ESE's works engine tuner

[TZ350]

TZ, are you going to see Yamaha rod to get those revs without smoking the poor RG crank?

AM6 rod kit.

There are a couple of these rotary valve Suzuki RG50 engine conversions in the works. Two 50cc another, possibly a turbo 70 or an 85. We have also found ways to get 110 cc's out of one of these. If the 110 materialises and works. We will take it to Christchurch for the next Battle of the Buckets.



Basic AM6 stuff is pretty affordable of Aliexpress.



After transfering the RG50 primary gear. GN125 clutches can be made to fit as well. Stay tuned for details.



Also GN125 clutch spring kits can work wonders for a standard RG50 clutch.

[Vannik]

I suspect EngMod2T as good as it is, is based on known good engines. We never got to see the ultimate RS125 and how big its crankcase volume would have been.

EngMod2T and 4T is not based on any engine but on thermodynamics and gasdynamics. Any shortcomings is from my lack of programming skills and/ or misunderstanding the physics. And from modeling combustion and scavenging as quasi-dimensional and not full 3D.

[F5 Dave]

I just usedDT175 springs and TS plates allowed 4rather than 3. But 100 power may unravel that.

[TZ350]

EngMod2T and 4T is not based on any engine but on thermodynamics and gasdynamics.

Good to know, thanks. I knew it was good and now understand why.

I just used TS plates allowed 4 rather than 3.

Yes, I remember you sharing that info. We have been doing that ever after you clued us in.

[Noxin]

Many team engineers at the track increased that to 0.7 as it was easier to tune and rev'd slightly harder.

What was the main effect that simplified the tune and harder rev?
Was it the lowered compression ratio or the squish gap itself?

[wobbly]

Increasing the squish gap, decreases the MSV. Small changes have quite significant effect on this parameter.
In the RSW going from 0.6 to 0.7mm gives a change of 48M/s to 42M/s = 12.5%

Lowering the MSV is analogous to retarding the ignition timing, as the reduction in the speed of the turbulent eddies exiting from the squish annulus
reduces the flame fronts burn speed thru the chamber - also with the upside of decreasing the losses due to compressing the trapped mixture later.
Retarding the timing or reducing the MSV, thus has the mixture burning later in the cycle, and this puts less heat into the piston and more heat into the pipe.

There is a minor effect from reducing the static compression ratio, and this has similar effects as the reduction in MSV - more heat into the pipe
As far as tuning goes the lower com and reduced flame speed allows higher egt numbers without getting into deto, giving a higher bulk gas temp and thus increased wave front speed thru the pipe = more overev power.