84305HO

I will be changing the heads on my car this season and wanted to ask if anyone has any experience with these gaskets ? Their compressed thickness of .015 would seem like a great way to increase compression. What is the downside.... and is there something else besides the standard .039. I guess a lot depends on the piston to deck height dimension of the motor.

V6camaroman

i was going to ask the same question. does anyone use these gaskets? im going to get a set for mine when i start to reassemble. are there any downsides of the gaskets?

todd200

I use them and haven't had any problems yet, but the motor only has 1000-1500 miles on it right now. When I installed them I was also installing new TrickFlow heads. TrickFlow told me NOT to use any coating other than what was already on the gasket on the head side. I did use copper gasket sealer on the block side.

84305HO

Todd, my combo is very similar, with 1200 miles on the motor and almost new (1 hr) AFR 190 heads. With a 68 cc chamber size I thought the thinner gasket would be a good idea.

Night rider327

iTrader: (13)

I use the fel-pro steel shims on all of my non decked or very little decked builds.

If iorn heads I use the 4.100" x .015" non coated steel shim ($18 for both gaskets at advance)

If alum. heads I use the 4.100" x .015" rubber coated shim ($40 for both)

On the non coated ones, I always put copper coat sealer on both sides. The coated ones go on dry.

Not only will the thinner gaskets build more compression, but they will also tighten the quench height. To me this is the best part. The right quench height will build more power, and fight off detonation better.

The best quench height is .035" to .045" under .035" and you run the risk of smacking a piston with a valve. Over .050" all benifits of quench is gone

BTW.. quench height is deck hight (how far piston is in the hole) + gasket thinkness.. Stock sbc decks are spec-ed at .025"

I got the non coated one on my 355 in my 88 camaro now, and the coated ones on my dad's 327 in his 82 firebird. No probs with them, no probs on any of the many others I used them on

five7kid

iTrader: (14)

Used them for the 305 upgrades in Nov '01. Have about 27k miles on them now.

CamarosRUS

So the 1094's are perfectly safe for alumnium heads?

ME Leigh

I used them on my aluminum LT1 headed 305

tmania

i had them on my 88 formula 350 with a cam burnt prom and headers and fast burn vortec aluminum heads and roller 1;5 rockers and vortec intake. the list went on and on i beat the sh** out of that car till i sold it . its now 6 years later and still see it driven with no one ever having headgasket problems . i used the.15 fel pro gaskets ....go for it!

Supervisor42

This is the true benefit of those steel shim gaskets. If your head and block surfaces are flat and you follow the torque sequence you don't need anything any thicker.
To quote Night Rider again: The best quench height is .035" to .045" .
This is impossible to achieve with a .039" gasket without decking the block.
My

CamarosRUS

A machine shop reciept for my motor says it was sq. decked .015. Im running Trickflow heads (64cc) and two valve relief Weisco flattops...roughly with the .015 gasket what will my quench look like?

Running a thinner gasket compared to the felPro 1010 I was using I'll have to check the piston to valve clearance but I'd like to get a rough guess if it'll even work.

Supervisor42

This depends on the cam and the lift of the valve at overlap, pistons and the depth of their valve relief knotch . Get some play-dough and mock it up without a gasket.
You need to know the piston to valve clearance anyway for RPM limits. Measure the actual piston to deck clearance with a depth micrometer since you don't know how far down in the hole it was before they removed .015 from the deck.
Measure, measure, measure.
This is the second part of the famous phrase "balanced & blueprinted"
Welcome to the world of engine building.

Night rider327

iTrader: (13)

1094's are 100% safe with alum. heads.

CamarosRUS.... I fully agree with supervisor42, You got to measure, measure, measure. With alot of the pistons out there now it's hard to say how far yours is down in the cyl. I seen some new slugs on a stock block that sat .40" in the bore where the stock ones was only .025"

Now just for a little info... GM spec on the SBC was a 9.025" deck height, piston in the bore .025"

If your shop took .015" off the decks then your new deck height is 9.010"

Quench height = amount at TDC that piston is in the bore + thickness of head gasket.

Remember it aint really safe to go tighter than .035" quench, so if your pistons sits like they 'should' that would mean they are only .010" in the bore and you would need atleast a .025" thick gasket to get you to the min safe limits. If that was the case I would look for a .028" to .032" thick gasket to put you in the gen. traget range of .040" where you will be safer, and won't have to worry about kissing a piston at high RPM use.

But again this is all just gen info.... Only way for you to know for sure how far your slugs are in the bores and what gaskets you need is to measure how far YOUR pistons are in the hole of YOUR block.

