ESE's works engine tuner

[RMS eng]

If Ive got this right the original image I posted is the latest RSA
Attachment 229367
Heres the earlier incarnation
Attachment 229366
shows they are always learning/developing

looks like maybe the wops did Jap and made a copy of an old yamaha ?,this is a photo of Ron Lechiens 1983 works OW125 and it has a disc valve motor and the disc is on the back of the motor.driven from a shaft running from the crank.see next to water pump,bike was said to be fastest that year.

[kel]

1983 works OW125 and it has a disc valve motor and the disc is on the back of the motor.

The early YZR500's OW54 to OW70's ran the rear rotary discs, I had no idea Yamaha ran them on the factory YZM's, always thought reeds were the prefered intake on all motocrossers from around 1980 on.

Question for Wobble - What was the thinking behind the dished pistons Kawasaki run on the KX125's? I cant see any clear advantage what with the reduced squish band and its effect on cooling, end gases etc

[Kickaha]

.
And I have an idea how I could make a variable port where the closing point can be changed, much like a blade power valve.

A friend of mine has one of those PVP engines down here, very tasty bit of kit and there was a FPE or BRC over here a few years ago racing, they're pretty much a newer improved Rotax clone, but anything would be an improvement over a Rotax

[TZ350]

Page 230

There are over 1,200 images on this thread, to find the interesting ones use “Thread Tools”, then “View Thread Images” near the top of this page. Using the sort options at the bottom you can view the images 70 at a time from the beginning. And it’s a quick way to find some of the interesting posts too.

Links and Interesting Quotes from the last 10 pages, other link lists can found on the decade pages starting with Page 80.

Re proposed change in rules to "Open Carb for All Air Cooled F4 2 & F5 4 Strokes".

I've checked the MNZ website for contact details for the Road Race Commissioners and called them. I only got through to one and he was aware of the proposed change and was happy to listen to my view of the change.

I encourage others to put their view forward as well. The commissioners and others are due to discuss the proposal and then make a decision. Generally it doesn't sound like they will be getting advice from people such as Wobbly but rely on people calling in.

Call them...... and to make it simpler here are the two to phone. I spoke to Neil.

Road Race Commission Chairman Peter Ramage 09 443 3111 a/h
Road Race Commission Neil Smith 03 5786208 a/h

A handy (and cheep) Porting Calculator from:- http://www.porting-programs.com/ is based on Blairs and Jennings work.

An interesting book by Eric Gorr……. http://books.google.com/books?id=4Me...page&q&f=false

Interesting read about the future of 2-strokes and direct fuel injection ........
http://www.dirt-bike-tips-and-pics.c...o-strokes.html

And Pictures……. http://www.google.co.nz/images?clien...w=1024&bih=574

For those that want to experement with different carbs for their bike........ all sizes of copy cat Keihin flat slides, 24-28-32-34. Cheap enough to modify or play with. http://www.alexwarehouse.com/OKO-carburettor-kit-24mm-26mm-28mm-30mm_p331.html

The normal ignition takes care of the ionisation channel; then as soon as the current starts to flow, the Emot-set sends a big extra current through this channel. It looks like this: http://www.youtube.com/watch?v=7BfQuxyWN90

And if you really want to know all about sparks, look here: http://www.madsci.org/posts/archives...3778.Ph.r.html

The Asian factories use SCM - 415 forgings, but for one off's then EN 36 or 39B case hardened to 58 - 62Rc is the shit. Mallory Metal slugs are the go for ballancing….

Right so some 4140/4340 would be the go should I do a short stroke crank. Wikipedia link on mallory metal. http://en.wikipedia.org/wiki/Mallory_metal

Crank wheels need a ductile core, so all the surfaces that wont be ground need to be painted with a copper based coating to prevent the hardening gas from thru hardening the whole part.

EN39B is the best material and is readily available.Heat treatments ltd can do all the processes including stress relief after rough machining the shape - talk to Adam there if you are going to do a crank.

A true Toroid shape was developed to control deto with unleaded fuel, the processes involved work just as well with better octain fuels.

The zero corner rad was a "secret" for years that I tried for the first time when working with Bartol on his Yamaha and my BSL cylinder layout - well before Thiel and Aprilia got onto it.

But its funny how people make "assumptions" that are usually revealed later as "errors". A CFD analysis of the Toroid head shows that the mixture ejected from the squish, actually adheres to the vertical wall, around the sharp corner, and rotates anticlockwise - opposite to what Frits shows. This is why it works even better with a flat top piston.
Who cares though - it works.

the Dellorto with the "Fiat Uno" stepper motor was soon replaced by the stock Keihin solenoid as shown in the pic above.
This was better than the original solenoid in that it can be "pulsed" or PWM controlled by the ECU to vary the fuel flow as needed when the Deto sensor ( on the head - from a Subaru) said bad shit was happening.

