ESE's works engine tuner

[TZ350]

Shit you should just blow some cold air into the carb and you will make the 30.

Got me thinking..................



How about this baby.

A small turbo intercooler with a fine ice water spray over the fins, just enough to keep the fins wet. The latent heat of evaporation of the water would cool the air passing through the intercooler and going to the carb.

Another thing I could do is have the inlet air drawn from a high pressure area on the front of the top fairing just like a RS does for its air box.

[Kickaha]

A small turbo intercooler with a fine ice water spray over the fins, just enough to keep the fins wet. The latent heat of evaporation of the water would cool the air passing through the intercooler and going to the carb.

I wouldn't have thought you'd be allowed anything which sprays fluid about externally regardless of how little

[kel]

Hello all, probably not the right thread for this but as I started out using this software to try and develop the 2 stroke thought Id post here ...
Ive been playing with engine performance and evaluation software called lesoft. Its adaptable to both 2 and 4 strokes but while Im having trouble sorting my model for the 2stroke the 4 stroke setup is fairly straight forward, with all my FXR data entered (64mm piston, 12:1 comp, etc) its suggesting the standard cam timing can be tweeked to give it a bit more go. Have attached the simulators output graph for standard timing, inlet change only and optimised inlet and exhaust timing, Ill update with a dyno run vs the simulators prediction in the near future. In the mean time if anyone else wants to give this software a go its available free from http://www.lotuscars.com/engineering...ware-downloads

[TZ350]

I wouldn't have thought you'd be allowed anything which sprays fluid about externally regardless of how little

Yes, does seem doubtful, as an alternative the inter cooler could be submersed in a sealed container of ice water, and change the warmed ice water between races.

Instead of having the drag from air blowing through a radiator, racing aircraft have submersed the radiator in a tank of water and let the latent heat of evaporation cool the radiator as the water boils off during a race.

[TZ350]

I measured up the difference between the transfer height and exhaust of the 27 and 29 hp cylinders today and it is only 0.5mm.



That hardly seems enough to make the difference seen in the two graphs.



The 27 hp cylinder with the good torque curve had been carefully setup using the bucket and vacuum cleaner motor flow bench and the transfer streams carefully matched.



I am now suspecting that more torque could be gained from flow testing the 29hp cylinder and matching the transfers than by just rasing them.



I have read (Jennings I think) that max hp is not affected so much by mismatched transfers but the torque curve is, and with mismatched transfers the power delivery becomes peaky.

[TZ350]

The Transfers on my 29.9 rwhp Suzuki GP125, decent dividers in the transfer tract might help too.



In the last few runs when I was getting a consistant high 29's the exhaust had this hole in it.

Hard to know if this helped or held me back from cracking 30.

[Yow Ling]

I wouldn't have thought you'd be allowed anything which sprays fluid about externally regardless of how little

is there a specific rule you are refering to?

[Kickaha]

is there a specific rule you are referring to?

No, but I haven't bothered checking whether there is anything that would allow you to spray fluids over the outside of your bike

I heard of a better idea which would involve building a container with the intake running through it and LPG circulating around the outside, apparently when it was tried on a Diesel Terrano it dropped the intake temp close to 40 degrees

It would also allow much more spectacular explosions when it was crashed wore through and ignited

[TZ350]

......... is anything that would allow you ........

"rules that allow you" novel way of looking at rules, I thought it was anything goes unless there was a rule disallowing it.

I heard of a better idea which would involve building a container with the intake running through it and LPG circulating around the outside, apparently when it was tried on a Diesel Terrano it dropped the intake temp close to 40 degrees

It would also allow much more spectacular explosions when it was crashed wore through and ignited

The liquid gas turning to vapor cools the inlet, that would work.

Actually you could use a water/air intercooler and run the LPG liquid to gas phase through the water side.



Latent heat of evaporation with explosions and fire, I am liking this idea more and more.............

[Henk]

If you do the LPG thing please warn me so I can go and hide behind something very big the first time you try it.

[Kickaha]

Latent heat of evaporation with explosions and fire, I am liking this idea more and more.............

Make sure you are videoing the meeting you try it at

[TZ350]

Chambers is experimenting with making cylinder sleeves.

When he gets his tecnique right and the shapes he wants he will make an alloy one.

[wobbly]

"I measured up the difference between the transfer height and exhaust of the 27 and 29 hp cylinders today and it is only 0.5mm".


That difference is HUGE in relationship to the transfer STA, and thus its effect on the Blowdown.
For example a 0.5mm change would raise a port from say 115.8ATDC to 114.5ATDC in a 50mm stroke engine.
That is a duration change of 131 Vs 128.4 ie 2.6* - night and day, when you consider that in a KT100 kart engine changing the transfers by 0.1mm = a difference of 1.5 Hp in 18.

When you are at the outer limits of what a porting setup can achieve, then tiny differences make a big effect.

[TZ350]

"I measured up the difference between the transfer height and exhaust of the 27 and 29 hp cylinders today and it is only 0.5mm".

That difference is HUGE in relationship to the transfer STA, and thus its effect on the Blowdown.

tiny differences make a big effect.

Thats the encouragement I need........... will have a go at it tonight.

[ac3_snow]

Thats the encouragement I need........... will have a go at it tonight.

If you don't mind me asking what tool do you use to change the transfer port heights? I'v noted your use of the long shaft die grind bits (very helpful!) and of course the dremel with flex shaft is magic for final port shape etc but the transfer ports seem pretty hard to get at. I don't know any dentists, is there another tool/method?