Copper exhaust gaskets for 454s?

[John F.]

Read somewhere that copper exhaust gaskets should be used for marine stuff. Is that accurate? Thanks.

[Bruce]

The only copper gaskets I've ever used were head gaskets.

[randall]

ive been using the ones that come with the manifolds for 10 years. the instructions say dry but a mechanic friend said to coat em with "perfect seal" so i do......seems to work so far.

[John F.]

Bruce/Randall-

Thanks.

John

[bob lico]

john what are you building? basicly have not used head gaskets in twenty years especially marine engines.we don`t use intake manifold bottom gaskets either.pro`s use "tubby" with no exceptions. never a leak if you don`t answer i will not explain, the subject may be off track but lets say this we do not use gaskets in a high performance or long endurane engine.

[Kevin]

Bob,
I'm listening.
Getting ready to install custom turbo kit on my 88 mustang gt. I am reading that no header gaskets are to be used. None on the turbo flange either. stricltly copper RTV. The instructions explicitly say do not use copper header gaskets. I have been using the copper re-usable header gaskets for 10 years on my long tubes with out failure. What gives?

[John F.]

I'm not pulling the heads. I'm just replacing the exhaust manifolds--so it'd be the exhaust manifold gasket. I'm always willing to listen Bob. Thanks.

[bob lico]

s&k speed shop lindenhurst, long island , ny .; instead of head gaskets block is o-ringed good for 16 to one compression at 9,500 rpm in big block. normally block is angle milled so unless your using homemade intake or hilborn injection you have to used high pressure steam gaskets around intake ports but the rest of the intake manifold is hardware store general electric bathtub sealant normally clear in color also used on oil pan rails the only substance in the world that will not leak oil on 427 small block chevy the oil rails are razor blade thin were the block is notch for rod throw clearance and "tubby" doesn`t leak!!! also timing chain cover and crank trigger .

[Rawleigh]

Hmmm, I was always told that the bathroom silicon sealer had too much salt in it an that it would corrode aluminum! Old wives tale . . . ???? Urban myth??? Inquiring minds want to know!!!!

[DRIFTER31]

Kevin...I believe heat from a hot turbo can possibly melt copper and a bit of it may be sucked up the turbo ex side.

[bob lico]

rawleigh also nice and easy for the builder to take apart. pro stock engine rebuilt about every 50 seconds of running time. offshore race boat last a entire season about 20 hours before rebuilt.aa/fuel about 20 seconds of running time so you must be concern with ease of rebuilting incidently no bolts are used every connection is crome-moly studs.produces perfectly distributed torque.engine is always preloaded prior to machine work, a example would be a open plate torque in place prior to boring and honing.align- boring main bearing caps are also done by first torque down bearing caps. some big block 500 cubic inch running in excess of 10,000 rpm consistly.

[Bruce]

Bob,
For the sake of the general boaters lets keep apples and oranges seperated.

No boater in their right mind is gonna yank an engine and have it o-ring'd when using a standard head gasket on 98% of the marine engine out there works just fine.

Kevin,
Many times in auto, space clearance is an issue even a few thousands for parts bolting up.

Also heat is a consideration. Depending on boost pressure dialed in, possible NOS installation many gasket materials would melt or get so hard they would crumble.

You could be pushing 1200 to over 1800 degrees in temp. Copper melts at just a little over 1900 deg F.

[bob lico]

ok bruce for joe boater with a stock 454 you definitly could use copper gaskets but again a pro rebuilting a stock 454 marine engine would use MLS ( multible layer steel) no opinion please! this is the real deal thats why s&k/richard zul get the big money world champion and no mistakes!!!! on exhaust manifold we would go with composite layer between exhaust port and stock exhaust manifold.

[bob lico]

lets clarify exhaust gaskets are a composite matalic layered material .like cmi. makes. cylinder heads on 454" mercruser would be perfect with the 8 to one compression /copper head gasket are just find especially if a little salt water intrusion.

