.21 head clearance how much ?
 

how much piston to head clearance should you have with a .21 ? and are most .21 the same ? Also this would be running with 30%.......


Also is the best way to measure this by putting a piece of solder through the glow plug hole, turn the motor over by hand... then measure that ??


if it does matter it would be for a n21bf and axe rossi mamba...


thanks

For the Axe i know the sweet spot to be .50mm on 25% nitro so would say .55mm/.6mm would be where you want to be on 30%nitro.
Thats at the coast though.

The normal head clearance for my .21 engines is 2.4 to 2.7 on piston to button. I usually shim my engines up to .90 to 1.0 for running 30%. I run RB and Novarossi motors.
The head clearance method using a piece of sodder is a great way to check head to piston clearance. Many people don't check this when they get new motors.

when you say 2.4 ~ 2.7 do you mean .024 ~ .027 inch.. because that would work to about .6 ~ .7 mm...

Thanks

.024 to .027 would work fine for 30%. Hard to tell what he was saying. :lol:

I run Novas and RB motors and they all run good in this range. At the shop we set all of our customer's motors here and they work fine.
TEX

My falt guys.. misplacing of the decimal point. You know what I was talking about!;)