.

[twotempi]

The Arrow race engine I did with pipes for a guy here in Tauranga

For Mr John Hudson ?? Unfortunately they used to tune it to a stand-still on race day. Should have gone very well - had all the special bits - but it never really did.

[RomeuPT]

The glued and screwed in port floor dam held up OK and the dyno results were better.

285043285044285045

Raised port floor Blue line.

285042

But I wouldn't read to much into it as this triple exhaust port cylinder made much better power before I "improved" it.

285046

All I did was tidy up around the inside of the main exhaust port area where the side ports converge and after I had finished that I found that some of the horses had bolted.

What was a stable of 29 became less than 20 ??????? ... :scratch:

Originally the the exhaust timing was 203 degrees duration, lowering the cylinder to 200 exposed the bottom of the exhaust port, the floor dam fixed that.

I was also going to try a power valve like piece in the top of the port but in the end a glued solution was not going to be satisfactory in the long run.

Messing with this has held me up so I have switched to working on fuel injecting a known good single exhaust port cylinder. I will try making another triple exhaust later.

I don't know if I understand. You had 24,8 hp and the raised floor get you in 29,5? That's huge!

[wobbly]

Yea, everything that went wrong with Hudsons bike was an obvious mistake but he always thought more was better, and spent so much wasted time
flying off on wierd arse tangents before getting even a basic runner under control.
A shame as you say, the initial settup was just fine.

[TZ350]

I don't know if I understand. You had 24,8 hp and the raised floor get you in 29,5? That's huge!

When I first tried the Triple Exhaust I got 29.5 rwhp (I had previously done better with a single port at 31 rwhp)

Tried to improve the Triple Exhaust and it fell to 18.6

Raised the exhaust port floor and went from 18.6 to 24.8

Thrown the cylinder in the bin and started again.

[TZ350]

The Arrow race engine I did with pipes for a guy here in Tauranga

285089

And here it is, beautiful job too.

[speedpro]

Hard case. Binning a 24.8hp cylinder.

[mr bucketracer]

285089

And here it is, beautiful job too.when it went it was good but seem to have alot of promblems cause he had a srewdriver in hand to much . lovey bike

[Drew]

Hard case. Binning a 24.8hp cylinder.I raised an eye brow too.

Is that because the stuff the port floor is now made of, won't last?

[TZ350]

TS125 Exhaust Port

285099

Rick with the exhaust port I figure, raise it to 25mm from the top of the cylinder and widen it to 40mm at the top and leave it the original width at the bottom.

We can set the port timing at work to open at 80 deg ATDC accurately using a degree wheel and the width at 73% when finishing up and radiusing off the edges.

[kel]

TS125 Exhaust Port

Rick with the exhaust port I figure,

Bloody hell, I go away for a few weeks and you're tuning the competitions bike. Wait, team mate :shit: :lol:

[Frits Overmars]

When I first tried the Triple Exhaust I got 29.5 rwhp (I had previously done better with a single port at 31 rwhp)

1 Tried to improve the Triple Exhaust and it fell to 18.6

2 Raised the exhaust port floor and went from 18.6 to 24.8

3 Thrown the cylinder in the bin and started again.
You work too hard, TeeZee. Leave out step 1 and step 3 and you'll end up with a clean bin and 37.7 rwhp:D

[RomeuPT]

When I first tried the Triple Exhaust I got 29.5 rwhp (I had previously done better with a single port at 31 rwhp)

Tried to improve the Triple Exhaust and it fell to 18.6

Raised the exhaust port floor and went from 18.6 to 24.8

Thrown the cylinder in the bin and started again.

I have to read better what you posted before...

[F5 Dave]

Just to invalidate testing, perhaps in test 1 there was some issue where the ring seal was disturbed. Who knows, that's the problem sometimes without following a methodical approach which is the luxury of perhaps those full time employed to do so. The rest of us just have to hope for consistency.

[wobbly]

Look closely at the toolbox item on the floor in front of the bike - says it all really, as this was used to set the spark gap on BR9 plugs run at over 17:1 on Methanol.

[twotempi]

I assume you are referring to the rather large hammer !! :niceone::niceone:

[twotempi]

Was a pity really as it had all the potential but never really lasted a race weekend. They used to turn up on Friday all bright-eyed and bushy-tailed for practice. By the afternoon the cylinders were off. On Saturday it would run in practice but in the afternoon seldom finished a race. On Sunday it became a display bike.

Would have very disappointing and fustrating to be pit crew. They seemed to be trying everything, but it was what I call a 'rainbow bike". Never got to the pot-of-gold at the end.

The old story - Get something simple running first , and be clever later. AND !! don't do your tuning/development at the track !!

[wobbly]

More disappointing to spend over a week grinding, welding & designing pipes, doing the crank balance etc, to have it run just fine ,once, on petrol.
Then as you say, tuned to death by people way cleverer than I could hope to dream of.

[Haufen]

When I first tried the Triple Exhaust I got 29.5 rwhp (I had previously done better with a single port at 31 rwhp)

Tried to improve the Triple Exhaust and it fell to 18.6

Raised the exhaust port floor and went from 18.6 to 24.8

Thrown the cylinder in the bin and started again.

I am pretty sure you did, but just in case: did you check the ignition timing with a strobe light each time? 10-15 degrees off could have the same effect.

[kel]

AND !! don't do your tuning/development at the track !!

I dont understand. Surely the track is the perfect place for final tuning, its also the best place to try development mods. Its all good and well to prove concepts through simulation and to carry out tuning on the dyno but its the on track performance that matters and that means tweeks, some of them less than minor. That big hammer may be an over kill though :lol:

[wobbly]

Wrong - a racing motorcycle engine can be very closely modelled near reality if the inputs are good enough.
The powervalve and ignition curve can then be transferred directly to the ECU, the thing can then be run in, and thrashed to death on the dyno.
All that is needed is fine tuning of the fuelling and ignition for best power.
Then go to the track with no fear that it will melt down if the best power egt numbers are programmed into the red lights on the dash to indicate where the jetting stands.
Look up RZ400 on UTube.
After that dyno session it went straight to the track with the same jets and setup, ran 4 off 20 minute sessions at full noise the whole time.
Needed one jet change on one side to get equal egts at 1245F.
Gearing and part throttle response is the game at the track - not development.

[twotempi]

I think they were running it on Methanol at the track when you had set it up for petrol !! Ain't going to work without proper testing, and is rather dangerous too.

By all means do your final tweaks at the track but it is no place for major changes such as a change in fuel.

And as an aside I seldom see a successful track-side rebuild of an engine. Most of the time it just ruins another perfectly good piston !!

The GP teams might manage it but club racers normally get a "fail"

[Grumph]

I've said it before but it bears repeating = Pro engine building #101 - Picking your customer....

Anyone who will buy me a drink can have the story of why I call Johnny Hepburn "heartburn"

The Arrow made it to the South Island once. Finished some of it's races, looked good but not particularly fast...Detuned ?

[bucketracer]

Look up RZ400 on UTube.

<iframe width="560" height="315" src="//www.youtube.com/embed/oJ9EUBRHQ3U" frameborder="0" allowfullscreen></iframe>

<iframe width="560" height="315" src="//www.youtube.com/embed/TE9am_QCzwc" frameborder="0" allowfullscreen></iframe>

[richban]

Hooked

Well I just spent the afternoon riding a couple of RGVs around at Manfield. So totally hooked on the things now. The handling was a bit poo, but when on the pipe I just wanted the fun to never end.

How many ponies do you {you being the people that know ie not me} could squeeze form an RGV250? I think one had a good 65 maybe and the other maybe low 50"s

So much fun. I see why you are all so mental now.

[Moooools]

Wrong - a racing motorcycle engine can be very closely modelled near reality if the inputs are good enough.
The powervalve and ignition curve can then be transferred directly to the ECU, the thing can then be run in, and thrashed to death on the dyno.
All that is needed is fine tuning of the fuelling and ignition for best power.
Then go to the track with no fear that it will melt down if the best power egt numbers are programmed into the red lights on the dash to indicate where the jetting stands.
Look up RZ400 on UTube.
After that dyno session it went straight to the track with the same jets and setup, ran 4 off 20 minute sessions at full noise the whole time.
Needed one jet change on one side to get equal egts at 1245F.
Gearing and part throttle response is the game at the track - not development.

