Head gasket

[Jusjofok]

Ok guys,
I think my small block has a bad valve, going to run a couple more tests before i pull the heads but I was wondering what kind of head gaskets to go back with. It is a 350 with double hump (492 castings) heads, 10:1 pistons, 350hp cam. I believe it currently has copper head gaskets but I haven't confirmed that. What do you guys recommend?
Thanks

[wagspe208]

If not o-ringed with receiver grooves...no copper. Cometic is the bad ass piece right now. Totally overkill for wht you are foing. Fel Pro 1003 or 1004 will last you forever unless you detonate the piss out of it of course. They are pretty resonably priced too.
Wags

[RiverRacer]

Ditto that, the Fel Pro's are more than adequate!..

[Wannabe]

It is one of those deals, you can spend more, but why. We are talking about a very small cylinder pressure in comparison to what Cometics work best in, and the like. If someone used copper without O-rings, they should be beat with a rubber hose fresh out of the microwave. If it does have O-rings, you are pretty limited to what you can use. SCE has a copper gasket with rubber around the water and oil passages. Those are nice for getting coppers to seal. If there are no O-rings, just grab a good set of Fel-Pro standard deal and go. Unless you have a major problem, they will seal for eternity.

[RiverRacer]

If this an older deal odds are it won't have a reciever groove, if so no big deal weather the block is o-ringed or the heads are pantographed just leave the wire in the grooves and have the surface skimmed flat done deal, now you can use the gasket of your choice, Fel-Pro!..:D

[Jusjofok]

Thanks for your help guys. I will go for the Fel Pro's cause the more I think about it the more I doubt they are copper. My old man built the skinny block back in the mid 70's when he worked for Chevy and I don't recall him saying anything about machine work on the block or the heads.
Anyway, is there any problem with corrosion and the Fel Pro's?
Thanks

[RiverRacer]

Anyway, is there any problem with corrosion and the Fel Pro's?
Thanks

Nope!.. ;)

[Jusjofok]

Ok, I just don't want them to rust away and give me issues...:eek:

[RiverRacer]

Ok, I just don't want them to rust away and give me issues...:eek:

As long as both surfaces are clean and flat, they will be sealed and no water will get to them!..

[AquaCraft]

Ok, I just don't want them to rust away and give me issues...:eek:

If rusting head gaskets is a problem/concern; you may be interested in Fel Pro Performance Marine Head Gaskets; part #17030 for small block Chevy; made with stainless steel core laminate.

They are available anywhere; here is a link to one source:

http://store.summitracing.com/partdetail.asp?part=FPP%2D17030&autoview=sku

[Moneypit]

If there is any doubt of the age/condition of the head bolts/studs, change them. Cheap insurance.............Ray

[RiverRacer]

If they're old stock bolts they should be replaced with new ARP's anyhow!...

[no longer here]

Hello Jusjofok...
Amazingly, it seems that many of these guys don't realize that your engine is, for all intents, a relatively stock 350. The 492 heads were a factory stock casting. The 10.0:1 compression ratio is standard.
AquaCraft has the right idea if corrosion is a problem with the stainless core gaskets, however, if I'm not misreading your address, you live in Kansas. DOUBTFULL that a salt water issue will befall you there, so composite head gaskets are fine.
If I'm not mistaken, "Pantographing" is only done on heads that have non-round holes in the head gaskets (like a big block Chevy, which you don't have), so don't concern yourself with that.
Your 350 will have a round hole (chamber shape) in the head gasket, and at 10.0:1, you don't need o-ringing, period. I believe the highest stock horsepower small block Chevy was a F.I. 327 , somewhere around 360 to 370 horsepower with factory "pop-up" pistons with 11.0:1 compression, and the heads held just FINE with factory head bolts. Get fresh bolts from your local Chevy dealer if you're unsure about them, aftermarket bolts are fine but not necessary, studs are overkill, but it's your money....
I see too many people get caught up in this, don't buy parts like you're running through Pep Boys with a magnet. Be realistic, and pragmatic about what the engine really requires.
The blue "perma-torque" Fel Pro's are pretty much the industry standard and are high quality, so don't but the racing stuff and keep your wallet fat and happy.

[RiverRacer]

Hello Jusjofok...
Amazingly, it seems that many of these guys don't realize that your engine is, for all intents, a relatively stock 350.

Who don't, LOL...:D:D:D

[Moneypit]

Hello Jusjofok...
Amazingly, it seems that many of these guys don't realize that your engine is, for all intents, a relatively stock 350. The 492 heads were a factory stock casting. The 10.0:1 compression ratio is standard. .

