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? steel shim gasket for sbc 400 ?

General engine tech -- Drag Racing to Circle Track

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6.50camaro
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Re: ? steel shim gasket for sbc 400 ?

Post by 6.50camaro » Fri Mar 20, 2020 4:41 pm

Don't know if this will help? Ferrea used to have a composite hg that was 4.205 bore x.035 thick. Sealed good and really had to scrape to get the grafoil coating (or whatever it was) off the block and heads . Can't remember about steam holes though . They stop selling head gaskets but they probably didn't make them just had one of the big companies like victor or the like make the gasket for them . I havent done any research into who supplied their gaskets . Dan

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Re: ? steel shim gasket for sbc 400 ?

Post by rebelyell » Fri Mar 20, 2020 8:26 pm

ProPower engines wrote:
Fri Mar 20, 2020 2:52 am
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.
Thanks PPE
Haven't checked 1003 either but I recall those are around 0.039 ish. Haven't checked the 604 gasket (maybe 10105117) or the 5746 to see IF they're large enough for 4.155" . IF they are, that's the ticket as the steam holes are easy. Thanks all!

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Re: ? steel shim gasket for sbc 400 ?

Post by econo racer » Sat Mar 21, 2020 7:10 am

The 10105117 will not fit. Its for 350 bore. Goes up as wide as 4.080. I have never seen a steel shim head gasket for the the 400 sbc. Sorry :(

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Re: ? steel shim gasket for sbc 400 ?

Post by swampbuggy » Sat Mar 21, 2020 8:34 am

Rebelyell, why are you opposed to a MLS head gasket ? Mark H.

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Re: ? steel shim gasket for sbc 400 ?

Post by rebelyell » Sat Mar 21, 2020 10:54 am

MLS' comparative cost. Comp & shim have always met My needs for 350 bores.

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Re: ? steel shim gasket for sbc 400 ?

Post by swampbuggy » Sat Mar 21, 2020 11:02 am

Roger 4, no need to spend money if it is not necessary. :wink: Mark H., North Carolina bloodline, Union County near Marshville.

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Re: ? steel shim gasket for sbc 400 ?

Post by Schurkey » Sat Mar 21, 2020 1:16 pm

I remember PDQ posting about using a hammer to re-form the bore edge of standard steel shim gaskets to make them fit the 400 bore.

Surprised he hasn't posted in this thread.

I looked at some steel shim gaskets I had sitting on a shelf, for the last build I did; I wasn't confident enough in my ability to re-form the bores. I had the block decked instead.

rebelyell
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Re: ? steel shim gasket for sbc 400 ?

Post by rebelyell » Sat Mar 21, 2020 1:39 pm

swampbuggy wrote:
Sat Mar 21, 2020 11:02 am
Roger 4, no need to spend money if it is not necessary. :wink: Mark H., North Carolina bloodline, Union County near Marshville.
:wink: Used to work in Wadesboro & my boss (great guy that Jay) lived in Monroe. Small world. Late father's family settled in (what would become) SC before first war for independence. Fourth ggf was Lt with Marion's Brigade & armourer to same.

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Re: ? steel shim gasket for sbc 400 ?

Post by ProPower engines » Sat Mar 21, 2020 1:59 pm

econo racer wrote:
Sat Mar 21, 2020 7:10 am
The 10105117 will not fit. Its for 350 bore. Goes up as wide as 4.080. I have never seen a steel shim head gasket for the the 400 sbc. Sorry :(
Just to be clear there is 2 gaskets listed by GM that get confused.
I do not have the part numbers on hand but the std. vortec head gasket is the same compressed thickness as the gasket for the 604 crate with aluminum heads.

If you have the GM part numbers post em up so we don't get confused again. The cost difference between the 2 gaskets is a substantial difference. Here the std vortec gaskets are $38/pair the others are about $38/each
Real Race Cars Don't Have Doors

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Re: ? steel shim gasket for sbc 400 ?

Post by rebelyell » Sat Mar 21, 2020 4:47 pm

Dunno if either of the below GM gaskets are std vortec L31 or 604 or ? but they are sbc

140966405
0.028 maybe an MLS it's SS & graphite about $39 each summit

3830711
0.026 shim about $15 each summit
dunno if this truly shim or comp as it's 0.026"
really think it's a Thick shim but not sure

10105117
0.026 comp about $26 each summit
shown in 2006 GMPP parts list for 602 vortec CT crate


handy 2006 GMPP download if ya don't have an old on w/ parts lists.
https://www.hsv-gts.ls2.com/gmperforman ... g_2006.pdf

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Re: ? steel shim gasket for sbc 400 ?

Post by Bill Chase » Sun Mar 22, 2020 8:25 am

Check Mahle catalogs, seems they have a .020 or maybe .025 steel shim available, as others have said... add the steam holes. Lingenfelter book on modifying small block chevy engines gives the location of steam holes and other deck plug options for the 400 factory blocks

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Re: ? steel shim gasket for sbc 400 ?

Post by Bill Chase » Sun Mar 22, 2020 8:31 am

Also, with a short fill and higher volume water pump to keep velocity high, are steam holes really necessary, I only say this because I have read so much conflicting information about these blocks that it is hard to decipher fact from fiction. And I have a standard bore 817 block that will be going to the machine shop very soon. The 3 shops around here do not want to touch them, they would rather sell you an shp block for 1700, or a blemished dart block for 1200. It is hard to argue if building any kind of 450 plus hp endurance pr street engine, but it sure seems like a waste to npt use the block when a solid 400hp and 450 tq will fit my needs and only see street use.

6.50camaro
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Re: ? steel shim gasket for sbc 400 ?

Post by 6.50camaro » Sun Mar 22, 2020 8:40 am

Speedway Motors has a 4.165 bore .024 steel shim gasket but no steam holes for $9.99 ea. . I have used these on 350'and 383 's with out problems . If you think you could do the holes might be worth the try. Dan

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Re: ? steel shim gasket for sbc 400 ?

Post by rfoll » Sun Mar 22, 2020 10:49 am

Many of the head gaskets in the Enginetech rebuild kits are about .010" thinner. I tried to decipher from their catalog if this was true for a 400, but couldn't find any info. It might be worth a call.
So much to do, so little time...

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Re: ? steel shim gasket for sbc 400 ?

Post by rebelyell » Sun Mar 22, 2020 12:53 pm

Thanks BillC & 6.50camaro & rfoll
will look into mahle's & speedway's gasket & ask Enginetech

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