Better still use an AC dyno and simulate the whole lot based on data collected from previous race meets.

That is what we are planning to do with the car next year when we have the AC dyno set up at the Newmarket campus. All simulated on Ricardo wave (A dirty 4 stroke equivalent to Engmod 2T except about 100x the retail price) and then onto the dyno for testing of a complete lap or race, gear changes and all. F1 have been doing it forever but it is not exactly easy to do on the cheap.

[F5 Dave]

Std good one 22 =52, F3 tune were getting 70 so there's your target, but it's a fair go of it.
Come to the light side Rich

[richban]

Std good one 22 =52, F3 tune were getting 70 so there's your target, but it's a fair go of it.
Come to the light side Rich

Yeah I am still bathing in the light.

Ok 70 sounds good. On it. Ideal squish band angle anyone? I hear there is a good pipe design guy lurking on this thread. Wonder what he might have for an RGV VJ 22 lying around in Tauranga?

[Grumph]

Std good one 22 =52, F3 tune were getting 70 so there's your target, but it's a fair go of it.
Come to the light side Rich

Many moons ago when those things were new, Suzuki NZ imported one direct from the Japanese F3 wars. They sent it to Grant Ramage who was leading the 250 prod champs on one. It wasn't particularly fast so it got sent to a NI tuner...who now tunes the bouncy bits of bikes. Grant got it back in time to bring it to a meeting at Wigram. Goes out in first practise and it comes back on a trailer. He was pitted next to us so i was interested...He pulls the heads off, grunts and says "thats fucked" and proceeds to get his proddy bike ready.
I ask what's happened and he says have a look...colours are good, bores look ok pistons intact - I ask again and he says look closer...
The arrow marking front on the bottom piston was pointing to the left side of the bike....Broken rod I assume.
I believe it was shipped back to Suzuki NZ....I never heard of it or saw it again

[F5 Dave]

Suzukis never seem fantastic with cranks. Keep the revs safe and should be fine. That's mx pwr from a proddy bike so totally feasible.

[richban]

Suzukis never seem fantastic with cranks. Keep the revs safe and should be fine. That's mx pwr from a proddy bike so totally feasible.

From what I have read so far. Looks like the port timing is out by .9mm from stock. So I can fix that with raising the barrels. Then I want to find the best cylinder head shape and raise the compression. I have some wossner pistons lined up for when I find out how bad / good the barrels are. Some good pipes and away we go.

That will take up most of the budget I think. shoe string

[speedpro]

Can't remember what model cylinder/head but I sleeved down a RGV cylinder for my bucket. Eventually I had the head welded and reshaped to conventional squish and chamber design with the plug upright in the centre. With everything else identical it instantly made about 10% more power and had more under the curve everywhere.

[richban]

Can't remember what model cylinder/head but I sleeved down a RGV cylinder for my bucket. Eventually I had the head welded and reshaped to conventional squish and chamber design with the plug upright in the centre. With everything else identical it instantly made about 10% more power and had more under the curve everywhere.

Cool. I have my eye on some SP heads. centre plug. Not sure if these is much difference in the squish band width or angle.

I will be back tracking through this tread a lot I think. Gold digging as there is so much of it. Maybe to much for the novice.

[husaberg]

Rich what class will you be racing in?

[F5 Dave]

I was going to say centre plugs and shorts. Maybe igni and some KX carbs with proper solinoids or maybe some old TZ carbs?

[richban]

Rich what class will you be racing in?


F3 maybe. Not really going crazy on the racing just fun stuff at this stage. To go anywhere near fast the handling needs sorting. Never driven a bus but might be similar to an RGV. So slow to steer and midd corner is poo no feel. I have a plan to get it close to my NSR. We will see how that works out.

[richban]

I was going to say centre plugs and shorts.

....Done....

[husaberg]

F3 maybe. Not really going crazy on the racing just fun stuff at this stage. To go anywhere near fast the handling needs sorting. Never driven a bus but might be similar to an RGV. So slow to steer and midd corner is poo no feel. I have a plan to get it close to my NSR. We will see how that works out.

ok F3 ya giving away a fair few cc's... Whats wrong with a RG150 top end or 2, then tuning it up, throw in a 54mm crank etc.
I seem to remember the RG250 crank is fairly close to fitting according to the webby thing.(Vincent Crabtree/VinCBR900) There is a proper full monty 54mm crank for one on TM at the moment. but you might need longer laces for that.

[Drew]

ok F3 ya giving away a fair few cc's... Whats wrong with a RG150 top end or 2, then tuning it up, throw in a 54mm crank etc.
I seem to remember the RG250 crank is fairly close to fitting according to the webby thing. There is a proper full monty 54mm crank for one on TM at the moment. but you might need longer laces for that.200 Wolf slugs @ 66mm, and a 57mm stroke ends up around 194cc per. It's legal to go out to 400cc two stroke in F3, might as well do it proper.

Do two strokes like to be that over square?

[richban]

200 Wolf slugs @ 66mm, and a 57mm stroke ends up around 194cc per. It's legal to go out to 400cc two stroke in F3, might as well do it proper.

Do two strokes like to be that over square?

Did i not mention shoe string. If I got 65hp and it handled like my NSR it would be fast and fun. I am happy to make up the numbers. It will look great and smell nice and do the odd wheelie. What more could you want. Oh and sound good.

[Drew]

Did i not mention shoe string. If I got 65hp and it handled like my NSR it would be fast and fun. I am happy to make up the numbers. It will look great and smell nice and do the odd wheelie. What more could you want. Oh and sound good.I don't recall anyone winning a proddy title, on an NSR once the VJ22 came out. Prolly needs a suspension rebuild.

Start a thread to discuss it I think. This one is getting kinda dragged off track.

[richban]

I don't recall anyone winning a proddy title, on an NSR once the VJ22 came out. Prolly needs a suspension rebuild.

Start a thread to discuss it I think. This one is getting kinda dragged off track.


Yes true. Might take this over to the racing section. Sorry 2 stroke tuners. As you were.

[TZ350]

Page 810...

Bucket Racing Video from Chrisc's thread http://vimeo.com/64253234

and Pictures of the bikes http://www.kiwibiker.co.nz/forums/showthread.php/153656-Chris-Bucket-photo-thread-Bandwidth-warning/page7

Exhaust port dam.


The stuffer plate for the exhaust port dam is held down by screws through the exhaust port floor, the glue is only there to seal it.


something on raised exhaust port floors from Jan Thiel

http://www.kiwibiker.co.nz/forums/images/misc/quote_icon.png Originally Posted by Jan Thiel

So that you might be able to raise the exhaust's 'floor'.This helps improve blowdown flow, as seen on a flowbench.In 2007 we started to raise the underside of the exhaust port.

The first results were very promising!But at the end of 2007 I retired, so I could not finish what I started.The idea was to raise the exhaust underside as much as possible until power dropped.

And then, with a smaller exhaust port underside it might have been possible to widen the A-ports more
without losing the fresh charge into the exhaust.




To make the raised floor work as part of an overall plan that was seen all the way thru by Jan at Aprilia, the area reduction at the port should be extended all the way to the flange.

Making this oval, and reducing the duct volume all the way to the exit then works with the 75% area guideline for T or tripple port duct exit geometry.



285398

Well at least its good to know I am on the right track but I sure would like to know if this is the limit or if I can take it closer to the top of the transfers.



285187

On the TS make the rear transfer ports as wide as possible and shape them like the ones in the picture.

285210

24mm Tillotson HL360A Pumper Carb

The original post has more info on tuning ideas for the port/reed Suzuki engines.

[TZ350]

Yes true. Might take this over to the racing section. Sorry 2 stroke tuners. As you were.

