Mission creep (herein of head gasket importunity)

A recent top-end maintenance issue became ("well, as long as it's apart anyway....") a full top-end job. Cylinders bored 040 over, new MAP (stock rod/compression) 78 mm pistons, and the head shown major love.

Added one of Jim Schmidt's Desaxe (wedge) base gaskets for fun while it's open. Cylinders just went back on today. On to the head... (and after that, back to the motor....)

I have 021 and 032 thickness copper head gaskets. "You must clay it, son." I know, but still would like to solicit thoughts on pros and cons of the choice. We have a lot of knowledge (and opinions!) on this board and I'd like to avail myself of it if I may.

Tx - B

I'm not sure of any real question here .
My recent motor rebuild today needed re-torque after only 250 of your miles .
Composite flame ring head gasket .

Thanks. I'm a retorquing freak so that won't be an issue.

I was soliciting opinions on 021 vs 032 head gasket.

Tx - B

If the pistons have valve pocket cutouts it's your call. With the wedge base you could use the .021 gasket with stock height pistons and a stock cam. You don't need to clay it. Clearance is all measurable with a caliper. Get the bottom end done and bolted down. Then measure how much the pistons stick up above the deck, subtract the head gasket thickness from the piston height and subtract the result from the depth of your squish band (the step cut around the combustion chamber for piston clearance)? That will give you the resulting squish depth. It'll probably be plenty deep enough for your stock cam lift. Or you can do whatever whomever disagrees with me using a bunch of technotalk suggests. lol

There’s bags of room in there. No problem at all using a .021 HG.

Thanks folks

This was the consensus of others as well, including the guy who did my rebore and headwork, so I've reassembled and turned over slowly with the kicker, all seems well.

Using a copper head gasket, what do folks do about retorquing? First heat cycle and 100 miles or so is my inclination (when I used a composite previously, I think I did 5-6 retorques over the course of the first 500 miles. Overkill, to be sure - but it didn't leak!). Even before then, after sitting cold overnight? Other?

Tx - B

BrianK said:

This was the consensus of others as well, including the guy who did my rebore and headwork, so I've reassembled and turned over slowly with the kicker, all seems well.

Using a copper head gasket, what do folks do about retorquing? First heat cycle and 100 miles or so is my inclination (when I used a composite previously, I think I did 5-6 retorques over the course of the first 500 miles. Overkill, to be sure - but it didn't leak!). Even before then, after sitting cold overnight? Other?

Tx - B

Click to expand...

Check it regularly Brian for you own peace of mind, but you’ll likely find that it doesn’t crush much at all.

BrianK said:

This was the consensus of others as well, including the guy who did my rebore and headwork, so I've reassembled and turned over slowly with the kicker, all seems well.

Using a copper head gasket, what do folks do about retorquing? First heat cycle and 100 miles or so is my inclination (when I used a composite previously, I think I did 5-6 retorques over the course of the first 500 miles. Overkill, to be sure - but it didn't leak!). Even before then, after sitting cold overnight? Other?

Tx - B

Click to expand...

What did you end up using for sealing the head gasket?

Your plan sounds good to me for the retorque. I've probably only done a retorque twice on the current copper head gasket I'm using. I used copper kote spray a gasket on it. No problems.

If you used Pliobond to seal the head gasket, the head won't move even if a bolt or two go out of spec a little. Kind of unlikely though. I used ARP thread goop on my head fasteners so I could get even torque without any thread bind. I have alloy barrels though, so not sure if I'm allowed to say what I did is relevant.

Edit: I read your other head related post where you said you used Pliobond after I wrote the above. You get hero status for doing it with Pliobond.

Yup, pliobond and copper wire. Using new CNW waisted bolts so here's hoping!

BrianK said:

Using a copper head gasket, what do folks do about retorquing? First heat cycle and 100 miles or so is my inclination (when I used a composite previously, I think I did 5-6 retorques over the course of the first 500 miles. Overkill, to be sure - but it didn't leak!).

Click to expand...

The last time I did the 650 head gasket (only because I head to rebuild the gearbox?!) I could only get solid copper for the spigotted barrels. My preference at the time being the previous, 20,000 mile, non-leaking composite gasket, i fitted the copper and did the overkill above, and it didn't compress much, but it is *completely* dry 4000 miles or so later.