Heat Sink Question

[GAK182]

I have a ntc3 with a .12 ABC Pullstart Engine. In between the heatsink and the piston sleeve, is there a washer? If it does and yourun with out it what will happen?
The manual doesn't go intothat much detail.

 

[newnitrofan]

There is most likely a washer there. It is a head shim. If you run without it there is a good chance that the difference in height will either do one of two things. It will either work just fine and raise compression or it will lower the head so much that it will get the piston to slap right into the glow plug or head surface and put a nice hole in the piston for you. It is generally not advised to run without it. Radio Control Car action advises against this. Later

 

[Somers Racing]

Taking head clearence measurements is totaly necacary. Taking it out would not be a good idea for a newbie. Very experienced drivers do this because they know what steps and percautions are needed. If the head clearence is ok and the piston isn't kissing the head, then you have to check the port timing to make sure that the engine won't detonate. Timing or to much compression and not high enough nitro mixture can cause detonation as well. As you can see, it is not a small thing to do. It takes lots of time and practice to get the process right.
Save your time and motor and forget about taking it out.
Learn to drive the car really well and then work on performance enhancements.
Peter
Hope this helps
Good luck

 

[GAK182]

Thanks for the info. I accidently took it out and lost it. That explains why it wont start with the new glow plug, the piston must hit the glow plug. It worked fine with my old glow plug, but not with the new one. Does anyone have a link?
Thanks