[prostcelica]

Hey Guys

I am getting a set of AFR 180's for my SBC 355. My issue is my pistons sit .025 down in the whole. If I use the gasket AFR recomends(felpro 1003) Ill end up with a quech of .066

I asked AFR about using .015 rubber coated steel shim (Felpro 1094) The said that gasket hangs out in the combustion chamber a little.

I know the best thing to do would be to zero deck the block but it is already assembled and I dont want to have to do that if I can avoid it.

Anybody using the felpro 1094 on an AFR head or have any suggestions??

 

[cdminter59]

head gasket help

The Fel-Pro 1094 is a steel shim gasket with a rubber coating. It is recommended that heads and block be very flat. Some even go as far and use studs for fastening the heads. I ran into the same problem with my big block. I thought about using steel shim gasket also. I decided to have the block decked to .005 and used the .036 Cometic head gaskets. They have a good rep and are re-usable. I have too much money tied up to take a chance on something like blowing head gaskets.

 

[prostcelica]

Head surface should be good as they are new. The block im not sure. It is a fresh rebuild that I bought from a freind of a freind. It looks like the deck was surfaced so it should be flat.

I see there is mixed reviews when I read online. some say they run a steel shim with an AFR head with no issue and some say not to do it.

I really dont want to break it down and have it decked if I can avoid it. I went out tonight and measured again (was in a hurry the first time) the pistons are more like .020 in the hole.

 

[S10 Racer]

I know this is'nt the most cost effective way but you could buy a set of Felpro gaskets and fit them to the head to see if they will "hang out" in the combustion chamber. You might also look at Flatout gaskets for your application.
https://www.flatoutgroup.com/default.aspx

 

[malc]

My pistons are 20 down the bore, 64cc heads, and I use Clevite Nitroseal Cylinder Head Gaskets


Bore (in) 4.125 in.
Bore (mm) 104.775mm
Gasket Material Nitroseal
Compressed Thickness (in) 0.026 in.
Compressed Volume (cc) 5.400cc

 

[6426yy]

http://www.summitracing.com/parts/NAL-14096405/

.028 GMPP gaskets

 

[prostcelica]

Thanks for the info guys!! much appreciated. What kind of heads are you using those gaskets on?? Think they will be ok with AFR??

 

[cdminter59]

GM head gaskets

Those head gaskets will not work for you. Your bore is 4.060. You can call Cometic and custom order your head gaskets. You would need .027 compressed thickness and 4.060-4.100 bore.

 

[prostcelica]

I said 355 but maybe I have that wrong because my bore is 4.030

isnt a 30 over 350 a 355??

 

[prostcelica]

AFR recomend this one but it is to thick
http://www.summitracing.com/parts/FEL-1003/

What do you guys think of this one?? it would get me into the correct quench area and it is the same bore size as the one AFR recomends but it is copper.
http://www.summitracing.com/parts/SCE-011152/?rtype=10

 

[cdminter59]

SCE Gaskets

The block has to be cut for O-rings when using those gaskets. That is alot of work and expense. BTW it doesn't matter about 4.030 or 4.060 the GM gaskets are for a stock bore (4.000) block.

 

[cdminter59]

Check these gaskets out at: Cometic Gaskets C5245-027 Cometic Chevrolet Head Gaskets or you can use any brand that you can find .027 compressed thickness and with a bore of 4.030-4.100 in MLS gaskets. The closer to your bore the better.

 

[6426yy]

The GM .028 gaskets will work fine I installed a set on a 355 last fall. The bore size is 4.100"
GM Performance Parts 14096405 - 0.028" Composition w/ Graphite - Small Block Chevy Head Gasket | SDParts - 1-800-456-0211
Or the set that malc recommended should also work.

 

[Guest]

you can use felpro Q 1094 because of the rubber that coats them i used them with my AFR heads and was told they wont work but they do work and its the same bore as your 355 so i can tell you from experience they will work.

its a .015 quench thickness gasket so its the best way to go

 

[cdminter59]

GM performance head gaskets

The information that Summit Racing has on those head gaskets differ from SDParts. Check out Summits website: GM Performance 14096405 - GM Performance Engine Gaskets & Seals - Overview - SummitRacing.com