Don Terrill’s Speed-Talk

I've really looked, with no luck:

Is there a steel shim gasket for sbc 400 (with steam holes) ?

Like 350 gaskets felpro 7733SH1 and 1094; but 400 gaskets with steam holes.

These have the Steam holes in them I have used them..

https://www.summitracing.com/parts/cgt-c5248-027

Malvn wrote: ↑Wed Mar 18, 2020 10:22 am These have the Steam holes in them I have used them..

https://www.summitracing.com/parts/cgt-c5248-027

Thank you Malvn, but seems those are MLS and I'm specifically seeking Steel Shim approx 0.015" - 0.020" range.

Malvn wrote: ↑Wed Mar 18, 2020 10:22 am These have the Steam holes in them I have used them..

https://www.summitracing.com/parts/cgt-c5248-027

Those are the gaskets I have currently on my engine. The piston was .025" in the hole and with a typical .040" gasket quench would have suffered. When it gets freshened, I will get the deck cut, it's cheaper than the gaskets and I will get the clearance I want. I had some copper shim head gaskets from somewhere that were supposed to be the correct bore size, but when dropped on the deck the edges were too close to the bore in places. Clearly the bore size was not as advertised. Anymore I just deck the block. If it's a factory block it likely needs a cleanup cut anyway.

rfoll wrote: ↑Wed Mar 18, 2020 12:38 pmAnymore I just deck the block. If it's a factory block it likely needs a cleanup cut anyway.

For true; and use the BHJ fixture. I've never seen an older factory block straight, square and perpendicular.

OK, pardon me as I regroup & gather thoughts. Memory had failed and perhaps returned. This is a project that has sat for long time.
Several years back 400 block was decked approx 0.010" and wiseco reverse dome pistons will set 0.015" in hole.
Deck was squared, trued and ready. It'll be a NA ≤ 10:1 street motor

I do Not want MLS gasket if I can avoid.

What I seek is a Composition gasket approximately 0.025" - 0.030" thick
Much like 350 gaskets V-R/clevite 5746 (0.026") or GM 10105117 (0.028")
But this is for a 4.155" bore 400 w/ steam holes.
Again, no MLS please; seek Composition.

I've down this road. If you have a stock bore there are a few possibilities. At .030 over mls is the only option I could find, and they ain't cheap.

I have made my own steam holes on composite head gaskets. Harbor Freight punch set and a block of wood under the gasket with one swift blow by a 5# hammer gets it done!

The steam holes are easy. A composition gasket with over 4.155 bore and under .040" compressed thickness is what you cant find.

rfoll wrote: ↑Thu Mar 19, 2020 9:23 am The steam holes are easy. A composition gasket with over 4.155 bore and under .040" compressed thickness is what you cant find.

Exactly

Take a look at the copper gaskets out there.

rebelyell wrote: ↑Wed Mar 18, 2020 7:21 pm OK, pardon me as I regroup & gather thoughts. Memory had failed and perhaps returned. This is a project that has sat for long time.
Several years back 400 block was decked approx 0.010" and wiseco reverse dome pistons will set 0.015" in hole.
Deck was squared, trued and ready. It'll be a NA ≤ 10:1 street motor

I do Not want MLS gasket if I can avoid.

What I seek is a Composition gasket approximately 0.025" - 0.030" thick
Much like 350 gaskets V-R/clevite 5746 (0.026") or GM 10105117 (0.028")
But this is for a 4.155" bore 400 w/ steam holes.
Again, no MLS please; seek Composition.

As I see it there is only 2 options
1 is to 0 deck the block
2 is to use a comp. head gasket that is close enough thickness to get your compression where you want it.

ProPower engines wrote: ↑Thu Mar 19, 2020 10:13 pm

rebelyell wrote: ↑Wed Mar 18, 2020 7:21 pm OK, pardon me as I regroup & gather thoughts. Memory had failed and perhaps returned. This is a project that has sat for long time.
Several years back 400 block was decked approx 0.010" and wiseco reverse dome pistons will set 0.015" in hole.
Deck was squared, trued and ready. It'll be a NA ≤ 10:1 street motor

I do Not want MLS gasket if I can avoid.

What I seek is a Composition gasket approximately 0.025" - 0.030" thick
Much like 350 gaskets V-R/clevite 5746 (0.026") or GM 10105117 (0.028")
But this is for a 4.155" bore 400 w/ steam holes.
Again, no MLS please; seek Composition.

As I see it there is only 2 options
1 is to 0 deck the block
2 is to use a comp. head gasket that is close enough thickness to get your compression where you want it.

Thanks PPE
Yup, I get all that but thought maybe others knew of a gasket I've overlooked.

I get its more about cost then anything but a simple fix.
The other option is Cometic.Custom order for the thickness you need.
They can and do make thinner gaskets for a 4.155 bore application. I was told that either .015 or.017 was as thin as they can go in GM stuff. They are limited by the material thickness's they must use.
There is a gray graphite style gasket that is about.030 compressed with steam holes in them that may do the job in a street application but not sure if they can be had any longer. I had some on the back shelf a while back saved for a econo build but would have to check if they are a large enough bore.

FYI
We used to run a 1003 felpro gaskets on a 4.155 bore blocks for circle track alky race engines years ago with the steam holes drilled as well as not drilled.
Never had heat issues and the gasket fire ring was about .010 from the bore edge. No fire ring burning either. Heads were stud'd for better clamp load as some blocks had the cracks between the bolt hole and steam holes repaired with silver solder then tapped and decked. No re-cracking as well.
I have not checked the fire ring ID for size on a GMP 604 crate engine head gasket. its .028 thick compressed. But what I am saying is it may be worth a check as the 1003 felpro was listed for a 350 bore size so you may get lucky.
You will have to drill the steam holes if the bore diameter works out but the GMP 604 gasket is similar to the standard 5.7/350 vortec head gasket in design. They stand up to 11to1 comp no problem.

Hope that may help.

At $80.00 each for the 0.27" thick head gasket, I was within $20.00 of the cost of decking the block and using gaskets from my large collection. I just couldn't bring my self to disassemble a new short block, (as in a new Little M), have it cut, and the effort to clean everything.