Oh I realize it. But you must take into account that car motors in boats need a little extra in a few places. Not a lot, just a little in the right places makes for a longer lasting, better running engine, and a more pleasurable boating experience. You are right, that most people go nuts, 850 CFM carbs on engines that actually need half of that, etc etc.....The good old K.I.S.S. method works best........MP

[Jusjofok]

Spike, I have a misprint in my original post, it does have 11:1 factory pistons. Brain fart :D And you are right, it is factory, nothin special here, only good reliable power...
Anyway, judging by everyone's post I don't think it will matter if I go with typical composite or marine head gaskets. Fel Pro's it is. I will get a set of new head bolts, after all, the thing is 35 years old and I doubt they have been replaced.
Thanks guys.

[RiverRacer]

the thing is 35 years old

Best surface the heads and block for a perfect fit= no leaks!..

[no longer here]

Jusjofok,
When you have the valve job done on your heads, if the machine shop is reputable, they should check the head surface. I said CHECK.
Not every set of cylinder heads are out of whack. They'll take a machined straightedge designed for checking decks and heads and such, and measure( I believe it's 2 thou in any 6") to see if it's necessary. Then, and only then, they will take a skim cut, just enough to remove any machining shadows.
I'm just saying this because it's "buyer beware" out there. Tell the machine shop to take only the minimum if the heads need re-surfacing. Some operators are heavy handed with machine operations.
You may, or may not know this as well, but the head bolts on small block Chevys go through the block deck into water jackets. After 35 years, there's going to be some rusty threads happening there.This is normal. Chase all of the head bolt threads so that your torque readings will be accurate. Clean the blocks deck surfaces as well....do a good job.
Also, because the bolts DO go into water jackets, you don't want the bolts to seep. Use a thread sealant of some sort ( I've found Gasgacinch to work well), coat the threads, torque in the proper order.
Small block Chevys have 5 head bolts around each cylinder, as opposed to 4, as Fords and Chryslers do, so the head gasket has a head start in the holding department.
When re-assembling, check every pushrod to verify that they are not plugged up, your valve train oils thru the hollow pushrods .
As a mechanic,BEFORE the heads go back on, if I were doing the job, there's something else to address.
Your engine has 35 years worth of carbon on the piston tops, now is the time to remove the carbon. Gas isn't what it was in '71, but your compression still is. Remove the carbon off of the piston tops, one at a time, by rotating that cylinder to Top Dead Center (all the way up in the bore), this way, you don't damage the cylinder walls. You can scrape(carefully), or use a small cup style wire brush on a drill motor, or a scotchbrite disc on a drill motor, etc. Just don't leave nicks in the dome, which should be approx 1/8" tall at 11.0:1. Nicks in the aluminum will aggravate a possible hot spot occuring, and that is the point to all of this.
Keep the debris out of the engine and adjoining cylinders as you go about this. Mask with plastic, cover with rags, whatever you feel comfortable with.Use a shop vac if you have one.
Like painting a house, sometimes the prep work takes longer than the job itself, but you'll be rewarded with a nice running engine.

[Jusjofok]

Spike,
I am very familiar with skinny blocks and fat blocks and am very particular with the machine shop work. I have been rebuilding stock chevy parts since a small child but very little marine application stuff. I moved to Kansas about a year ago and haven't found a machine shop that I am comfortable with. Back in OKC there were only a couple that we use. I always check some of their work before I even carry in my heads, the old WD-40 and a blowgun trick, any bubbles from around any valve and you walk out to find another shop.
As far as head bolts leaking I have never had any trouble with that, always just used a tiny bit of oil and let the gasket do the rest.

[Jusjofok]

Ok, I pulled the heads last night. It does have copper head gaskets but they have no o-rings, they appear to be solid copper. Anybody know anything about these? Just interested to see if someone thought they had a better idea at the time or something.
Thanks

[wagspe208]

Ok, I pulled the heads last night. It does have copper head gaskets but they have no o-rings, they appear to be solid copper. Anybody know anything about these? Just interested to see if someone thought they had a better idea at the time or something.
Thanks

Sure, they are for high cylinder pressure..tons of nitrous, blown applications, etc. Without o-rings...well technically if there are no o-rings someone half assed the project. No offense to someone. Go with the composite gaskets and be happy for years.
Wags

[wagspe208]

BTW, the o-ring will stick up above deck (or head depending upon builder) about .013, there will be a receiver groove in the head (wider than the o-ring, and about .020 ish deep). The wire pushes the copper into the groove making a bad ass seal. The sharp corners of the groove are actually the seal point. (this is according to forcell and clark..now clark...the biggest copper gasket guys in the day)
Wags