tough question....

[XCredrider]

Heres something for you 250r guru's. I am going to be puttin a new topend on my R. I have a Duncan Racing head. How can you tell the cc's of the head? Also What is the maximum safe comp. with 91-93 octane gas. Im wondering because i dont know what head gasket to get. The atc(thin), CR(med) or trx(thick). .thanks in advance

Kody

[zedicus00]

first the cr gasket is the thinest then the atc then the trx. second if the dome is removable from the head the cc will be stamped on the dome. otherwise hav it microwed. max safe compression is 180 but thas not a hard an fast rule there are a lot of variables. i touch 200 on 91 oct withought any problems. depends on altitude. cylender setup, pipe, temperature, spark plug. (i run a bp5es) which is waaay hot.

[Rich250RRacer]

Take a stock gasket, any thickness, and carefully remove the rivets that holds the pieces together. Now you can discard the center piece and use either one or both remaining pieces. If you use both make sure to use some Three Bond sealer.

[XCredrider]

Thanks Guys...one last question..how do you get the dome out? I've never been told how or seen how.

[zedicus00]

itl press out provided its actually got a removable dome. i put a socket on the back side right where the spark plug goes then put all my weight on the edge of the other side an popped it out. when u put it back together through the head piece in the oven at about 300 degrees for 1 min or so and through the dome in the freezer over night. then when u put them together the dome will fall into place the temperature will normalize and u will be set.

[beerock]

Originally posted by Rich250RRacer
Take a stock gasket, any thickness, and carefully remove the rivets that holds the pieces together. Now you can discard the center piece and use either one or both remaining pieces. If you use both make sure to use some Three Bond sealer.

dont discard the center piece, you can use that as well as a standalone gasket just use permatex spray copper gasket on it ;)

[zedicus00]

i just use one of the outer pieces. the center piece is way to thik i think.

[beerock]

Originally posted by zedicus00
i just use one of the outer pieces. the center piece is way to thik i think.

its thinner then all 3 isnt it?

I used to use it with a cut head to get the compression i wanted ;)

[zedicus00]

tru, theres so many combinations of head and gasket setups u can very the compression almost infenetly

[Rich250RRacer]

The center piece is the thickest of all three and it is the only part that is different on all three gaskets. It's been awhile since I measured one, but I believe the top and bottom are about .010
I don't think I would use the center piece alone, since it is stainless steel and wouldn't seal very well against the cylinder or head by itself.

[beerock]

it seals fine with the spray;)

[pro6]

I used to use the cr gasket, but now I buy the trx because you get two gaskets for the price of one. yeah:D