ESE's works engine tuner [Archive] - Page 70

NSR143

29th March 2015, 21:02

Toilet or fry pan I couldn't care.
You don't need to explain it, I was there. I saw him go down, I saw him choose not to come in, I saw you guys hand him the trophy. You called it wrong, he should have been black flagged.
Its supposed to be one rule for all Steve. Bad call, very bad call.

If you saw him clearly go down why did YOU not report that to an official? We were unsure of the situation and had to have faith that the rider did the right thing. It is after all a riders prerogative to re-enter for a check and should not require a black flag. As the laps progressed several people questioned the situation but it was still unclear so we allowed him to ride on with a view to a penalty IF at the end of the race it was clear that the bike had gone down. In our view if he had not gone down and we called him in that would have been a lot worse for us. Initially we discussed a penalty of 30 seconds, the steward encouraged a penalty of 20. We had both riders reps, Nathaniel and Dave, 4 race officials and the steward present to discuss the situation and apply the penalty. No situation like this is easy to make a decision on.

Drew

29th March 2015, 21:58

If you saw him clearly go down why did YOU not report that to an official? We were unsure of the situation and had to have faith that the rider did the right thing. It is after all a riders prerogative to re-enter for a check and should not require a black flag. As the laps progressed several people questioned the situation but it was still unclear so we allowed him to ride on with a view to a penalty IF at the end of the race it was clear that the bike had gone down. In our view if he had not gone down and we called him in that would have been a lot worse for us. Initially we discussed a penalty of 30 seconds, the steward encouraged a penalty of 20. We had both riders reps, Nathaniel and Dave, 4 race officials and the steward present to discuss the situation and apply the penalty. No situation like this is easy to make a decision on.

This is the wrong thread for this guys.

Drew

29th March 2015, 22:06

This is the wrong thread for this guys.

So I've started one.

fatbastd

30th March 2015, 17:03

The door opened both ways when you had the use of one of the bikes !!

Well spotted James. I stand corrected: the door does sometimes work both ways! Was thinking rather more in relation to Yamahas...

Bring more bikes out!

twotempi

31st March 2015, 11:29

Well spotted James. I stand corrected: the door does sometimes work both ways! Was thinking rather more in relation to Yamahas...

Bring more bikes out!

Up to now there was little point as 125's and 250's got lumped in with the 1300 Mac trucks.

But now the Classic Club is running a "Group 3" which is 72 Juniors, 72 & 82 250's, and 72 & 82 125's which are a lot more compatible.

Had 25 on the grid at the festival ( more than the 89/82 Seniors and 89/82 Juniors combined !! ) with more people interested so expect this number to increase.

And yes, the Yamahas will be there next year.

Also some buckets may be eligible and would be most welcome.

fatbastd

31st March 2015, 16:35

Excellent. Good effort. Encouraging. Will get the TA sorted then!

TZ350

31st March 2015, 18:21

The Classic Club is running a "Group 3" which is 72 Juniors, 72 & 82 250's, and 72 & 82 125's. Also some buckets may be eligible and would be most welcome.

What would the fuel rules be? any possibilities for 2T Buckets and methanol? .... :D

twotempi

31st March 2015, 20:10

Fuel rules are Race/Avgas petrol ( NO nitromethane Robert !!!! ) however methanol may be used for the following classes

1) Pre 72 and pre 82 Four-stroke

2) Pre 72 Two-stroke

If you have pre 82 two-stroke you are stuck with petrol.

Later than 82 would fall into the pre 89 group and I doubt it would be worth considering going there .

F5 Dave

1st April 2015, 06:18

Rules often seem to be a bit anti about fuel additives. . . such as premix oil if taken as written.

TZ350

1st April 2015, 07:21

Rules often seem to be a bit anti about fuel additives. . . such as premix oil if taken as written.

Thankfully that rule in Miniature RR that prohibited Alcohol and Fuel additives has now disappeared, so you can use all the normally available pump fuels that you can buy at your local petrol station including E10 and Av Gas and also pre mix your oil legally too, makes things much easier. The properties of Leaded and Un Leaded fuel is defined in appendix E and Methanol is specifically banned in the general fuel regulations for most classes of racing including this one and Nitro is specifically banned for all classes.

Dutch Fisher

2nd April 2015, 08:47

Do I mind a bit of peer review? Not at all.
Did I miss your post? No.
Am I interested? Yes.
Can I find the time to discuss the subject? Alas; the racing season has broken out....

I noticed, Qatar was a cracker.

Oh well I won't hold my breath on a discussion. except to say
Error 1: Your 180 deg out on TDC and BDC
Error 2: TBA on further details

Happy racing season everyone!!

ken seeber

2nd April 2015, 11:20

husaberg

2nd April 2015, 13:07

[QUOTE=Dutch Fisher;1130847802]Oh well I won't hold my breath on a discussion. except to say
Error 1: Your 180 deg out on TDC and BDC
Error 2: TBA on further details
QUOTE]

DF. I just must be too old and too dumb, but where in the hell are you coming from? Actually I don't want an explanation at all, all I want is positive & constructive dialogue.

I think he is Ken.
Pretty sure he is refering to a paper Frits did
I think what the Fisher is suggesting is there is a typo.
Also that he too enjoyed the racing and understands Frits may not have the time at the moment for open dialogue.
Just my thoughts. I don't see it as sarcasm anyway.

Dutch Fisher

2nd April 2015, 20:55

DF. I just must be too old and too dumb,
No, I doubt that

Actually I don't want an explanation at all
Sorry, your about to get one

all I want is positive & constructive dialogue.
This is!

Pretty sure he is refering to a paper Frits did
Nope, purely the posted computer produced graphics pic

I think what the Fisher is suggesting is there is a typo.
Not a typo, a calculation error

Also that he too enjoyed the racing and understands Frits may not have the time at the moment for open dialogue.
Love racing. don't we all and correct

I don't see it as sarcasm anyway.
Not today, come back tomorrow

Here the explanation: Frits has calculated the inertia with variables and values and some mathematics. Looks like the details he has on the RSA125. However there is an error in a sum regarding the trace line vs engine degrees.
The second error is the use of a variable incorrectly applied. I'm 99.8% which one it is, but without the variables and values. I won't be 100%.

How did i get to this result by just looking at a graph : Pattern Recognition (google it and fry your noggin)

Happy Easter everyone

TZ350

3rd April 2015, 10:53

Oh well I won't hold my breath on a discussion. except to say
Error 1: Your 180 deg out on TDC and BDC
Error 2: TBA on further details

Mr Dutch Fisher, sounds like you know a thing or two, it would be nice to see you post some of your own work.

We have learnt a lot from Frits and his posts/pictures and hope you can contribute to that too, probably needs to be presented in simple terms for us with pictures of your own work to illustrate your point .... :)

Dutch Fisher

3rd April 2015, 19:49

Mr Dutch Fisher, sounds like you know a thing or two, it would be nice to see you post some of your own work.

We have learnt a lot from Frits and his posts/pictures and hope you can contribute to that too, probably needs to be presented in simple terms for us with pictures of your own work to illustrate your point .... :)

Tz thanks for your kind words
However you presume too much of me, i know bugger all.

Sadly my work has nothing to do with ICE, you'd be looking at sqwiggles on paper all day long and thinking WTF.

I've learnt too from Frits, Jan, Wob, Francis, even others you wouldn't consider 'tuners'. Like most things in life, you garner opinion, weigh up if you understand what's said, if it makes sense, if its relevant to context, and any negatives to the above, question the source. Some info the these guys know is still commercially sensitive, 2T are not dead yet, so you can understand you may not get an answer directly.

Here's a nugget

Sit down with your fav beverage, close your eyes, and visualize a 2T engine. Start at ignition just before TDC and slowly go thru all the stages of expansion and the forces produced. Think of the action and reaction (3rd law of motion) to the forces on the moving and non-moving parts. In your mind's eye apply the gas force to the top of the piston then follow the chain of force thru the system always with action/reaction in your frontal lobe.

With inertia, gather this nut:

The piston-rod-crank is a drive/driven system (think of this from the point of view of the piston), gas pressure 'drives' the piston which 'drives' the rod which 'drives' the crank and so on.
When the force of gas is spent, the system then becomes 'driven'.
The piston is 'driven' by the rod which is 'driven' by the crank. The driven force is a stored force held in the rotating weight of the crank added during the drive phase. The trace line on Frits' graph is a product of the drive/driven system.

There is a 'give away' as to why the trace is 180* out.

I tell you what boys and girls, anyone want to hazard a guess what that is?

Come on, get those brain cells warmed up

adegnes

3rd April 2015, 19:58

I'm getting ss90 flashbacks

Dutch Fisher

3rd April 2015, 20:01

I'm getting ss90 flashbacks

You better see a doctor about that

adegnes

3rd April 2015, 20:06

You better see a doctor about that

Hehe, sorry, was douchey of me.

bucketracer

3rd April 2015, 21:22

I'm getting ss90 flashbacks

Yep ....... I guess Dutch is going to entertain us with his sophisticated wit and superior cleverness for a while, lucky us. :laugh:

Dutch Fisher

3rd April 2015, 22:01

SS90 vs TZ350

Is that like RUN-DMC vs Jason Nevins but without the music and streetdance

Yep ....... I guess Dutch is going to entertain us with his sophisticated wit and superior cleverness for a while, lucky us. :laugh:

Yeah someone got to balance out your superior thickness #ohthehumanity

seattle smitty

4th April 2015, 03:55

Trust me, welding the cases the main tunnels will be miles out of round and the deck will be warped to buggery.
Just use Devcon F and score the surface and bead blast clean, the stuff will never come out.
If you are really worried you can wind in several self tapping screws that sit up into the epoxy so it cant move even if the surface grip is lost.

Did you ever have the chance to find out whether the Devcon F will stand up to methanol? Nitro?

My notion was that rather than use any major quantity of epoxy alone, when doing major port re-shaping, the safer way would be to use just enough epoxy (and maybe a bolt/screw from the outside) to glue a piece of aluminum into the port, and you'd do your reshaping on the aluminum piece. But I only ever tried this with a pair of little boost-ports that I thought were angled badly. If there's an epoxy that will stand up to fuel, it would save some time and effort by eliminating the need to glue chunks of painstakingly-shaped aluminum into the existing ports . . . .

bucketracer

4th April 2015, 04:04

SS90 vs TZ350

Is that like RUN-DMC vs Jason Nevins but without the music and streetdance

Yeah someone got to balance out your superior thickness #ohthehumanity

Dutch, you were made welcome here by a group of open friendly people, abusing our hospitality is easy to do but does not make you clever ....

Dutch Fisher

4th April 2015, 04:34

... sorry, did you say something dear chap

adegnes

4th April 2015, 04:40

I regret the ss90 remark, would be sad with that kind of situation all over again.
Sorry Dutch, it wasn't called for at all.
Please excuse my ignorance, and let's get back to the meaningful discussion of interesting topics.

richban

4th April 2015, 08:26

Well there are 2 sets of 40mm lectron's on there way for the 300's. The guys at Lectron have been so helpfull. They are machining them nice a skinny so they can sit close side by side. They are also moving things like idle screws so they can be accessed form the outside of each carb. This now means we can make shorter intake manifolds with less bend and carb spacing. This will give lots more room in the air box and adjustability with bell mouth length.

So the plan is looking like a simple spigot type inlet that transitions from the round carb to the rectangle stuffer of the VF3 reeds. It looks like both the stuffer and carb have the same cross section area. I don't know but I figure thats good to keep things moving in an orderly fashion into the reeds. I will post some pics and a bit of a review on the tuning when we have them setup.

crbbt

4th April 2015, 09:48

looking forward to your lectron review before I put one on the RS125

richban

4th April 2015, 09:55

looking forward to your lectron review before I put one on the RS125

Well pending that. I can say, the customer service and enthusiasm is a 10 out of 10. Super helpful guys.

speedpro

4th April 2015, 12:25

Super helpful guys. and here Sir is your bill - $$$$$$$

peewee

4th April 2015, 14:22

Did you ever have the chance to find out whether the Devcon F will stand up to methanol? Nitro?

My notion was that rather than use any major quantity of epoxy alone, when doing major port re-shaping, the safer way would be to use just enough epoxy (and maybe a bolt/screw from the outside) to glue a piece of aluminum into the port, and you'd do your reshaping on the aluminum piece. But I only ever tried this with a pair of little boost-ports that I thought were angled badly. If there's an epoxy that will stand up to fuel, it would save some time and effort by eliminating the need to glue chunks of painstakingly-shaped aluminum into the existing ports . . . .

devcon site says the F putty has a 'fair' rating for methanol. test was 7 day cure and 30 day submersion. inside the engine the exposure should only be a few hours at a time then its purged with gas. so it should hold up just fine. hard to say what will happen with nitro.

remember that low temp brazing rod i was using on them cylinders ? well it works real good in some situations. once you have to put filler in two areas in close proximaty to each other is when you run into trouble. after you get the first area filled and try to heat the second area, the first area of filler starts to melt and you have a mess. i gave it a good effort but it just wasnt possible for what i was trying to do. but for some situations i would highly recomend it. building up the floor of an exh tunell it would work like a charm. decided to buy a new tig welder in the next few weeks for the areas i cant do with the low temp rod. filling in the trenches of the crankcase transfer entries ill probly avoid heat altogether and use devcon f. cylinder ill weld or use a combo of weld and low temp rod. if the welding heat distortes the cylinder alittle i can always just wack a couple thousands off the top and bottom decks to straighten it back up. them bearing pockets in the crankcase will be a nightmare to fix if they get warped so ill stay with epoxy down there

richban

4th April 2015, 15:14

and here Sir is your bill - $$$$$$$

330 US each plus 70 bucks for custom alts. Bargain in my book.

seattle smitty

4th April 2015, 16:53

Haven't forgotten your low-temp rod, Peewee, just waiting to see how it holds up for you. That stuff has a lot of zinc in it, which your base metal doesn't, and in asking around among welding professionals, I haven't found one who likes the stuff. Of course, they are talking about its use for joining metal, not for building up a surface. But some of them have had to spend a lot of accumulated time over the years grinding out low-temp filler metal that was used by someone else, and that didn't hold. So far as I know, none of it has an AWS spec or is certified in any way, and at least here the welding suppliers don't carry it. Now, I'm NOT saying it can't work; it very well might be just fine as you are using it, which is what I'm waiting to hear.

peewee

4th April 2015, 17:17

for something structural like joining two pieces together i dont think i would dare trust the brazing rod. besides the hts2000,durafix, etc, i also have some of the brazing rod from hobart but i havent used it yet. not sure what the difference is between it and all the others i have, maybe its all the same stuff. http://www.ebay.com/itm/Hobart-Low-Temperature-Aluminum-Brazing-Rods-8-pk-1-8in-Dia-Model-770206-/400880760898?pt=LH_DefaultDomain_0&hash=item5d565af842

F5 Dave

4th April 2015, 17:20

So I thought casting ally had zinc in it to help it flow. Old Honda stuff used to look greyer than Yam.

speedpro

4th April 2015, 17:24

330 US each plus 70 bucks for custom alts. Bargain in my book.

Agreed, not bad for custom carbs

jasonu

4th April 2015, 17:53

Agreed, not bad for custom carbs

They are a total bargain at that price (if they work of course).
The way Richban was talking I thought $1000 was about right.

AndreasL

5th April 2015, 04:27

Hi all,

Other duties have keept me away from this thread so I have a lot of catching up to do.

Hope someone can give his thoughts about my matter.

Old piston port 50cc.
"New" after market cylinders are not very accurate but all lines up ok except the inlet port roof.
At BDC both piston rings are below said roof.
The upper edge of the piston sits above the roof by 1.5-2mm.
Put some light to the bore and it's easy to see looking in to the intake.

On one of my other project engines I am messing around with machining the cylinder base, test fit different Pistons etc. This one needs to be more of a simple quick fix.

I hear you say "Make a boost port and fit a reed" and absolutely, it's the sensible solution. For my "real" engine that is.

So, will the edge of the piston seal enough to not let it effect much or anything?

I have not tried but maybe EngMod2T is able to simulate even stupid and bad designs of this sort? For pipes I know to well that bad designs are no problem ;)

Thanks a lot for any ideas.

bucketracer

5th April 2015, 08:18

Old piston port 50cc.
"New" after market cylinders are not very accurate but all lines up ok except the inlet port roof.

At BDC both piston rings are below said roof. The upper edge of the piston sits above the roof by 1.5-2mm. Put some light to the bore and it's easy to see looking in to the intake.

My guess is 1.5 - 2 mm will be enough of a seal but will the rings or ring ends get snagged in the inlet port?

This problem could not be modeled in EngMod.

twotempi

5th April 2015, 09:09

Can you machine 1-2mm off the base of the cylinder to lower ?? You may have to re=do the other ports but as it is the rings will almost certainly snag.

husaberg

5th April 2015, 09:14

Hi,
The outside diameter is 93.5 mm

"I note there seems to be a couple of different styles.
From a triangular early Rotax type to a asymmetrical chamfer an the intake side. and I think one for the 125 single"

:

Francis seeing as we are today on the thread and we are talking about carbs, can I trouble you to share some information on your carburettors.
They look incredibly short in intake length, as well as beautiful

AndreasL

5th April 2015, 11:31

Thanks for the input.

One of the ring openings are really close to the port opening but by turning the piston 180* around it will work.

I have a cylinder with the base shaved of 2.3 mm. That one is not ready yet and made fore slightly longer stroke. If doing the same to this combo the transfer port floor will sit to low etc.

So if we all think 1.5-2mm will seal I will take the easy way out with this one.
More takers are welcome. :)

F5 Dave

5th April 2015, 17:33

Can you machine 1-2mm off the base of the cylinder to lower ?? You may have to re=do the other ports but as it is the rings will almost certainly snag.
Almost certainly as the kawi triples had a bit hanging down for that porpoise.

. . . except plenty of us run centre pegged rings over boost ports. How wide the inlet is would be the deciding factor I guess.

