Do you use gaskets on your exhaust manifolds? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hotrodhomi · 09-29-2007, 07:32 PM

Today I removed my Ceramic Coated Hedmans and I am going to replace them with Corvette 2.5” ram horns. My question is, do I need a gasket for the ram horns? I’ve been using copper gaskets for my Hedmans and I haven’t had any problems. The directions say “no gaskets”, but that just one mans opinion. I want to know if that is the best method.

corn · 09-29-2007, 07:38 PM

Either way is fine with manifolds. Cant hurt, but I dont use them...

berencam · 09-29-2007, 07:39 PM

i dont really see a problem with using a gasket even if the directions dont want you too...wouldnt hurt anything imo. not a expert tho...

hotrodhomi · 09-29-2007, 07:42 PM

Should I use the copper gaskets or is that over kill?

BCOWANWHEELS · 09-29-2007, 07:46 PM

every engine i,ve dissasembled has exhaust gaskets. and i,am 53 yrs old. they come in every gasket kit i,ve ever bought also.
bob

**jaros44sr** · 09-29-2007, 07:48 PM

Dang, we must be doing the same thing, only 4 hours apart. I'm up to my intermediate mounts, hangers should be here tomorrow

Good question, I was wondering that myself. I'll let you find out, so I can follow

BCOWAN just said to use copper gaskets, he must have been typing at the same time

jeffspower · 09-29-2007, 07:51 PM

With new manifolds on head port surfaces that are not eroded, a gasketless installation will NEVER leak unless the bolts work loose or break. A gasket WILL eventually burn out. This isn't the case with all engines, but the SBC is almost fail- proof to run without gaskets.

**jerry moss** · 09-29-2007, 08:28 PM

as long as the manifolds are surfaced flat, you don't use gaskets. i've been at the same muffler shop for over 22 years and we have the manifolds surfaced, clean the head and bolt them up metal to metal. as long as everything is clean and smooth it won't leak--ever.

Andy4639 · 09-29-2007, 08:32 PM

Never used them with the ram horns. I clean both sides of the mating surfaces and bolt them up.

herb101 · 09-29-2007, 08:37 PM

Hmm - I guess the carbon will build up fairly soon and fill in the minor gap between the freshly machined surfaces? I don't think I've ever had a manifold that was actually flat. They all seem to shrink a bit toward the center siamesed ports and twist a bit when they do.

Herb

berencam · 09-29-2007, 07:46 PM

i dont see why not.

woodridge · 09-29-2007, 08:20 PM

Small blocks came from the factory without gaskets. I always clean both surfaces and apply a thin coat of aviation permatex. Never had a problem.

herb101 · 09-29-2007, 08:25 PM

Wow - news to me! I have never seen one without the gaskets. Even my old International has a steel shim plate gasket (like an old head gasket).

Are we all talking about the cylinder head to manifold interface or the manifold to down pipe interface?

Herb

Truck Hippy · 09-29-2007, 09:29 PM

I have installed manifolds with and with out gaskets and I couldn't tell the difference. Use um if you got um, if not, forget um, lol.

jake60 · 09-29-2007, 09:42 PM

1950's small blocks came from the factory with exhaust gaskets but I don't think later small blocks came with them. I "think" if gaskets are used, there is less chance for the bolts to loosen however I don't always use gaskets and have never had any problems.

**jaros44sr** · 09-30-2007, 08:30 AM

Thanks ESLL, that was the other question I had. I was going to safety wire bolts, but the locks on bolt heads is a better way to go. I don't know why I didn't remember that

Sport/Truck · 09-30-2007, 12:04 PM

I broke a stud when removing my stock nuts....
s/t

EAST SIDE LOW LIFE · 09-30-2007, 02:24 PM

Quote:

Originally Posted by Sport/Truck

I broke a stud when removing my stock nuts....
s/t

**********************************************************

Were they brass? As this is rare if they were. It doen't hurt to soak them in advance a day or so before you plan on removing your manifolds. Getting the remains of the stud out could be a problem as you do not want to cause damage where the stud threads into the manifold.

esll.

