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)

[PeeGreen 914]

If you're going that far why not do the rings? You may as well start with a fresh set.

[euro911]

Kevin - honing the jugs and installing new rings is relatively cheap in the realm of things ... although your compression readings were actually pretty good (IMG:style_emoticons/default/confused24.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?

[r_towle]

By removing the head gaskets you will be changing your compression ratio.
Just keep that in mind.
It also changes your valve geometry.

Why not just get a new set of head gaskets and put the heads back in place???

Rich

[rhodyguy]

and source a set of euro spec pistons for "while you're in there". it never ends.

k

[kconway]

By removing the head gaskets you will be changing your compression ratio.
Just keep that in mind.
It also changes your valve geometry.

Why not just get a new set of head gaskets and put the heads back in place???

Rich

Rich,
I was hoping to hear this might be a viable option from the community. I know my limitations and screwing with the valve geometry goes far beyond what I comfortable with.

Is there any tricks while using the head gaskets to help eliminate the possibility of a leak?

[kconway]

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. Bounght 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...

[Cap'n Krusty]

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

[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)

[dbgriffith75]

Hmm... I guess I'm not familiar w/ "lapping." What is this? Not that it matters much to me- my heads are already installed w/ gaskets. Just curious.

And how have some of you handled reinstalling the cylinders/pistons? The way I did it, and this probably wasn't the best way, was I installed the pistons in the cylinders, froze the wrist pins to shrink them, then pushed the piston out the bottom enough to reconnect the pistons to the connecting rods. Pins slid right in as they were frozen... well, mostly. It did require some light tapping w/ a ball peen hammer. For future reference is there a better way to do it?

Sorry- don't mean to jack the thread- but it is a related topic.

[bryanc]

Competition Engineering in Phoenix makes some copper head gaskets that work fairly well. You can get them in various thicknesses to compensate for the deck height. I used them on my rebuild and have been happy with them.

[kconway]

Competition Engineering in Phoenix makes some copper head gaskets that work fairly well. You can get them in various thicknesses to compensate for the deck height. I used them on my rebuild and have been happy with them.

Bryan,
do you have contact info for CE?
Kev

[orange914]

By removing the head gaskets you will be changing your compression ratio.
Just keep that in mind.
It also changes your valve geometry.

Why not just get a new set of head gaskets and put the heads back in place???

Rich

Rich,
I was hoping to hear this might be a viable option from the community. I know my limitations and screwing with the valve geometry goes far beyond what I comfortable with.

Is there any tricks while using the head gaskets to help eliminate the possibility of a leak?

if you want to eliminate the head gaskets/lap the cyliders then why dont you mic. the old head gasket thickness and add base shims of equal thickness? no valve geo work neded then (IMG:style_emoticons/default/poke.gif)

[bryanc]

Competition Engineering in Phoenix makes some copper head gaskets that work fairly well. You can get them in various thicknesses to compensate for the deck height. I used them on my rebuild and have been happy with them.

Bryan,
do you have contact info for CE?
Kev

The page from their site about the gaskets: here.

You probably will need to give them a call. Mic your current gaskets and see what they can do for you.