AndreasL

5th April 2015, 18:30

The responsibility is all mine and the rings will work…I say. ;)

So what I'm a bit uncertain about is if ~2mm will seal enough.
As I stand now I say it's worth a go.

Still interested in any thoughts on this matter. Even if just for theoretical reasons.

Thanks.

Lef16

5th April 2015, 20:22

Hello there!This is my first post here although i've been reading this thread for a long time.
Unfortunatelly I'm not able to read all 1000+ pages,so I'm sure I've lost a lot of information.I'm a novice tuner from Greece,mostly working with exhaust pipes.
Untill now I was working with trombone type pipes...before I discover the Aprilia GP style exhaust.I've read what wobbly said about header and diffuser % of the tuned length and diffuser steepest angle placement,but I cannot undertand the trombone pipe(1st dif angle<2nd dif<3rd dif angle) suck action compare to Aprilia type(1st dif<2nd dif>3rd dif),especially for lower rev enines(9500-10500 for example),and the effect on power curve.
Here is an exhaust I designed for a Yamaha 200cc engine for road use,68x57mm,~42-45hp,with almost 30% header and 67% diffuser,small 21.77 pipe to cyl ratio,shallow baffle angle and 935.2mm for ~10000rpm(194* ex).Unfortunatelly my Engmod2T demo has expired long time ago so I cannot run the simulator and see the pressure waves and power curve :angry: I was wondering if wobbly could tell us more about this design and if it was better to use the trombone pipe design.
Sorry if you're tired of reading this and sorry for my English.
Cheers!

TZ350

5th April 2015, 20:33

Unfortunatelly I'm not able to read all 1000+ pages,so I'm sure I've lost a lot of information. and sorry for my English. Cheers!

Your English is a whole lot better than my Greak.

Sorry I don't know enough to help but while you are waiting for Frits or Wob to reply, take a look at page 1000 there is a bit of a directory there that might help you find more info on pipes or anything else that you might be interested in like transfer angles, exhaust duct sizing etc etc.

seattle smitty

6th April 2015, 04:07

Lef16, possibly you are misunderstanding the term "trombone pipe," . . . or maybe I am (anyway, one of us will learn something here). I believe the term refers to an expansion chamber that can be slid in and out, like a trombone, changing the tuned length. This is the universal practice in outboard racing (although we call them "slider-pipes"), but it's a lot harder to accomplish on a motorcycle, sled, kart, jetski, etc. The sliding section is (except in some old karts) in the header area close to the cylinder. The trombone pipe(s) could have any number of diffuser sections, any number of baffle cone stages. The point is that it slides in and out, usually over a roughly 10cm range.

(Now we'll see if the others agree with my use of the term . . . .)

TZ350

6th April 2015, 07:48

(Now we'll see if the others agree with my use of the term . . . .)

Looks good to me, and here is a YouTube vid Frits posted some time ago.

<iframe width="560" height="315" src="https://www.youtube.com/embed/mvV4xbFKs0g" frameborder="0" allowfullscreen=""></iframe>

Trombone pipe

Follow the links for more on trombone pipes.

I am very taken with the Trombones possibilities and after using EngMod2T to simulate it.

oh got that wrong more than usual.......:clap: can't find the post either ROB but found these.........

Lef16

6th April 2015, 09:26

As I said before,my English is not perfect.By trombone I meant the typical-header -> 3stage diffuser where every diffuser has steeper angle than the previous part-2 stroke pipe.
Anyway,I think wobbly or Frits understood what I wanted to say and I'm waiting for their answer with suspense!!
Cheers :msn-wink:

husaberg

6th April 2015, 13:22

False. A better descrition is given in the second page that Husa posted above. In case you missed that: each gear has its own centrifugal clutch, and all gears except the highest gear have unidirectional freewheels (called dog-bone clutches because of the shape of the locking elements in them) so they can be overriden by a higher gear.

No news about the FOS cylinder, except that everything takes way more time than it should.
The trombone pipe works a treat and the sealing is bullet-proof now, but with a six-speed gear box you hardly benefit as far as lap times go. On our kart tracks fewer gears might actually yield better lap times; Richard Maas is investigating that now.

Just been re- reading and couldn't help but wonder if the system is fully functioning, did anyone solve the sealing issue of the sliding surfaces.

Further with the aprilia RSW / RSA exhaust port, the exhaust stub fitted to the barrel is approximately 40mm long and roughly has an internal diameter of 43mm, the port shape within the barrel is not round leaving a large step upon the upper and lower surfaces, how,why what is going on here ? I'm aware this is common to several engines but I have never spent the time to ask myself as to what may be the reason for this, I can only imagine there must be a good reason for this but I'm unable to think of one

With a variable header length you do not need to artificially raise the exhaust gas temperature, so you need neither the power jet nor the ignition retard.
The 50 cc engine with trombone pipe that I wrote about some time ago, runs strongly from 7,000 to 17,000 rpm without power jet and ignition retard.

Note: the power jet in the Aprilia RSW / RSA is gradually closed and the ignition is gradually retarded till 10° before TDC. These engines rev to 14,500 rpm. But I am convinced that with a trombone pipe they would function much better still.

I am very taken with the Trombones possibilities and after using EngMod2T to simulate it, it looks like the Trombone is much better at extending a pipes upper range than plumping up the lower part of the torque curve below the pipes natural operating point.

So if you have an engine with a pipe good for 13K and a mechanical limit of 14 then its not much point in making a 13K trombone that can run 6K from 12 to 18.

After looking at the EngMod simulation results I think it makes better sense to discard my 13K pipe and design a pipe that’s a strong torque monster at 8K with the trombone effect extending its range out 6K to the engines 14K limit.

268214

That’s the approach I am going to take when I make one of these for Beast-2.

A trombone and power valve combination would be even better.

More news from Richard Maas. Did his trombone pipe give the desired results? O yes. At 10,000 rpm it gives 4 HP more than the same engine with a fixed pipe. It runs over 17,000 rpm without the need for a powerjet and with a fixed ignition timing. It is miles better than an engine with an exhaust power valve. And the mapping of pipe length, ignition timing and powerjet pulse width has yet to be carried out. Maybe the powerjet can disappear altogether.
Only problem so far: the piece of pipe that is fixed to the cylinder, is shrouded by the pipe that slides over it, so it gets very hot. Too hot for the Viton O-ring that is taking care of sealing. Any bright ideas, anyone?

As I said before,my English is not perfect.By trombone I meant the typical-header -> 3stage diffuser where every diffuser has steeper angle than the previous part-2 stroke pipe.
Anyway,I think wobbly or Frits understood what I wanted to say and I'm waiting for their answer with suspense!!
Cheers :msn-wink:

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130454469&highlight=richard+maas#post1130454469

wobbly

7th April 2015, 08:02

Here is a WR200 pipe used with a 196 Ex, simmed at around 78 crank Hp @ 10250.
The pipe that was posted has a too short and too shallow header length, and isnt fat enough to get a good diffuser action.
The two stage rear does nothing of any use I can figure out.
A nozzle on the front end needs to start at around 75% of the port effective area, with the header starting at 100%.

F5 Dave

7th April 2015, 08:17

Sorry? How many HP?

wobbly

7th April 2015, 08:44

Yes, not a typo - and translated into a real 67RWHP on a DynoJet.

Lef16

7th April 2015, 09:11

My setup is 194* ex,boost ports to open 87 atdc,125* main tr,128* secondary and boost,14.5 compression ratio,also the YPVS will be disabled.
Wobbly,does the power band in your engine starts at 8000rpm?
I designed this exhaust for public street daily use,with long power band,thats why the shallow header and thin pipe,and also because of a little bit crap transfer ducts.Shall I try your exhaust with my setup?
What if I try a Blair type or a modern(according to engmod) pipe?
Cheers!

jasonu

7th April 2015, 09:14

wobbly

7th April 2015, 09:44

That was a big bore for drag racing engine.
The pipe is designed to work with all the other components and cant simply be fitted to any old WR200 and work correctly.
Blair or "modern " derived pipes in EngMod are simply a place to start, get the full code and start learning what does and doesnt work well.

Lef16

7th April 2015, 09:58

I thought that only here in Greece wr200 engines or moped engines with wr200 crank/cyl(73 or 74mm) were tuned for drag racing :D
Anyway,what about this design for public road use with a wide power band?I don't think my crap transfers will work with a very fat pipe.

F5 Dave

7th April 2015, 10:02

Would seem to be a considerable improvement on, say 1/2 a CPI RZ400. I remember Chris Sayle thinking about trying to find a couple or WR barrels with the notion trying to fit to Anstey's TZ.

wobbly

7th April 2015, 10:19

The CPI cylinder is hamstrung by the 102 bore centres of the RD/RZ cases, the WR has super swoopy transfer ducts by comparison.
That later pipe is better, but the header is still too shallow, and the basic design is derived from a full noise road racing type pipe.
To get a wider range the final diffuser needs to be the steepest, as having the steep mid diffuser helps to put the max BDC Ex port depression
earlier in the cycle - increasing the overev power.
Not what you want in the application.

husaberg

7th April 2015, 17:03

The guy that did the American tzr400 or whatever it was mentioned WR200 as it I think had aux exhaust ports.

Hi Guys
It was one of those projects where the guy came to me wanting to put a big bore job on his stock barrels. My thinking was that a lot of the big bore kits I have seen end up not making much of an improvement in the peak horsepower without LOTS of work. I started looking around for some cylinders to use that were already a bigger bore. That is when I found the DT 200 cylinders and after looking at one I thought that I could get two of them on the TZR 250 lower end. I would have liked to use WR 200 cylinders with the triple exhaust ports but they are a lot harder to find. The crank was stroked to 56 mm and 110 mm were installed. I did some dyno testing with a DT 200 lower end and was able to get 40 horsepower and a nice spread of power with the power valve. I know that the stroke on the DT was 1 mm longer but I thought it would give me at least a good indication of what the twin would be like. It wasn't to far off even though the guy didn't want to have me build a set of pipes like the one I used on the dyno and he decided to use the Jolly Motos that he all ready had. I didn't do much porting on the cylinder just a good clean up. The reed valves are for a Blaster and the carbs are 34 mm flat sides. I made a head for the DT that uses replaceable combustion chamber inserts. When I built the twin I made a head for it also. Makes it easy to try different combustion chambers or repair it if there is something damaged. I order to get the cylinders to fit on the lower end I had to cut the sides of the cylinder and then weld up the holes that appeared. Linking the power valves together took me a while to figure out. What I ended up doing was making a piece that fit into each end of the power valves and making a stud that went all the way through both power valves to hold every thing together. I made the stud out of drill rod and so far it has held up fine. That is most of the info and if you have any questions let me know and I will try and answer them. One other thing that I forgot to mentioned is that I have actually built two motor that were kind of similar. The other one the guy wanted to use big bore Athena TZR 125 cylinders. The guy went through some teething problems with the plating on the Athena cylinders. I don't think that the guy with the Athena cylinders ever pu tit on a dyno that I know of. Both of the motors used a Zeel ignitions.

Gary :yes:
http://www.rzrd500.com/500phpBB3/viewtopic.php?f=3&t=7172&sid=b9e9abbf81c701d9d4a54f785a728344&view=print
TZR250's are case reed and I guess the centre's are much wider that the Banshee
They also have a 50.6mm Stroke

Would seem to be a considerable improvement on, say 1/2 a CPI RZ400. I remember Chris Sayle thinking about trying to find a couple or WR barrels with the notion trying to fit to Anstey's TZ.

From memory someone tried a tz v twin big bore with Dt200 or something bits, I think it was Ansteys, pretty sure Kicka or Grumph posted something about it.

Oh it was You Dave Grumph and Kicka

A mate was looking at building a 400 twin from a (think it was his old B model) TZ back in the day (for Anstey) in a similar fashion, but it never really got past planning stage.

Yeah, you must have an eidetic memory, W. That TZ when it was sold was probably the best in NZ....but it went downhill quickly.

If the present owner of the barrels can find a V twin TZR, there's an F3 bike to fit the current regs. And there are aftermarket pistons available for the 200 which weren't about at the time the barrels were done.

PS you must go into a lot of sheds too......

I will suggest it to him, Brian still had the barrels a while back , although the 3XV V Twin goes for silly money if you can find one

Last i heard Brian was working in Akl....but his son had started junior MX. At the speed he does projects the boy may be old enough to ride it if it ever gets done.

I have a memory of Mark telling me Antspiss had asked him what was involved - and being severely discouraged when he was told how much work it took.
These two were unusual in that they had the TZ bits, enough money, enough time,the right equipment and motivation...
The motivation was to show the "diesel tuner" - me - that they could do it and it would work. All I had to do was taunt them occasionally that it would never run....

ken seeber

7th April 2015, 23:43

jasonu

8th April 2015, 02:11

senso

8th April 2015, 06:01

Here’s one for you rule interpreting guys.

Taking the NZ Bucket rules, where it states “Engines must be derived from non-competition motorcycles,” could someone:

a. Extreme ask. Melt down a non competition cylinder, eg a H100 or Suzuki A100 and cast an entirely new design cylinder with that molten material?
b. Less than extreme ask. Completely remove the guts of an appropriate cylinder, probably water cooled, and refit an entirely new internal port set and cylinder arrangement, the external sort of resembling the original?
c. Mild ask. Remove the CI liner and then fit a plated aluminium liner?

The cylinder must be from the same model/brand of the engine that it is bolted on?
Is there an age limit for the cylinder?

Do what a lot of people on Portugal do, grab an Rotax cylinder(from an Aprilia RS 125, road legal, so its okey), the thing is that you guys also have capacity limits, but over here there are lots(more than 10) yamaha dt lc 50 base engines with rotax 122 and rotax 123 cylinders, there is at least one that has the 160cc Polini kit for the rotax engine, there is one vespa 50s getting one(but that one is based in some quatrini crankcases, but none the less, its just a mather of time before someone slaps a rotax cylinder in some old original vespa 50s crankcases).

Grumph

8th April 2015, 07:38

Here’s one for you rule interpreting guys.

Taking the NZ Bucket rules, where it states “Engines must be derived from non-competition motorcycles,” could someone:

a. Extreme ask. Melt down a non competition cylinder, eg a H100 or Suzuki A100 and cast an entirely new design cylinder with that molten material?
b. Less than extreme ask. Completely remove the guts of an appropriate cylinder, probably water cooled, and refit an entirely new internal port set and cylinder arrangement, the external sort of resembling the original?
c. Mild ask. Remove the CI liner and then fit a plated aluminium liner?

Ken - over the years plenty of cylinders have been cast for buckets in NZ, mostly water cooled. On a set of cases originating as a road bike , no problems legally. Personally, i've never seen a motor with home made cases and road based cylinder but this would equally satisfy the "non competition" requirement.
Both cylinder and cases home made....well even with a road crank, dubious at best.
One rule that is conspicuous by it's absence here is the aussie requirement for road frames too, hence the use of early RS frames as they went through a period of being cheap and available...

Flettner

8th April 2015, 08:30

Anything is legal, so long as you don't get caught<_<

Actually the rule was ( is? ) so long as you make it yourself it's within the rules, cases, cranks, gearboxes, cylinders etc.

F5 Dave

8th April 2015, 09:22

Its all just a jolly shame that the Japanese et all didn't continue with the 70s trend of making 100cc versions of the 125s & the cry for cheap commuter bikes kept them pouring into the country so we were left with lots of NSR/TZR/RGV/Mito 100s to play with.

peewee

8th April 2015, 11:08

hey guys does anyone have info on these carbs ? like a model number/name or what bikes they might of been standard equipment on so ill know where to search. they look perfect for a project i have but couldnt find anything that looked like them from a google search. it appears to say mikuni on the side but other than that im stumped

F5 Dave

8th April 2015, 11:13

Plain old RGV (or RS250 Aprillia). Come in a few sizes 26, 32, 34 in same body. Can be bored to 35ish. Some models have solenoids for emissions.

peewee

8th April 2015, 11:16

mikuni RGV is the model name ? im asking because ill look through ebay and such but without a model name i may not get very far

F5 Dave

8th April 2015, 11:22

Suzuki RGV250 was bike fitted to (as Aprilia RS250 uses the RGV engine).

peewee

8th April 2015, 11:46

thnx mate i found some. so if they all use the same body/slides/floatbowl etc, then the only difference is the larger ones were bored at the mukini factory ? if thats the case then couldnt the 26 be bored to 35 since the body would be the same or am i missing something ?

2T Institute

8th April 2015, 12:57

There is no 28mm RGV mikuni only 32/34mm which is the same body, the 28mm is from a TZR 250 and isn't the same type of carb. DT 200 also uses a 28mm, the 30mm off a WR200 is very rare.

peewee

8th April 2015, 13:20

ok from my little bit of research just now, it appears most or maybe all the rgv250 used the mikuni TM34S carb, which i assume is a 34mm. for what ever reason the parts fishe shows some bike models had a flex tube idle screw on both carbs and some only had the flex tube screw on one carb with the other carb using a standard screw and jam nut. perhaps the carbs are the same other than the idle screw assembly, far as i can tell anyways. i think a pair of these carbs should work just dandy

peewee

8th April 2015, 13:36

hmm i found this spec sheet. maybe the early bikes had 34mm carb and everything after '92 has 32mm. http://www.motorcyclespecs.co.za/bikes/Suzuki%203.htm

F5 Dave

8th April 2015, 13:40

The earlier vj21 had 32 and the vj22 had 34 although jap home models differed.

A mate has a vj23 (96) but can't quite remember what carbs it has

F5 Dave

8th April 2015, 13:45

There is no 28mm RGV mikuni only 32/34mm which is the same body, the 28mm is from a TZR 250 and isn't the same type of carb. DT 200 also uses a 28mm, the 30mm off a WR200 is very rare.
Ahh ok but the RG150 runs that body effectively an RGV 125 but not quite. Has a crazy offset 26mm. In same body as 34. No one in street stock class ever fitted one. Much.