Gladstoneiroc

iTrader: (1)

Just making sure. With these gaskets, should I or shouldn't I use copper coat sealer? This will be factory iron heads with factory iron block.

CamarosRUS

Nig....so the gasket might be a bit too small? When referring to quench...what about the space between then top of the piston and the piston ring?? That will add a little bit won't it?

Dialed_In

iTrader: (3)

You'll be fine with a stock block that hasn't been milled. The pistons usually sit down in the bores a good bit. I square decked mine (not zero) and the pistons were still in the hole .020-.022" so the .015" gasket puts the quench area about as good as it's gonna get without zero decking. They should be fine for your setup but measure your deck heights.

CamarosRUS

Dialed...if you're referring to me my block was square decked .015.

F-BIRD'88

I've used these .015" thick gasketr many times on different motors. Never had a problem. I always install head gaskets clean and dry. If a gasket sealer was nessessary GM, Ford and Chrysler would use it on their factory assembled motors. They don't. Take the hint.

Clean means oil free. Clean the block and head surface with brake parts cleaner to remove the protective/storage oil that your machine shop puts on the heads to keep them from rustiing.

me2

I also have a question about the .015 gaskets.Stock 350,
RPM al. heads milled .030 That makes them 64cc. Flat top pistons, 4 valve notches .In the hole .021 .022 .The quench will be about 36 or 37.What will be my compression ratio?

Thanks,
me2

F-BIRD'88

what is the engines bore size? standard ? (4.00) oversize ?

if its a standard bore the cr is 10.36:1
if its a .030" overbore the cr is 10.49:1

me2

Thanks F-bird-88

That sounds a little too high to run on pump gas?
What size head gasket would you use.This is a 4.00 bore.

Thanks

me2

smallblockv8

I have a other question: I must re-torque the Felpro 1094 ??

davidz

iTrader: (3)

It's not just piston-to-valve that you need to worry about. It's also piston-to-head.

I had a stock eliminator 350 that I had blue printed. Minimum deck height and factory steel shim gaskets. Trying to squeeze as much compression as I could.

After I set the NHRA J/SA record and had to disassemble the engine to certify it's legality, the tech inspector showed me where the pistons were smacking the heads.

The motor went back together with thicker head gaskets.

ownor

iTrader: (5)

anyone about this one? got me interested

Supervisor42

The answer is no. This is the main reason that GM went to the steel shim gasket after the dark ages. They started milling a decent surface on the heads and block decks and no longer needed the fat cheeseburger gasket that needed to be retorqued after break-in heat cycles.
They could bolt the engine together at the factory and it wouldn't have to be touched for 150,000 miles.
I kinda wonder: why do people pay to have their block zero-decked and then have to run a fat gasket that needs to be retorqued?

GTA Sammy

iTrader: (1)

I've used Fel-Pro's steel shim 1094 .015" Head gasket 2 times already...
First on a Iron headed truck engine, The second on my AFR headed GTA engine...
Worked great, sprayed them with copper spray a gasket both times... (Permatex No.101MA / UPC 80576)

I'll soon find out how the Aluminum heads liked them when I peel them off this current engine to put them on top a new 383 I'm building....
Let you know then....

I'd recommend them.....

Holy smokes... this thread started out in 2005!!!
I've never re-torqued them...

89stkformula

iTrader: (1)

yea gtasammy Did your felpro 1094s gaskets stick out a little bit past your afr 180 heads on bottom corners ? I am curious because mine do a little. Did you ever have any leaks?

GTA Sammy

iTrader: (1)

You can see the headgasket on the outside of the head where it mates to the block, but I don't ever remember it shrouding the combustion chamber if that's what you mean.
Never gave me a problem... Ever

89stkformula

iTrader: (1)

Yea that's what meant around the outside of the block. I am happy to hear you didn't have any leaks. What intake were or are you using?

Bill Chase

I know this is an old thread. But are there any problems using these on a high mileage undocked block? It's a 91 y body with 104,000 and I will be putting 65cc heads on it. I need to keep quench tight and compression as close to stock as possible. and really do not want to pull the short block at this time because it is in good condition.

Any problems with an un-decked factory surfaced block?

GTA Sammy

iTrader: (1)

No problems bud... Giver!!!

Your pistons won’t be higher than your block deck, and the thin gaskets will defn tighten up your quench.

I’ve coated all of my head gaskets for insurance,
and swear by that copper spray stuff I mentioned above...

Even sprayed the MLS gaskets that I just put in my 5.3 CCSB.
when I’m done boosting the GTA I’ll be boosting the truck