All 2T tuning and racing adventure is interesting, Team ESE has not got to serious suspension and chassis tuning yet, as we are still struggling to get the engine and chassis we want together first, but I am sure chassis tuning will become part of the story too.

[richban]

All 2T tuning and racing adventure is interesting, Team ESE has not got to serious suspension and chassis tuning yet, as we are still struggling to get the engine and chassis we want together first, but I am sure chassis tuning will become part of the story too.

Well the bike is almost together so I might just finish it and do a base dyno run. Then pull it down for the rebuild and keep you posted here on how things are going. The cool thing is that in about a month there will be 4 more 250 2 strokes singing around the track. 3 x RGVs and one Aprilia RS.

[Drew]

Well the bike is almost together so I might just finish it and do a base dyno run. Then pull it down for the rebuild and keep you posted here on how things are going. The cool thing is that in about a month there will be 4 more 250 2 strokes singing around the track. 3 x RGVs and one Aprilia RS.Your mate that brings in the Tyga fairings, is he included in the "singing around the track"?

[richban]

Your mate that brings in the Tyga fairings, is he included in the "singing around the track"?

Yep he is. His bike is going rather well now.

[G Jones]

At 01.30 AM it took me some thinking to kick out the inches and the thou's. But I finally worked it out.
That rule of thumb says: ring gap = 0,4% of bore. Jan Thiel found this to be critical; we use 0,5% of bore as a minimum.
Using too wide a gap may loose you some power. Using too tight a gap may turn the ring into a very effective oil scraper which can lead to a giant seizure.Sorry to drag up an older post - but I would like to confirm some thoughts on ring gap when running chrome rings.
With our 64mm bore (TZ350) - we've recently been using Wiseco rings - which when new tend to gap at about 0.5mm (0.65mm on a worn set) - and wondering if we are giving away any appreciable power - I do have some Goehtze 64mm rings which I can gap a lot tighter - but last time I tried that - I did have a "giant siezure" - so have been setting the gaps a lot wider - so could we gain a bit - or leave it wide...?
Thanks.

[Gigglebutton]

All 2T tuning and racing adventure is interesting, Team ESE has not got to serious suspension and chassis tuning yet, as we are still struggling to get the engine and chassis we want together first, but I am sure chassis tuning will become part of the story too.

If I get my shit sorted and alter your frame. :angry2:

[bucketracer]

I think TeeZee, is finding it hard work to develop the engine he can see in his minds eye, still full marks for perseverance.

[senso]

200 Wolf slugs @ 66mm, and a 57mm stroke ends up around 194cc per. It's legal to go out to 400cc two stroke in F3, might as well do it proper.

Do two strokes like to be that over square?

Around here its very common to use 54mm bores with 43 to 46mm stroke, even more over square than that, and there are engines pumping out more than 30hp reliably, go for it.

[richban]

Around here its very common to use 54mm bores with 43 to 46mm stroke, even more over square than that, and there are engines pumping out more than 30hp reliably, go for it.

With limited budget on the RGV project I think splitting the money between a mild strong engine and fixing the lazy handling and will produce a great little bike. If I come across another engine then it will get the stupid treatment over time. From riding a two bike's on the same track one with a 22.5 deg rake and 85mm trail and the other with 25 deg rake and a 94mm trail. Some changers need to be made to the RGV.

[Drew]

With limited budget on the RGV project I think splitting the money between a mild strong engine and fixing the lazy handling and will produce a great little bike. If I come across another engine then it will get the stupid treatment over time. From riding a two bike's on the same track one with a 22.5 deg rake and 85mm trail and the other with 25 deg rake and a 94mm trail. Some changers need to be made to the RGV.

It's not all about the headstock and triple clamps. If the RGV is shorter, it has the extra rake to accommodate. I'd get some nice cartridges for the forks, and a decent rear shock before I started fucking around with the geometry.

[richban]

It's not all about the headstock and triple clamps. If the RGV is shorter, it has the extra rake to accommodate. I'd get some nice cartridges for the forks, and a decent rear shock before I started fucking around with the geometry.

Nah. It is shit. Both bikes are running the same wheel base. Trustmeiknowiknowwhatiamdoing. Tiz the future.

[TZ350]

TS125 Exhaust Port

285099

Rick with the exhaust port I figure, raise it to 25mm from the top of the cylinder and widen it to 40mm at the top and leave it the original width at the bottom.

We can set the port timing at work to open at 80 deg ATDC accurately using a degree wheel and the width at 73% when finishing up and radiusing off the edges.

285186

Rick Dinamik2t posted this coloured picture of the transfer duct angles.

285187

On the TS make the rear transfer ports as wide as possible and shape them like the red ones in Dinamiks picture. Don't raise them as they are close to what we need now and they can be finished of later using a degree wheel for accuracy.

285210 285211 285213

This is Chambers RG50, with your pumper you will be able to follow the natural angle of the TS's inlet tract which is to steep for an ordinary carb.

Coker Race Products RG60 Racer, looks like some ideas there for modifying the TS's inlet port and read block.

http://www.cokerraceproducts.com/SUZUKI%20RG60%20enginespecsWeb1.pdf

The divider glued into the inlet port floor and the way the angle of the read block is changed and the cutting away of the rear of the cylinder all look like good ideas to try on the TS.





(http://www.cokerraceproducts.com/SUZUKI%20RG60%20enginespecsWeb1.pdf)

[Drew]

Nah. It is shit. Both bikes are running the same wheel base. Trustmeiknowiknowwhatiamdoing. Tiz the future.How does the swingarm pivot-headstock measurement compare?

It's your bike, do what ya like of course. But geometry should never be changed before suspension, it's like doing huge port and carb work an an old two stroke that has no chambers, before you do the pipe....Pointless.

[mr bucketracer]

How does the swingarm pivot-headstock measurement compare?

It's your bike, do what ya like of course. But geometry should never be changed before suspension, it's like doing huge port and carb work an an old two stroke that has no chambers, before you do the pipe....Pointless.rgv's handle like crap even with suspension sorted. nsr's handle way better but found not as fast . guess more rgv's raced over nsr's is because there were 10 rgv's to 1 nsr in there hay day

[wobbly]

Depens how you look at it.
If both bikes have shit suspension, then the one with good geometry will always be faster.
Thing is its insanely easy to get good working geometry.
Drop the forks 20mm thru the clamps and jack up the rear ride height 10mm,and it will change the angle from 24 to 22 and the trail from 90 to 80 in a few minutes work.
Unless the rear is fixed, then making different dogbones is easy etc etc ( name a tech that would spot that trick in 250 proddy ).
Emulators are cheap as,and then you get to fiddle with oil to adjust the rebound/comp rates real easy, without paying RT a fortune to get cartridges in there.
Then start looking at sprocket sizes to get more anti squat working, to stop the wobbly front end from unloading and shaking the shit out of you around the Hampton sweeper.
But of course ,good tuneable suspension makes going faster a doddle to organise - as long as you know what to do.
As an example all it took was 2 clicks of Ohlins rear comp damping and 10mm of fork drop for Discombe to loose 1/2 a second of lap time at Puke and take the 82 Junior non slicks lap record without breaking out a 70 year old sweat.

PS - over square Vs square in a 2T is shit, end of story.
Just look at the years Yamaha's suffered with 56/50.6 at the hands of Mr Square - Hondas engines.
It took till 2000 when the 500s square setup was bolted onto Jaques and Nakano's 250 that they even looked like building a fast engine.
And in the same year,the factory Yamaha 125 was a second a lap faster with Harolds square cylinder and crank on board.
Any perceived advantage of the revs capable from a short stroke is far outweighed by the lack of bore real estate needed to achieve the STAs required for better power ability.
But, its the old story of whats available and what can be achieved without too much brain or bank account damage.
A well oversquare 400 will be way faster than a closer to square 250 if done properly.
At 70 Hp the road based 250 is verging on unrideable, the 400 would be tame as shit - I got 96 with nothing outrageous.

[Rick 52]

TS125 Exhaust Port

285099

Rick with the exhaust port I figure, raise it to 24.5mm from the top of the cylinder and widen it to 40mm at the top and leave it the original width at the bottom.