I've bored a 32 to 35 from both sides and a dremel tickle in middle. Plus shorten the lid to get the travel.

KR250 tandem has smaller 28s like TZR but without pj.

RomeuPT

8th April 2015, 13:49

The cylinder must be from the same model/brand of the engine that it is bolted on?
Is there an age limit for the cylinder?

Do what a lot of people on Portugal do, grab an Rotax cylinder(from an Aprilia RS 125, road legal, so its okey), the thing is that you guys also have capacity limits, but over here there are lots(more than 10) yamaha dt lc 50 base engines with rotax 122 and rotax 123 cylinders, there is at least one that has the 160cc Polini kit for the rotax engine, there is one vespa 50s getting one(but that one is based in some quatrini crankcases, but none the less, its just a mather of time before someone slaps a rotax cylinder in some old original vespa 50s crankcases).

Já são tantas? Fogo, que brutos :/

And then they drag race on open 50cc class :weird:

koba

8th April 2015, 14:41

I think the carb is a Mikun VDxx?

I.E. VD32

There are quite a lot of differences across the models, I think the one from the RG150 is a 28 and is offset.
The slides vary in height (Not just cut away angle) and the 28 has a different needle jet arrangement to the RGV ones I have got.

The RGV 32's should be dirt cheap as people upgrade to 34's.

It think various models have many variations with powerjets, solenoids etc.

F5 Dave

8th April 2015, 16:14

Before getting too excited the solenoid are an air bleed not a PJ snd. 28 then I stand corrected.

Muciek

9th April 2015, 04:25

I have 2 of them 34mm's and each one is different. One does have amixture screw but no Powerjet passage (not drilled)and 2nd one does have powerjet but instead of having mixture screw it have additional jet in front of the body. One had MJ290 and 2nd (with PJ) MJ190.

adegnes

9th April 2015, 05:17

So, after punching through to the cylinder studs in numerous places while trying to cut somewhat decent transfer and exhaust ducts into my cheap airsal scooter kit, I got fed up, scrapped it and went looking for something less annoying to work with.
The EMOT cylinder is out of the question, just can't justify the price for my use(read girlfriend would kill me), same with the newer ktm sx50 topend.

Found the iame m50.
http://www.chi-motos.de/gambio/product_info.php?info=p1241_iame-cylinder-minimoto-50cc.html

Looks promising indeed!
On the downside it has a cast iron liner but that also makes for easier porting without the constant fear of flaking nikasil. It's not terribly expensive either.

310632310633310634310635310636

Here's a dyno run, performed by someone called "V-man Racing" from sweden, rw hp with the engine mounted in a minimoto.
http://www.minimotoscene.co.uk/forums/showthread.php?58120-New-IAME-Engine-by-Parilla
310637

The peak rpm numbers and graph doesn't match up, don't know what's up with that, either way it looks pretty impressive for an out-of-the-box fifty.
edit: the graph and numbers do match, I was just reading it wrong...
Am I right in thinking that with a pipe better optimized for peak power, sacrificing the massive powerband/overrev, and maybe paired with a rotary inlet and a bigger carb(suited for someone with a variator=me), this could really be something?

I'm exited, ordering one as soon as I can afford it.

senso

9th April 2015, 06:38

adegnes

9th April 2015, 06:59

There are also nicasil versions of that cylinder, available for as low as 50€, but I would have more "faith" in a cheapish iron liner than in the nicasil plating of a 50€ cylinder.

Seems like a baby rsa, so cute :baby:

What!? Where are these 50€ copies you speak of?

Yeah, I'm with you on the more faith thing.

Haha, I apparently "blogged" this reply to...

adegnes

9th April 2015, 07:28

Those things on the exhaust side of the water jacet are optional coolant fittings btw.

Attached a pdf from the manufacturer of the bike the engine is fitted in "Blata Ultima", backing the dyno figures.

Edit: oops, that pdf is of Blata's own engine, not the IAME. They are claiming 12kw@11500 from the 2015 model.
http://shop.goped-scooter-tuning.de/epages/15355238.sf/en_US/?ObjectPath=/Shops/15355238/Products/050509-1

senso

9th April 2015, 07:56

I think this is the cylinder, but yeah, its not a 50cc, its a 40cc cylinder, a friend of mine sent me some pictures and it is sort of a mini RSA cylinder and it seems to have enought meat to bore out to 40mm(for 50cc), so, no really related to that IAME cylinder.
http://shop.goped-scooter-tuning.de/epages/15355238.sf/en_US/?ObjectPath=/Shops/15355238/Products/010616

adegnes

9th April 2015, 18:13

The username "sb07" is popping up on various minimoto forums, I think he's posting here to, maybe he can shed some light on the subject.

husaberg

9th April 2015, 20:23

The username "sb07" is popping up on various minimoto forums, I think he's posting here to, maybe he can shed some light on the subject.

He's on Pitlane.

dark art

10th April 2015, 13:12

The EMOT cylinder is out of the question, just can't justify the price for my use(read girlfriend would kill me), same with the newer ktm sx50 topend.

After comparing several 50cc cyinders, including the IAME one, the ktm was the cheaper cylinder!
Is not so expensive as most people think, directly from KTM.

Flettner

10th April 2015, 14:22

Off topic but, there was some discussion a while back on nikasiling LM13 alloy. It would seem no problem, plates well.

136kg136ps

11th April 2015, 00:17

Smokers are everywhere, this is yesterday in Ponte Vedra Beach Florida.These guys fly up and down the beach and on Christmas dress up as Santa and drop bags of candy.

RomeuPT

11th April 2015, 14:15

So, after punching through to the cylinder studs in numerous places while trying to cut somewhat decent transfer and exhaust ducts into my cheap airsal scooter kit, I got fed up, scrapped it and went looking for something less annoying to work with.
The EMOT cylinder is out of the question, just can't justify the price for my use(read girlfriend would kill me), same with the newer ktm sx50 topend.

Found the iame m50.
http://www.chi-motos.de/gambio/product_info.php?info=p1241_iame-cylinder-minimoto-50cc.html

Looks promising indeed!
On the downside it has a cast iron liner but that also makes for easier porting without the constant fear of flaking nikasil. It's not terribly expensive either.

310632310633310634310635310636

Here's a dyno run, performed by someone called "V-man Racing" from sweden, rw hp with the engine mounted in a minimoto.
http://www.minimotoscene.co.uk/forums/showthread.php?58120-New-IAME-Engine-by-Parilla
310637

The peak rpm numbers and graph doesn't match up, don't know what's up with that, either way it looks pretty impressive for an out-of-the-box fifty.
Am I right in thinking that with a pipe better optimized for peak power, sacrificing the massive powerband/overrev, and maybe paired with a rotary inlet and a bigger carb(suited for someone with a variator=me), this could really be something?

I'm exited, ordering one as soon as I can afford it.

Very low port and almost 17hp out of the box, impressive!

peewee

13th April 2015, 13:38

TZ350

13th April 2015, 18:14

More EFI

That unleaded 96 is bad stuff, I had been using AvGas on the dyno, and filling the workshop with smoke, with no problems but swapped to 96 to save some coin. After 20 - 30 hours work sucking 96 fumes I got real sick and have not been able to do any dyno work for a few weeks now.

Other guys at work who did a lot of petrol station gas compressor service jobs say they experienced much the same when the country changed to unleaded. Leaded AvGas is not great but 96 with its aromatics and toluene are even worse I think, from a health point of view E85 (mostly Ethanol) would be my pick of fuels to work with.

On the dyno it was relatively easy to set the EFI for WOT (main jet) runs but the lower throttle settings have been hard to get right on the dyno. The load experienced by the bike from a rolling road dyno is just not the same as riding it on the road, the engine does not react the same way on the dyno.

So the answer is to ride it, and the other day I got a small laptop (notebook??) computer from surplus traders that sits nicely on top of the tank.

310757

On the Alpha-N map screen there is a yellow highlight marker that indicates the current active cell on the map. The plan is to get out into the fresh air and ride the bike around quietly to find the bad spots in the map and adjust them. The Ecotrons software allows you to make adjustments on the fly.

If it was a car you could have a friend drive while you tuned the EFI system but with the bike I will have to stop to make changes. Anyway I did a little test ride tonight and the idea looks promising.

chrisc

13th April 2015, 18:20

I like your style doc

http://media.giphy.com/media/qSTSnzuVr0SU8/giphy.gif

speedpro

13th April 2015, 18:42

I wonder if the rules about texting and driving cover tuning your EFI and driving. Probably not as who would have thought?

I see it still as a moving target unless you can keep a more or less steady state and monitor numbers.

I may be able to use an inertia dyno which has a monster disc brake fitted. Just need to make a big bracket to mount the bike rear axle, dyno sprocket, and some chain. Then I'll be able to hold certain load and rpm points and monitor the lambda. Further investigation this weekend.

speedpro

13th April 2015, 18:46

hey guys has anyone tried mounting some plastic inserts into the voids of a rz style crank ? seems like it would be easy enough to do, anybody know what type of plastic material the manufacturers use ? ktm been using that plastic stuff for sometime but i dont know what it is. it may need a very long rod to recover the lost volume. maybe 125mm rod or perhaps longer, which would bring on another hurdle because the lower rod pin on them long rods is bigger. thats one thing i always hated about these twin cranks is the huge voids between the crank cheeks

I've seen where carbon fibre was used. A couple of screws were placed in each face and carbon string wrapped round them. Blanks were fitted where the CF was not wanted, then each wheel was placed in a mold and the glass poured in. A vacuum was applied to extract any air and once set each wheel was removed and finished off. Assembly was as usual. As far as I know it's been problem free.

wobbly

13th April 2015, 18:47

UHMWP is the stuff to use for filling the crank, with Csk screws thru into threaded holes in the wheels.
But in the RZ/Banshee I believe the positive effect of the long rods of increasing the case volume would not be helped much by
" smoothing " the wheel shape, as they then also decrease the case - ruining more than helping.

Frits Overmars

13th April 2015, 22:11

hey guys has anyone tried mounting some plastic inserts into the voids of a rz style crank ? seems like it would be easy enough to do.Fitting inserts to smooth the wheel shape will reduce the crankcase volume, reduce the stirring that homogenizes the fuel/air mixture, shroud the big end bearing from that mixture, and introduce the risk of the inserts coming loose. Are you sure you want any of this?

ken seeber

13th April 2015, 23:32

Fitting inserts to smooth the wheel shape will reduce the crankcase volume, reduce the stirring that homogenizes the fuel/air mixture, shroud the big end bearing from that mixture, and introduce the risk of the inserts coming loose. Are you sure you want any of this?

Jeez Frits, that just adds a whole new meaning to the term "get stuffed" :killingme

Martin1981

14th April 2015, 00:18

husaberg

14th April 2015, 01:08

But if the engine NEEDS the smaller crankcase volume? And the rsa engine also has smooth crankwebs that do not help stirring?:confused:

Edit: okay, if ANY engine needs the smaller crankcase volume? the banshee engine obviously doesn`t need it.

With the RSA/ RSW Most of the volume is concentrated in the transfer ducts. Then there is the volume inside the piston of course, and the 1 mm shear-avoiding clearance at all surfaces of the crank.
But that is not nearly enough volume. If you take another look at the Aprilia crank below, you will notice that the space between the crank webs is the same as the space needed for the big end bearing. In other words: the crank webs have flat insides, good for another 60 cc or so, if I remember correctly.
310767
Additional benefits: the con rod has an easier time pushing the mixture aside as it moves between the webs, and the big end bearing gets a lot more cooling and lubrication because it is not shrouded in any way.
Because there are no overhung bobweights, the crank webs are stuffed with tungsten to get the balance factor right.
In the RSA125, the con rod was lengthened from the RSW's 115 mm to 120 mm to create even more crankcase volume.

The paddling is a mixed blessing; it creates aerodynamical drag but it also greatly improves the homogenity of the mixture.
Smooth, full-circle crank webs have the advantage that there is little mixture hiding in nooks and crannies. An example of it's importance: in a certain engine there were 20 mm spaces between the crankshaft bearings and the seals. these ill-accessible volumes acted as pneumatic dampers on the crankcase pressure fluctuation. Filling those volumes with plastic bushes gave a measurable improvement.

Summary: you need a large crankcase volume. Ideally all of this volume should be situated in the transfer ducts. In real life you will also need to lodge part of this volume between crankshaft and piston, i.e: use a long con rod. Avoid nooks and crannies. Crankshafts should be small and smooth. Big end bearings must never be shrouded by recesses in the crank webs or by stuffers.

The picture below shows, wait for it, an RSA125-crank with stuffers...
After Jan Thiel went into retirement in 2008, some geniuses at the factory grabbed their chance to 'correct' the errors that Jan left behind, without even testing the result because 'everybody knows the smaller the crankcase volume the better'. But they never could understand why a 2011 RSA125 was slower than a 2007 model (just look at the 125 cc top speeds on any GP-track). O, the joy of working with Italians.....
310768
Frits Overmars 2012

.....

In theory enclosed cranks are good. Jan Thiel did some experiments at Aprilia with a kart engine that had its reed valve at the front: the incoming mixture had to move against the direction of crank rotation. And although the crankcase stretched over the crank webs, reversing the direction of rotation brought another HP. So the crankshaft does have an influence.
But in practice, if you reduce the distances between crankshaft and crankcase walls to less than 1 mm, the viscous friction of the mixture between the surfaces really costs power at high rpm. And if you make the clearances so tight that lubricating oil can no longer reach the big-end and crankshaft bearings, it will also cost engines
Another negative aspect: any volume with a narrow 'entrance' between the crankshaft and crankcase surfaces acts as an hydraulic damper on the Helmholtz-resonance in the crankcase.
Aprilia has avoided this by making the space between the crank webs as wide as the big-end bearing. As a result the crankcase volume of the 125 cc RSA engine at TDC is about 650 cc,(or 675 maybe) so the exhaust pipe really has some volume to breathe from.
So much for the fairy tale of high crankcase compression

Crank stuffers? An Aprilia RSW125 has a TDC crankcase volume of 650 cc. An RSA125 has 675 cc and a bit more power. See where this is going?
Frits has also mention previously that the Reed Valve Derbi that produced 49 (I think) HP after some work by Jan had an even larger crankcase volume than the RSW and RSA.

I remember Jan saying that the crankcase volume of the Derbi reed valve engine was even larger than that of the rotary engine. And after Jan had laid his hands on it, that reed valve engine was the strongest 125 cc reed valver ever.
You see, the volumes of the transfer ducts and the volumes between the crank wheels and inside the piston are largely equal, and the volume of the reed cavity is a lot larger than the volume of a rotary inlet duct.

When Jan Thiel went to Derbi to design the bike we now know as the Aprilia RSA125, he encountered the 125 cc reed valve Derbi ridden by Lorenzo the previous season. Jan played around with the reed valver as well, because he wanted to find out the differences between reed valve and disk valve power. He managed to extract 2 HP more from the reed valver than anyone else had ever done before (never mind the fairy tales of reed valve 125s producing over 50 HP; those Horses must have been Shetland ponies, probably measured at the piston ring).
My graph shows the power curve for the Aprilia RSA, the Aprilia RSW and that best-ever reed valve Derbi. It's not quite in the same league as the rotaries, hmm?
310769
EDIT: Shame on me; I discovered that I posted a wrong graph (and I do not have the correct one at hand here in Holland). Power curve DERBILOR shows the reed valve Derbi as Lorenzo rode it. After Jan finished playing with it, it had 49 HP. Still, the best-ever disk valver produced 10 % more power than the best-ever reed valver.

Well 41 or so of the words are mine.
I wonder if there is any job opening for a Physicists secretary.
Click on the pics to make them bigger

Martin1981

14th April 2015, 01:18

Husa, thanks for your post. a rotary valve engine needs a big crankcase volume, i know that jan thiel and frits told us many times. but ask wobbly if a reed valve engine also needs the bigger the better crankcase. and the banshee engine IS a reed valver.

husaberg

14th April 2015, 01:26

Lef16

14th April 2015, 01:41

For sure bigger case volume is better,but I think Jan Thiel said on pitlane that you need the most of the volume to be on the transfer ducts on the cyl and case transfers,will bigger volume between the crank webs help on BDC??
Plus,can tranfers like the RZ's handle a very big volume in the cases and also a fat Aprilia type exhaust?
Cheers

Martin1981

14th April 2015, 03:59

Ok, so what do you think wobbly? i am about to put my 1986 cr 125 engine together again. should i use the stock crankshaft with the sheetmetal tins that are "wrapped" around the crankwebs to reduce the crankcase volume or should i take the other crank that has the tins removed by me because thinking bigger crankcase is always better because Jan and Frits said so? i don`t know....

Muciek

14th April 2015, 04:23

You need to shoot for actual ccr number. ( They were mentioned earlier here , for membrane engine with good duct's , average, and rotary valve) And It was 1 post above that You want most of the volume above the crank wheels, with the crank "being without holes and empty spaces"...

wobbly

14th April 2015, 08:32

It has been my experience with many reed engines that do NOT have any where near all the design elements correct ( like the Derby did after Jan )
for making big bmep numbers - that going under 1.3 CCR yields no better power.
As always there is alot more to this than meets the eye, as I have recently done a little more work on a KZ10B kart engine.
I spent hours stripping and machining 5mm off the reed face on the case and enlarged the trenches for the reed block screws to make it fit.
Now this ( my ) engine makes 47 Hp at 13,000 so must have most of the ducks in a row - but it now has a 5 mm spacer behind the reed.
So a blanket statement that claims big cases make more power in reed engines is over simplifying rubbish.
But as part of that test session I fitted some experimental plastic plugs to the piston and ground the Aux around to bore centre with
nice radial pockets on the rear entry walls.
This added 3.8 Hp at 14,000, a 10% increase in power over the stock setup at that rpm - now thats a result.

Martin1981

14th April 2015, 08:32

yes muciek, i know all that because i read every post of wobbly. but i am a little bit confused because jan thiel obviously went the other way and enlarged the crankcase more and more not only on the rotary valve engine but also on the reed valver.

so what is right? the bigger the better or a certain ccr like wobbly is saying?

