Dear All
I have a converted Ryobi 31cc engine in my 1/6th scale Spitfire.
I am getting 6100 rpm on an 18/8 prop, this is not quite enough for the spit.
The question is what kind of rpm are other people getting with this set up.
A friend of mine told me that some people are getting nearer 7000 with this set up.

Regards Phil G.

are you running the stock carb?

while most think that 7000 rpm is where it is at, I got better static thrust with a 16x8

Darin

Dear Darin
Yes I am using the stock carb.
We are now putting diferent piston rings on, they are the ones from Frank somebody in the US.
Sorry I can't remember his other name.
Regards Phil G.

Hi nmacwarbirds! I was getting 8100 rpm's on an APC 18x6W prop, I was using the orignal carb with the venturi opened up to .400 in diameter, gutt out muffler and the reed valve stop set at 1/8 inch clearence I am at sea level using regular gasoline (87 octane) and amsoil at a 50:1 ratio but you can use a good synthetic 2 stroke oil at a 40:1 ratio,now I am using the same engine,but I've changed to gasoline/ethanol mixture(60/35 %) Nitro 5% and amsoil at 50:1 ratio (about 2.3 oz. per galon) and using a glow plug as my ignition source and I am getting 8000 rpm's but better torque and power.

aeronut is right on about the muffler, try running it without the muffler, put the Frank Bowman rings in it and you should be there . Is it a twin ring model?

ps if you end up getting a new carb for it get a wt499 it will work for gas and if you like, run it on glow as well.

Darin