We can set the port timing at work to open at 80 deg ATDC accurately using a degree wheel and the width at 73% when finishing up and radiusing off the edges.

Magic! Thanks Teezee

[Rick 52]

Bloody hell, I go away for a few weeks and you're tuning the competitions bike. Wait, team mate :shit: :lol:

I little healthy competition between team mates is ok Kel :eek5:

[richban]

Depens how you look at it.
If both bikes have shit suspension, then the one with good geometry will always be faster.
Thing is its insanely easy to get good working geometry.
Drop the forks 20mm thru the clamps and jack up the rear ride height 10mm,and it will change the angle from 24 to 22 and the trail from 90 to 80 in a few minutes work.


For me it about creating a bike that when you jack the back and drop the front it is a fine tune to something already good. If you adjusted the NSR as mentioned it would be a twitchy nightmare.

You mentioned a 400 were you talking the inline or a possible RGV 400 hundie. That would be something I would be keen to look at down the track for sure.

[wobbly]

Na I disagree, when you HAVE to drop the forks that much and have to lift the rear as well, it sure as hell isnt a fine tune - its a major change to get
the piece of shit into the ballpark.
The NSR is pretty good in that respect, and a fine tune plus suspension fiddling would work well straight away.
But the RGV is a mile away from good numbers,and it would be mandatory to put in serious work before you could even begin to see benefits from Emulators etc.

I havnt looked into a big bore RGV seriously at all.
But I have all the bits here for a NSR300 that will be a rocket when done properly ( which it hasnt been yet with that bunch of Honda Fags on their forum rubbishing the "non HRC " work done by Tyga etc).

[Drew]

But the RGV is a mile away from good numbers,and it would be mandatory to put in serious work before you could even begin to see benefits from Emulators etc.Since the VJ22 has cartridge forks, I think something would need to be really fucked before emulators made an improvement.

[wobbly]

Sorry, yea I know now the 22 has cartriges,but what I was trying to point out was that even with trick shit SP forks revalved with Ohlins stacks etc
all that would be a waste of time unless the chassis geometry was corrected to something like decent numbers we all know about.
And the fact it costs virtually nothing to get those numbers, easily, why would anyone go ahead and spend up on the suspension before fixing the chassis for free.

[F5 Dave]

My RG/RGV/RZ hybrid has VJ22 front & rear, but with Race tech & ohlins back. When I got it it steered like a chopper. Some serious elevation till I got 23deg & then transformation city.

[2T Institute]

Hooked

Well I just spent the afternoon riding a couple of RGVs around at Manfield. So totally hooked on the things now. The handling was a bit poo, but when on the pipe I just wanted the fun to never end.

How many ponies do you {you being the people that know ie not me} could squeeze form an RGV250? I think one had a good 65 maybe and the other maybe low 50"s

So much fun. I see why you are all so mental now.

You can get 65hp with just bolt on bits and an ignition. However, you will run into the problem of the shit RGV piston which at 65hp is at their limit. The pin boss will disintergrate and take out the cylinder on the right that or the tang between the arch will break off.
A YZ125 piston is better to use, cranks are easily rebuildable and you use a DT or LC 125 rod for big improvement over standard. We change them to bottom guided thrusts good to 12,500 now.
Free hp available in keeping coolant temp under control which run over 70deg.
Been using Nitron rear shocks which tick all the boxes.

[FastFred]

http://www.nzsuperbike.com/2013/07/avalon-biddle-takes-another-podium-in.html?utm_source=bp_recent&utm-medium=gadget&utm_campaign=bp_recent

285226

Av takes 3rd in Italy,

285225

Av with her Mum and The Team.

[TZ350]

You can get 65hp with just bolt on bits and an ignition. However, you will run into the problem of the shit RGV piston which at 65hp is at their limit. The pin boss will disintegrate and take out the cylinder on the right that or the tang between the arch will break off.

A YZ125 piston is better to use, cranks are easily rebuild able and you use a DT or LC 125 rod for big improvement over standard. We change them to bottom guided thrusts good to 12,500 now.Free hp available in keeping coolant temp under control which run over 70deg.
Been using Nitron rear shocks which tick all the boxes.

Hi Rich

We have been using original RGV rods centered in the piston boss and regularly rev them to 13k plus. I recall hearing somewhere that if the rod has to much side play it can vibrate and eventually break.

2T thanks, its interesting to hear that the 5mm longer LC rods are OK to use.

We also use early 56mm Wiseco YZ pistons.

285257285258

The YZ Piston Crown Height as measured from the centre of the pin to the top edge of the piston is 0.4mm shorter on the Flat Top 1993 YZ piston (629M) than the RGV and the Domed 86-88 YZ piston (559M) is 0.6 (aprox) taller than the RGV.

[dinamik2t]

Have you ever tried the super-short Cagiva Mito pistons, TZ ?

http://www.mitaka.co.uk/CATALOGUE/VERTEX.htm

[2T Institute]

Have you ever tried the super-short Cagiva Mito pistons, TZ ?

http://www.mitaka.co.uk/CATALOGUE/VERTEX.htm

Yes they are a great piston miles better than th RGV shitters.

Rob I don't use RZ or LC 250/350 rods but I found a 125 either DT/ LC/RD that was available in a 105mm. I much rather the air cooled RD rod in 110mm.

For the RGV with a 105mm rod the TZ 4DP piston is best. The YZ runs the ring end gap on the bridge between the B and C ports and I don't like that for several reasons.

[F5 Dave]

Hi Rich

We have been using original RGV rods centered in the piston boss and regularly rev them to 13k plus. I recall hearing somewhere that if the rod has to much side play it can vibrate and eventually break.

2T thanks, its interesting to hear that the 5mm longer LC rods are OK to use.

We also use early 56mm Wiseco YZ pistons.


The YZ Piston Crown Height as measured from the centre of the pin to the top edge of the piston is 0.4mm shorter on the Flat Top 1993 YZ piston (629M) than the RGV and the Domed 86-88 YZ piston (559M) is 0.6 (aprox) taller than the RGV.

So you are using WC pistons in an Air cooled engine? Thought the idea was the AC pistons had more taper to cope with more heat expansion. No issues there?

[richban]

Sorry, yea I know now the 22 has cartriges,but what I was trying to point out was that even with trick shit SP forks revalved with Ohlins stacks etc
all that would be a waste of time unless the chassis geometry was corrected to something like decent numbers we all know about.
And the fact it costs virtually nothing to get those numbers, easily, why would anyone go ahead and spend up on the suspension before fixing the chassis for free.

Yep. Thats is why I am going to fix the chassis first. Thats what I have been on about from the start. I am usually misunderstood.

[richban]

You can get 65hp with just bolt on bits and an ignition. However, you will run into the problem of the shit RGV piston which at 65hp is at their limit. The pin boss will disintergrate and take out the cylinder on the right that or the tang between the arch will break off.
A YZ125 piston is better to use, cranks are easily rebuildable and you use a DT or LC 125 rod for big improvement over standard. We change them to bottom guided thrusts good to 12,500 now.
Free hp available in keeping coolant temp under control which run over 70deg.
Been using Nitron rear shocks which tick all the boxes.

Cheers For the info. The bikes I have ridden so far had stock temp gauges and I was wondering what the actual temp was the whole to I was riding. Another easy fix. I am going to use wossner pistons coz I know a guy who knows a guy.

[mr bucketracer]

FXR's are awesome, no doubt.
But don't be too discouraged, the fastest rider in Wellington is on a 2 stroker. If he makes it to Taupo for buckets that would be real interesting.

So like you say, it's not so much 2 vs 4 or how much HP, it's the quality of the rider, and Wellington has the best riders.no no the palmy boys

[Forgi]

The glued and screwed in port floor dam held up OK and the dyno results were better.

285043285044285045

Raised port floor Blue line.

285042

But I wouldn't read to much into it as this triple exhaust port cylinder made much better power before I "improved" it.

285046

All I did was tidy up around the inside of the main exhaust port area where the side ports converge and after I had finished that I found that some of the horses had bolted.