Flettner

14th April 2015, 08:38

Off the pipe you want a reasonably small crank case, on the pipe it almost can't be too big. Assuming a good pipe and port design.
You kind of need dual cankcases volumes.

Martin1981

14th April 2015, 08:56

ok and that spacer BEHIND the reed keeps the intake tuned length correct?

Frits Overmars

14th April 2015, 09:02

i am a little bit confused because jan thiel obviously went the other way and enlarged the crankcase more and more not only on the rotary valve engine but also on the reed valver.Jan did not enlarge the crankcase volume on the Derbi reed valve engine; it was already big; a reed case has a lot more volume than a rotary valve duct.

Frits Overmars

14th April 2015, 09:10

Off the pipe you want a reasonably small crank case, on the pipe it almost can't be too big. Assuming a good pipe and port design. You kind of need dual crankcases volumes.True, Neil. Off the pipe you need a pump with the minimum amount of dead volume; on the pipe you'll want the engine to breathe directly from open air (mixed with a bit of fuel and oil). But that oil has to pass through the crankcase to keep the bearings happy. Hence my 24/7-setup

wobbly

14th April 2015, 09:22

There are several issues involved with the reed engine and its case volume - that has effects not seen in an RV setup.
The bigger the case the less are the pressure swings from piston movement and the pipe action ( assuming the same depression at the Ex port created by the pipe )
around BDC.
This changes the tuned frequency of the case vol, but this also requires thinner reeds to get them open fast and far enough.
Of course changing the reed stiffness then changes the intake tuned frequency,they then hit the reed stops and flutter uncontrollably - and so it goes on and on.
I tried machining the KZ10B case back to make the volume smaller as I already had the 5mm laser cut spacer from a test making the case bigger by pushing the reed block outward.
This failed miserably, so of course you then go the other way - this also failed,but only partially in that I did not then try differing reeds to compensate as I should have.
Adding a spacer behind the reed block HAS NOTHING to do with the intake length, this is already as short as it can be, with the rubber manifold recessed into the reed stuffer.
All I can say is that from a huge amount of sims and real world reed engine testing, that a very well tuned engine with good power capability ( bmep ) likes the case down near 1.3.
An engine with less power ( bmep ) capability ( for whatever reason ) tends to respond better to the case closer to 1.4.
When you are making 8 Bar and or 14 Bar BMEP of course these exceptions to the norm tend to prove the rule of thumb.

Flettner

14th April 2015, 11:15

True, Neil. Off the pipe you need a pump with the minimum amount of dead volume; on the pipe you'll want the engine to breathe directly from open air (mixed with a bit of fuel and oil). But that oil has to pass through the crankcase to keep the bearings happy. Hence my 24/7-setup

Might get to try that soon, the sleeve engine cases are not too far off finished. First I will be running just normal reeds.
You may have seen earlier, LM13 plates well. I've had all my Heat Ranger cylinders done. I sent them an offcut from the casting process to test first. FOS pattern has stalled due to having to get these Heat Ranger engines out.

peewee

14th April 2015, 15:01

Summary: you need a large crankcase volume. Ideally all of this volume should be situated in the transfer ducts. In real life you will also need to lodge part of this volume between crankshaft and piston, i.e: use a long con rod. Avoid nooks and crannies. Crankshafts should be small and smooth. Big end bearings must never be shrouded by recesses in the crank webs or by stuffers.

this is why i was thinking you could stuff the voids near the big end pin (but not shroud the big bearing) on these twin cylinder cranks like the pic i posted, either with carbon fiber, the material that wobbly suggested or simply using plastic like ktm has done for years, then of course just screw the stuffer into the side of the cheek. then the lost volume from stuffing the voids, you can gain that volume back via longer conrod. if my thinking is correct, this would now put all your volume above the crank cheeks and at the transfer entry, rather than have voids down low in the crankcase during the transfer phase. maybe the performance difference wouldnt be much but atleast you would end up with a rod ratio probly around 2.15-2.2 ( just guessing as i havent calculated it), which doesnt seem like a bad thing for high rpm

wobbly

14th April 2015, 15:21

But by adding the stuffers into the crank you loose more volume than you gain by adding 115 long rods ( that fit straight in )

peewee

14th April 2015, 16:22

But by adding the stuffers into the crank you loose more volume than you gain by adding 115 long rods ( that fit straight in )

from my calculations i think your right but who said anything about using 115 rods :cool:. theres even longer rods that fit right in :cool:. might even be something around +120mm that would fit right in, or require just a alittle machine work, i havent looked into this option yet though. just eyeballing the size of the stuffers needed, im guessing somewhere around 120mm is what would be needed to be at 1.33ish, this is just a guess though. i had it written down somewhere but with 64 bore,58 stroke, 118 rod and 513 series piston (standard wristpin location), it was 1.31 if i recall, ill try and find my notes. i do have a crank sitting around i could check the volume of the voids and get a pretty good idea what length of rod would be needed to recoup the stuffer volume, based off my previous calculations. ill have a answer in the next few days as im curious to this

TZ350

14th April 2015, 17:49

Things going on at Team ESE

310776310775

Chambers is trying his hand at water cooling a GP100 cylinder.

He made 22 hp with this cylinder before when he ran it at Taupo a few years ago, but now that we know a bit more about 2T tuning I expect he will be able to improve on that.

310777310778

Husa put me onto this KE175 rotary valve cover.

Much bigger RV disk than the GP125's one. And it looks like I will be able to get it to fit Ok, so its looking ever more promising for the air cooled, plenum chambered, power valved, variable chamber pressure, digital ignition, fuel injected, broad power spread 36rwhp GP/RGV125.

Richban sent me a good NSR250 cylinder for version 2. I already have some RS pipes so with a few mods to make the cylinder as close as possible to an RS125 cylinder (but with a power valve) and a re stroke of the GP crank, I won't hold my breath, but who knows, maybe it could be the first Bucket to touch 40.

Flettner

14th April 2015, 18:14

husaberg

14th April 2015, 18:23

Things going on at Team ESE

Chambers is trying his hand at water cooling a GP100 cylinder.

He made 22 hp with this cylinder before when he ran it at Taupo a few years ago, but now that we know a bit more about 2T tuning I expect he will be able to improve on that.
.

Make a cylinder.

Aren't those GP100's 3 port anyway?

chrisc

14th April 2015, 19:50

Nope. Single like the 125

husaberg

14th April 2015, 22:54

Nope. Single like the 125

I was mean three transfers rather than 5?

Back re the crankcase volume seeing as I have had no job offer (as yet) from Frits.

Something Wob I think and Grumph had said about the Reed valve Hondas having the shorter rods with the reed valve engines.

Long vs Short rods

I think (if I have got this right if I haven't the panel will fix it and burn me later at the stake)

Short rods have a higher acceleration rate away from and until about 90 degrees either side of TDC and BDC. This could be an advantage with a reed valve engine.
Conversely after 90 degrees either side of TDC or BDC the longer rod then actually accelerates more but then slows again nearing either side of TDC or BDC. Dwelling for longer.

Honda stuck with shorter rod despite huge amounts of R&D money with I guess was thrown about.
I don't know the rod length of of the Yamaha and Suzuki Cagiva GP500's but none of them seem that long either

Note I believe The longer rod should have less thrust friction as most of the this acceleration occurs with the piston and rod in a more parallel position though.

I note RAW on a Superkart has noticed the carburation is very different when he went to longer rods but I guess the burn will be different and so would be the optimum carb and especially the ignition timing.

Frits Overmars

15th April 2015, 00:52

Long vs Short rods: (if I have got this right if I haven't the panel will fix it and burn me later at the stake).
Short rods have a higher acceleration rate away from and until about 90 degrees either side of TDC and BDC.
Conversely after 90 degrees either side of TDC or BDC the longer rod then actually accelerates more but then slows again nearing either side of TDC or BDC. Dwelling for longer.I'm sure you've grasped it Husa, but the way it comes out of your keyboard indeed deserves burning. And your and is simply wrong. You might damage the younger brains here!
Short rods have a higher acceleration rate approaching and leaving TDC but a lower rate approaching and leaving BDC. That is all there is to it.
I posted the graph hereunder before, but it may not have sunk in with everybody, so I made an additional sketch.
310781 310783

When the crankshaft rotates away from TDC, the big end pin pulls the con rod downward. But because the rod also has to sway sideways, the small end drops more than the big end. The sketch (made with MS-Paint, so everyone can understand) shows a crankshaft with a 100 mm stroke, rotated through an angle alpha of about 70°.

On the right there is a 220 mm rod. Because of the swaying the small end has dropped an additional 4,8 mm.
On the left there is a 110 mm rod. Because of the swaying the small end has dropped an additional 9,9 mm, although the angle alpha is the same on both sides of the sketch. It's as simple as that.

Dutch Fisher

15th April 2015, 03:20

Frits, I don't understand, is my brain damaged?

Frits Overmars

15th April 2015, 04:30

Frits, I don't understand, is my brain damaged?Dunno, Dutch. I've got a hunch that your brain is not all that young. Anyway, if you keep reading what I write, you're exposing it to danger :whistle:.

Martin1981

15th April 2015, 04:44

Frits, you said that the best rotary valve engine has 10% more power than the best reed valver.

can you also tell us how much better is a case reed engine than a cylinder reed engine (in%)?

Frits Overmars

15th April 2015, 05:26

Frits, you said that the best rotary valve engine has 10% more power than the best reed valver. can you also tell us how much better is a case reed engine than a cylinder reed engine (in%)?Nope. The 10% was not a calculated but a measured value; it was based on Jan Thiel's work with the reed valve and rotary valve Derbis.
I doubt if we can persuade Jan to come out of retirement and start tuning a cylinder reed engine for us (he doesn't like reed engines anyway).

wobbly

15th April 2015, 09:32

Long rods that affect the case volume then influence the carb tuning dramatically as well.
I did a Rotax 257 single years ago for sprint kart racing, filling the crank webs with that UHWMP stuff.
This raised the case com form down near 1.3 up to about 1.35.
It needed complete rejetting and the main dropped from a 185 to a 165 due to the much stronger signal across the jets.
Going the other way on a 250 tandem twin by fitting long ( 120 ) rods and making full circle ( no pockets ) cranks, the jets then need to be huge
in size by comparison.
Honda used the short rod for years in the customer engines, but when push came to shove the final version used to win the last 250GP title used a long rod, for a reason obviously.
The big reed boxes that design had from day one, gave a relatively big case volume by default.

In my experience if a case reed is done as well as it can be ( look at a TM - KZ10 ) then there is very little difference in power if a cylinder reed
is also done properly with plenty of intake STA via piston cutouts and big Boyesens or floor ports.
The only real difference is that the boost port duct does not have a proper inner wall, and thus the flow regime is not as well controlled.

Flettner

15th April 2015, 11:53

speedpro

15th April 2015, 12:08

Have a look at a YZ250, the standard reed stops almost block the back port off completely! Bad Yamaha.
V force fix the situation nicely, no reed stops.

Would the reeds mask the boost port in their lift position and are they lifted when flow through that port is happening?

peewee

15th April 2015, 14:08

hey guys ive sorted this out with fairly good accuracy, i believe. the voids are about 5cc each so each crankcase would lose 20cc since theres 4 voids per crankcase. by lifting the cylinder 5mm via longer rod you gain back 23.25cc, this is with 64mm bore. so there you have it. feel free to double check with 100% accuracy but i think my numbers are close enough. i used clay against the inside then used some plastic over the top that conformed to the cheek radius , then added oil. if for some reason my numbers are way off, i guess ill have to buy everyone a beer :lol:

F5 Dave

15th April 2015, 14:21

Where are you from? Hmm, no, sorry. We'd be ok if Martin or Frits were buying.:drinknsin

Sorry little harsh, just kidding.

TZ350

15th April 2015, 16:13

310801310802

Turbocharged 2T

310799310800

http://www.apriliaforum.com/forums/showthread.php?185518-Gen-II-Port-Fuel-Injected-Turbocharged-Morini-build&highlight=turbocharged

husaberg

15th April 2015, 19:54

I'm sure you've grasped it Husa, but the way it comes out of your keyboard indeed deserves burning. And your and is simply wrong. You might damage the younger brains here!
Short rods have a higher acceleration rate approaching and leaving TDC but a lower rate approaching and leaving BDC. That is all there is to it.
I posted the graph hereunder before, but it may not have sunk in with everybody, so I made an additional sketch.

When the crankshaft rotates away from TDC, the big end pin pulls the con rod downward. But because the rod also has to sway sideways, the small end drops more than the big end. The sketch (made with MS-Paint, so everyone can understand) shows a crankshaft with a 100 mm stroke, rotated through an angle alpha of about 70°.

On the right there is a 220 mm rod. Because of the swaying the small end has dropped an additional 4,8 mm.
On the left there is a 110 mm rod. Because of the swaying the small end has dropped an additional 9,9 mm, although the angle alpha is the same on both sides of the sketch. It's as simple as that.

No Frits you give me far too much credit, I didn't understand it at all properly.
I think I do now though.
I was trying to gain some insight as to why Honda stayed with the shorter rods and more acceleration
But looking at it again more acceleration at TDC might actually be helpful re the reeds.
but swings and roundabouts.
Maybe they just had a plenty of forging capacity in that size of rods.
Then again you could write many many books with what I can't figure out. Geel free to do that btw.
http://i.imgur.com/o5oKsfh.gif

looking at how this drawing works for the reed does raise a few schemes re the 24/7 though.

koba

15th April 2015, 20:00

An interesting side read about an engine in development with a local engineering firm.

http://engrich.co.nz/?page_id=310

mr bucketracer

15th April 2015, 20:19

An interesting side read about an engine in development with a local engineering firm.

http://engrich.co.nz/?page_id=310i'v seen the engine , very nicey made but only taken 15 years to build (-;

husaberg

15th April 2015, 20:24

i'v seen the engine , very nicey made but only taken 15 years to build (-;

F-ing amateurs.........I could stretch that out to 20 easy.....

chrisc

15th April 2015, 20:46

What are those four things in the top of the head and where are the transfer ports? :nono:

Martin1981

15th April 2015, 21:03

Where are you from? Hmm, no, sorry. We'd be ok if Martin or Frits were buying.:drinknsin

Sorry little harsh, just kidding.

No problem Dave, if we start a 2 stroke fanatic barbeque in New Zealand someday, you will get the finest beer from Germany! if it is fine in comparison to New Zealands beer...:drinkup:

TZ350

15th April 2015, 21:53

Page ... 160

Eliminating technical development is the last thing I want. Besides, defining what is allowed will make the rulebook five times as thick and there will always be omissions. For example, you won't be allowed to change your tire pressures if the rulebook doesn't say that you can.

Oh I agree. The alternative does exist, though, there are competition classes that basically specify a standard production vehicle and a very short list of permissible alterations. The objective is obviously to remove any variables other than the pilot.

And while I don't have a problem with that I don't find such racing very interesting. Probably because I'm a singularly inept pilot. I do enjoy seeing technical innovation reaping rewards, though. I guess the trick is balancing the rules in order to penalise both skill sets as little as possible.

I agree. In Dutch moped racing there are two classes with a lot of technical freedom. Together they share one page in the rulebook with room to spare. That part of the rulebook is 'allowed unless mentioned'.

There are also two classes where the bike has to remain 99% standard. Together they occupy 8 pages in the rulebook. They also cause eight times the amount of discussion at scrutineering. This part of the rulebook is 'forbidden unless mentioned'. And let me tell you: I hate to write this kind of rules.

These standard classes came into being because of the increasing number of riders that don't know a spark plug from an exhaust pipe. They offer great racing but zero technical inspiration; they have produced riders at european championship level, but decent mechanics are threathened with extinction.

my time would be better spent focusing on handling, but that's not nearly as interesting as making hp.

Oh, but it is. Once you experience what you can achieve by turning a pair of shock absorber knobs, you'll be hooked.

Old technology is what we have to work with and the first step to making more power with the ports in the right place on these outdated engines is to organise sufficient effective cooling for the target power output.

True, and it's not only valid for old engines. Modern engines are not so prone to seizing, but they won't produce real power either without good cooling.

http://www.kiwibiker.co.nz/forums/images/misc/quote_icon.png Originally Posted by Frits Overmars
Nowadays an engine needs a large crankcase volume, all the port area you can cram into the cylinder circumference, good ducts for efficient flow and directional control, an exhaust that sucks and blows hard at the appropriate moments, and cooling, cooling, cooling.

Nowadays an engine needs a large crankcase volume, all the port area you can cram into the cylinder circumference, good ducts for efficient flow and directional control, an exhaust that sucks and blows hard at the appropriate moments, and cooling, cooling, cooling.

speedpro

15th April 2015, 22:11

That engine is interesting with the 360 crank but with a 180 reciprocating counterbalance in the lower case. Sort of like the Ducati supermono idea but for a parallel twin. It looks to be properly reciprocating as well rather than pivoted like the supermono.

chrisc

15th April 2015, 22:15

Swoon. Proton anyone?

Kenny Roberts Collection for sale (http://rmdmotors.com/kenny-roberts-collection/)

http://rmdmotors.com/wp-content/themes/rmdmotors/images/image.php?width=600&height=450;&image=http://rmdmotors.com/wp-content/uploads/2011/01/DSC00296.jpg

Frits Overmars

15th April 2015, 22:17

An interesting side read about an engine in development with a local engineering firm. http://engrich.co.nz/?page_id=310I must say their craftsmanship looks good, even if it's a foulstroke. But their 'unique tungsten balance system' reminds me of the 'mass compensation' in the BMW F800, so maybe it's not so unique after all. And they forgot to mention the aircooling which really must be unique these days. Can't understand why they did that.

