I've got the 8BA rebuilt and ready to put the heads and intake on. I'd like to check valve clearance since the heads have been machined and I put a higher lift cam in. In the rebuild manual, or somewhere else, they said to check clearance with modeling clay and the old head gaskets with the heads torqued. I chunked the old head gaskets months ago. So, can I check the clearance with my new gaskets, and then take the heads off to check the clay then reuse them? I'm using a new set of the copper clad gaskets and can get another set of the asbestos type if I need them. I guess the real question is "can I use the same gaskets for clearance checking then for running?" Thanks.
You can't re-use head gaskets after they've been torqued. Save the copper clad for final. I wouldn't even use them to mock up for claying, too easy to damage them. The non-clad ones are shit. Use them for claying proceedure.
You can also install the heads without gaskets and just let them set on loosely. Turn the engine over and look and feel for any movement to assure clearance on both sides. After installing the new gaskets it'll give you enough space to assure there's not a problem.
I reuse my big bore copper composite head gaskets.I also run 10 lbs boost at drags,so far 2 years no problems.
Use you gaskets for checking clearance, just don't torque the crap out of the bolts the gaskets will be fine. Tighten the bolts to seat lighty you will not compress the gastets to distortion and get a very accurate clearance measurement.
a old timer told me if you take a propane torch (or any kind of torch) and heat them up a lil (really just a lil bit) it makes em work well.. Ive been doin that several times on my rd 400 works totally good!! only the copper ones though!!!!!
I never reuse head gaskets and always check valve clearance without a head gasket, like it was said lay the head on without torquing and if you want use the clay to get an excat idea where your at. I always felt if you check the clearance with the headgasket and it doesn't hit it because it's a thousandth away when your revving the crap out of the motor it may push the valve just enough to tap the head. Thats why I always check without a gasket.
Any idea what the final thickness of a set of copper gaskets after torqing the heads? Do you think I'd hurt anything bolting the heads to the block without a gasket? How much torque? Thanks.
I don't rember the thickness of the gasket off hand but you don't tighten the bolts down or torque them while testing valve clearance. Just lay the head on with no gasket hand tighten a couple head bolts just to hold the head from falling off......unless you have head studs then just lay it on there......turn the motor over and watch/feel/listen to the head to see if it moves, again for a close measurement of your clearance put some clay on the valve to see how much it compress's. after the gasket is on you should still leave at least 0.040 for clearance no less. So if you check without the gasket and it doesnt hit you will be fine since the gasket is thicker then 0.040
re: re-using copper head gaskets... I've done it many times with good results by: a) annealing (softening) the gasket with heat. It's gotta glow; then let it air cool. b) Permatex sells a gasket-inna-can paste which is a colloidal suspension of copper dust and rubber cement. The rubber cement is there to hold the dust in place; spread a thin coat on either side of the annealed gasket and let it dry; re-assemble. annealing the gasket allows it to take the required 'set' needed to seal surfaces, the copper paste manages to fill the voids on 50+ year old engines that are sure to be there. I tried annealing/resealing dry on Pops' Model A and the damned thing leaked coolant; the combo of an annealed gasket and the paste sealed it tight as a rat's ass (pops term, not mine).
Copper clad flathead gaskets are usually about .050" torqued. If you are checking clearance without a gasket, no need to bolt down tight. Keep the heads loose enough that they can raise up if something does hit them. This is without spark plugs so air doesn't lift them either. If you make two or more full revolutions without the heads lifting, you have enough clearance. If you want to check them with clay after that, you only need to slightly snug them and you don't need to put in every bolt either. Add .050" to whatever the clay measures and you will get reasonably close to the clearance with the gasket.
Just to clarify, you can anneal and reuse solid copper head gaskets, You can NOT heat and reuse copper clad head gaskets.
yea.........and just in case anybody is throwing away any solids, throw them over here........My address is.................
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