I'm doing the final assembly of my engine before I throw it into the car, and I just have a couple questions before I fully take the plunge. I had new pistons installed into my block (flattops with valve recesses, bored .020 over), had the block decked and had the bottom of the head shaved slightly to ensure a good mating surface. The new pistons protrude out of the cylinder bore slightly past the deck of the block. I understand that this is alright, as long as you run the correct thickness gasket. I am using a gasket out of the master rebuild kit that the machine shop gave me.

I have put the head on and torqued everything together, and then spun the engine over by hand and did not feel any valve to piston contact. I would like to put some modeling clay on the top of the piston and then torque everything down, do a full revolution, and then see how far down into the clay the valves go in order to make sure that the valves and pistons are not too close.

Would it be ok for me to reuse the head gasket even after torquing it and untorquing it about three times, or is this a bad idea?

I'm really afraid that if I do it wrong, I'm going to be out the money spent on the engine, and I just want to make sure it's done right.

Please help!

I'd say for your final assembly, use a new head gasket....why risk using a used one!

Tom

i did the same thing and have been running that HG with no problems

I'd have to agree with Tom on this one, even though Jason has had no problems. Just for piece of mind a new HG should be used, especially since you have shown concern about it. After all you have done and invested, why risk it?

Do you still have the old one? You could use it just for measurement purposes and then install the new one when you're doing the final assembly.

I know I wouldn't be using that HG on the final assembly after crushing it three times. Even though others might have done it before without problems, you are expressing concern that would most likely remain in the back of you mind everytime you drove the car. Daniel's suggestion is the route I'd take. Head gaskets are cheap compared to potentially blowing one.

I didn't reuse it when I did the clay test. It sucks throwing away a brand new $20-$30 gasket, but it's just part of the rebuild cost, I guess.

that's true, for $20 bucks it's not worth it. i actually only put it on once, took it off, and then put it back on, but hearing 3-4 times seems like a bit much

No no no no no no no no!!! Do NOT re-use the head gasket. There are TON of reasons not to do it, but, my main point is: Due to the pain and effort involved with replacing the gasket, do you REALLY want to take this shortcut? Get the best head gasket known to man and install that. You can do shortcuts in other areas (where it's easy to replace later), but, don't do it here.

Would you re-use a condom 3-4 times?

Thanks for the input. I was assuming that it would be a bad idea, but I wanted to check with you guys. I got a pretty high quality HG from my rebuild kit, and after I torqued it, I realized that I probably should have used the old one for the measurement.

Are felpro gaskets really as bad as everyone says?