No problem Dave, if we start a 2 stroke fanatic barbeque in New Zealand someday, you will get the finest beer from Germany! if it is fine in comparison to New Zealands beer...I don't know about NZ-beer (yet). I hope it isn't anything like Aussie beer; I tried that and it was like making love in a canoe: f*cking close to water :whistle:

Dutch Fisher

15th April 2015, 23:09

Swoon. Proton anyone?

Kenny Roberts Collection for sale (http://rmdmotors.com/kenny-roberts-collection/)

Roberts has been trying to sell those bikes for about 4-5 years now, still no cheque in the post.

I still can't fathom why the modesto mafia boss went with, and still doggily stayed with, the 3 cyl design (as opposed to a 4).

Frits, your a journo, any rumbles from the press pack as to why? #ijustdontgetit

husaberg

15th April 2015, 23:27

Kenny told the press pack at the time it was because the lap times for the 500 fours was not much better than the 250 twins (which was true)
He reasoned he could build a smaller frontal area and have a better handling bike that was easier on tyres and easier to ride.
ie more consistently fast over the whole length of the race.
He was also getting not much development at all from Yamaha. Doing most of within his own team

From memory the 500 twins could be lighter but not I believe the 3's.
I have a few articles about it. I have likely posted them eons ago.

But the main reason was he was Kenny.

I also note that Kenny lost his tittle to Freddy on a slower Honda 500 3.
The advantage was the three was more nimble and better on tires.
I think the weight of the 3 and 4 was actually similar at the time.
Plus Spencer was f-ing incredible at the time helped.

2T Institute

16th April 2015, 01:24

Long v's Short rod, I don't think the mechanics are the over riding factor. I think the tuning window is wider on the shorter rod, longer rods do odd things to carburation. So you have to try to disregard most of your prior knowledge. Keep going with the longer rod and you come out ahead.

That version of the V3 was the sweetest sounding two stroke ever, had such a shrill high pitched wail. The whole V3 thing was a bit of a schmozzle with the original TWR designed shitbox engine even having solidly mounted carbs. Wasn't until 2 semi retired engineers from GP's (Yoda and Oguma san) completely redesigned the engine did it go and handle as good as it should. Real tragedy was just as they got that triple hammering it was 4T time with a sad case of "deja vu all over again" and built his own 4T engine, then it started to really go when HRC gave them a RC 211V V5 engine <_<

Frits Overmars

16th April 2015, 02:28

Frits, your a journo, any rumbles from the press pack as to why?I stopped writing motorcycle articles for a living in 1981, Dutch. But if you ask me, Roberts could never forget being beaten by Fast Freddy on the Honda triple,
just like Husaberg says.

Dutch Fisher

16th April 2015, 02:41

I guess being beaten by the Gallina Suzukis 2 years in a row didn't hurt that much, as he wasn't driven to building a square-4 disc valver

F5 Dave

16th April 2015, 08:13

I must say their craftsmanship looks good, even if it's a foulstroke. But their 'unique tungsten balance system' reminds me of the 'mass compensation' in the BMW F800, so maybe it's not so unique after all. And they forgot to mention the aircooling which really must be unique these days. Can't understand why they did that.

I don't know about NZ-beer (yet). I hope it isn't anything like Aussie beer; I tried that and it was like making love in a canoe: f*cking close to water :whistle:
its a mixed bag here for beer. We`re now doing a lot of really excelent beers but the main mcdonalds brands are terrible. Dont ever try the sadly named nz beer steinlager and think it representative.
The belgians, they do some unnatural things with beer.

wobbly

16th April 2015, 08:43

KRs reasoning was exactly the same conclusion we came to at BSL when working thru what to build for the 500GP class.
The tripple had a 10Kg weight advantage over the 4 and if this goal could be met then it would have a better power to weight
than what Mr W was trying to do at Aprilia with the big twin.
Honda were doing the 500 twin and the factory version had reportedly 140 Hp at the sprocket, so we figured around 155 was needed for a 3
and that is what we ended up getting.
Getting down to weight was quite another thing though, and even with fully CNC machined frames/swingarm parts and Ti pipes it was still over weight.
The issue KR had was that there were big ego's involved along with some very clever ideas that Mike Sinclair and others were wanting to use
like ducted cooling as seen on the Britten,but in the end what KR said went and the team went thru all manner of painful iterations of designs
that really waisted time and money.
This was exemplified by one design that was done by the guy who did Freddies tripple,that vibrated so badly it was impossible to hang onto the bars
and made less power than Hondas twin.
That engendered the typical comment from KR after he gave the BSL a throttle handful in the pits at PI,simply saying to his team " those fuckers know
way more about balance than any of you cunts".
Not so charming but sadly true at the time.

wobbly

16th April 2015, 09:00

Re the RZ/Banshee crank.
The best way to get what is really needed is to add the plastic inserts each side of the pin, and machine off the stepped
up area opposite.
Then rebalance it with some extra Mallory - the stock crank wheels were designed for a 250, now the same wheels are used with 68MM and bigger
pistons with longer and heavyer rods.
So its miles out of balance to start with,as you can see I have added a single Mallory slug that was intended to correct for 73mm big bore 485cc.
Machining off the step gets you some volume as well as giving the flush inner face like an Aprilia.

chrisc

16th April 2015, 10:14

Sorry to interrupt the really interesting speak on the KR and triples.
Rob, you might be interested in this little 50.

http://www.motociclismo.es/pruebas/off-road/articulo/yasuni-50-proto-automatico?hc_location=ufi

<img src="http://www.motociclismo.es/media/cache/article_big/upload/images/paragrapharticle/19744/paragrapharticle-52200-531749c87dacb.jpg" height=450 width=600>

<img src="http://www.motociclismo.es/media/cache/article_big/upload/images/paragrapharticle/19744/paragrapharticle-52202-53174a02563f9.jpg" height=450 width=600>

Yow Ling

16th April 2015, 13:37

richban

16th April 2015, 17:17

I have all the bits to give the 300 a freshen up now.

New ported barrels, new reeds and pistons. Still lots to do with prepping barrels and pistons with duct radius etc. The bike should be all back up and running on saturday though.

310821

husaberg

16th April 2015, 18:22

A slower MV3 with Ago beat a much more powerful 500 Four Honda as it would actually go around corners. Even Hailwood could not make up for that.

310825 310828

The battle in the 500 cc class is between Hailwood and Giacomo Agostini with the MV. Hailwood complains, that he has to fight two opponents: Ago and his Honda, which, although it has a superb engine, has very bad road holding. At the end of the season, both riders have the same number of points and both have 5 wins; Hailwood has two second placings, but Agostini has three seconds and so becomes world champion
In the 250's Ossa single cylinder nearly took the crown from Yamaha's 250 V4 disk valve
310826 310827

Ossa 250 GP bike with monocoque. In 1969 they came third in the GP world championship, the small Spanish outfit even beating the all conquering V4 Yamahas on three occasions. They lead the championship in 1970 until, at the Isle of Man TT (which in those days was a key round in the championship) their rider, Santiago Herrero, was killed in a crash. Ossa withdrew from racing forever
1963 Morini nearly did the same with singles when the Honda 250 fours ruled the tracks.
310829310830

Provini signed to race for the Moto Morini factory. In 1963 he waged a season-long battle with Honda's Jim Redman for the 250 world championship. Each rider won four races and the title wasn't decided until the final race in Japan, with Redman winning the championship over Provini by two points

Top speed is only achieved maybe once in a race (for a very short period of time at that) yet there are many corners to brake into, accelerate out of and go around.
Paraphrased Jerry Burgess. The man behind Doohan and Rossi for most of their success.

Dutch Fisher

16th April 2015, 18:53

What's happened to Jerry Burgess?

Retired, and now sipping peña colorada on a sun terrace back in Oz ?

Or starring in the latest Mission Impossible film wearing a Ducati Corse shirt ?

Frits Overmars

16th April 2015, 19:56

http://www.motociclismo.es/pruebas/off-road/articulo/yasuni-50-proto-automatico?hc_location=ufi

There are so many spelling mistakes in that article its almost unreadableThose spelling mistakes have a name. It's called Spanish. It's a language. Like English. ¿Comprende? :shifty:

Frits Overmars

16th April 2015, 20:05

A slower MV3 with Ago beat a much more powerful 500 Four Honda as it would actually go around corners. Even Hailwood could make up for that. In the 250's Ossa nearly took the crown from Yamaha Morini nearly did the same with singles when the fours ruled the tracks.
Top speed is only achieved maybe once in a race (for a very short period of time at that) yet there are many corners to brake into, accelerate out of and go around.
Paraphrased Jerry Burgess. The man behind Doohan and Rossi for most of their success.Racing is not about being fast. It is about not being slow anywhere. Handling is everything. (but power won't hurt, provided it's controllable).

Frits Overmars

17th April 2015, 04:18

In the 250's Ossa single cylinder nearly took the crown from Yamaha's 250 V4 disk valve.
In 1969 they came third in the GP world championship, the small Spanish outfit even beating the all conquering V4 Yamahas on three occasions.Been there, didn't see that. To my knowledge the Ossa 250 never entered the GP-arena against the Yamaha works V-fours. Maybe because Yamaha withdrew the V-fours at the end of 1968, hm?
In 1969 Ossa rider Santiago Herrero battled with Yamaha works riders Rodney Gould and Kent Andersson on Yamaha twins, and with Kel Carruthers and Renzo Pasolini on Benelli fours. It was a great season: two screaming two-stroke twins, two howling four-stroke fours and the Ossa single that looked and sounded like a moped by comparison, but often showed its competitors the way, even on ultra-fast tracks like Francorchamps. Been there, did see that.

husaberg

17th April 2015, 17:12

Been there, didn't see that. To my knowledge the Ossa 250 never entered the GP-arena against the Yamaha works V-fours. Maybe because Yamaha withdrew the V-fours at the end of 1968, hm?
In 1969 Ossa rider Santiago Herrero battled with Yamaha works riders Rodney Gould and Kent Andersson on Yamaha twins, and with Kel Carruthers and Renzo Pasolini on Benelli fours. It was a great season: two screaming two-stroke twins, two howling four-stroke fours and the Ossa single that looked and sounded like a moped by comparison, but often showed its competitors the way, even on ultra-fast tracks like Francorchamps. Been there, did see that.

I did wonder why I couldn't get a pic of a 1969 250 V4 that would likely be why lol.
But he did get a third two fifths and a sixth in 1968 on the OSSA. Well according to the Net anyway. Not so sure weather it was a monocoque then though.
My parents might were at least married by then though even though I was a fair few years away from being conceived.

Herrero friendly manner, super talent and mechanical skills made him an attractive proposition to the OSSA factory and Giró offered him a job developing the OSSA 250cc race bike.

He worked harmoniously and effectively with Eduardo Giró on the development of the OSSA monocoque, which featured a 6 speed rotary valve engine and together they began to surprise the motorcycling world. On the OSSA 230 cc bike with no fairing and 30 HP, they won 250cc Spanish Championship in 1967.

The combination promised to be highly competitive, so for 1968 they stepped up to 250cc Grand Prix racing.

Although the single cylinder Ossa had 20 HP less than the powerful V4 Yamahas of Phil Read and Bill Ivy, the OSSA was a massive 20kg lighter and its monocoque frame was much stiffer, giving it superior cornering and braking ability. The Yamaha’s swept the championship but, Herrero left the GP paddock in no doubt that the little OSSA was quick and dependable. He finished seventh in the championship and claimed a third place in the final race of the season at Monza. He would once again take the 250cc Spanish National Championship.
http://www.motorsportretro.com/2010/03/santiago-herrero-ossas-favourite-son/

In 1968, he would move up to compete in the 250cc Grand Prix world championship. Although the single cylinder Ossa had 20 horsepower (15 kW) less than the powerful V4 Yamahas of Phil Read and Bill Ivy, the Ossa was 45 pounds (20 kg) lighter and its monocoque frame was much stiffer, giving it superior agility.[2] The Yamahas swept the championship, but Herrero left no doubt that the little Ossa was quick and dependable. He finished seventh in the championship and claimed a third place in the final race of the season at Monza.[1] He would once again take the 250cc Spanish National Championship.

1969 would be a big year for Herrero. He began the year winning his first grand prix at the opening race of the season in front of his countrymen at Jarama.[1] After retiring from the German Grand Prix with mechanical problems, he returned with a victory at Le Mans.[1] He followed this with third place at the Isle of Man TT, a considerable accomplishment considering his horsepower deficit on the infamous Snaefell Mountain Course.[1] He triumphed again at Spa and was leading the championship points race when he was beset by bad luck.[1] He crashed in the rain at the Ulster Grand Prix and suffered a broken left arm.[2] Most observers considered his championship hopes dashed, but Herrero showed true grit by coming back to finish in a remarkable fifth place at Imola.[2] At last race of the season in Yugoslavia, he held a one point lead in the championship. He started the race in the lead but crashed on the seventh lap, ending his championship hopes.[2] He would finish third in the world championship.[1] He repeated as Spanish 250cc champion for a third consecutive year
http://en.wikipedia.org/wiki/Santiago_Herrero

http://en.wikipedia.org/wiki/1968_Grand_Prix_motorcycle_racing_season

kel

17th April 2015, 18:52

But he did get a third two fifths and a sixth in 1968 on the OSSA.
In 68 the bike suffered from reliability issues. In 69 it had 42hp, weighed under 100kg and had a top speed of over 140mph. Not bad for a single cylinder air cooled engine! Plus it had that classic fat rotary valve power delivery, it supposedly pulled hard from 6500 to 11000rpm!. At Spa-Francorchamps Herreros average speed of 188.74kph was faster than the 500cc class runner up!
This was a wonderful machine and was in part the inspiration behind my air cooled rotary valve racer, now if only I could fit a comparably huge head into my chassis :scratch:

Grumph

17th April 2015, 19:46

In 68 the bike suffered from reliability issues. In 69 it had 42hp, weighed under 100kg and had a top speed of over 140mph. Not bad for a single cylinder air cooled engine! Plus it had that classic fat rotary valve power delivery, it supposedly pulled hard from 6500 to 11000rpm!. At Spa-Francorchamps Herreros average speed of 118.74kph was faster than the 500cc class runner up!
This was a wonderful machine and was in part the inspiration behind my air cooled rotary valve racer, now if only I could fit a comparably huge head into my chassis :scratch:

You use an RS chassis I think ? Cast up your head, slightly over size with very large end pieces. machine it to fit into the frame tightly and bolt it to the frame...voila, you're using the frame mass as a heat sink and additional area....

ken seeber

17th April 2015, 21:09

I know you guys are rule driven in terms of being specifically air cooled for F4, but has anyone tried blowing air thru a watercooled engine? I know the specific heat of air is a ¼ of water and that its thermal conductivity is far, far less, but the one thing going for it is that the volumetric flow rate is far greater, given a decent blower, and you may get the benefit of a later model engine with its better port arrangement. Also, the total effective volumetric air flow rate could be much higher than air wafting thru the fairing, plus you would be cooling closer to the heat source rather than at the end of the fins. And of course, no water leaks.
Maybe just a product of the too many top quality Australian beers I guess. Just can't wait for the response to this though :violin:

I don't know about NZ-beer (yet). I hope it isn't anything like Aussie beer; I tried that and it was like making love in a canoe: f*cking close to water :whistle:

Ocean1

17th April 2015, 21:23

I know you guys are rule driven in terms of being specifically air cooled for F4, but has anyone tried blowing air thru a watercooled engine?

Or just fill it with paraffin. Which should be legal as long as it remains solid, no?

husaberg

17th April 2015, 22:10

Or just fill it with paraffin. Which should be legal as long as it remains solid, no?

I suggested that about 4 years ago.

have a look here http://autospeed.com/cms/A_110772/printArticle.html
IT would/could also be a very trick alternative to water cooling a barrel in combo with a water cooled head on a 100cc.

This site is one of the best resoures for all sorts of real interesting stuff.

Another thing to consider is an Marine oil cooler as an intercooler.

http://autospeed.co.nz/cms/title_The-Complete-Guide.../article.html

'Performal'
What is happening is that the Performal is melting - it is changing from a solid to a liquid at 50 degrees. And when it undergoes that change in state, it can absorb lots of energy without altering in temperature. Instead of heating the material up, the energy from the stove is being used to separate the material's molecular bonds.

Until all of the Performal has changed from a solid to a liquid, its temperature will not change. That's what the above graph shows - and you can see that the temp is being held constant, even though we're continuing to pour in the heat energy from the stove. It's only when the Performal has completely melted that its temp will start to rise again - and then the rate of temp increase will be dependent on the specific heat of Performal in liquid form, which might be different to its specific heat in solid form.

"Performal"?

The potential on the right car is huge: but what actually is bloody "Performal"? Time to let you into a secret - and some of you may have already guessed. "Performal" doesn't exist but a substance with very similar characteristics is commonly available. It is called paraffin wax, and is sold for use in making candles. Specifically, its typical characteristics are:
•Melting point: 52 degrees C
•Specific heat: 3.27 kJ per kg per degree C
•Specific heat of fusion: 210 kJ/kg

So to increase the temp of 1kg of the wax from 47 to 52 degrees takes 16.35kJ, but to push it past 52 degrees takes nearly 13 times as much energy. (Or, to risk causing confusion, you could dissipate in it a power of 14kW for 15 seconds to melt 1kg.)

Paraffin wax is non-toxic, doesn't explode (although it will catch fire if you expose it to a naked flame) and is easily handled. Special waxes designed specifically for this change-of-state heat storage purpose are also available with melting points in 10-degree C increments from 50 degrees to 100 degrees C, however their availability is obviously less than simple candle wax.

http://www.autospeed.com/cms/article.html?&title=The-Fusion-Intercooler&A=110772

Abstract

Mesophase pitch based graphite foams (GFs) with different thermal properties and pore-size were used to increase the thermal diffusivity of phase change material (PCM), paraffin wax, for latent heat thermal energy storage application. To predict the performance of the Paraffin-GFs as a thermal energy storage system, their structure, thermal diffusivity and latent heat were characterized. Results indicated that thermal diffusivity of the Paraffin-GF can be enhanced 190, 270, 500, and 570 times as compared with that of pure paraffin wax. Latent heat of Paraffin-GF systems increased with the increasing of the mass ratio of the paraffin wax in the composite. Moreover, pore-size and thickness of ligaments of the foam played a key role in improving the thermal diffusivity and the storage capacity of the Paraffin-GF system: small pore-size (less paraffin wax were filled) and thicker ligament in GF resulted in a higher thermal diffusivity; large pore-size (less paraffin wax were filled) and thinner ligament in GF resulted in a larger latent heat.
http://www.sciencedirect.com/science/article/pii/S0927024810000474

Ocean1

17th April 2015, 22:42

I suggested that about 4 years ago.

