Head Gaskets, Uggg Options

[kconway]

So, I've been reading here that head gaskets are a thing of the past, I guess lapping is in. That said...I pulled the heads off a few weeks ago and sent them out for a rebuild. It had head gaskets on it.

Whats the process for lapping cylinders to heads? Do I pull the cylinders/pistons off the rods as a whole to preserve the rings? Toss the rings and rering too? I did a compression test recently with good results, 135-140-140-138.

I was just going to replace pushrod tube seals...this is getting out of hand.

What would you do?

Kev (IMG:style_emoticons/default/blink.gif)

[toon1]

How many miles on the motor?

The cyl has to come off to lap them to the head

If it where me, ( belive me ,I've BTDT) I'd take the cyl. off, replace the rings, hone the cyl's. inspect the pistons, lap the cyl's to the head put it together and run it. You will gain a bit of compression by removing the head gaskets

BTW, what are you doing to the heads?

Hell if you have tore down this far, why not rebuild it?

Engine is out of the car while car is being painted. Bought car with PO said was a fresh rebuild, no paper to prove it.

I was resealing and going thru the pushrod tube seals when I found a few valve stems were damaged so I sent the heads for rebuild. Shop finds cracks around plug holes and yada, yada, yada...

If the top of the cylinders are nice and flat, and the heads were done right, there is ABSOLUTELY NO REASON to "lap" the cylinders to the heads. Old wives tale. You're introducing a randomness to the case/cylinder/head precision fit. Unless you have the hand/eye coordination of a milling machine, you can't possibly hold each cylinder perfectly perpendicular to the heads and lap each one to exactly the same amount. That said, if the heads were step cut to eliminate the gaskets, you MUST shim the barrels (after calculating the deck height and chamber volumes) to correct the compression.

The Cap'n

(IMG:style_emoticons/default/agree.gif) wht the cap'n ( hard not to).

you may want to pull the rod caps and plasigauge the clearance just to make sure. You can do this without splitting the case.

If you change the top, it put's more stress on the bottom.

If anything it will give piece of mind.

WOW cap'n, are you going soft? You did'nt blast him for wanting to remove the head gaskets! (IMG:style_emoticons/default/biggrin.gif)