My crankpin was made by heat treatments. machined, heat treated, and ground. Hasn't let go yet but still early days. 20mm ends with a 22mm centre, offset .75mm. Very helpful guys.

Setting up an IgniTech Ignition . There are more pictures and a vido on the original post.

......setting up NedKellys IgniTech programmable Ignition.......

Here is TKR's home site, http://www.tkrj.co.jp/product/index.html
There is a 13mb PDF download catalog with dimensions.

Eric’s cockpit video of the 125cc 187mph down run:
http://www.youtube.com/watch?v=Vz_r_3yqqR4

John’s cockpit video from last year of a 50cc 141mph return run:
http://www.youtube.com/watch?v=mYINrhTNiyM

If it was possible to get a port/duct layout like an RGV cylinder ( even thats not a very good example) into an aircooled, the 25% increase in cubes would make it a very potent machine.

Yamahas SAE paper on transfer ports http://www.2stroke-tuning.nl/media/pdfjes/porting.pdf

Some Links I've been reading that may be useful regarding handling etc..
http://www.motorcycle.com/how-to/cha...sics-3444.html
http://www.fatbaq.com/mainpage.phtml?topic=sag
Current Model 125 Specs Straight from the maker:
http://world.honda.com/HRC/products/...e/rs125r/spec/
Another on aerodynamics:
http://www.sportrider.com/tech/146_0106_aero/index.html

Interview with Jan Thiels about his work with Rumi ............
Translated version:- http://translate.google.co.nz/transl...24%26bih%3D574 %26prmd%3Divns

[F5 Dave]

A friend of mine has one of those PVP engines down here, very tasty bit of kit and there was a FPE or BRC over here a few years ago racing, they're pretty much a newer improved Rotax clone, but anything would be an improvement over a Rotax

Yeah, that's what I was thinking, how they'd moved on, but a mate has a 256 Rotax from 1980 & it had the measure on the equivalent TZs of the time.

We had it on the dyno some years back & with smaller Mikunis rather than the Mag Delortos & pipes made for NZ goattrack tracks of the time it still made 60hp with a big fat curve & something silly like 10,000 rpm 'cause you can't rev them with the tiny bigends.

Had some idea about buying it & fitting some aprilia rods & going post classic &/or bears, but the one off ally frame it's in is an 83, so its only good for bears & we don't have much up here. + it wasn't easy to pushstart by yourself (sometimes), though some rollers would cure that.

[TZ350]

A friend of mine has one of those PVP engines down here, very tasty bit of kit ........

Thanks for the pointer, did a search on PVP supercarts and found http://www.pvpkart.com/



Yummy looking inlet ports.........



Inlet Opens 136 BTDC Closes 83 ATDC. calculated from their mm BTDC figures.



From what I can make out, Inlet Opens 148 BTDC Closes 86.5 ATDC with soft close.



Sintered Clutch Plate, just what I need for those ripping starts.

[TZ350]

More yummy bits.............

[TZ350]

Recently I got myself (Ebay) a 38mm carb with Throttle PS and Electric PJ from a motor crosser.

Wobbly told me that on those the PJ nozzel is to low and starts to flow to soon for a road racer and the MX ones are hard to tune.



I couldn't afford to buy a good second hand TZ or RS unit. So I figure that moving the discharge nozzel.



And adding an adjustable jet from a large model aero engine could be worth a try.



On the dyno I have seen how a leaner mixture rev's on further and how richining it up for best power the over rev drops off.

I think that as the rpm goes up the mixture strength on an ordanery carb at max rpm goes over rich.

And at the moment I think the idea is that the PV is shutoff after peak power to get back to the correct mixture and by retarding the ignition at the same time extend the over rev, but I am sure there is more to it.

I would love to know more about how this type of carb should be used and/or setup.

[wobbly]

The FPE superkart engine that won the NZ road title at Manfield a few weeks ago makes 92 RWHp on the Dynojet 168 I use.
Still not quite as good as the RS250 setup we did that won at Laguna Superkart Worlds a couple of years ago.