What was a stable of 29 became less than 20 ??????? ... :scratch:

Originally the the exhaust timing was 203 degrees duration, lowering the cylinder to 200 exposed the bottom of the exhaust port, the floor dam fixed that.

I was also going to try a power valve like piece in the top of the port but in the end a glued solution was not going to be satisfactory in the long run.

Messing with this has held me up so I have switched to working on fuel injecting a known good single exhaust port cylinder. I will try making another triple exhaust later.

Ok Wob, I got it, I've just thought that maybe...

Teezee! It's a pity that you haven't tested the port floor dam held up before the improvement when the engine was stably 29 ps.

If you have any further result I'm interested!

[mr bucketracer]

Got my cases back today, they have been bored for the RGV cylinder.

232931

Cylinder fits Ok

232930

The position of the reed block.

232928

Speedpro told me there is a nice little curved ledge inside the cases that is just right for the reed assembly.

232929

So the reed should fit Ok

232927

Now I have to make up a spacer plate and reed block assembly, how hard can that be???..... :scratch:did you ever finsh this engine rob ?

[TZ350]

Teezee! It's a pity that you haven't tested the port floor dam before the improvement when the engine was stably 29 ps. If you have any further result I'm interested!

Yes, I didn't realy think about it then, but when I get the new triple port cylinder done, a floor dam will be something I will try.


did you ever finsh this engine rob ?

No the 100cc H2O project got shelved when I hit 30hp with the aircooled.

Sure a 100cc H2O might be better and maybe races can be won on low 20's hp, Nat D has done it, but personally I would need miraculous assistance myself.

For now, it interests me to try and push the 125 aircooled with its class 24mm carb restriction out to a reliable 36rwhp.

And I have ideas about how I can do that, but it all takes time.

[twotempi]

did you ever finsh this engine rob ?


If you knew TZ350 you wouldn't ask this question !!!! :yes::yes::yes::yes::yes:

[RomeuPT]

Ok Wob, I got it, I've just thought that maybe...

Teezee! It's a pity that you haven't tested the port floor dam held up before the improvement when the engine was stably 29 ps.

If you have any further result I'm interested!


Me too.
Teezee I understand you screwed in a piece to raise the port floor, but glued? What you mean? You used some kind of epoxy? Have had used high temp epoxy for two times in the exhaust port, but the epoxy burned out of shape after half an hour of riding

[TZ350]

Me too.
Teezee I understand you screwed in a piece to raise the port floor, but glued? What you mean? You used some kind of epoxy? Have had used high temp epoxy for two times in the exhaust port, but the epoxy burned out of shape after half an hour of riding

Yes, high temp epoxy to seal the plate. I fastened the plate in with screws, the epoxy was mostly for sealing around the sides and under the plate.

I did not expect the epoxy to last long, but hopefully long enough to get some meaningful dyno runs. I did about half an hour, 10-12 runs and it held up ok. The last two pictures were taken after the dyno session.

285357285356285354285355

If I go there again I will take more care making the plate a better fit and not needing so much sealant.


The glued and screwed in port floor dam held up OK and the dyno results were better. Raised port floor Blue line.

The dyno results were posted here.

[husaberg]

I guess i missed the original reasoning or i can't find it but is the dam about minimizing reversion like the stepped headers?
couldn't you incorporate the bulge in the beginning with your latest cylinder with a simple raising of the cylinder?
Or was it just to test it's effectiveness.

[TZ350]

couldn't you incorporate the bulge in the beginning with your latest cylinder with a simple raising of the cylinder?

On the GP the bottom edges of the ports are 1.75mm below the piston top edge, so I can't raise the cylinder enough to form an exhaust port dam without badly screwing up the transfer timing.


I guess i missed the original reasoning or i can't find it but is the dam about minimizing reversion like the stepped headers?

Initially the floor plate was because I had mucked about with the cylinder so much the piston skirt at TDC was not sealing at the bottom of the exhaust port and the dam was only going to be level with the piston at BDC.

Then I remembered that Jan and Frits had talked about experiments where raising the exhaust port floor made more power by reducing short circuiting.

285367

This is the business side and I assume it is what they meant, but I have no idea really or any idea how high it could be.


is the dam about minimizing reversion like the stepped headers

285363

This side of the dam is the un intended consequence and I think it really needs to come right out to the flange face. I will try that next time.

The idea worked well enough for me to think I will give it another go when I make the next triple port cylinder.

[Frits Overmars]

Then I remembered that Jan and Frits had talked about experiments where raising the exhaust port floor made more power by reducing short circuiting.And by reducing the exhaust duct volume and to help guide the washed-through mixture back over the piston edge into the cylinder.



285363

This side of the dam is the un intended consequence and I think it really needs to come right out to the flange face. Lenghten it up to the flange face and make a smooth transition, like Wobbly advised.

[RomeuPT]

On the GP the bottom edges of the ports are 1.75mm below the piston top edge, so I can't raise the cylinder

This is the business side and I assume it is what they meant, but I have no idea really or any idea how high it could be.



I think you are very high already, or just at max. As frits said here or elsewere, the area of exhaust port under the transfer opening is useless. Sorry frits if I said it by my words or something....

[richban]

Hi Guys

I have what look like old Sugaya pipes for my RGV. They don't quite fit the later double brace swing arm on my bike. I need to run the hack saw through them twice to get them on. Both cuts would be on the final cone before the skinny pipe to the muffler. I can tig them up nice after cutting but don't want to wreck them. Any advice welcome. Cheers.

[jasonu]

Hi Guys

I have what look like old Sugaya pipes for my RGV. They don't quite fit the later double brace swing arm on my bike. I need to run the hack saw through them twice to get them on. Both cuts would be on the final cone before the skinny pipe to the muffler. I can tig them up nice after cutting but don't want to wreck them. Any advice welcome. Cheers.

I wager you will need to make more than 2 cuts. They always look easier to fit before you start.

[F5 Dave]

So you are intending to cut & rotate, cut & rotate? Think Jason is right, do small angles & a few cuts.

The P model SW is stiffer & much lighter than the Banana so think of that as a bonus.

[richban]

So you are intending to cut & rotate, cut & rotate? Think Jason is right, do small angles & a few cuts.

The P model SW is stiffer & much lighter than the Banana so think of that as a bonus.

Yep yep thats the plan. I was wondering if it was lighter. Good to know.

[wobbly]

If you are cutting the rear cone then take the stinger off.
Cut as straight as you can, rotate, mark them and use a 7" diameter disc to get both surfaces dead flat.
Tac in several places around, then you can shove a bar up inside with a rad ground on the end to tap the join dead flat.
Then run around and weld.
Rehammer the joints on the mandrel bar clamped in a vise again after welding to stress relieve and flatten the joints.

[richban]

If you are cutting the rear cone then take the stinger off.
Cut as straight as you can, rotate, mark them and use a 7" diameter disc to get both surfaces dead flat.
Tac in several places around, then you can shove a bar up inside with a rad ground on the end to tap the join dead flat.
Then run around and weld.
Rehammer the joints on the mandrel bar clamped in a vise again after welding to stress relieve and flatten the joints.

Thanks for that will do. It has been repaired badly at the front as well so I will cut it and fix it up there as well.

The other pipe has a stinger length that is very long in compassion. Is it ok to shorten it a little?285382285383

[2T Institute]

Hi Guys

I have what look like old Sugaya pipes for my RGV. They don't quite fit the later double brace swing arm on my bike. I need to run the hack saw through them twice to get them on. Both cuts would be on the final cone before the skinny pipe to the muffler. I can tig them up nice after cutting but don't want to wreck them. Any advice welcome. Cheers.

Sugaya's tend to be very peaky you'll need a ignitech/Zeeltronic to cover the mid range hole, they tend to work with the old 'kit' set up.

[tdc211]

And by reducing the exhaust duct volume and to help guide the washed-through mixture back over the piston edge into the cylinder.

Lenghten it up to the flange face and make a smooth transition, like Wobbly advised.




