HOME and how to join Forum Open Area General Scott topics What rpm from a 1929 500 cc scott flying squirrel ? Re: Power and revs

#6090
Roger Moss
Participant

Power figures quoted are fiction, but rev safe limit of 5000 is about correct for standard long strole cranks.
I once had my REP on an inertia dyno, the accuracy of which I cannot vouch. Ted Parkin has UE 7373 now and it had a lot of work done that certainly would not be economic for the works to do. It recorded 27 bhp and my estimate was that it would do about 95 mph.
A rolling road inertia dyno is not a good test for a Scott, which is why I use Dave Holmes water brake H&F dyno. In this case you can hold each selected rev at full throttle and balence the dyno to it in equilibrium.
A fully gas flowed engine with siamese open pipe will get up to about 26 / 27 bhp between 2000 rpm and 4500 rpm. It is this spread of power that is so special on a Scott.
If a resonant pipe is fitted then expect another 8 / 10 bhp
My best estimate of the output of a standard 600 LS Scott engine with unmodified breathing and standard exhaust would be 18 / 19 bhp
I heard that the factory wrote a bhp figure on the documentation that would please the owner. I have not checked the speedos but remember they were obliged to be within 5% at 30 mph but only within 10% otherwise.
I would expect a 500LS to give 15 / 16 and a 600 SS about the same
However, the torque figures are much higher than you would normally expect and it is this that makes them so special.
If you have loads of torque, you can gear up and get all the performance you want without over revving the engine.
All I do is to make them breath a little better and LEAVE THE EXHAUST AND TRANSFER PORTS ALONE!!!
So many engines have been ruined by altering these.
You can see BHP and torque graph in Yowl Dec 05
Happy New Year All