Sport/Truck · 09-30-2007, 02:42 PM

Quote:

Originally Posted by EAST SIDE LOW LIFE

**********************************************************

Were they brass? As this is rare if they were. It doen't hurt to soak them in advance a day or so before you plan on removing your manifolds. Getting the remains of the stud out could be a problem as you do not want to cause damage where the stud threads into the manifold.

esll.

no, not brass. The broken part came out without an issue. I'll be using the brass in the future though.
s/t

EAST SIDE LOW LIFE · 09-30-2007, 04:11 PM

Quote:

Originally Posted by Sport/Truck

no, not brass. The broken part came out without an issue. I'll be using the brass in the future though.
s/t

**********************************************************

Glad to hear that you managed to remove the broken stud with out further issues. I think you will be happier with brass nuts as they are longer so they cover more of an thread area to make them easier to remove. I purchased mine from a company called Zip Products ask for Larry and say hello from John in Nanaimo, B.C.

esll.

09-29-2007, 07:32 PM	#1
hotrodhomi Registered User Join Date: Apr 2004 Location: Sacramento Posts: 3,737	Do you use gaskets on your exhaust manifolds? Today I removed my Ceramic Coated Hedmans and I am going to replace them with Corvette 2.5” ram horns. My question is, do I need a gasket for the ram horns? I’ve been using copper gaskets for my Hedmans and I haven’t had any problems. The directions say “no gaskets”, but that just one mans opinion. I want to know if that is the best method. __________________ '72 2wd blazer, bagged w/ watts link & EDC '72 C10 "Lowered Farm Truck" STOLEN 5-18-11 '66 impala ht

09-29-2007, 07:38 PM	#2
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	Re: Do you use gaskets on your exhaust manifolds? Either way is fine with manifolds. Cant hurt, but I dont use them...

09-29-2007, 07:39 PM	#3
berencam Registered User Join Date: Aug 2007 Location: branson mo Posts: 933	Re: Do you use gaskets on your exhaust manifolds? i dont really see a problem with using a gasket even if the directions dont want you too...wouldnt hurt anything imo. not a expert tho... __________________ 69 chevy c10 350 3 speed manual wood bed build thread here r.i.p. 70 c10 auto 350 build here

09-29-2007, 07:42 PM	#4
hotrodhomi Registered User Join Date: Apr 2004 Location: Sacramento Posts: 3,737	Re: Do you use gaskets on your exhaust manifolds? Should I use the copper gaskets or is that over kill? __________________ '72 2wd blazer, bagged w/ watts link & EDC '72 C10 "Lowered Farm Truck" STOLEN 5-18-11 '66 impala ht

09-29-2007, 07:46 PM	#5
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: Do you use gaskets on your exhaust manifolds? every engine i,ve dissasembled has exhaust gaskets. and i,am 53 yrs old. they come in every gasket kit i,ve ever bought also. bob __________________ I BELIEVE IN JOHN 3:16

09-29-2007, 07:48 PM	#6
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,543	Re: Do you use gaskets on your exhaust manifolds? Dang, we must be doing the same thing, only 4 hours apart. I'm up to my intermediate mounts, hangers should be here tomorrow Good question, I was wondering that myself. I'll let you find out, so I can follow BCOWAN just said to use copper gaskets, he must have been typing at the same time __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim Last edited by jaros44sr; 09-29-2007 at 07:49 PM.

09-29-2007, 07:51 PM	#7
jeffspower Well, Whoop-dee-do! Join Date: Mar 2003 Location: Easton, Mo. pop.- me & scarcely a few others Posts: 2,302	Re: Do you use gaskets on your exhaust manifolds? With new manifolds on head port surfaces that are not eroded, a gasketless installation will NEVER leak unless the bolts work loose or break. A gasket WILL eventually burn out. This isn't the case with all engines, but the SBC is almost fail- proof to run without gaskets. __________________ '68 GMC shortbox 4x4 350/SM465/T221- bought it in '83 SOLD '72 K20 500 Cad/TH400/NP205 SOLD '92 Chevy 2500 6.5 mech TD 4L80E crusty daily driver '72 Monte Carlo... sweet low mile toy '11 Dodge Challenger IE 392 6spd... midlife car