I just raised one up 5mm from bdc, welded and replated. After adjusting timing and the power valve I was getting some where. Was also a smooth transition. Had great over rev . Then my dyno box broke when I was making some progress. To say it was a flawed test is a understaement. I did not see any bad side effects and was making good power.

[richban]

Sugaya's tend to be very peaky you'll need a ignitech/Zeeltronic to cover the mid range hole, they tend to work with the old 'kit' set up.


Yes I think after reading a lot in the last few days an ignitech is in order no matter what.

The old 'kit' setup? Do you mean the 1.4mm base gasket and some compression. Seams lots of people talk about that being a good idea. And the 22d10 box?

[TZ350]

http://www.aircooled-rd.com/default.asp?txtPage=longrod.htm

Worth a bit of a look.

[husaberg]

Yes I think after reading a lot in the last few days an ignitech is in order no matter what.

The old 'kit' setup? Do you mean the 1.4mm base gasket and some compression. Seams lots of people talk about that being a good idea. And the 22d10 box?
http://imageshack.us/scaled/landing/81/48301117th7.jpg

http://imageshack.us/scaled/landing/135/47867690ji4.jpg

http://imageshack.us/scaled/landing/81/21667591zu0.jpg

http://imageshack.us/scaled/landing/86/99514991ws5.jpg

[TZ350]

285398


I think you are very high already, or just at max.


I just raised one up 5mm from bdc.

Tdc211 its encouraging to hear you have got good results with your 5mm dam, and Romeu its hard to measure mine with the cylinder off but it looks like the dam is about 6mm or so above the piston and still 5mm or so below the top of the transfers.

Well at least its good to know I am on the right track but I sure would like to know if this is the limit or if I can take it closer to the top of the transfers.


Then I remembered that Jan and Frits had talked about experiments where raising the exhaust port floor made more power by reducing short circuiting.


And by reducing the exhaust duct volume and to help guide the washed-through mixture back over the piston edge into the cylinder.

285400



To make the raised floor work as part of an overall plan that was seen all the way thru by Jan at Aprilia, the area reduction at the port should be extended all the way to the flange.

Making this oval, and reducing the duct volume all the way to the exit then works with the 75% area guideline for T or tripple port duct exit geometry.

285399

Lengthen it up to the flange face and make a smooth transition, like Wobbly advised.

Now :facepalm: I understand what Wob meant and why, thanks Frits.

[richban]

http://imageshack.us/scaled/landing/81/48301117th7.jpg

http://imageshack.us/scaled/landing/135/47867690ji4.jpg

http://imageshack.us/scaled/landing/81/21667591zu0.jpg

http://imageshack.us/scaled/landing/86/99514991ws5.jpg



Ahhhhhhhh ha.

[husaberg]

Ahhhhhhhh ha.

Ahhhhhhhhh.......sole? Grasshopper
do you speakey the lingo?;)
I guess Sir Stephen does,(Brian Demargerine) if you need it translated,where is the Japanese corespondent?
I will post some stuff in a minute. re the 54mm stroke RG250 crank going in the RGV250 courtesy of Vincent Crabtree. (VinCBR900)
With a bit of luck he might fill in the gaps as well.
Did i mention how close the stud spacing on the RGV are to my RSV copy molds?
He mentioned the center bearing needed to be changed. but from memory the spines rotor taper etc were all the same.


Hi,
I can try and dig it out of my archives - what you up to?

Basically, the best option for 54mm crank is to modify an RG250 from the mid 1980s. This is almost a direct fit, but the crank centre need modifying from 2 main bearings to 1 so machining down with a nice wide roller bearing from a TZ350.

If you want to run the TS200 cylinders, first of all find some which is difficult,so it is easier to get ZRT600 cylinders/heads from a Canadian/US snowmobile, and have steel powervalves that don't fall in and lunch the motor. You may have to do some crankcase boring. Then use Yamaha 66mm blaster pistons on TZ350 rods and a spacer plate to set the port timing for 180 degrees exhaust open, skimming the cylinder deck for the correct compression. This should get you something which runs but is not optimised - ports, ignition, powervalve control, carburetor etc. Then develop from there...

http://www.rgv250.co.uk/forums/index.php?/topic/5415-rg200-base-gasket-fits-rgv250-crankases/page-2

[richban]

Ahhhhhhhhh.......sole? Grasshopper
do you speakey the lingo?;)
I guess Sir Stephen does,(Brian Demargerine) if you need it translated,where is the Japanese corespondent?
I will post some stuff in a minute. courtesy of Vincent Crabtree. (VinCBR900)

Looks like that was all a long time ago. There is loads of stuff on the RGV UK site. So much to sift through. Some say raise the barrels, another's says go piston flush and machine squish into the head. I will go with whatever makes the most toque. If going with a machined head squish. Is there a rule on the radius from the squish edge to cylinder. Or sharp edge transition. My head is spinning.

[wobbly]

There is only one rule grasshopper,NO radius from the squish into the bowl.
The other rule is to pull the squish down to the mechanical limit - ie probably around 0.7mm on an RGV then adjust the width to get around 38M/Sec MSV, usually 45 to 50%.
This generates good response and " torque" as you put it - but for sure will need a digital to retard the top end advance to get the overev back.

[richban]

There is only one rule grasshopper,NO radius from the squish into the bowl.
The other rule is to pull the squish down to the mechanical limit - ie probably around 0.7mm on an RGV then adjust the width to get around 38M/Sec MSV, usually 45 to 50%.
This generates good response and " torque" as you put it - but for sure will need a digital to retard the top end advance to get the overev back.

Yes 'torque' thats the stuff.

Thanks for that. I am getting my head around this all. The plan is forming. Cheers again.

[2T Institute]

Yes I think after reading a lot in the last few days an ignitech is in order no matter what.

The old 'kit' setup? Do you mean the 1.4mm base gasket and some compression. Seams lots of people talk about that being a good idea. And the 22d10 box?

Yep that's the old kit set up, it's been surpassed now mainly due to it pushing peak power up to 12,200 or so and allowing it to rev to 13,000. You can join the dots what happens after a hour of that.

If I was going to fit aprilia rsw cylinders I would fuck around with a old RG crank. How is Vince these days? Tell him I've picked up his torch about using inline kart engines :2thumbsup

[richban]

Yep that's the old kit set up, it's been surpassed now mainly due to it pushing peak power up to 12,200 or so and allowing it to rev to 13,000. You can join the dots what happens after a hour of that.

Good to know. Well i will not be going down the route for sure. Cheers.

[husaberg]

Yep that's the old kit set up, it's been surpassed now mainly due to it pushing peak power up to 12,200 or so and allowing it to rev to 13,000. You can join the dots what happens after a hour of that.

If I was going to fit aprilia rsw cylinders I would fuck around with a old RG crank. How is Vince these days? Tell him I've picked up his torch about using inline kart engines :2thumbsup

Tell him yourself i sent him a link..........
My take on using the RG crank is yes, it is likely not as good as a custom one,Of course is dearer than staying stock, But if you were going to tune up an old RGV for decent HP It would be silly not to rebuild the crank.
So seeing as the crank is getting rebuilt anyway you might as well rebuild the one with more stroke and thrown in some longer rods at the same time.

Don't you have something to do with a new crank for the RGV anyway Lozza?

[TZ350]

Bucket Racing Video from Chrisc's thread http://vimeo.com/64253234

Pictures of the bikes http://www.kiwibiker.co.nz/forums/showthread.php/153656-Chris-Bucket-photo-thread-Bandwidth-warning/page7

[2T Institute]

Tell him yourself i sent him a link..........
My take on using the RG crank is yes, it is likely not as good as a custom one,Of course is dearer than staying stock, But if you were going to tune up an old RGV for decent HP It would be silly not to rebuild the crank.
So seeing as the crank is getting rebuilt anyway you might as well rebuild the one with more stroke and thrown in some longer rods at the same time.

Don't you have something to do with a new crank for the RGV anyway Lozza?

Having the crank pins indexed at 0-0 deg is as important as having it run true. I didn't do that much just found the bits , Gravmax88 was the smart one that rebuilt the crank and made it all work with big end thrusts.

