Originally posted by Taylor-Racing
Hmmm . . OK.
The new IFMAR rules as at November '02 now permit conical plugs, it seems, together with some other changes.
Will EFRA fall into line on these rules before the Euro's. Also, EFRA has some strange 5.0mm carb rule or something, doesn't it?
Nope.... EFRA rules state some ruling about the engine, basically are:
- Engines must have 4 ports (including exhaust).
- Exhaust transfer height: Unlimited (rather than the 4.5mm that ROAR specifies).
- 7mm max of crank passage.
- End of crank passage should be perfectly round with none chamfer breaking the end (a little tolerance is admitted - 0.5mm max). Actual JP crank is illegal, but the actual Novarossi crank is legal.
- Conical glowplugs allowed.
- 5.5mm max diameter of the carburetor.
- 5.2mm max diameter of the exhaust stinger and 82dB max spl measured at 1 meter of distance.
- 10mm long (minimum) of the exhaust stinger.
- Fuel should have a maximum of 16% nitro.
- INS box enforced.
Is a quick and rough draft of what is allowed under EFRA rules, but probably enough to make you an idea of the rules that apply to the engine.