[Bruce]

Bob,
Rebuilt 100's of small blocks and big blocks in marine application in the last 30 years using nothing more than FelPro marine gasket sets.

Never had a failure due to gaskets.

There is no need to use expensive high end parts on stock engines, none what so ever.

Occasionaly I ran into some water head who thought he was a racer in his Sea Ray and blew engines because he ran them hard.

I neither had the time or patience for short pecker posers like that and sent them on their way as they were more trouble than their wallet provided.

There are multiple layers in engine building depending upon application.

Joe weekend certainly doesn't want me building him a 30k engine for his stern drive and sure as hell ain't gonna pay for it.

Apples and oranges.

Now back to the original topic of exhaust manifold gaskets.

[bob lico]

ok bruce telling me about hign end parts you elected to play with kb hemi did you ever start with a donovan block first? your into heavy metal bro and should be open minded.you cannot walk into s&k and bother the master engine builder unless you have a fist full of dollars .the losers are weeded out . in all due respect i would never consider the slightly higher price of a head gasket for all the grief a blowed head gasket could cause.you don`t buy that cheap beer at 7-11 by any chance do you?

[JP Dalik]

Dear John F
By reading the on topic comments in the first few responses
I thought I read that the copper could be a problem (thanks Bruce) and that it would be best to use the standard manifold material and coat it as per Randall's experience. (thanks Randall)

If however you are looking for answers to questions you've never asked this thread could give you all the information you've never needed to know.

Am I following correctly?

[scooter28]

the only time i ever use mls gaskets is for the cylinder head when using high compression and aluminum heads and cast iron block. they handle the differing expansion rates better. and yes on high end engines o-ring blocks are the u know what but as bruce said no were near being a good idea for a cruising boat motor.

i highly reccomend the felpro gaskets been using em for years and the only time i've ever seen a failure is usually the mating up parts fault. like heads being warped and what not i did have an issue once where the coolant leaked but i think its because i tried using the copper spray coating to see if it made any improvment which it didnt. lol

once again one of the reasons copper is used for exhaust is when headers are used which have issues with expanding at different rates then the head. one of the best gaskets ive used for headers was doubling up two paper felpro gaskets soaking them in water and bolting the headers on while still wet.

long story short u should be okay with copper gaskets but when using some big ol cast iron risers the felpro gaskets should never do u wrong.

[Tony Meola]

JP,

I like the way you cleared that up.

[bob lico]

and thats exactly why i ask before i spoke sort of by the way did you know.

[John F.]

Thanks guys. Its all good. I'm putting new manifolds on my 31-year old 454s that are tired. Sooo, I'll use the gaskets included in the kit. I do enjoy reading all the motor stuff, even though I understand about 10% of it. If only the last manifold bolts would come off.....

[bob lico]

john every day should be a learning experiance .most of us on this board enjoy our 31 bertram and anything related .some of us may or may not be experts in one of these related fields like capt. patrick in the fiberglass field. he does these elaborade fiberglass layups that most of us could only obseve but really don`t have the facilities or talent. personlly i feel it would be inpossible to "build " a engine in your garage you may asemble one but you would need harry barb`s shop to build one. head gaskets are always calculated in the building process because of application and final compression.there are many procedures in building but there is one in pre-assembly that requires a machine shop behind you. the engine is assemble with only one ring on the piston (use a old ring) because each ring is custom fitted to the cylinder . you would bring a piston up to top dead center and check the top of the piston to the flat of the block . each piston and back is written down and must be made the same (within 2/1000 )either mill the top of the block or fly cut the piston , that is envolved because each piston is balance to 1/10 of a gram . that is why a engine builder gets 35,000 per engine it takes a week just to assemble. that being said it makes it differcult for a engine builder to let everything "slide" and put together a clunker on the garage floor or use anything but the best of the best to build with.how do you let one out the door knowing your name and reputation is written on it as well as build it again if it fails???again this is racing application but if that what propels your business then then you have to do it.

[Bruce]

This thread is closed due to an accident in the produce section.