ESE's works engine tuner

[peewee]

why guess. theres already some vinamold photos around here some where of the rsa transfer passages that show pretty clear the rearward angle

[wobbly]

You are ignoring the huge hook on the A port front wall.The flow angle points right in front of the boost port.

[dutchpower]

Scan rsw/rsa aprilia

[husaberg]

...../..

You are ignoring the huge hook on the A port front wall.The flow angle points right in front of the boost port.

Scan rsw/rsa aprilia

[crbbt]

Thank you for your responses!

I drew (solid edge drew) a line from the edge of the squish band to the center of the combustion chamber. tangential to the squish radius

that distance was approximately 2.5mm above the crown of the piston.

[tdc211]

You are ignoring the huge hook on the A port front wall.The flow angle points right in front of the boost port.

not ignoring it, just thought it would be more radiused on top there

[Muhr]

...../..

Below is a test I did on an RSA port setup (as close as I could), with a transfer intake speed at 350m/s for a time period of 0.002s

[TZ350]

Well now we know. Water injection on a 2S may not be a good idea. B/E failed after a water leak allowed the motor to drink all the cooling water. Interesting that the vaporized copper thrust washer found its way everywhere including into the little end brg.



The lengths I had to goto to get a 6 speed gearbox, waste of time for Bucket racing, better off with a 5 speed and a wider power spread. The Kawasaki KE175 rotary valve is a winner. much larger than the old Suzuki one.

Waiting on a new special big end pin. Cross drilled for direct BE oiling. I am going to use a small peristaltic pump arranged to deliver a small amount of oil when the motor is running. The oil will be feed through the crank from the drive side end.

[F5 Dave]

Bear in mind Rob you race at one of the 2 dinkiest tracks in NZ. 6 speed Ruapuna no question but I'd say Kaitoke too.

[Frits Overmars]

Water injection on a 2S may not be a good idea. B/E failed after a water leak allowed the motor to drink all the cooling water.

Drawing conclusions faster than Lucky Luke can draw his revolver? I'd rather say that a water leak on a 2S may not be a good idea. Better try it on a 4S .
I wouldn't apply water injection either, but not for fear of leakage. Water injection can markedly improve power at low revs, but practice (with a close-ratio 6-speed gearbox) has shown that a good rider never needs to go that low.

The lengths I had to go to to get a 6 speed gearbox, waste of time for Bucket racing, better off with a 5 speed and a wider power spread.

If your power band is both wide enough and strong enough, less gear changes will get you around a circuit quicker. That is especially true on kart tracks.

Waiting on a new special big end pin. Cross drilled for direct BE oiling. I am going to use a small peristaltic pump arranged to deliver a small amount of oil when the motor is running. The oil will be feed through the crank from the drive side end.

Such a setup can increase big end life tenfold. Way to go!

[TZ350]

.
Yes, the cross drilled B/E was suggested by Flettner and he is helping me organise it.

[husaberg]

Drawing conclusions faster than Lucky Luke can draw his revolver? I'd rather say that a water leak on a 2S may not be a good idea. Better try it on a 4S.
I wouldn't apply water injection either, but not for fear of leakage. Water injection can markedly improve power at low revs, but practice (with a close-ratio 6-speed gearbox) has shown that a good rider never needs to go that low.

If your power band is both wide enough and strong enough, less gear changes will get you around a circuit quicker. That is especially true on kart tracks.

Such a setup can increase big end life tenfold. Way to go!

Which dovetails to my question in 1997/98 when unleaded was introduced into GP the crankshaft life of Hondas NSR500 was decreased from 1500 miles to 500 miles (nothing to do with the big bang to screamer either as it was all NSR500's)
Also that year there was a rash of seizures on all the makes of bikes not just the hondas
Does leaded fuel really provide more lubrication in a two stroke or was it just that the revs were raised that year to make up for the shortfall in compression or were the techs just not used to the differing characteristics of unleaded?

[Frits Overmars]

Which dovetails to my question in 1997/98 when unleaded was introduced into GP the crankshaft life of Hondas NSR500 was decreased from 1500 miles to 500 miles (nothing to do with the big bang to screamer either as it was all NSR500's)
Also that year there was a rash of seizures on all the makes of bikes not just the hondas
Does leaded fuel really provide more lubrication in a two stroke or was it just that the revs were raised that year to make up for the shortfall in compression or were the techs just not used to the differing characteristics of unleaded?

https://www.kiwibiker.co.nz/forums/s...post1130459870

[husaberg]

https://www.kiwibiker.co.nz/forums/s...post1130459870

Cheers It still doesnt explain the rash of seizures unless they were over run induced as well?
Interestingly Motocourse (Cameron i think) Mentioned that the Japanese knew with the leaded high octane fuel that they knew the engines comp ration was to high for peak power but they prefered it that way for higher low end and mid range performance the "overcompressed" engines offered. Doohan hated the unleaded engines and referred to the engines as "road bikes" rather than race bikes their after.

[wobbly]

The unleaded fuel reacted very differently to tuning and it took the engineers ( and Elf ) some time to find the optimum.
Less com, more advance and richer made the best power .,more so with the later Mits 31+ fuel blend , very rich mixtures were the norm.
Whereas early on the mindset was still,lean it down to go faster ,very wrong as it turned out.