Which head gasket?

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R

rez

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I got the 30.5 cc kit with the 2mm stroker crank. I put it in, it ran great for about 1.5 tanks. All of a sudden it started running really crappy, didnt want to tune or idle or anything. Come to find out the head gasket is leaking. The directions for DDM were kind of unclear to me when I was putting the motor back together. it came with a flat copper gasket and a round copper .040" gasket. I put them both in. The directions said to only use the round one if you had the colored headkit. I put the flat gasket in but it was hitting when I spun it by hand. I put them both together and called it good. Now it leaks, which gasket(s) do I need and what is the proper way to put them?
 
A 30.5 is not made for a Stroker from the factory. One shop cuts the 2 mm in the head and some stack the gaskets on the cyl to case surface to allow for taller stroke. If the later is what you have you will need to run the spacer of .080 plus the head gasket.


Keeping one sealed with this setup is dificult , that is why I run 35 bore with 30 stroke.


Another contribution to a leaking head gasket is the pipe mount. If it can not move some. Then with the Redcat chassis flex you have just made a big levar to pry on the two small cyl bolts.
 
Here is the kit that I got I am 99% sure. http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.4757/.f


It came with the round copper gasket, paper gasket and the thin copper gasket.I put the two copper ones in and no paper one. I will take it apart sometime this week. I may be able to stick the paper one and the flat copper one in and call it good. Maybe tonight after I do my homework I will tear into it a bit.
 
Something seems really fishy with the TDC "squish" on the cylinder head you bought...almost like the manufacturer forgot to machine the cylinder for the additional stroke. I have this kit and only used one base gasket with no issues. I would call DDM and run it past them.
 
I emailed them but they were confused about what I was trying to tell them. It came with directions that included the .040" round copper gasket and the billet head kit. It also came with a flat copper gasket and the paper gasket. I will tear into it and try it with the flat copper gasket and the paper gasket if it all looks okay since I never tried the paper gasket out.
 
This link you sent is the non-machined head kit so you will need the gasket and another .080" or 2 mm of spacer to go in between the head. use a good sealant and torque your head bolts to 65 in lbs.
 
For those less familiar with engine, to built a 30.5 you can buy a machined head and a non machined head (came from stock 29cc 28str.) you paid less for a non machined kit, also the power curve are different due to all port 1mm higher.
 
I didn't realize that. It still puts out real good power. I had the lhs order me the ESP 28cc kit for my fg, maybe I will get one for my TT also since it is just a new top end.
 
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