ESE's works engine tuner

[Bert]

Because Team ESE also enjoy 4-Stroke technology and have a few XL/SL100 and 125 engines in a big box somewhere, we flogged this link and posted it here for future reference, thanks Kel.

Kel's post uncovered some interesting reading:
http://www.powroll.com/Tech_crfproject.htm
Not quite what I'd do with a 80 but cool engineering anyway..

Yea well the windscreen motor off a split screen Morris Minor could be made to work as well.
That version has the poxy single bearing setup, same as ZXR, but is even worse in that it only drives a single cable off the pulley,thus needing spring return.
The newer R1 version of the RZ servo has really good bearing supports in the case for the shaft and has push/pull - just buy one.

Eyes out for a R1 then until i find one at the right price the ZX6 unit that I've had for a while; will have to do...

[husaberg]

Yea well the windscreen motor off a split screen Morris Minor could be made to work as well.

That version has the poxy single bearing setup, same as ZXR, but is even worse in that it only drives a single cable off the pulley,thus needing spring return.
The newer R1 version of the RZ servo has really good bearing supports in the case for the shaft and has push/pull - just buy one.

Personally I think the Morris Minor windscreen motor may be out I think it could be 6 volt positive earth after all.
Seriously now
I did offer tz350 a rz servo to try for free I even suggested a splitter cable of the throttle cable ala auto lube pump on Yamaha.
As I thought the servo seemed to be overkill on a bike where it would be nearly always low throttle opening =low revs wide throttle opening= high revs.with very little of anything else
Wobbly what did you think of my regurgitation of the alpha rotary drive to slim the motor up?

[wobbly]

Sorry I missed the "alpha" drive,point me at it to look.

[speedpro]

The "alpha" drive wasn't such a success on the Enterprise, which is why they stuck to the standard Warp engines.

[husaberg]

http://www.lortim.demon.co.uk/alpha/index.htm[/URL]

Sorry I missed the "alpha" drive,point me at it to look.

This is it a narrow disk valve set up, don't know why I typed the word (drive) for though?

One engine used the half circle crank as the disk valve so the engine looked piston port but was disk valve.

There is pics of about three versions of the engine here below.

Alpha also used to do a knife edged kind of eliptical cross section streamlined shaped conrod that also looks like it would show promise as an idea in a modern engine.
It may have been hollow section when i next get to where the parts are I will post a pic of the conrod.
The conrod was wider to up primary comp also as well as presenting a streamlined cross section to the direction of the incoming charge.
The first pic shows an example of one.
Alpha is a company that used to make full circle cranks for Villiers Greeves etc and big ends for all sorts of bikes.

I know these are old ideas but back in the 50s-60s alot of ideas where tried but the metalogy of the time was lacking behind the ideas example Villiers had Toroidal heads in 1962-63 on the starmaker engine and they stole that from diesel technology only later to be rediscovered 30 odd years later for gp bikes.
so why not look back.

[wobbly]

The idea seems ok untill you start drawing the thing.
I did a very quick sketch and you can see that very little flow will occur until the opening "edge" of the crank is well past the port.
It does have symetry of flow in its favour, that is why the rear mounted inlet on a RSA is alot superior, but I dont see that this setup would work better than an ordinary side mounted disc valve.

[husaberg]

The idea seems ok untill you start drawing the thing.
I did a very quick sketch and you can see that very little flow will occur until the opening "edge" of the crank is well past the port.
It does have symetry of flow in its favour, that is why the rear mounted inlet on a RSA is alot superior, but I dont see that this setup would work better than an ordinary side mounted disc valve.

I think (and I could be well wrong to)
That the direction of the flow is more towards being at right angles to the crank to get around this, That’s what it seems to me in the other pics.of the various models of engines.

The idea I thought was to get the advantage asymmetrical inlet timing and not have the charge have to get around the edges of the crank like a conventional disk valve.
I also think this approach to disk valve design layout maybe might allow for a bit more cylinder wall for transfers?

My thinking also was tz350s bike is getting wide now with all the gear hanging off the side.

Now a different idea for your input.

Some one brought up a advance retard idea earlier but to get it to work the weights would have to be build out of antimatter (maybe speedpro has some left over from his star trek jibe)

The other idea I had was posted back a couple of pages ago with a retarding conventional disk valve for more top end without the losses down low.
If you had a contra rotating Disk valve with a jackshaft to reverse the direction with a bob weighted in this case retard (much like a bob weight centrifugal distributor advance on a 50s Morris minor or 70s ford escort)
I suppose only in reverse hence the jack shaft.
Ie the faster it goes the more retard.
(The more retarded the disk valve timing the more top end according to graham bell anyway)
This idea also would give the advantage at small degrees of disk openings of a larger flow area from the larger disk because it is offset from the gear off the crankshaft without the increase in crankcase/crankshaft size.

