ESE's works engine tuner

[TZ350]

free blowys

Yes it is a generous offer and I intend living a long time, but seriously I am very grateful to Wob for his help and tuning advice.

Hopefully we can get a bit of reliable hp and a decent power spread from the air cooled RGV project.



RGV250 dyno run, 60+ rwhp, I am looking to do better than 30 hp with the single cylinder air cooled Suzuki GP/RGV125 half Beast.

[wobbly]

Doing 30 RWHP means a crank power of around 35.
Do that at 12500 rpm and we are looking at 10 bar bmep - easy enough, even if not everything is done right.
At 10500 and that is 12 bar bmep, being aircooled and on a 24mm carb a 125 I believe would have to be so specifically designed and perfectly executed for that rpm
it would be completely useless everywhere else - Im still sleeping safe in the knowledge there wont be any need for random knob gobbling on my part.

[TZ350]

Doing 30 RWHP means a crank power of around 35. Do that at 12500 rpm and we are looking at 10 bar bmep - easy enough, even if not everything is done right.

This is realistically where I expect to get to with some reliability and a decent spread of power.

[wobbly]

Thank Christ for that, I can help no end with that endeavour as long as it doesnt involve shit I expect ( sorry - I would like ) my wife to be adept at - sucking the chrome off a tow ball.

[husaberg]

Thank Christ for that, I can help no end with that endeavour as long as it doesnt involve shit I expect ( sorry - I would like ) my wife to be adept at - sucking the chrome off a tow ball.

Those ones come with strings attached

[bucketracer]

.... and on a 24mm carb ....

TeeZee probably hasn't forgotten about his plenum idea for dealing with the handicap of having to use a 24mm carb.

[TZ350]

Yep, have not forgotten. With a carb, fuel dropped out inside the plenum, fuel injection into the transfer ports was my attempt to fix the puddling in the plenum issue, if I can get the fuel injection sorted we will re visit the plenum idea.

[lodgernz]

In my quest for ultimate power, I have collected quite a few pistons from various 2T engines, and have carefully measured them all.
Most have an offset gudgeon pin, and mostly it is offset about 2% of bore toward the inlet side, but I have two pistons with offset of more than 4% toward the exhaust.
I've measured these two a dozen times to confirm this.
If I use one of these, is it going to cause me grief? Actually they always cause grief, but will these be worse?

[wobbly]

Not enough effect on power to make bugger all difference, it will just rattle more or less when cold.

[lodgernz]

Not enough effect on power to make bugger all difference, it will just rattle more or less when cold.

Thanks Wobbly, that's reassuring.
I thought the offset was always toward the inlet side. What do you think would be the reasoning behind offsetting the other way?

[F5 Dave]

Not enough effect on power to make bugger all difference, it will just rattle more or less when cold.

Like its owner

[husaberg]

Thanks Wobbly, that's reassuring.
I thought the offset was always toward the inlet side. What do you think would be the reasoning behind offsetting the other way?

Depends on the direction of rotation if it has a jackshaft in its origonal home ie arround 82 tz's the engines ran backwards
The effects of pin offset can be modeled in sims TZ did one a while back just to see the effect of a desaxel design.

[SwePatrick]

Wobbly, A question.
Can one ask you to make a calculation for a pipe(Friend will build pipe himself)?
Ofcourse nothings for free, i understand that.
If yes, can i pm you?

Best regards
Patrick
Sweden.

[lodgernz]

Like its owner

That's cruel Dave, I roll rather than rattle. Then I pick up the bike and carry on

[lodgernz]

Depends on the direction of rotation if it has a jackshaft in its origonal home ie arround 82 tz's the engines ran backwards
The effects of pin offset can be modeled in sims TZ did one a while back just to see the effect of a desaxel design.

Thanks Husaberg, but the piston that is offset toward the exhaust is from a bike that rotates the usual way, i.e clockwise if looking from the right, with exhaust at the front.
Seems like the consensus is that it would rattle a bit but not cause any damage.