[tdc211]

285433


Raised floor 1st pull. I had power valve in the normal position .
Usually with the valve in this position the curve is straight.

This engine is smaller than my other posts at 103cc. I was able to hit 30hp at 12200 and a straight curve with some tuning.

[bucketracer]

I have been following this thread.

285440

Here is my output shaft steel wheel dyno chart of my mx piped engine, a few ccs over 100.



285433

Raised floor 1st pull. I had power valve in the normal position .
Usually with the valve in this position the curve is straight.

This engine is smaller than my other posts at 103cc. I was able to hit 30hp at 12200 and a straight curve with some tuning.

Interesting graphs, any chance of an overlay comparison of the original and the 30hp one with the raised exhaust port floor (easier to see whats going on), pictures?

[Yow Ling]

285433


Raised floor 1st pull. I had power valve in the normal position .
Usually with the valve in this position the curve is straight.

This engine is smaller than my other posts at 103cc. I was able to hit 30hp at 12200 and a straight curve with some tuning.

What is the "normal" position ? How much did you raise the floor?

[tdc211]

Interesting graphs, any chance of an overlay comparison of the original and the 30hp one with the raised exhaust port floor (easier to see whats going on), pictures?

There is no original graph with a normal floor on this exact engine. This was a junk cylinder that needed plating so I filled up the floor and this bottomend has less stroke. I have done enough of these to know it is a straight line curve with a normal floor. After adjusting the valve to open faster the curve straightened out, no more dip.
It wanted more blowdown in the midrange. But remember the valve was set up for a normal floor on this pull. Really not suprising.
The floor raised 5mm did not hurt peak power. I am sure of that. I think it may have helped. But dyno box broke [new one is here] So we will see.

[tdc211]

This raised ex floor engine is totally different in port timings and head design than the bigger engine.
Has more blowdown timing by 1 degree and different transfer timings and 3% less on the squish area.
I figured might as well change it, sense it is a smaller engine and see what happens with the raised floor.

[TZ350]

After your tests it would be interesting to know if you think there is a worthwhile improvement and where like mid range or just coming onto the pipe, top end etc. Graphs would be good. I am making a new cylinder and it would be encouraging to know how the raised port floor is working out for you.

[richban]

Well I have my SP heads. Thank you very much Scott. As I will be machining them for compression and squish and o ring. I was wondering if trying to put a toroid shape in there will be a good idea. I am not sure there is enough meet in the dome to get much on a curve up to the plug.

Also the tape measure showed more of the RGVs short comings. It is very long. 1380. 40mm longer than my NSR. I looks like Mr Suzuki only messed with the chassis when they released the VJ23.

[kel]

looks like Mr Suzuki only messed with the chassis when they released the VJ23.
No, no, no :brick:
The VJ23's motor is different in almost every respect, different angle V config, different bore and stroke, different porting etc etc.

For discussion on after market heads try this link. http://www.apriliaforum.com/forums/showthread.php?140618-head-veronesiracing

Back in the day some people skimmed the heads for production racing, top of the barrell too. But then the chrome flacks so I wouldn't recommend that.

[richban]

No, no, no :brick:
The VJ23's motor is different in almost every respect, different angle V config, different bore and stroke, different porting etc etc.

I was talking about the chassis not the engine. I am well aware of the differences in the complete bike. Also I was not talking about skimming the barrel. I was talking about the head. Maybe I should re-read what I wrote but it seamed straight forward when typing it.

[kel]

I am well aware of the differences ... I was not talking about skimming the barrel ... it seamed straight forward

:lol: It was general banter.

[wobbly]

To do a toroid properly you need to drop the plug tip to approx 6mm from the piston crown.
Means welding the chamber and counterboring the plug seat face.
Very difficult to do repeatable and accurately unless done on CNC.
I model the piston dome and the head shape in SolidWorks to generate a solid then I have an accurate curve the toolpath follows and a calculated volume.

[F5 Dave]

The SP heads (from the 2secs I held them yesterday) are very shallow large radius chambers like a new moon slither. Never seen heads quite that shape, certainly unlike std (though memory of std RGV head much more foggy, but sure it was taller & on-the-piss plug position).

Would be interesting to throw a plug in & see how low it goes to a flat surface.

I've made templates out of Kneedit (pushed in a chamber & sectioned) I want to replicate, but to do two the same for a twin would be too hard for my lathe skills.

[richban]

To do a toroid properly you need to drop the plug tip to approx 6mm from the piston crown.
Means welding the chamber and counterboring the plug seat face.
Very difficult to do repeatable and accurately unless done on CNC.
I model the piston dome and the head shape in SolidWorks to generate a solid then I have an accurate curve the toolpath follows and a calculated volume.


I will apply the K.I.S.S rule to this one. Sp head will stay normal shape.

I might try it with the old heads. From what I can see they are the same casting, just plug location is different.


Wobbly did you mess with the RS chassis much on the 400 project? From what I have read so far they seem a little lazy in the front like the RGV. I have not riden one yet so can't comment from personal experience.

[richban]

I want to replicate, but to do two the same for a twin would be too hard for my lathe skills.

I have done a little solid modelling before so might try that and employ Sketchy's skills and his great little CNC setup. I will post a pic of the heads later.

[wobbly]

I fitted shorter dogbones, that helped make room for the fat pipes, and the big Marchesinis and slicks lifted the rear a heap.
Plus Andys one has CNC tripples holding the RS250 2006 forks with less offset that dropped the trail as well.
The slow steering isnt surprising as the whole bike is so close to a sexed up RGV its ridiculous.

[Flettner]

richban, we can CNC from a solid model too. We have done quite a few for Wobbly.
Autoflight Ltd
07 824 1978

[Frits Overmars]

.. tripples holding the RS250 2006 forks with less offset that dropped the trailHuh ?


The slow steering isnt surprisingIndeed it isn't; not when you reduce the offset, which will increase the trail.

[wobbly]

Shit I cant peek sideways at a lesbian without you looking over my shoulder Frits, dead right about the offset number - of course.
Glad someone is awake.

[richban]

richban, we can CNC from a solid model too. We have done quite a few for Wobbly.
Autoflight Ltd
07 824 1978

Great. Good to know who is out there and wanting to work on jobs like this.

[richban]

Huh ?

Indeed it isn't; not when you reduce the offset, which will increase the trail.

Funny. In my head is was the opposite as well. Maybe its a southern hemisphere thing or just people from Tauranga.

Well so far with the RGV project the main focus has been on the handling after riding one on the track. So now the frame will be sent to a secret location to have 2 degrees knocked out of the head stock. Also the swing arm will have a small amount of work so I can run a shorter chain. With bugger all budget this should transform the bike. I plan to run around 25-27mm rear sage and around 38mm in the front. This should have the bike running on track with 84 - 85mm of trail with a rake of 22.5 and shorter by 25mm from the massive 1380 it is now.

Well thats the plan anyway. Not sure what tyres I will end up with yet.

Edit: But the rubber will be stock profiles.

[F5 Dave]

.. . So now the frame will be sent to a secret location to have 2 degrees knocked out of the head stock. . . .
They probably told you they were going to section & weld. They told me about this really sturdy steel beam, about 15kph will sort out a degree, but if you're brave 20k will do a couple:innocent:.

[Frits Overmars]

Shit I cant peek sideways at a lesbian without you looking over my shoulder Frits, dead right about the offset number - of course. Glad someone is awake.I devour your every word, Wob :msn-wink:

[wobbly]

If I could stand up, you would be keeping me on my toes.
Thanks for the help.

[richban]

To do a toroid properly you need to drop the plug tip to approx 6mm from the piston crown.
Means welding the chamber and counterboring the plug seat face.
Very difficult to do repeatable and accurately unless done on CNC.
I model the piston dome and the head shape in SolidWorks to generate a solid then I have an accurate curve the toolpath follows and a calculated volume.

Some pics of the Heads.

Somebody has had a go at one and machined one wonky then stopped. The other one is untouched but has big pits in the squish area. Should be fine after skimmed and squish machined in.