If you took this design a step further you could spin the whole engine in reverse like the later tz250s (pre v twin)
With this you can run a wider exhaust port because the piston thrust would be acting on the inlet (which has more cylinder wall for support rather) than the exhaust port.
And run the disk in conventional rotation direction for retard .I don't know if I am explaining it well I might have to draw a picture

[kel]

I know these are old ideas but back in the 50s-60s alot of ideas where tried but the metalogy of the time was lacking behind the ideas example Villiers had Toroidal heads in 1962-63 on the starmaker engine and they stole that from diesel technology only later to be rediscovered 30 odd years later for gp bikes.
so why not look back.

Great to see these early designs. With the current RSA's rear disk design the flow is unobstructed by the crankwebs plus the disk would offer less friction and better sealing.

[kel]

TZ mentioned how the Honda RS pipe inlet is larger than the GP exhaust port outlet, while this is common place on 4 strokes for the purpose of AR I wasnt aware it was used on 2 strokes but on reviewing RSA photos I came across this


Jan Thiel "One wants the pressure wave coming back into the cilinder but NOT the burned gases that are hot and can cause detonation!"
Makes sense.

[kel]

And -
TZ I think Jan could be pleased with your efforts/experiments with varible inlet timing, when asked what he would have liked to develop further on the RSA he replied "there were many ideas about a variable tailpipe! and also about variable inlet timing". You never know mate, direct the questions to the right people in the european forums and you may just get an answer from the master himself

[kel]

OK last post then I'll go and work on my motor
Classic designs from the past, what about a twin rotary disk single, Yamahas 125cc RA41 from 1961


pictures courtesy of http://www.deraceheldenvanweleer.nl/....html#msg12169

[Yow Ling]

If you took this design a step further you could spin the whole engine in reverse like the later tz250s (pre v twin)
With this you can run a wider exhaust port because the piston thrust would be acting on the inlet (which has more cylinder wall for support rather) than the exhaust port.
And run the disk in conventional rotation direction for retard .I don't know if I am explaining it well I might have to draw a picture

which TZ's are you referring to, the first reverse rotating tz was the tz250h, my understanding is that this was to remove the piston thrust from the inlet which was a piston port and move the piston thrust to the exhaust side. the reverse cylinder tz250 W ? was a case reed so didnt have the piston trying to jump out the inlet problem. running the engine through a jackshaft costs hp so you need a good reason to do it

[husaberg]

Yow Ling;1130079065]which TZ's are you referring to, the first reverse rotating tz was the tz250h, my understanding is that this was to remove the piston thrust from the inlet which was a piston port and move the piston thrust to the exhaust side. the reverse cylinder tz250 W ? was a case reed so didnt have the piston trying to jump out the inlet problem. running the engine through a jackshaft costs hp so you need a good reason to do it.

I think the jackshaft cost them a hp but they got a bike that would last races.

I am open to correction but my understanding was it ran in reverse because the exhaust port was so wide on the (I think G models) they were becoming extreme piston eaters.
Yamaha didn't want to lower the output by narrowing the ex port so they ran the engine backwards so the piston rode on the more supported inlet cylinder wall. I’ve got the full story in a Yamaha history book somewhere. I post the article when I come across it.

I think it coincided with the pv so my guess is the tz250h model. Defiantly not the reverse cylinder and was piston port.
with the contrarotating disk I think the top end gain without midrange loss and the gain from the larger disk would more than compinsate.

Although the rsa engine sure looks sweet I guess Jan is the same dude who was the lead designer at aprilia through the 90s when Mad Max was king (whithimner .. sp?)

[bucketracer]

TeeZee Interesting Idea

From http://www.rgv250.co.uk/forums/index.../page__st__740

Just booked up a dyno session towards the end of may to check the bikes running ok so the first race on it should be in june, also to try out the new top fairing air scoop and new airtube and i have also made a couple of new shaped bellmouths to try out as well, when i made some before i made a long one and a short one the long one gained two bhp at the top end but lost some midrange the short one gained 1bhp at the top end but re-gained the midrange back, so i have tried to make a bellmouth with the bhp of the long one and midrange of the short one a mixture of the two one of them i have made an alloy plate to fit to it so that i can try it without the plate fitted then fit the plate and try it again,i want to see what difference the plate will make will it work like one bellmouth when opening the throttle giving the midrange of the short one then when fully open give the top end of the long one one can only suck it and see.
barry

[bucketracer]

I am open to correction but my understanding was it ran in reverse because the exhaust port was so wide on the (I think G models) they were becoming extreme piston eaters.
Yamaha didn't want to lower the output by narrowing the ex port so they ran the engine backwards so the piston rode on the more supported inlet cylinder wall. I’ve got the full story in a Yamaha history book somewhere. I post the article when I come across it.

I asked Dad (TeeZee) and he said he remembers the "G"s as piston eaters, the skirt edge on the inlet side would get hammered in by the bottom edge of the extra wide inlet port. As the piston thrust side is on the same side as the inlet and the thrust tipped the piston skirt into the inlet port, pistons would have to be replaced every meeting or so.