ESE's works engine tuner

[husaberg]

Chambers had me order one of these today for his RG50.

Pretty cheap of Ebay, it may be a good, inexpensive ignition (hopefully), anyway when it turns up I will let you know how it goes.

Careful with the ebay it might be a Chinese, they do a version of the engine. The real ones are not that dear from KTM..The new 09 on engines one is the same too.
I have one here, I probably know where there is a few actually, most people racing them carried spares or knew someone else who did........ They are teeny tiny.........
The KTM's clutch doesn't come in till about 9000 rpm and they rev past 13000 plus are made for a racing 50 so they should be sweet.

They are made be Selecta, I think they made the ignition generator for the RSA too...
Frits would be able to confirm.

[Frits Overmars]

They are made be Selecta, I think they made the ignition generator for the RSA too... Frits would be able to confirm.

I would. But in case you wish to Google, try Selettra http://www.selettra-ignitioncoil.it/...gnition_k.html

[husaberg]

I would. But in case you wish to Google, try Selettra http://www.selettra-ignitioncoil.it/...gnition_k.html

Speeling correction available by a world renown physicist as an optional extra.......

[TZ350]

Ever tried CH3OH2?

Methylhydronium, I will need some help understanding this as a fuel?

So Chambers is using an RG50 frame? From the stories on this forum I get the impression that Av knows her racing, so I wonder: did she ever ride that 50?
And what did she comment? An RG50 frame is almost as stiff as a wet newspaper...

Chambers has a RG50/RS frame combo being built up for Av, the RG50's are something us lesser mortals knock about on for shits and giggles and to use as donkeys for developing 50cc motors.

You seem obsessed with that Air Correction Jet. This screams for an on-off powerjet!

Yes its my little obsession, I had under appreciated the air correction jet before, guess most do. And an on-off powerjet would be great, I would love it but it would require a more complicated infrastructure for the RG50s than we want at the moment.

For now I am finding it quite interesting seeing where we can get to by using the main and "air correction jet" to massage the fuel curve.

[TZ350]

Careful with the ebay it might be a Chinese, they do a version of the engine. The real ones are not that dear from KTM...

At $49 USD it will most likely be Chinese, I guess we will see if its up to it. Otherwise I will need some pointers to genuine KTM ones.

http://www.selettra-ignitioncoil.it/..._minibike.html

Actually I have just had a look at Selettra and they do a programmable digital version of the KTM 50 ignition and some real nifty generators.

[Frits Overmars]

Methylhydronium, I will need some help understanding this as a fuel?

You're right; that won't burn. It was a typo; it should read CH3NO2, not CH3OH2. Maybe this will help

[Ocean1]

Maybe this will help

What will help is 8.7 times the fuel in every stroke.

[Peter1962]

Speeling correction available by a world renown physicist as an optional extra.......

Husaberg, there is a striking difference in picture 1 and the two others concerning the balance shaft. I do not remember that this specific item has been discussed on the forum, so my question is : what was the reason to change the balance shaft in the aprilia RSA ?

[TZ350]

... it should read CH3NO2 ...

That I understand, I have some out in the shed too....

[Frits Overmars]

Husaberg, there is a striking difference in picture 1 and the two others concerning the balance shaft. I do not remember that this specific item has been discussed on the forum, so my question is : what was the reason to change the balance shaft in the aprilia RSA ?

Picture 1 shows the original RSA125. The other pictures show 'improved' versions; after Jan Thiel retired, certain geniuses at the Aprilia factory seized their chance to 'correct the errors that Jan made'. For example they padded the insides of the crank webs in order to reduce the crankcase volume 'because everybody knows this should be as small as possible'.
They also changed the left-side balance disk into an asymetrical balance weight because that was a little lighter. They never thought about the windage that such an asymetrical body causes at 14,500 rpm.

Funny thing: those later, improved versions were never as fast as the original RSA...

[wobbly]

Re the long stroke RSA theory - it took Jan Thiel and his 100 underlings god knows how many hours/weeks/months/years to get the real thing working.
Next time I have a month spare to do all the iterations of ports/pipes/ignition etc I might get somewhere near finding out what is possible with a 52/58.8
when simmed correctly, ie it aint going to happen.
It just isnt easy at all.
I do know for sure that up above 14,000 rpm even the tiniest change in something like the combustion parameters VibeA and VibeM make huge variations in the effective spark event.
Likewise stinger diameter, a change of 0.2mm will instantly create no power at all or death deto, luckily I havnt been hit by a rod exiting thru the screen.
The wave action is hugely powerful at that level of bmep and rpm, trying to simulate reality correctly is just as hard ,I believe, as actually doing it in the workshop.

Re the T bridge on a RS125,I dont think any advantage is to be had in actual out flow characteristics by shortening the bridge - the biggest blowdown effect is gained by having the correct
radial hooks just outboard of the bore.
Reducing the heat radiating area of the bridge affecting the backflow temp may well be a gain, you will have to wreak a cylinder to find out I guess.
I have seen several tuned cylinders with the top of the bridge alot shorter in length than the bottom.

I havnt tried the Selletra ignition you have shown ,but in a KZ2 the homologated Selletra equivalent of the PVL for ICC classes makes around 1.5 Hp less from 11.000 upward in a straight back to back.
The timing curve is identical - so it can only be the energy level in the spark gap causing the issue.
For any single race engine now I always use a P2 Ignitech and fire both CDI channels into a single low impedance coil, its the only way to better the power produced in a RS125 Honda for example
as this has a DC DC CDI from the factory.

[trevor amos]

Wob, once more, thank you for your thoughts on the bridge question.

I certainly don`t fancy destroying a good barrel to prove a moot point, if you can`t see an obvious benefit then I would have no chance to be able to reason it through!

Trevor.

[TZ350]

Getting ready for Mt Welly tomorrow.



Chambers RG50.



NedKellys RS/Aprilia 50 with pumper carb.

The RG50's :- https://www.flickr.com/photos/sonscc...2063815/page2/

[TZ350]

Someone asked me about how I was going to arrange the cooling fins on the Beast.



I did not want to rely on turbulent air randomly blowing over the fins. My plan is to angle them and use ducting to direct an air blast onto them that aggressively scavenges between the fins right down to the roots. And to arrange some more ducting to carry the hot air back to the low pressure area behind the bike. That way cool air is directed between the fins and the warm air is effectively drawn away.

With the motor angled down, the RS pipe slots in perfectly and with the steep angle I will need to run a dry sump arrangement for the gearbox to avoid flooding the rotary valve and clutch while the gears are starved of oil.

The plan is for the gearbox oil to drain into a catch tank and then be pumped back and splashed over the gears. And while I am at it, the catch tank might as well have some cooling fins and ducted air too.

[husaberg]

Someone asked me about how I was going to arrange the cooling fins on the Beast.


.

What size is that chain going to be