09-29-2007, 08:28 PM	#8
jerry moss Born Psycho Join Date: Feb 2001 Location: brentwood,cal,usa Posts: 4,890	Re: Do you use gaskets on your exhaust manifolds? as long as the manifolds are surfaced flat, you don't use gaskets. i've been at the same muffler shop for over 22 years and we have the manifolds surfaced, clean the head and bolt them up metal to metal. as long as everything is clean and smooth it won't leak--ever. __________________ jerry moss 72 cheyenne super K20- tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,tow hooks,bumper guards,toolbox,aux. fuel tank,posi front and rear,plus other goodies!!! SOLD 69 suburban K20-tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,4 inch all spring lift,4 speed, 14 bolt full floater, dana 44 HD,warn winch,posi front and rear,tow hooks,plus other goodies. 73/80 chevy/gmc K20 SB400,turbo 400,205,tilt,a-c,gas hog. 77 K/5 cheyenne blazer-daily driver/beater. SON HAS IT NOW BRENTWOOD,CALIFORNIA

09-29-2007, 08:32 PM	#9
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,943	Re: Do you use gaskets on your exhaust manifolds? Never used them with the ram horns. I clean both sides of the mating surfaces and bolt them up. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

09-29-2007, 08:37 PM	#10
herb101 Used Register Join Date: May 2005 Location: Live Oak, TX Posts: 379	Re: Do you use gaskets on your exhaust manifolds? Hmm - I guess the carbon will build up fairly soon and fill in the minor gap between the freshly machined surfaces? I don't think I've ever had a manifold that was actually flat. They all seem to shrink a bit toward the center siamesed ports and twist a bit when they do. Herb

09-29-2007, 08:20 PM	#12
woodridge Senior Member Join Date: Feb 2005 Location: Maynardville, Tn Posts: 3,030	Re: Do you use gaskets on your exhaust manifolds? Small blocks came from the factory without gaskets. I always clean both surfaces and apply a thin coat of aviation permatex. Never had a problem. __________________ SEMA Network- Protect our Hobby! 71 C30 in pieces, starting to come together. Click here for A Place For Tennessee Truck Enthusiest To Meet

09-29-2007, 08:25 PM	#13
herb101 Used Register Join Date: May 2005 Location: Live Oak, TX Posts: 379	Re: Do you use gaskets on your exhaust manifolds? Wow - news to me! I have never seen one without the gaskets. Even my old International has a steel shim plate gasket (like an old head gasket). Are we all talking about the cylinder head to manifold interface or the manifold to down pipe interface? Herb

09-29-2007, 09:29 PM	#14
Truck Hippy Registered User Join Date: Aug 2002 Location: Hickory, NC. Posts: 776	Re: Do you use gaskets on your exhaust manifolds? I have installed manifolds with and with out gaskets and I couldn't tell the difference. Use um if you got um, if not, forget um, lol.

09-29-2007, 09:42 PM	#15
jake60 Registered User Join Date: Jul 2006 Location: Buffalo Park Posts: 75	Re: Do you use gaskets on your exhaust manifolds? 1950's small blocks came from the factory with exhaust gaskets but I don't think later small blocks came with them. I "think" if gaskets are used, there is less chance for the bolts to loosen however I don't always use gaskets and have never had any problems. __________________ "Common sense is very uncommon" Rudyard Kipling

09-30-2007, 08:30 AM	#16
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,543	Re: Do you use gaskets on your exhaust manifolds? Thanks ESLL, that was the other question I had. I was going to safety wire bolts, but the locks on bolt heads is a better way to go. I don't know why I didn't remember that __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim



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09-30-2007, 12:04 PM	#17
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: Do you use gaskets on your exhaust manifolds? I broke a stud when removing my stock nuts.... s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe. Last edited by Sport/Truck; 09-30-2007 at 12:05 PM.

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