So you did mate. Did anyone ever do the sums to see how much would be required to deal with the waste heat energy involved in an average bucket race? Wouldn't surprise me if just a couple of litres would do the job. Getting the bloody stuff cooled in time for the next race might be interesting.

husaberg

17th April 2015, 22:49

Moooools

17th April 2015, 23:23

So you did mate. Did anyone ever do the sums to see how much would be required to deal with the waste heat energy involved in an average bucket race? Wouldn't surprise me if just a couple of litres would do the job. Getting the bloody stuff cooled in time for the next race might be interesting.

I conservatively estimate 107 litres.

My reasoning:

30hp engine: 22.4 kW

For four stroke we run on the assumption that 1/3 goes to the crank, 1/3 goes out the pipe, and 1/3 goes to the water. That is all I know So I wills stick with it for now. Corrections welcomed.
That means if 22kW is getting to crank, 22kW is going into the cooling.

22kW of heat rejection for 10 mins is 60x10x22 = 13422kJ of heat.

I am running on the assumption that we don't want the water to get over 50 degrees C as that is what you all like to run your engines at. Also assuming that the water begins before race at ambient temp of 20 degrees C.
That is a change of 30 degrees throughout the race.

Specific heat of water at 20deg = 4.18kJ/kg.K
That means for 30deg temp change one kg of water can absorb 125kJ of heat.
We need to absorb 13422kJ

13422/125 = 107kg = 107l

***Assumptions***
1/3,/1/3,1/3 rule of thumb
No heat lost in to other systems
The engine outputs 30hp for the full race. (probably more like 50% for some tracks, even less for the likes of mt Welly)
Cp is constant.
**************

Even with less conservative numbers, the radiator looks pretty good.

Frits Overmars

18th April 2015, 00:24

In 1968... the Yamahas swept the championship, but Herrero left no doubt that the little Ossa was quick and dependable. He finished seventh in the championship and claimed a third place in the final race of the season at Monza.So he did encounter the V-fours, although he didn't do battle with them. It escaped me.
Herrero friendly manner, super talent and mechanical skills made him an attractive proposition to the OSSA factory and Giró offered him a job developing the OSSA 250cc race bike. He worked harmoniously and effectively with Eduardo Giró on the development of the OSSA monocoque, which featured a 6 speed rotary valve engine and together they began to surprise the motorcycling world. On the OSSA 230 cc bike with no fairing and 30 HP, they won 250cc Spanish Championship in 1967.Girós rotary brainchild did not start as a monocoque bike; here is the 1966 tubular frame version with Herrero in the saddle.
310851310852

Frits Overmars

18th April 2015, 01:08

..has anyone tried blowing air thru a watercooled engine? I know the specific heat of air is a ¼ of water and that its thermal conductivity is far, far less, but the one thing going for it is that the volumetric flow rate is far greater, given a decent blower...
Maybe just a product of the too many top quality Australian beers I guess. Just can't wait for the response to this thoughYou should be careful what you ask for, Ken :devil2:.
So the specific heat of air is a ¼ of water; I'll take your word for it. And for really good engine cooling we need 1 liter water per 1 crankshaft-Hp per minute.
Let's assume a modest 30 Hp for a bucket, then we'll need 30 kg water/minute. Or 120 kg air/minute.
The density of air is 1,225 kg/m³ so we'll need an air flow of 97,959 m³/minute.
The coolant hose pillars on a typical 125 cc cylinder have a 16 mm diameter, but let's be generous and assume 20 mm.
Then we'll need a flow velocity of 311813 m/minute, or 5197 m/s. That's a little over Mach 15. I'd like to see the blower...
I'm pretty sure that blower will absorb more than 30 Hp. Just as well, because air 'cooling' your cylinder at Mach 15 would melt it in no time at all.

OK, maybe we don't really need 30 liter water per minute; maybe the engine will survive at only 10 l/min. Switching to air will then only require Mach 5.
That's a little above the top speed of the SR-71 Blackbird spy plane that had to be made completely from titanium because alu couldn't stand the heat...

Frits Overmars

18th April 2015, 01:41

Yamaha withdrew the V-fours at the end of 1968.
I did wonder why I couldn't get a pic of a 1969 250 V4 that would likely be why lol.here's something to comfort you Husa.
310853310854310855310856310857

Frits Overmars

18th April 2015, 01:42

... And some more. Don't forget to zoom in.

seattle smitty

18th April 2015, 04:20

Just from looking at photos, and not from any but the barest familiarity with racing motorcycles, but it seems to me that even though some of you, and others throughout the sport, have fabricated air-scoops and deflectors, there is more that could be done in re-directing airflow. The front tire/rim is a truly awful barrier to having any kind of decent airflow to the radiator or the fins of an air-cooled engine, and could hardly be worse for creating turbulent eddies of air behind it. Whether the tire/rim could be any less bad aerodynamically with something like spun aluminum "full-moon" wheel covers (which would add some undesiralble unsprung weight), I don't know. But in my youth I got to ride on the radial-engine propliners of the day, including the L749 Lockheed Constellation, with its four 3350 twin-row Wright engines. Ten thousand take-off horsepower apiece, yet at the fuel-saving slow 230mph cruising speed, with nothing but ram-air, UN-obstructed ram-air, those engines went thousands of hours between overhaul.

I'd like to know if anybody has studied the ACTUAL air-flow entering the radiator or cooling fins on specific motorcycles, as opposed to the ASSUMED air-flow, because I don't think you can assume anything, given the turbulence-making front tire. An example of why you can't assume anything here is the (rather silly) controversy about how to reduce the ASSUMED drag of the tailgate of a pickup truck. Guessers will tell you that when your bed is empty, you can save a little fuel by dropping the tailgate. But such people don't understand what the air is doing as it comes over the cab . . . or that it changes at different highway speeds. Unsurprisingly to anyone who has some feel for low-speed aerodynamics, when a big consumer magazine did tests on a number of different pickup trucks, they found that some of them showed a small mpg gain with the tailgate down, some did better with the tailgate UP, and some showed no worthwhile difference with it up or down. To my mind this is sort of like the supposedly air-directing shrouds that Suzuki used to put over the fins of their old air-cooled 2-stroke street bikes; a good idea IF the air is ACTUALLY flowing fore-and aft, and it very well might not be. My point is that I don't think you can assume what's happening with the wake turbulence of your front tire, or how much air is blowing through your radiator or cooling fins, how much is burbling off to the sides, or whatever. And, that maybe with considerable attention to this area, you could get a lot better cooling.

(FWIW, when I make these long posts, I am ASSUMING that by CAPITALIZING key words I am improving readability. If this is more irritating than helpful to readers, say so and I will DESIST):facepalm:

Frits Overmars

18th April 2015, 07:31

....To my mind this is sort of like the supposedly air-directing shrouds that Suzuki used to put over the fins of their old air-cooled 2-stroke street bikes; a good idea IF the air is ACTUALLY flowing fore-and aft, and it very well might not be. That's an assumption, isn't it?
BTW, capitalizing whole words is considered shouting on the world wide web. Please don't shout, Smitty; I'm not blind.

Dutch Fisher

18th April 2015, 07:45

IF the air is ACTUALLY flowing fore-and aft, and it very well might not be.

Yes i think your right there Smitty.... in a 200mph side wind #Gulp #Aerodynamicsoutofthinair

Ocean1

18th April 2015, 09:35

I conservatively estimate 107 litres.

My reasoning:

30hp engine: 22.4 kW

For four stroke we run on the assumption that 1/3 goes to the crank, 1/3 goes out the pipe, and 1/3 goes to the water. That is all I know So I wills stick with it for now. Corrections welcomed.
That means if 22kW is getting to crank, 22kW is going into the cooling.

22kW of heat rejection for 10 mins is 60x10x22 = 13422kJ of heat.

I am running on the assumption that we don't want the water to get over 50 degrees C as that is what you all like to run your engines at. Also assuming that the water begins before race at ambient temp of 20 degrees C.
That is a change of 30 degrees throughout the race.

Specific heat of water at 20deg = 4.18kJ/kg.K
That means for 30deg temp change one kg of water can absorb 125kJ of heat.
We need to absorb 13422kJ

13422/125 = 107kg = 107l

***Assumptions***
1/3,/1/3,1/3 rule of thumb
No heat lost in to other systems
The engine outputs 30hp for the full race. (probably more like 50% for some tracks, even less for the likes of mt Welly)
Cp is constant.
**************

Even with less conservative numbers, the radiator looks pretty good.

Two significant difference between water and a designer-wax: #1: You're not allowed water.

#2: Cooling water isn't changing phase from solid/liquid/gas. The various thermal waxes are designed to phase change at a specific temp. Applying heat initially simply warms the wax up, but as the temperature approaches that required to change the wax from solid to liquid the temperature simply stops rising. And it'll remain constant as the wax soaks up the huge quantities of energy required to change phase.

So a wax designed to change at 50deg and absorb 13422kJ will only need a small portion of that 107 litres.

But I'm not a process engineer, which is why there's some numbers missing from the above. :D

chrisc

18th April 2015, 10:19

The rules say:

Solo motorcycles shall have two engine capacity classes:
F4 2 stroke 55-100cc
2 stroke 55-125cc air cooled
4 stroke 55-150cc

F5 2 stroke 0-50cc
4 stroke 0-100cc air cooled

Whilst there is anyway some interpretation to be had with rules, they do not say that the 125s are allowed anything but water-cooling, they say air cooled. Therefore, wax cooling or whatever other matter state changing cooling would seem to be against this simple rule.

TZ350

18th April 2015, 10:38

I am ASSUMING that by CAPITALIZING key words I am improving readability. If this is more irritating than helpful to readers, say so and I will DESIST):facepalm:

I have been breaking my posts down into smaller bite sized paragraphs with the hope of improving readability.

TZ350

18th April 2015, 10:51

I'd like to know if anybody has studied the ACTUAL air-flow entering the radiator or cooling fins on specific motorcycles, as opposed to the ASSUMED air-flow, because I don't think you can assume anything..... like the supposedly air-directing shrouds that Suzuki used to put over the fins of their old air-cooled 2-stroke street bikes; a good idea IF the air is ACTUALLY flowing fore-and aft, and it very well might not be.

When I was looking at improving the air cooling performance on my bike I came across an article on motorcycle radiators. The assumption was that the wind blew through the radiator but this was not necessarily so, the bulk of air could very well be moving sideways across the radiator.

The only way to have air move through the radiator was to have a depression behind it and this was not always present, even when going fast. But there is always some sort of depression behind a moving motorcycle and the idea was to form a duct from the back of the radiator to the low pressure area at the back of the motorcycle. That way the air at the front flowed through the radiator to fill the depression behind it.

This thinking is influencing how I arrange the air ducting for my new bike.

husaberg

18th April 2015, 10:56

I conservatively estimate 107 litres.

My reasoning:

30hp engine: 22.4 kW

For four stroke we run on the assumption that 1/3 goes to the crank, 1/3 goes out the pipe, and 1/3 goes to the water. That is all I know So I wills stick with it for now. Corrections welcomed.
That means if 22kW is getting to crank, 22kW is going into the cooling.

22kW of heat rejection for 10 mins is 60x10x22 = 13422kJ of heat.

I
***Assumptions***
1/3,/1/3,1/3 rule of thumb
No heat lost in to other systems
The engine outputs 30hp for the full race. (probably more like 50% for some tracks, even less for the likes of mt Welly)
Cp is constant.
**************

Even with less conservative numbers, the radiator looks pretty good.

Two significant difference between water and a designer-wax: #1: You're not allowed water.

#2: Cooling water isn't changing phase from solid/liquid/gas. The various thermal waxes are designed to phase change at a specific temp. Applying heat initially simply warms the wax up, but as the temperature approaches that required to change the wax from solid to liquid the temperature simply stops rising. And it'll remain constant as the wax soaks up the huge quantities of energy required to change phase.

So a wax designed to change at 50deg and absorb 13422kJ will only need a small portion of that 107 litres.

. :D

that third third third rule Mooools used. The assumption that all the exhaust heat loss needs to included puzzles me?
Also as I pointed out there are other forms 570 times more efficient than paraffin wax, food for thought.
The rest Ocean covered with the phase change.

The radiator is good, but what I spit balled was just a dodge, a musing. The radiator works because it has plenty of cooling air and the water is pretty efficient.

Grumph

18th April 2015, 11:26

When I was looking at improving the air cooling performance on my bike I came across an article on motorcycle radiators. The assumption was that the wind blew through the radiator but this was not necessarily so, the bulk of air could very well be moving sideways across the radiator.

The only way to have air move through the radiator was to have a depression behind it and this was not always present, even when going fast. But there is always some sort of depression behind a moving motorcycle and the idea was to form a duct from the back of the radiator to the low pressure area at the back of the motorcycle. That way the air at the front flowed through the radiator to fill the depression behind it.

This thinking is influencing how I arrange the air ducting for my new bike.

When the factories started using pressurised airboxes I watched with interest the frame mods which were required - steering heads which were effectively box sections to allow air passage. If you're going to harness the low pressure wake air Rob, you may want to look at a box shaped frame - specifically a wedge shaped box, large open end at the rear,smaller inlet duct at the front. Maybe fold up a monocoque ?
Remember the Britten radiator is in the seat so as to use the low pressure wake to drag air through it.

kel

18th April 2015, 12:09

The rules say:

2 stroke 55-125cc air cooled

Whilst there is anyway some interpretation to be had with rules, they do not say that the 125s are allowed anything but water-cooling, they say air cooled. Therefore, wax cooling or whatever other matter state changing cooling would seem to be against this simple rule.

Why? Obviously the intent of the rule is direct air cooling with no other medium involved, but I don't see the word "direct" anywhere in the rule.

Frits Overmars

18th April 2015, 12:23

Obviously the intent of the rule is direct air cooling with no other medium involved, but I don't see the word "direct" anywhere in the rule.If you look at it that way, water cooling is air cooling too, unless you leave the radiator at home and apply a total loss water cooling system, which would be forbidden because of the water spillage on the track.
Writing watertight rules ain't easy :no:.

Ocean1

18th April 2015, 12:54

Ocean1

18th April 2015, 12:57

Writing watertight rules ain't easy :no:.

Sure it is. You just have to define what IS allowed, rather than what's not.

And in doing so you eliminate any technical development whatsoever.

F5 Dave

18th April 2015, 13:02

Just hit buy for a mustang intercooler pump which supposedly does 30l/m, only drawback 2.8A which is twice what my galley pump draws, hopefully charging cct can keep up.

Anyone have a decent cheap temp gauge idea? I've been through 3 Daytona ones over the years.

Frits Overmars

18th April 2015, 13:36

Writing watertight rules ain't easy
Sure it is. You just have to define what IS allowed, rather than what's not. And in doing so you eliminate any technical development whatsoever.Eliminating technical development is the last thing I want to do. Besides, defining what is allowed will make the rulebook five times as thick and there will always be omissions. For example, you won't be allowed to change your tire pressures if the rulebook doesn't say that you can.

Ocean1

18th April 2015, 13:56

Eliminating technical development is the last thing I want to do. Besides, defining what is allowed will make the rulebook five times as thick and there will always be omissions. For example, you won't be allowed to change your tire pressures if the rulebook doesn't say that you can.

Oh I agree. The alternative does exist, though, there are competition classes that basically specify a standard production vehicle and a very short list of permissible alterations. The objective is obviously to remove any variables other than the pilot.

And while I don't have a problem with that I don't find such racing very interesting. Probably because I'm a singularly inept pilot. I do enjoy seeing technical innovation reaping rewards, though. I guess the trick is balancing the rules in order to penalise both skill sets as little as possible.

kel

18th April 2015, 14:29

If you look at it that way, water cooling is air cooling too

Agreed, I even considered testing this theory but figured I'd be disqualified by some supplementry ruling introduced on the day.

wobbly

18th April 2015, 14:33

kel

18th April 2015, 15:41

We have been thru all this bollocks before.
Here we have a group where the majority have trouble getting the ports in the right place, even more trouble stopping what is very basic
old technology from seizing regularly, yet we are deep into a discussion about bloody wax filled heads.
Sure - interesting, but how relevant really.

Interesting take on the discussion.
I for one have only had one actual seizure, and that was due to overheating. My old tech air cooler with its ports in the wrong place is making an easy and fat 29+ rear wheel hp, there's more in there but how do I effectively cool it? Personally I feel the discussion is both interesting and relevant. Of course my time would be better spent focusing on handling, but that's not nearly as interesting.

cotswold

18th April 2015, 17:09

Interesting take on the discussion.
I for one have only had one actual seizure, and that was due to overheating. My old tech air cooler with its ports in the wrong place is making an easy and fat 29+ rear wheel hp, there's more in there but how do I effectively cool it? Personally I feel the discussion is both interesting and relevant. Of course my time would be better spent focusing on handling, but that's not nearly as interesting.

You have an NF4 chassis when you get it set up well only Rods TZ would be any better handling.

TZ350

18th April 2015, 17:11

... trouble stopping what is very basic old technology from seizing regularly, yet we are deep into a discussion about bloody wax filled heads. Sure - interesting, but how relevant really.

Old technology is what we have to work with (until unrestricted MX85's come along :devil2:) and the first step to making more power with the ports in the right place on these outdated engines is to organise sufficient effective cooling for the target power output.

