Hi

I have the Novarossi RR12L5 long stroke engine fitted to an Fw-05 with JPL 6mm pipe.

I'm running 16% Nitro and a No 5 Novarossi plug. The head clearance is 0.018" (It has a 0.3mm shim in)

The engine doesnt seem to have any top end power. I have toi use the lowest top end gear to get it to rev out. If i use a taller gear it doesnt get to top speed.

I need about a 15% increase in power. Anybody have any idea what could be the problem? Motorman?


Cheers

One thing is to step the nitro up to 30% the .03 shim is enough for 30%. It will be night and day difference between 16%and 30%. You should be fine with the plug that your running.

In Europe the rules say 16% nitro max.

I was going to try 25% but havent yet. I have a new manifold to try first and have swapped the engines over in my cars, Rossi Pixy for the RR12L3 to make a comparison

Im no motor master, but I have some experience with this engine.

1st, pls stay 16%, its enough for this engine. I assume the motor still in good condition.
Why you using no.5 plug ? is the engine only performs well in very hot condition ?

There are a few options for you!

1. go with higher nitro content
2. what kind of weather in your area? if it is hot and humid then you need to use colder plug.
3. if you go higher nitro, then you need to increase headshim, trust me you really need extra headshim! I had bad experience with headshims. if you dont run enough headshim on 30%, it will be over compressed and crack the piston!

Ziggy, you can first by using the shortest manifold you can find. Go with a pipe that would also give you the shortest pipe combo. Shorter pipe length will give you better top end at the expense of some bottom end. But then again, the bottom end of the FW05R is already very good...

Also like some already suggested, add one more copper shim to increase the combustion chamber height. It works for me and the engine revs much more easy at the top end.

If you still cannot get the engine to rev high, then the only option is to gear as low as possible (using Kawahara 0.8 crown gears) to get as low FDR as you can to shift the gearing to accomodate and take advantage of the engine powerband.