There looks like quite a bit of meat in the casting. Plug tip looks like is in the correct place already (The piston crown will be flush with bore). What do you think Wobbly?


285578285579285580

[wobbly]

Yep, looks fine.
The flat squish area should have 0.1mm taper upwards from the bore edge.
As I found the piston will clip the inner edge first when the vertical gap is at the mechanical limit for the rpm.
This is the sort of shape you are after.

[richban]

Yep, looks fine.
The flat squish area should have 0.1mm taper upwards from the bore edge.
As I found the piston will clip the inner edge first when the vertical gap is at the mechanical limit for the rpm.
This is the sort of shape you are after.

Fab. Thanks once again. Now time to try model it up.

[F5 Dave]

What sort of gas will you run? Comm ratio expecting to run?

[richban]

What sort of gas will you run? Comm ratio expecting to run?

Avgas. Not sure, Whatever keeps the Squish velocity under the number Wobbly gave me. Going around in circles at the moment.

Looks like before I can design my head I need to figure the exhaust port timing. I had a play. Squish band width is 8.5mm and 0.75 squish. I need to measure up the heads again to see how much I need to machine of the top to get the inner dome diameter small enough. Now I see why so many people use inserts.

Learning all the time.


285597

[Neal]

What squish area ratio are you aiming for ?

[136kg136ps]

Wob,would that 6mm plug tip to dome figure hold true in any bore size?

[richban]

What squish area ratio are you aiming for ?

50% at this stage.

[wobbly]

You dont really need the Ex timing to establish the head geometry, and yes the 6mm number seems to work with most " usual " combustion chamber geometries.
Avgas works with anything from around 192 to 202 Ex duration at around 15.8 full stroke.
Smaller bores or lower bmep setups can go 16.2, big bore oversquare or very high bmep like slightly less at 15.5, air cooled of course needs alot less.
As long as you hit the lower mechanical squish depth limit, then adjust the width to hit 38M/Sec MSV you will have good squish turbulence that helps the flame speed - reducing any tendency to deto
the end gasses.
That MSV number is meaningless in the context of all but hitting the head when within the normal rev limits, but as a guide it works every time.
The sharp bowl edge increases the flame speed, and a very deep angle away from that edge into the bowl is synergistic by pulling the turbulence further into the combustion space, again increasing the flame propagation speed,
over a wider band.
Pushing the combustion parameters this hard means a digital ignition is mandatory to balance the timing against the high peak cylinder pressure now being generated.

[G Jones]

As long as you hit the lower mechanical squish depth limit, then adjust the width to hit 38M/Sec MSV you will have good squish turbulence that helps the flame speed - reducing any tendency to deto
the end gasses.
I wonder if you would mind telling the method for working out the " lower mechanical squish depth limit" ? - is there a simple rule for that - or is it much more complex ?
Thanks :niceone:

[wobbly]

No free lunch today except that its all been done before and in most cases a guide is available.
It depends upon the stroke length, the piston weight and the crank integrity.
Suffice to say that a 125 single will usually go down to 0.65mm when spinning to 14000
A 250 twin like the RGV with a single middle bearing will go 0.75 spinning to 12,000
A 250MX type with 72mm stroke is OK at 1mm spinning to 11,000.
But I stress again, as I dont want the Honda faggots off their forum abusing me that the NSR wont rev if taken below 0.8mm - the ignition has to be optimised
to work with a combustion chamber that is designed correctly, and does actually do what its supposed to.
A stock PGM simply wont cut it - but then we wont be using HRC parts, so they just cant be any good at all, as everyone should realise.

[G Jones]

Honda faggots off their forum abusing me that the NSR wont rev if taken below 0.8mm :eek5: :facepalm: :laugh:
Sorry - couldn't resist that - I'll not be using any H parts now or ever if I can avoid it...
I was just trying to tease out of you what the limit might be for a TZ350 - in this case with a Hoeckle crank (pro-digital Ignition) - we're down at approx 0.75mm at the moment - and it appears to be ok - although I'm not sure if I'm brave enough to take it any further...
The "not free" lunch was pointing in the right direction though...
Thanks.

[richban]

You dont really need the Ex timing to establish the head geometry, and yes the 6mm number seems to work with most " usual " combustion chamber geometries.
Avgas works with anything from around 192 to 202 Ex duration at around 15.8 full stroke.
Smaller bores or lower bmep setups can go 16.2, big bore oversquare or very high bmep like slightly less at 15.5, air cooled of course needs alot less.
As long as you hit the lower mechanical squish depth limit, then adjust the width to hit 38M/Sec MSV you will have good squish turbulence that helps the flame speed - reducing any tendency to deto
the end gasses.
That MSV number is meaningless in the context of all but hitting the head when within the normal rev limits, but as a guide it works every time.
The sharp bowl edge increases the flame speed, and a very deep angle away from that edge into the bowl is synergistic by pulling the turbulence further into the combustion space, again increasing the flame propagation speed,
over a wider band.
Pushing the combustion parameters this hard means a digital ignition is mandatory to balance the timing against the high peak cylinder pressure now being generated.




More fantastic help. Thanks yet again. I have been using this ( http://www.torqsoft.net/squish-velocity.html) calculator to look at the MSV and as a design guideline.

It does want the captive compression that I will not be able to work out until I know the timing. But might just wing it. Was looking at around 15.1. static.


Looks like to get the shape I want without welding up the heads I will have to take around 1.5mm off the top if the head. It will be pushing it. If I feck them up then inserts will have to be made.

[wobbly]

A TZ350 will run 16.2 with a proper toroid as its bmep is pretty low, and can run at 0.85mm spinning to 11200.
Miss a gear and hit 12,000 and the pistons clip the head, this is with one of the good aftermarket cranks, I would stick with 1mm if using the soft Yamaha junk.
These piston port engines love the deto free high com of a toroid, with way better mid power, and the overev comes back with the new ignition retard available from HPI etc.

Work backwards from the trapped com cc used in the program, as you know already what 15:1 is - easy calc = engine cc/14

[Yow Ling]

Rich, Heres the head Wob did for my RGV100 VJ22
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130150762#post1130150762
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130149522#post1130149522

if he has the fixture for boring the head skull maybe it would be easier, if you cock the cc shape its only an inch of brass to fix it

[Neal]

Has anyone done comparison tests for different squish area ratios ? Eg 40% vs 45% vs 50% . Just curious

[wobbly]

Yep, I did that as a job for a cylinder manufacturer in Belgium.
All that the lower MSV does when reduced by narrowing the squish width is to reduce power and increase deto.
You can get a little of the power back by increasing the timing ( offsetting the lower amount of squish induced turbulence ) but then of course you run into even more deto issues.
Pulling the squish depth down to the mechanical limit then shooting for a good MSV number is the end of the story and works every time.
I have had serious flame wars at times with people convinced that "big" engines are completely different, but they havnt even come close to the 70RWHp we used to get from a 250MX on Avgas
in open class karts.

[F5 Dave]

Eek. What sort of revs does one have to spin one out to to achieve that?

[richban]

What a funking lemon. Just started to strip the top ends. Only got as far as removing the barrel on the bottom cyclinder to find 3/4 of a piston and a completely shaged bore. At that point I gave up and am now having a beer thinking of how I should proceed with what is now turning into a complete engine rebuild.

[husaberg]

What a funking lemon. Just started to strip the top ends. Only got as far as removing the barrel on the bottom cylinder to find 3/4 of a piston and a completely shagged bore. At that point I gave up and am now having a beer thinking of how I should proceed with what is now turning into a complete engine rebuild.

The more beer you drink the less shagged it will become. Oddly the exact reverse thing happens with ugly chicks though:argh:

Dare I say 54mm stroke crank and RG150 cylinders or maybe something a little different;)

[richban]

Dare I say 54mm stroke crank and RG150 cylinders or maybe something a little different;)

Tempting. But part of the reason I like these bikes is that fact they are 250cc. If I wanted to go big I would just build 690 single 4 stroke. Still will one day.