If you want to explore the limits of what is possible with the old engines then, its figuring out the cooling first, then making power. Otherwise you really will keep seizing all the time.

And like Kel said, we would probably be much better off looking at handling and setup and putting a lot of thought into our riding technique, but thats boring for some of us. My interest is building bikes first, then trotting them around at a pace I understand, turns out that is quite a bit slower than others manage.

How much can hp help a good rider, its a good question.

As I have recently been sent an official MNZ report written after dyno testing of the top three standard production bikes at a recent meeting where there were some very good riders on supposedly equal machinery.

At the end of the day there was a feeling around the pits at HD that the winner who took it away by a country mile may be benefiting from a power advantage.

But more on this episode later.

F5 Dave

18th April 2015, 17:16

You have an NF4 chassis when you get it set up well only Rods TZ would be any better handling.
Wrong. On a kart track they under steer. A GPR framed bike handles way better and so would a NX4. DDs bikes have further work to jack the rear up more than poss std I'm trying that next.

peewee

18th April 2015, 19:04

speaking of cooling systems , i was looking for info on the 2016 ktm 2t bikes because i heard rumor that ktm will have a 350cc 2t this year, maybe its all rumor as i couldnt find any evidence of it. ktm seems to be keeping the new 2t hidden for the most part but i found something kind of neat that i havent seen on any of the other jap mx bikes. appears ktm is starting to look more closely at the little things. they designed new gaurds in front of the radiators to better direct the air. 10% better cooling efficiency while maintaining the same coolant capacity and radiator surface area as previous years. maybe its old hat but ive had a ton of mx bikes and they always have just plain old plastic gaurds in front of the rads.

"KTM’s engineers put lots of thought into their radiator design. Rather than just put old-school plastic guards on the front of their radiators, KTM used wind tunnels to design a new radiator guard shape that flows more air (and is made from a stiffer plastic to help the flow and act as a radiator brace). The radiator shrouds also seal against the outer edge of the radiators to direct airflow into the radiator’s cores. There is a new filler cap and filler neck that seals better than last year’s design. The end result of all of this work is that the exact same capacity and surface area produces 10 percent better cooling efficiency"

TZ350

18th April 2015, 19:41

310886

Ducting ... food for thought.

Moooools

18th April 2015, 20:18

Two significant difference between water and a designer-wax: #1: You're not allowed water.

#2: Cooling water isn't changing phase from solid/liquid/gas. The various thermal waxes are designed to phase change at a specific temp. Applying heat initially simply warms the wax up, but as the temperature approaches that required to change the wax from solid to liquid the temperature simply stops rising. And it'll remain constant as the wax soaks up the huge quantities of energy required to change phase.

So a wax designed to change at 50deg and absorb 13422kJ will only need a small portion of that 107 litres.

But I'm not a process engineer, which is why there's some numbers missing from the above. :D

Oooops. Thought you were talking about water. I completely failed at reading the previous thread entries. It was late and was in that 'hey I could work that out mode'.

My revised estimate is 44kg of wax.

I got to this by adding the energy of heating the wax from 20deg to 50deg to the energy expended in melting the wax. Which is 305kJ/kg.

13422/305 = 44kg.

You would also run into problems with ensuring you don't end up with all of the wax around the cylinder boiling and the rest being at ambient temperature. With a liquid it is easy to pump around but a solid will experience a temperature gradient.

The reason it isn't 507 times better than water is that the energy required to melt it only happens over a couple of degrees. It is kind of a one time event and is hard to compare to heating water.

Water has a Cp of 4.18 but you get to heat it through 30deg. 30*4.18 which is 125.4kJ/kg. SO the wax is only about 2.5 times as good for the same temperature range at 305kJ/kg.

Moooools

18th April 2015, 20:42

that third third third rule Mooools used. The assumption that all the exhaust heat loss needs to included puzzles me?
.

It isn't included. The rule goes that if you measure an output of 30hp at the crank, there is also 30hp going to the exhaust stream, and also 30hp going to the cooling. The engine is putting out 90hp and you can get 30 of that to the rear wheel pretty much.

husaberg

18th April 2015, 20:44

It isn't included. The rule goes that if you measure an output of 30hp at the crank, there is also 30hp going to the exhaust stream, and also 30hp going to the cooling. The engine is putting out 90hp and you can get 30 of that to the rear wheel pretty much.

Cheers that makes more sense.

Oooops. Thought you were talking about water. I completely failed at reading the previous thread entries. It was late and was in that 'hey I could work that out mode'.

My revised estimate is 44kg of wax.

I got to this by adding the energy of heating the wax from 20deg to 50deg to the energy expended in melting the wax. Which is 305kJ/kg.

13422/305 = 44kg.

You would also run into problems with ensuring you don't end up with all of the wax around the cylinder boiling and the rest being at ambient temperature. With a liquid it is easy to pump around but a solid will experience a temperature gradient.

The reason it isn't 507 times better than water is that the energy required to melt it only happens over a couple of degrees. It is kind of a one time event and is hard to compare to heating water.

Water has a Cp of 4.18 but you get to heat it through 30deg. 30*4.18 which is 125.4kJ/kg. SO the wax is only about 2.5 times as good for the same temperature range at 305kJ/kg.
Read the link in my post read all the way to the endhttp://www.autospeed.com/cms/article.html?&title=The-Fusion-Intercooler&A=110772

•Melting point: 52 degrees C
•Specific heat: 3.27 kJ per kg per degree C
•Specific heat of fusion: 210 kJ/kg

So to increase the temp of 1kg of the wax from 47 to 52 degrees takes 16.35kJ, but to push it past 52 degrees takes nearly 13 times as much energy. (Or, to risk causing confusion, you could dissipate in it a power of 14kW for 15 seconds to melt 1kg.)

Then consider there is a substance that is actually 570 times more efficient than simple paraffin wax.http://www.sciencedirect.com/science/article/pii/S0927024810000474
This was on the first page of a google a few seconds at most.
The required energy to phase change is huge.

As Wob inferred it is just a diversion bandaid I found in a few seconds on google When the real answer is water cooling.
But as Rob found when he did the 24mm venturi There are ways around technical rules.

Frits Overmars

18th April 2015, 23:00

there are competition classes that basically specify a standard production vehicle and a very short list of permissible alterations. The objective is obviously to remove any variables other than the pilot.I agree. In Dutch moped racing there are two classes with a lot of technical freedom. Together they share one page in the rulebook with room to spare. That part of the rulebook is 'allowed unless mentioned'.
There are also two classes where the bike has to remain 99% standard. Together they occupy 8 pages in the rulebook. They also cause eight times the amount of discussion at scrutineering. This part of the rulebook is 'forbidden unless mentioned'. And let me tell you: I hate to write this kind of rules.
These standard classes came into being because of the increasing number of riders that don't know a spark plug from an exhaust pipe. They offer great racing but zero technical inspiration; they have produced riders of european championship level, but decent mechanics are threathened to become extinct.

.. I feel the discussion is both interesting and relevant. Of course my time would be better spent focusing on handling, but that's not nearly as interesting.Oh, but it is. Once you experience what you can achieve by turning a pair of shock absorber knobs, you'll be hooked.

Old technology is what we have to work with and the first step to making more power with the ports in the right place on these outdated engines is to organise sufficient effective cooling for the target power output. If you want to explore the limits of what is possible with the old engines then, its figuring out the cooling first, then making power. Otherwise you really will keep seizing all the time.True, and it's not only valid for old engines. Modern engines are not so prone to seizing, but they won't produce real power either without good cooling.
Nowadays an engine needs a large crankcase volume, all the port area you can cram into the cylinder circumference, good ducts for efficient flow and directional control, an exhaust that sucks and blows hard at the appropriate moments, and cooling, cooling, cooling.

Yow Ling

18th April 2015, 23:08

Cheers that makes more sense.

Read the link in my post read all the way to the endhttp://www.autospeed.com/cms/article.html?&title=The-Fusion-Intercooler&A=110772

Then consider there is a substance that is actually 570 times more efficient than simple paraffin wax.http://www.sciencedirect.com/science/article/pii/S0927024810000474
This was on the first page of a google a few seconds at most.
The required energy to phase change is huge.

As Wob inferred it is just a diversion bandaid I found in a few seconds on google When the real answer is water cooling.
But as Rob found when he did the 24mm venturi There are ways around technical rules.

You seem to have substituted "570 times higher thermal diffusivity" with "570 times more efficient than" I cant see the similarity myself

husaberg

18th April 2015, 23:34

You seem to have substituted "570 times higher thermal diffusivity" with "570 times more efficient than" I cant see the similarity myself

570 times more Efficent at thermal diffusivity than paraffin wax
Thermal diffusivity is a measure of thermal inertia.
My guess is this is the stuff added...... Pyrolytic carbon.
https://www.momentive.com/Products/Main.aspx?id=22860
It seems from a quick peak that when arranged and treated properly to conduct most of its heat in one direction only.

Which made me think of a diode. Form 3 again. What's that year 8 schooling now.

I wonder if there was such a thing as a heat Diode. Well it turns out there actually is.
http://en.wikipedia.org/wiki/Thermal_diode
http://newsoffice.mit.edu/2009/thermoelectric
http://www.popsci.com/technology/article/2009-10/overheating-microchips-may-find-relief-one-way-heat-diodes
But like I said I am only spit balling

http://i.imgur.com/ZGcChkf.gif

Yow Ling

19th April 2015, 08:11

here is a thermal diode

310890

husaberg

19th April 2015, 09:50

here is a thermal diode

Yeah I seen that and I have seen the Propane thermal engine
But the diodes turns waste heat directly into electricity at 18% efficiency at the moment. (Three birds one stone.)
Which I guess is about half the efficiency of a old coal fired power station.

peewee

19th April 2015, 14:37

what you guys think. picked up some new used carbs to try. ill need to make a proper intake manifold but it shouldnt be to difficult considering they will be a nearly straight on shot. any advice for converting these to methanol ? oh ya and should the manifold be as short as possible ?

Moooools

19th April 2015, 20:58

Cheers that makes more sense.
Then consider there is a substance that is actually 570 times more efficient than simple paraffin wax.http://www.sciencedirect.com/science/article/pii/S0927024810000474
.

You seem to have substituted "570 times higher thermal diffusivity" with "570 times more efficient than" I cant see the similarity myself

Yow has it right. A higher thermal diffusivity in this case will just cause a lower temperature gradient through the wax (570 times lower though!). You will still need 44kg of the stuff.

husaberg

19th April 2015, 21:13

Yow has it right. A higher thermal diffusivity in this case will just cause a lower temperature gradient through the wax (570 times lower though!). You will still need 44kg of the stuff.

Nah the original post your KG's don't add up.
Read why they use Paraffin wax.
Your calculations miss the phase change.
I am not interested in its ability to shed the heat afterwards, only is ability to draw it away. Ie one plane heat conductivity

Moooools

19th April 2015, 21:59

Nah the original post your KG's don't add up.
Read why they use Paraffin wax.
Your calculations miss the phase change.
I am not interested in its ability to shed the heat afterwards, only is ability to draw it away. Ie one plane heat conductivity

No I accounted for the phase change.

98kJ/kg comes from heating the solid wax from 20deg to 50deg.
210kJ/kg comes from the phase change.

Still only ~305kJ/kg.
13422/305 = 44kg.

It doesn't matter if the wax gets 570 times better at conducting heat; it can still only absorb 305kJ/kg for this temperature change.

husaberg

19th April 2015, 22:16

No I accounted for the phase change.

98kJ/kg comes from heating the solid wax from 20deg to 50deg.
210kJ/kg comes from the phase change.

Still only ~305kJ/kg.
13422/305 = 44kg.

It doesn't matter if the wax gets 570 times better at conducting heat; it can still only absorb 305kJ/kg for this temperature change.

but to push it past 52 degrees takes nearly 13 times as much energy.
How many bikes do you know that run under 52 degrees?
Also races are not indefinite periods of time.
Nor is power output. Percentage of time at full throttle rarely exceeds 2 percent.
Also its not only wax though is it if you use a composite.

Haufen

20th April 2015, 00:13

What kind of coolant is allowed in MotoGP racing? Is it pure water only, or are you allowed to mix with some anti-corrosives, too?

senso

20th April 2015, 03:55

Give the bluish tint that the RSA cylinders have in some photos I would risk to say that they run some coolant liquid that is more than just plain water.

Yow Ling

20th April 2015, 06:01

Percentage of time at full throttle rarely exceeds 2 percent.
.

you need to ride a bucket at ruapuna, probably closer to 50% wot, maybe more

Grumph

20th April 2015, 06:56

Also races are not indefinite periods of time.
Nor is power output. Percentage of time at full throttle rarely exceeds 2 percent.

There are two rules of thumb here husa.

1/ The smaller the bike, the longer a race seems to take...

2/ The smaller the bike the longer the proportion of a lap it will be on full throttle.

The last is very real and applies regardless of circuit size though obviously bigger circuits show up any shortcomings whether mechanical or cooling, quicker.
Pukekohe in particular was death for small bikes with only two spots each lap where the throttle was closed. Even the aussie V8's were reporting around 60% of each lap on full noise.

wobbly

20th April 2015, 08:51

The intake length question depends entirely on the rev range to be used.
What rpm at peak and max will be used in the twin.

And re the question about what engines run under 52*C the answer is all of them should be.
Karts run best at around 42 to 45 and any GP bike over 50* is simply throwing away HP - the difference between
50* and 60* is 2 to 3 Hp when making near to 50.

FastFred

20th April 2015, 09:48

Moooools

20th April 2015, 11:07

but to push it past 52 degrees takes nearly 13 times as much energy.
How many bikes do you know that run under 52 degrees?
Also races are not indefinite periods of time.
Nor is power output. Percentage of time at full throttle rarely exceeds 2 percent.
Also its not only wax though is it if you use a composite.

In this case your understanding is wrong. http://en.wikipedia.org/wiki/Enthalpy_of_fusion
The 210kJ/kg is the enegry taken to push it past 52 degrees.

I accounted for a 10 minute race. That is where 13422kJ came from 22.xxkW x 60 seconds x 10 minutes = 13422kJ.

My assumption was full throttle all the time. This is a common assumption for cooling design. Mainly because if your cooling fails, so does everything else, which is shit.

If you wanted to live on the wild side, you could maybe assume a 50% average throttle (50% of maximum engine power that is) for the entire race. Congrats: 22kg of wax.

peewee

20th April 2015, 12:09

The intake length question depends entirely on the rev range to be used.
What rpm at peak and max will be used in the twin..

in engmod ive got it set to 11000 rpm for peak power. if i port it to the time areas eng mod is saying and use an apropriate pipe then i should be good i think.

TZ350

20th April 2015, 16:17

2T's dominate at Mt Wellington Sunday.

Mt Wellington, First A grade race, two strokes 1 - 2 - 3 and 4. Second A grade race finishing order, two strokes 1 - 2 and 3 with one of the 4 having crashed out, Dave M sets new lap record 28.9 something riding what I think is a Speedpro tuned MB100 based 2T in an Aprilia 50 chassis.

Getting fast in A grade. Great to see the 2T's leading the pack. http://www.amcc.org.nz/index.php/menu-bucketracing/bucketracingnews.html

Hi all,

Yet another great day of racing in the sunshine at Mt Wgtn. Our good fortune with the weather over the past couple of seasons continues and two lap records were set this weekend!

Congratulations to Dave Manuel for his 28.913-second lap record in F4 race 1! And in race 2, Dave put some serious pressure on Nathanael Diprose and came away with the win. It was Nathanael's first loss (in either F4 or F5) and first crash in a points race this season.

Congratulations also to Rick Ford and Henk Zeeven for lowering their own sidecar lap record to 34.522 seconds. They were chased all the way by Dean and Erica which undoubtedly gave them the necessary hurry up. It was great sidecar action for the spectators.

The details are published on Mylaps here: http://www.mylaps.com/en/events/1125894

Current F4 points: http://organisation.mylaps.com/championship/view.jsp?id=38264
Current F5 points: http://organisation.mylaps.com/championship/view.jsp?id=38265
Current B-Grade points: http://organisation.mylaps.com/championship/view.jsp?id=38262
Current C-Grade points: http://organisation.mylaps.com/championship/view.jsp?id=38263
Current Sidecar points: http://organisation.mylaps.com/championship/view.jsp?id=38266

We even have some pitbike points since the guys were using transponders this time: organisation.mylaps.com/championship/view.jsp?id=42900 (http://organisation.mylaps.com/championship/view.jsp?id=42900)

The AMCC website bucket racing news page is updated here: http://www.amcc.org.nz/index.php/menu-bucketracing/bucketracingnews.html. This includes all the current lap records at Mt Wellington.

Happy viewing.

Tim

Holy crap look at the pace of A grade! Congrats Dave, that's a stupid lap time right there.

You're telling me, I ran sub 31s clockwise for the first time ever I think, good enough for fifth and sixth

What an awesome weekend at Mt Wgtn.

F4 A-grade saw 2Ts place 1-4 in race 1 with Dave Manwell 2nd and Gary 3rd. Manwell was on a mission but Nathaniel held him out for the win. Race 2 looked to be shaping for a repeat. Dave put a move on Nathaniel in the sweeper but Nathanial wasn't having any of it and shut the door on Dave good & proper with the result that Dave lost a lot of ground and spent a moment on the grass. I was flagging and saw Nathaniel go past with no Dave in pursuit and thought the worst, but Dave flew on past a moment later. It seemed that Nathaniel could pull a length or 2 on the straight but Dave made it all back in the sweeper by carrying some serious speed all the way. Running clockwise, exiting the infield onto the back straight he had it sliding sideways. Pretty impressive to watch. Nathaniel was caught back up in a couple of laps and the pressure put back on. Possibly he succumbed to that pressure, but whatever, he slid off on the infield a few laps later and his race was over. Gary was having a good tussle of his own but managed to hang on for 2nd. So race 2 has 2Ts in places 1-3. When I heard Dave had set a new lap record I thought it must have been in the 2nd race given how he seemed to be riding to catch Nathaniel but the time was from race 1.

