440 Head Gasket Advice

[LR1970]

Hi, can I use steel shim gaskets for aluminum heads? Some posts say yes, some say no. I have a 440 with aluminum heads and to get 10.1 compression I calculated a .020 head gasket. Can anyone recommend a gasket I should use.

Thank you.

 

[toolmanmike]

Hi, can I use steel shim gaskets for aluminum heads? Some posts say yes, some say no. I have a 440 with aluminum heads and to get 10.1 compression I calculated a .020 head gasket. Can anyone recommend a gasket I should use.

Thank you.

Has the block been decked?

 

[493 Mike]

No steel shim with aluminum heads. Did the head manufacturer not recommend their choice of gasket?
Mike

 

[LR1970]

Block will be decked

 

[LR1970]

Yes, they recommend a 0.039 thickness but I was wondering if there is a thinner one others are using.

 

[gkent]

Decked or not decked is not the sole determining factor. What's important is the actual finish on the deck and the head - whether they've been decked or not. The finish will determine whether you can use an "MLS" gasket.

If the head manufacturer recommends a specific "thickness", that's based on a specific piston and their head volume with a stock deck height ... to yield the advertised CR.

As for a "steel shim" head gasket, as long as its teflon coated - which most are - it will be fine. I'd guess nine out of ten guys running aluminum heads are using teflon coated steel gaskets. Good luck finding a .019 though !!

 

[toolmanmike]

I have seen quite a few recommendations for the "Print-o-seal type gasket from Fel Pro. They are probably not available very thin though. Hopefully some members here will chime in that they have used the steel shim gaskets with good results.....or not.

 

[1968rt]

.027 is the thinnest you can get from Cometic

 

[Rebelrouser]

May be old school, but nothing better than a copper head gasket with an O-ring in the block for a gasket that thin. And if you follow instructions, they do not leak water. I bought my own tool to install O-rings because machine shops kept installing the block O-ring too tall the main reason for leaks. And you can get the thin thickness you want. I got a street car with a 340 supercharger been together 6 years with copper head gaskets and no leaks. If copper was not good, top fuel would not use them.

 

[lewtot184]

I think the simplest and most reliable solution, ( if 10:1 is a must), is to mill .020" off heads and use a felpro gasket.

 

[lewtot184]

Another thing to think about is piston compression height vs quench distance. A .039" gasket is usually the safer choice; unless you have 88cc edelbrock heads or open chamber iron heads.

 

[Gunner1]

Have you checked your piston to head and piston to valve clearance’s? I’ve run a few small block chevies at .027 p to h. But the pistons didn’t have much rock in the bores. And when we pulled one down for more work the only carbon on the heads quench pad was where the piston info was stamped on the piston. Know your deck heights first.

 

[67_satellite]

Hi, can I use steel shim gaskets for aluminum heads? Some posts say yes, some say no. I have a 440 with aluminum heads and to get 10.1 compression I calculated a .020 head gasket. Can anyone recommend a gasket I should use.

Thank you.

You can do it,but it will imprint the bead around the cylinder into the head.

 

[gkent]

Bullshit. The bead is embossed and meant to flatten out - making the seal.

 

[451Mopar]

Maybe paint the steel shim gasket with copper coat and try it out? If it dosen't work you can mill the heads and use a thicker gasket.
With the steel shim, retorque the heads after a few heat cycles.

 

[RemCharger]

You can do it,but it will imprint the bead around the cylinder into the head.

It won't just by bolting on... but will with use after repeated heat cycling. Alum vs iron. That's why manufacturers use a multi layer gasket.

 

[gkent]

Maybe .... after a few years !!

 

[RemCharger]

That's the look you give when you pull the heads off and the cyl head surface is f#*ked

 

[451Mopar]

The regular Fel-pro 8519 PT gaskets will also leave the sealing ring mark in aluminum heads, but there was no problems with it that I had.
maybe an issue if removed and re-installed the head, but cutting the head surface will remove it.

 

[beanhead]

Hi, can I use steel shim gaskets for aluminum heads? Some posts say yes, some say no. I have a 440 with aluminum heads and to get 10.1 compression I calculated a .020 head gasket. Can anyone recommend a gasket I should use.

Thank you.

I got to meet and chatter with Herb McCandless years ago. I distinctly remember him saying at one point in the conversation "nah, don't ever use a steel shim gasket with aluminum heads..."
Now being the internet and all I'm sure people will say "I do it all the time it, works great"....
I'll take Herb's word for it.
I prefer the ol' trusty 8519 FelPro for anything up to about 11.5-1. Seals great, doesn't need any special deck finish and only cost about $25 a piece...plus the slightly bigger bore size works well with our old factory blocks that typically have slightly larger (sometimes ridiculously larger) bore chamfers.