Gasket between cylinder case and head?

[Joe L.]

Re: Gasket between cylinder case and head?

Woops, I wasn't reading. The Cadillac 4.9 and 4.5 engines had Al blocks with iron heads IIRC. Steve

Steve------


Yup, that's the one. The Cadillac 4.1, 4.5, and 4.9 OHV engine family. Besides the Vega, that's the only other engine family I know of that used an aluminum block with cast iron heads. There was a basic difference between the Vega and Cad engines, though. The Vega engine used cylinders bored directly into the high silicon alloy aluminum block material. The Cad family used cast iron cylinder liners in the aluminum block.

[John H.]

Re: Gasket between cylinder case and head?

Steve------


Yup, that's the one. The Cadillac 4.1, 4.5, and 4.9 OHV engine family. Besides the Vega, that's the only other engine family I know of that used an aluminum block with cast iron heads. There was a basic difference between the Vega and Cad engines, though. The Vega engine used cylinders bored directly into the high silicon alloy aluminum block material. The Cad family used cast iron cylinder liners in the aluminum block.

Joe -

Also, the Vega engine had free-standing siamesed cylinder bores with no "deck"; the Cadillac engines had conventional cast construction with a deck on the block. The free-standing bores with no deck to support them and the differential expansion rate between the aluminum block and the iron cylinder head virtually guaranteed head gasket failure if the engine overheated, but it was Ed Cole's design, and nobody dared question it.


OpenDeck800.JPG

[Terry M.]

Re: Gasket between cylinder case and head?

Thanks Joe for filling that out. I should have remembered the later C3s, and more so the L98 since I put an L98 in my 1967 Chevelle.
Perhaps I should not have started dragging the thread that far, but no limits were put on the original or subsequent posts and I knew the Gen II LT-1s originally had MLS exhaust manifold gaskets. I just was not able to be as thorough as you.

BTW: If anyone feels they have to have exhaust manifold gaskets for their Corvette the MLS gaskets are far superior to any other design, if they will fit your application.

[Richard M.]

Re: Gasket between cylinder case and head?

It might be prudent to define the engine(s) you are talking about. When you get beyond the Gen I engines some used exhaust manifold to head gaskets. My Gen II LT-1s have exhaust manifold to head gaskets. I am not sure about the LS series, I would have to do some looking.

I was only referencing his info regarding his '71 and figured I was safe with that one only. I had no idea about later ones, until I read further into the thread. Lots of good info followed.

So....to research my LS2 and your LS7 exhaust manifold gasket inquiry and usage. Both use gaskets according to the parts information I just looked up. Here's a pic of your setup and reference page....

http://store.gmpartshouse.com/parts/2007/Chevrolet/Corvette/Z06/?siteid=214638&vehicleid=188518&section=EXHAUST%20SYSTEM

The only caveat of course is that it shows the gaskets are available OTC, but not positive if they were built that way.

Joe -

Also, the Vega engine had free-standing siamesed cylinder bores with no "deck"; the Cadillac engines had conventional cast construction with a deck on the block. The free-standing bores with no deck to support them and the differential expansion rate between the aluminum block and the iron cylinder head virtually guaranteed head gasket failure if the engine overheated, but it was Ed Cole's design, and nobody dared question it.

That Vega block looks arranged a bit like the "no deck" '72 Jaguar new V12 I rebuilt a few years ago, it has separate cast iron liners in the aluminum block but siamesed also. Thankfully separated when the valve seat dropped on the #5B cylinder. Due to a poor flowing radiator and overheat, on cool down back home, 3 days later the seat dropped down on the Wife's (noisy, crunching sound)start-up attempt to take it to work. It took out the piston and cracked the liner.

Popped the bad liner out, replaced it along with the piston, and good to go. Got involved in other stuff too while it was apart.

104_14.JPG 084_19.jpg 006_6.jpg 038_13.jpg

[Kevin G.]

Re: Gasket between cylinder case and head?

Thanks to all that replied!

Great information, unexpected learning!
But now, I'm not sure if I know more or less?

[Terry M.]

Re: Gasket between cylinder case and head?

I was only referencing his info regarding his '71 and figured I was safe with that one only. I had no idea about later ones, until I read further into the thread. Lots of good info followed.

So....to research my LS2 and your LS7 exhaust manifold gasket inquiry and usage. Both use gaskets according to the parts information I just looked up. Here's a pic of your setup and reference page....


The only caveat of course is that it shows the gaskets are available OTC, but not positive if they were built that way.



That Vega block looks arranged a bit like the "no deck" '72 Jaguar new V12 I rebuilt a few years ago, it has separate cast iron liners in the aluminum block but siamesed also. Thankfully separated when the valve seat dropped on the #5B cylinder. Due to a poor flowing radiator and overheat, on cool down back home, 3 days later the seat dropped down on the Wife's (noisy, crunching sound)start-up attempt to take it to work. It took out the piston and cracked the liner.

Popped the bad liner out, replaced it along with the piston, and good to go. Got involved in other stuff too while it was apart.

[ATTACH=CONFIG]52677[/ATTACH] [ATTACH=CONFIG]52680[/ATTACH] [ATTACH=CONFIG]52678[/ATTACH] [ATTACH=CONFIG]52679[/ATTACH]

That Jag is an interesting bit of kit there Rich.

It is interesting what one learns here. There is a wide range of talent and knowledge here.

[Joe L.]

Re: Gasket between cylinder case and head?

The only caveat of course is that it shows the gaskets are available OTC, but not positive if they were built that way.

Rich------


They were built that way.

[John H.]

Re: Gasket between cylinder case and head?

The Vega engine used cylinders bored directly into the high silicon alloy aluminum block material.

Joe -

Correct - After boring and honing, the Vega cylinder bores were acid-etched to expose the free silicon particles, and the aluminum pistons were iron-plated to be compatible with the bores. This technology never caused ANY problems at all, and was also used by Mercedes-Benz and Porsche well into the 90's, known as the "Nikasil" process; cast-in iron liners replaced it as a cost savings (piston plating with four different materials was an expensive 13-step process).


PistonPlating.JPG