Those Aprilia chassis are pretty good. Anyone who has ridden Dave's one really likes it and of course Tim's 50 goes round corners pretty good as well. Both of them are superb riders of course. Gary had his MB flying but he was definitely pushing the limits of a stock MB chassis even if it now has RS125 running gear. One moment exiting the back straight had him pull over to check the front wheel wasn't loose or jamming on something. The likely problem was that he was slightly off his usual line and ran over ripples which caused a bit of an upset.

Cricket was the only 2T in F4 B-grade riding Gary's MB100. He had a handy power-weight ratio and used it to advantage. Having said that he does seem to like diving up the inside of other riders at the end of the sweeper. He placed a fairly handy 5th in both races.

Gary had the camera on for the points races so hopefully we'll have video to post later.

No changes to either bike since Tokoroa. In fact they were put in the shed after Tok' and pulled out for this weekend. They are now back in the shed and will probably only get looked at when we pull them out for the next meeting, unless the new billet watercooled heads turn up. Really looking forward to getting hold of them as both bikes fade badly after a couple of laps at the moment.

Alright ladies, here's some photos from the weekend. There aren't many because I only stuck around for practice, qualifying
Wish I stayed around longer to see the lap record being beaten and the Dave taking on Nathaniel - finally someone has to do it!
It was fun taking photos again, even if I went there to ride :facepalm:

Anyone got a clutch cover I can buy?

CLICK HERE FOR ALBUM
https://www.flickr.com/photos/sonscc/sets/72157652099920135/

https://farm8.staticflickr.com/7594/17013788357_00cd31627a_c.jpg (https://flic.kr/p/rVs7wz)

https://farm8.staticflickr.com/7638/16601049003_bf7ff738ce_c.jpg (https://flic.kr/p/rhYHuP)

https://farm8.staticflickr.com/7668/17035082219_d02ac102e1_c.jpg (https://flic.kr/p/rXkfs8)

https://farm6.staticflickr.com/5452/17033723040_38baa0b4c9_c.jpg (https://flic.kr/p/rXdhq1)

https://farm8.staticflickr.com/7676/17035110959_7a265a5ae0_c.jpg (https://flic.kr/p/rXkoZD)

Kickaha

20th April 2015, 18:03

you need to ride a bucket
Yes he does, I doubt it will happen in my lifetime

wobbly

21st April 2015, 08:34

Here is the intake model for a HV Lectron 40 with Honda RS125 manifold on CR125 VF3.
This is 3rd harmonic tuned to 11,000 with end correction and 2/3 reed length.
Going 10mm longer gives +1 Hp at 8000 but looses that above 11,000.
Works perfectly on RZ or TZ400 with CR125 reed box welded on.

peewee

21st April 2015, 13:52

for now i think ill stay with the original cylinder inlet and vf4 reed. to give a simple answer, does a short intake manifold usually work better at high rpm than a longer one ?

wobbly

21st April 2015, 16:03

There is no short answer, as we are talking about the interaction of the particular intake harmonic tuned
length and the petals natural frequency, so its complicated as hell.
You can tune to have the intake length work at peak power to enhance that area, but its just as possible to go alot longer
and pick up a heap of mid, with no loss up top by using a different harmonic.
How much crank power are you shooting for - as the small Banshee VF3 and 4 very quickly run out of flow - also needing big Boyesens
and piston cutouts to work well.

seattle smitty

21st April 2015, 16:38

"KTM’s engineers put lots of thought into their radiator design. Rather than just put old-school plastic guards on the front of their radiators, KTM used wind tunnels to design a new radiator guard shape that flows more air (and is made from a stiffer plastic to help the flow and act as a radiator brace). The radiator shrouds also seal against the outer edge of the radiators to direct airflow into the radiator’s cores. There is a new filler cap and filler neck that seals better than last year’s design. The end result of all of this work is that the exact same capacity and surface area produces 10 percent better cooling efficiency"

But did they only wind-tunnel-test just what shows in your photo, Peewee? Or did they also test the airflow in front of those radiators as disturbed by the tire/rim/brakes/forks/fork-clamps/etc. ??

TeeZee, I like that 3-part bad/okay/good diagram. Notice that in the "good" version, velocity is traded for pressure immediately in front of the radiator core.
Aircooled recip aircraft engines all have "pressure-cowlings." Interestingly, when a cowling was built for the gigantic Pratt & Whitney R4360 28-cylinder radial, with four rows of seven cylinders (two sparkplugs each, 56 per engine), it was found that the aft-most row of cylinders ran cooler than the cylinders in the other three rows!

peewee

21st April 2015, 17:21

wobbly im shooting for around 90hp which i dont think is unreasonable if everything is done right. as you know my low temp brazing rod idea failed, atleast for the large amount of welding that needed to be done but im going to have a new tig machine soon, so ill be able to weld all the apropriate areas. inside the trans ducts, water jackets for the aux exh, stud pockets for the boyens, etc.

ill have plenty of case volume, slightly below 1.32. i am a little concearned the 34mm down sloped carbs i just picked up may no be sufficient but i really dont know. maybe they will be fine, one guy claimed he bored some to 36mm but im sure they were extremely thin. vf4 looks good in engmod, far better than the yamaha block. nothing much else i can do besides cut the inlet off and do a cr125 inlet like you mentioned but i dont want to attempt that right now.

i just picked up 2 stock heads. one i plan to use and the other is junk but im going to cut it open and see how thick the combustion chamber is. what i want to do is use the good head with a chamber design like what the rsa had, if theres sufficient material to do so

smitty i have no idea exactly how ktm did the wind tunell test. the only info i have at this time is what i posted, as that was the only info given in the article. could they be stupid enough not to account for all obstructions like you mentioned (tire, forks, fender, etc) ??? :laugh:

Dutch Fisher

22nd April 2015, 09:08

What kind of coolant is allowed in MotoGP racing? Is it pure water only, or are you allowed to mix with some anti-corrosives, too?

Distilled Water, with Glycerol anti-freeze. The Glycerol has noncorrosive properties and raises the boiling point of water, it also reduces the surface tension of water. To further reduce surface tension Acetone can be added in a ratio of 1 drop to 1 litre of water.

jasonu

22nd April 2015, 12:19

2T's dominate at Mt Wellington Sunday.

Mt Wellington, Dave M sets new lap record 28.9 something riding what I think is a Speedpro tuned MB100 based 2T in an Aprilia 50 chassis.

What direction around the track was this time set?

speedpro

22nd April 2015, 12:21

clockwise +ten characters

jasonu

22nd April 2015, 16:05

clockwise +ten characters

Sheeeittt that's fast. Last century I did a 31 something on Darrin Gossamers RG50 and thought that was pretty good, now it's rubbish, probably not even good enough for top 10.

TZ350

22nd April 2015, 16:24

Haufen

23rd April 2015, 04:22

Distilled Water, with Glycerol anti-freeze. The Glycerol has noncorrosive properties and raises the boiling point of water, it also reduces the surface tension of water. To further reduce surface tension Acetone can be added in a ratio of 1 drop to 1 litre of water.

Thanks, do you happen to know the percentages of water and glycol which were used? I am wondering because as water has a higher thermal capacity than glycol and thus switching from the typical 50/50 mix to pure water would be an easy 5 deg C drop or so in the coolant temperatures.

F5 Dave

23rd April 2015, 06:08

Pen rite 10 tenths is mixed at a lower ratio like 4:1 and is track legal. Will be a corrosion inhibitor (important for good heat transfer over the long run). But is not an antifreeze, but skidoos aside who cares?
Water wetter is another option

FastFred

23rd April 2015, 14:41

do you happen to know the percentages of water and glycol

Glycol is illegal for Road Racing in NZ, because radiator water spills leave a dangerous greasy mess on the track if it has glycol in it.

lodgernz

23rd April 2015, 16:27

Dutch Fisher

23rd April 2015, 18:48

Thanks, do you happen to know the percentages of water and glycol which were used? I am wondering because as water has a higher thermal capacity than glycol and thus switching from the typical 50/50 mix to pure water would be an easy 5 deg C drop or so in the coolant temperatures.

2-5% Glycerol. The need to stop micro pitting in the Magnesium and Aluminum parts used in the cooling system is why it's used. Mg and Al don't like an alkaline solution touching them so the pH level has to be lowered to a more acidic level. The pH level drops in pure water as its heated anyway, but starting with a pH of about 6 helps.

We were talking about Glycerol, not Glycol. They're not the same

Correct

richban

24th April 2015, 20:16

Well she's all back together now. Really happy with the first tuning run. A very fat 11% power increase over the old barrels. In the pic you can see some work in progress. chopped the piston skirt and put a radios on the duct and bridges. The exhaust ports are way bigger and the B ports are cut back around towards the boost a lot more then the old barrels. Also I have a new massive radiator to keep temps under control. She sat a 55 happy as on the dyno.

Can't wait to unleash the new power.

speedpro

24th April 2015, 20:44

Saw "300 Update" from Richban and immediately thought it was a report on his new bucket

Henk

24th April 2015, 20:51

Saw "300 Update" from Richban and immediately thought it was a report on his new bucket

Bucket has been at 325 for the last two years.

Pumba

24th April 2015, 21:05

He is not even trying to hide it and has written the side of the cylinder. Presume it 415cc per pot Rich?

richban

24th April 2015, 21:19

Saw "300 Update" from Richban and immediately thought it was a report on his new bucket

Oh dear. Well for your info. The bucket has a buggered big end. So I will maybe give it a birthday and maybe take it to the next oversize......:whistle:

F5 Dave

25th April 2015, 00:03

Stop giving him shit, I've actually seen it and its only 154

Cubic inches.

Lucas M

25th April 2015, 07:54

Frits Overmars

25th April 2015, 09:19

... It is way better rideable than the old one... The difference in the two powerbands responds from different compression ratios, the old was 15:1, the new 9,5:1. When somebody wants to know how you managed to improve the engine so much, feel free to tell the truth; no-one will believe you :D.
(Well, I will).

By the way, did you join that german forum we talked about? If so, what's your nickname?

TZ350

25th April 2015, 09:38

Hello guys. It´s me again. Maybe you remember me from page 1082.

There is some new stuff I want to show you. I have done some machining on the cylinder, the head and I built a new exhaust (slightly different dimensions).

311000

I was able to gain 0,5rwhp but the more important fact is the bandwidth after peak hp. It is way better rideable than the old one, because the hp don´t drop too fast (old dotted blue, new one red, both hp at the real wheel)

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The difference in the two powerbands responds from different compression ratios, the old was 15:1, the new 9,5:1. I am satisfied with my engine and in the moment I don´t plan to change something on it.

Riding video:
https://www.youtube.com/watch?v=49X465mPmHM

Some stuff I built:
https://www.facebook.com/EPsimson

Greetings from Germany
Lucas

I very much like the extra cooling fins that have been added to the crankcase and the improved power curve with the lower compression ratio is very interesting, food for thought, thanks for showing us.

Team ESE are working on RG50's and courtesy of Kel (drawings) and Sketchy (machining) we have heads with inserts.

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I remember Frits suggesting to me to try a lower ratio so when I get my own 50 going I am going to explore lower compression ratios and try different head shapes too, thanks again for showing the results of your work.

Larry Wiechman

25th April 2015, 13:35

What is at work here? The lower compression ratio produces a higher EGT and allows the pipe to produce more over-rev?
Is the corresponding loss below 11,800 also a function of pipe temperature or a victim of less efficient combustion?

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=311001&d=1429911358

husaberg

25th April 2015, 14:08

I can only speak for the Aprilia RSA: its big end bearing is bulletproof. On the test bench it lasts a full season. But on the track it all depends on the rider.
Flashback: when leaded fuel got banned in GP racing, the Aprilias went from a 19.5:1 compression ratio to 14:1. Works riders Harada and Rossi had no problems (on the contrary: the engines became much more flexible) but Capirossi suffered one big end failure after another.
The datalogger revealed the reason: when signor Capirossi came upon a slow corner, he shifted down three times and then grabbed the front brake. In that order. Engine braking they seem to call it. Engine breaking more like...
With the previous 19.5 compression ratio engine braking was such that the revs went up to 15,000 for a moment. But with the 'unleaded' compression ratio Capirossi's engine revved to 17,500. Bye bye big end :facepalm:.

Wobbly has a point here. limiting the ignition retard yields cooler exhaust gas which may even result in your whole engine running cooler.
And in case you fear a loss of overrev, consider lowering the compression ratio. Helps against deto too...
(and in case you fear a loss of power, you could be pleasantly surprised)

Move to unleaded might benefit the thermally challenged as well as a drop in comp

Depends largely on the end use and the bmep capability of the engine.
The defining factor is the dynamic compression - this is created by the addition of the static com and that created by the combination of trapping efficiency and the delivery ratio.
The higher the trapping and delivery efficiencies are then the max static com that can be tolerated short of detonation ,is reduced.
But a good example is a conversion I did to a brand new TM KZ10 kart engine.
This was designed to run in open class and has a 60mm piston giving 152cc.
The regulations only allow unleaded pump gas, and initially it was run with the standard straight line ignition.
I played with a few combinations of com and static advance with a det sensor bolted to a head stud.
This engine would have state of the art trapping and delivery numbers , especially with a VF3 and 36mm carb in place of the 30mm regulated unit.
Thus a fairly low com was needed to get the right combination of peak power and overev capability when pushing up against the over advance created by the non retarding ignition.
It ended up with 13.2:1 full stroke and this setup was right back at the original numbers of 15* advance and 1180*F - the lower egt caused by the excessive advance.
Any lower on the com and the peak dropped ( 58Hp crank @ 12800 ) but any higher and the peak remained constant but it detoed in the overev at 14400 +.
This deto could be suppressed by going richer, but then the power suffered everywhere.
With a proper ignition I would guess at 13.8 :1 and an egt up at 1280 as unleaded burns alot faster than AvGas and added to the extra retard able to be dialled in with a digital.
...............................

wobbly

25th April 2015, 16:27

If you look at the numbers that matter then the performance increase gets put into perspective.
At 9000 its 3 hp down in 8 = a 37.5% loss.
At 12200 it has gained 0.5 in 14 = a 3% increase over baseline - for sure worth having.
So overall the mods are really a colossal failure, but when the rev band really is simply moved to the right by 700 rpm then this will probably
allow a couple of teeth to be added to the rear sprocket and the engine will then accelerate faster to the same terminal speed.

Frits Overmars

25th April 2015, 22:38

What is at work here? The lower compression ratio produces a higher EGT and allows the pipe to produce more over-rev? Is the corresponding loss below 11,800 also a function of pipe temperature or a victim of less efficient combustion?
The higher EGT not only yields more over-rev; it works over the entire power curve, so the pipe is now 'too short' below 11800 rpm.
As a result, below 11800 rpm the cylinder filling will suffer compared to that of the original high-compression engine, combustion will be slower, that will raise the EGT even more, and this 'chain reaction' causes the substantial power loss below 11800 rpm of the low-comp engine.
In addition, the high-comp engine has a bigger expansion ratio, hence less-energetic exhaust gas, that will do less harm at the torque hole at 2/3 of max.torque rpm.
In short: the low-comp engine has more potential because it feeds its exhaust pipe with more-energetic exhaust gas, but it is also more pipe-dependent.
It may also take more advantage of a programmable ignition, but I'm not sure if this is allowed in the Simson-class that Lucas is riding in. Lucas??

... when the rev band really is simply moved to the right by 700 rpm then this will probably allow a couple of teeth to be added to the rear sprocket and the engine will then accelerate faster to the same terminal speed.Right, Wob. You could say that if we move the low-comp power curve to the left (or the high-comp curve to the right), the low-comp curve will fit over the high-comp curve everywhere. But rather then moving the whole curve by 700 rpm, I would propose to move each rpm point of the curve by 5,9% (high-comp max.power is delivered at 11550 rpm; low-comp max.power is delivered at 12235 rpm; 12235 / 11550 = 1,059).
With such a percentage-operation the curve will not simply be moved, but it will be stretched or compressed; the zero rpm-point will always remain zero rpm, as it should.

As it happens, I just received a mail from Neels van Niekerk, better known as Vannik, the brain behind EngMod2T. Neels has been playing with my power range concept and he also appears to visit the Kiwibiker forum. It was a pleasant surprise that he sent me both Lucas' power sheet and the corresponding power range graph.
The power range concept compares power curves on the basis of the acceleration that they can provide, and as Wobbly already predicted, the low-comp engine (the red power range curve below) is a winner, when geared appropriately.
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TZ350

26th April 2015, 17:51

Finally getting some place with the EFI after strapping a small laptop onto the tank and riding the bike around looking for the bad spots in the map. I can now wind it out, throttle off and have it come back onto the throttle again. Its now ride-able enough to make it worth taking to a practice day for further refinement.

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Dyno runs recorded at 100-90-80-70-60-50-40 and 30% throttle.

I have made more power in the past but the point of these dyno runs is that it is running reasonably well at different throttle openings and it is also something of a guide for refining the Alpha-N map some more.

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Its a two stage injector system with three injectors, the middle 60 g/min unit is for starting, slow running and over run after shutting off. A pair of 80 g/min units provide fuel as the engine comes on the pipe then the middle injector chimes in again so all three are firing as the rev's get around 10,000 rpm.

I checked the data logger and the middle injector is chiming back in at 9,500 rpm on WOT so I have achieved one of may aims, squirting raw fuel at the underside of the piston crown to cool it when the engine is making real power, I am very happy with that.

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My Ecotrons 2T two stroke Alpha-N map for the 125 is no where near 100% yet, plenty to refine but at last it is ride-able.

This is the first time I have felt truly optimistic and I am now looking forward to riding it in an actual race.

Ecotrons EFI kits .... http://www.ecotrons.com/products/2_stroke_small_engine_fuel_injection_kit/

The biggest issue was selecting the right sized injectors, I had chosen ones that were to big, to big and there is not enough range of tuning adjustment and it took a while to work my way down to quite small injectors.