The powerjet carb is controlled by the Ignitech with a combination of throttle position and rpm in a "truth table".
In general the solenoid is activated with 12V ( no fuel flowing) below 4000 rpm and 75% throttle on the TPS.
Above 75% and around 12400 rpm it is activated again to lean off the fuel curve over the top of the pipe.
Looks like you will be able to reverse the fuel exit, blocking off the hole on the throttle bore side, and take off fuel from the outside bung, thru a needle jet and into the top of the venturi next to the slide.

[TZ350]

Wobbly had a look at my RG150 cylinder and this is what he had to say:-

""I have the RG150 sitting here side by side with the RGV. No contest - dump ( sell )the 150 as its in good nik..

The RGV has much smaller duct entries and thus will simply need some filling of the case walls to get a good entry shape.

The RG150 would have way too big taper down to the port area of the 50mm bore, in comparison the RGV will have alot better area ratios and is technically a better basis for sleeving down the small amount needed to get 50mm.

The 150 has a water way in the bridge, that is a good idea in itself, but makes the bridge a huge flow reducer thru the duct down to the exit flange, luckily the bolt pattern is the same. ""

So RGV cylinder it is, the reed valve TF100 cases are away now being bored for the RGV cylinder spigot.



I already have a set of GP rotary valve cases half finished that Bucket has been working on for me.



Also I have started converting a set to a bigger rotary valve for a better inlet port shape/area.

[TZ350]

It sure looks like there are some very interesting 2-Stroke projects being worked on out there. I love seeing pictures of other peoples projects posted on the ESE thread.

Not sure who sent me this, but I remember they said it was ok to post the pictures.

TeeZee check the following link:
http://www.pro-x.com/downloads/Technical.pdf

And check Connecting rod dimensions, there you will find all details.

Best Regards,
Hans van Hulten
International Sales
PMI Europe BV
www.pmi-europe.nl
Pesetaweg 32 - 2153 PJ - Nieuw Vennep - The Netherlands
Tel: +31 (0)252 687713 (ext. 5101)
Fax: +31 (0)252 689252
hvanhulten@pmi-europe.nl

The link came with some photos of their own 125 conversion to water cooled 100cc F4 project.

A sleeved RG125, they made their own sleeve and tell me that the RGV barrel is much the same as the RG125 one but they are both narrower across the transfers than the RG150 one, so some case filling is required if your going to fit a RGV250 cylinder onto a RG150 crankcase.

Their RG125/RGV100 engine looks a much neater solution than fitting an RGV250 cylinder to a GP or TF bottom end like I am doing and their RG engine fits very well into the RS chassis, anyway its a good looking job and they are streets ahead of me.

Another fast bucket heading to track near you and Taupo hopefully.

[kel]

Question for Wobble - What was the thinking behind the dished pistons Kawasaki run on the KX125's? I cant see any clear advantage what with the reduced squish band and its effect on cooling, end gases etc

Anyone?
Kawasaki ran these in the KX's from 88 to 90 (maybe other years as well?) while they ran standard dome pistons in the KR1's of the same era, why, what was the advantage of the dished piston with is narrow squish band?

[F5 Dave]

Not sure by any stretch but I would venture that they thought having a nice hemisphere for a combustion chamber made a pretty picture of burning gas. Whether that turned out to be the best way to heat the air above the piston to increase the pressure, for that is all you are trying to accomplish - if you didn't have the inconvenience of having to burn gas to do it, (& do it many times in quick succession) is mute. Flow over the piston from the transfers can't have improved.

Nice idea to try, wrong side of the compromise. 'Course I could be wrong, but Kawa-too-much-saki gaffed on the KR1 pistons as well, at least in terms of ring pegs.

[wobbly]

Well funilly enough that Kawasaki piston gave rise to the idea of a toroid shape.
I think they were trying to get the plug closer to the centre of the combustion area, but of course it shagged the squish action as well as the transfer flow regime.
The toroid shape does everything right and there is no reason to use anything else.

[F5 Dave]

I wonder at what point there are diminishing returns for the Toroidal shape? In the 50s - & I mean the cc class, not the decade, I'm not that old, we use tiny chambers & tight small squish areas. Seemingly you can do no wrong with such a small chamber and a traditional shape, the conclusion is that you end up with a shallow dome quite close to the piston. The spark lead is short to every point of the chamber.

However pushing the idea a friend built a very shallow rectangular chamber, (with a normal narrow squish), so much so that the bike didn't start as the piston closed the sparkplug gap. A quick linish of the top of the (admittedly fairly domed RG50 piston) fixed that. On testing in such a shallow area he found that he could get very measurable better results by trimming back the plug earth strap, ultimately using a side entry racing plug. The strap of a normal EGV was shielding the burn it appeared.