Quick response needed on t-maxx Q.

[aj200415]

My buddy has a t-maxx and i am working on it. IT has the 2.5 engine. He put the American CNC Machining Giant cooling head for 2.5 maxx (part# 5263???) on it. I am putting it back on and there is no shim. I asked him about it and he didnt know. Is it supposed too? Do i need one on it? will it hurt it?

The reason y i had to fix it is because the piston broke on one side and i got another for it. Could this have caused the side to break off of the piston head?

 

[Tarant]

I dont think so, the stock head has no shim(If I can remember right) so I dont think you will need one.

 

[bustedgears]

It shouldn't "hurt it" but it could cause a slight air leak. It wouldn't cause the side of the piston to break off, unless it hit the head (highly unlikely).

It will work without it.

 

[aj200415]

thank you so much guys. i wanted to break it in and start it now cause i gotta race this weekend!!!

 

[olds97_lss]

Every engine should have a shim. Your not getting the right compression ratio and you run the risk of bad air leaks. While not running the shim may not directly cause the piston to crap out, it may have done it indirectly with bad fluctuating temps from a bad air leak.

The 2.5 comes with a shim from the factory.

Here's a pic from the 2.5 parts explosion:

Part #5229 is the shim.

 

[aj200415]

well, we monitor the temps and they stay around 235-265 degrees