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-   -   Should I Run Exhaust Manifold Gaskets? (http://67-72chevytrucks.com/vboard/showthread.php?t=761667)

Dodge68charger 04-13-2018 10:43 AM

Should I Run Exhaust Manifold Gaskets?
 
Should i Run Exhaust Manifold Gaskets With My Ram Horn Exhaust Manifolds. I Bought Them Soft Aluminun Gaskets And Heard Conflicting Storys Whether To Run Them or High Temp Sealer?

Also What Should I Use The Seal The Threads On The Pipe Plugs On Them?? Thanks
Posted via Mobile Device

sick472 04-13-2018 11:48 AM

Re: Should I Run Exhaust Manifold Gaskets?
 
I don't think Ram Horns used manifold to head gaskets from the factory, but I would recommend using some IF you do not plan to have the old mani's plane machined. A particular person would also have the head surfaces trued up too. I suspect most people just use metal composite gaskets to avoid the machine work and deal with replacing them every so often. I have never trusted any High Temp Gasket Sealer in this area, but some people will say otherwise. I don't think it can hurt, but I bet the actual temps are too high for something in a tube regardless of what the tube says it can handle.

LockDoc 04-13-2018 11:50 AM

Re: Should I Run Exhaust Manifold Gaskets?
 
Quote:

Originally Posted by Dodge68charger (Post 8237328)
Should i Run Exhaust Manifold Gaskets With My Ram Horn Exhaust Manifolds. I Bought Them Soft Aluminun Gaskets And Heard Conflicting Storys Whether To Run Them or High Temp Sealer?

Also What Should I Use The Seal The Threads On The Pipe Plugs On Them?? Thanks
Posted via Mobile Device


I have always used the stock GM gaskets with no problems, just make sure that the flanges are nice and clean, and smooth....

LockDoc

racerop 04-13-2018 12:08 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
The pipe plugs should be “npt” threads
just crank them tight if they leak.

josuito 04-13-2018 01:02 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
I have gaskets with ram horn manifolds on my truck, so far no problems at all. We didn't use any thread sealer for the pipe plugs, just plug and play.

I used FEL-PRO MS9275B manifold gaskets from rockauto they're easy to install, just bolt the manifold and drop these guys in. :metal:

toolboxchev 04-13-2018 03:08 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Quote:

Originally Posted by LockDoc (Post 8237396)
I have always used the stock GM gaskets with no problems, just make sure that the flanges are nice and clean, and smooth....

LockDoc

X2 on that, they work fine. When the exhaust manifold bolt loosen lets them burn. Keep em tight!

special-K 04-13-2018 09:45 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
GM used gaskets, so that is best. GM builds things right, and the proof is in the pudding with 67-72s. Would you rather scrape a little remaining gasket or sealant from every inch of both mating surfaces?

stsalvage 04-15-2018 05:52 AM

Re: Should I Run Exhaust Manifold Gaskets?
 
I have a problem with that.Gaskets means more money that a auto maker has to put out there.All the ones i've seem come off trucks Race cars from the 60-70's that ran dirt track racing.They had a belt sander that would plain them and you bolt them right up to the head.In all 35 years never used gaskets for exhaust manifolds for Ram horn's of the 1975-87.It use to cost 10 dollars a side now its 20.00 its hard to find that bench wide sander but when there flat there flat and they bolt right up

trac209 04-15-2018 11:44 AM

Re: Should I Run Exhaust Manifold Gaskets?
 
If you don’t use gaskets you can bet they will leak that’s for sure

CSTGURU 04-15-2018 01:23 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Small block chevs never ever had exhaust manifold-to-head gaskets ever. always direct metal to metal. They will never leak that way, its for sure the way GM did it. pull any low mile still original car or truck apart, and you will see no gaskets. even my 91 truck is metal to metal. and all my 1960's gm cars and trucks were too, and still are.
If you use those felpro or other gasket kit gaskets, they will blow, its only a matter of time.

Now if you are talking about a straight 6, they yes, there was a gasket.

Just my 2 cents, dont shoot my if you disagree.

B. W. 04-15-2018 03:56 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
1 Attachment(s)
Hey CSTGURU, I'm not shooting you! All late model small blocks (vortec) had mls gaskets from the factory. Pic is L31 manifold with stock gasket:

Steeveedee 04-15-2018 07:08 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
On any engine SBC that I worked on (from the '55s until the early '80s) that had never been touched, I never found gaskets. This is also true of Buicks that I have worked on. I've put gaskets on when they came in the gasket set, though. I think that the later model stuff requires gaskets because of the different expansion coefficients between aluminum and iron. But I quit wrenching for a living in '84 when I graduated university. Still work on my own vehicles, though. I'll see what I have when I pull the engine out of the truck, this year.

CSTGURU 04-15-2018 07:27 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Ha, no worries! I an just talking pre-vortec/ls stuff. I my world, i dont even look at modern vehicles. 72 and older for me, except for an all original 91 silverado i inherited, but would otherwise never own

leddzepp 04-15-2018 09:22 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Quote:

Originally Posted by CSTGURU (Post 8238875)
Small block chevs never ever had exhaust manifold-to-head gaskets ever. always direct metal to metal. They will never leak that way, its for sure the way GM did it. pull any low mile still original car or truck apart, and you will see no gaskets. even my 91 truck is metal to metal. and all my 1960's gm cars and trucks were too, and still are.
If you use those felpro or other gasket kit gaskets, they will blow, its only a matter of time.

Now if you are talking about a straight 6, they yes, there was a gasket.

Just my 2 cents, dont shoot my if you disagree.

I won’t shoot you. I agree. I’ve been waiting for someone to say it :lol:

I’ve never run gaskets with ram horn manifolds, other than a solid steel donut between the head pipe. Make sure all surfaces are flat. I’ve never had any leaks. I just make sure everything is right periodically.

jerry moss 04-15-2018 10:29 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
i'll risk pi$$ing some people off here BUT i've been doing exhaust in the same shop over 33 years and have never used gaskets on a small block or big block. i have the manifolds machined flat, clean the head real well and torque them down starting from the middle out and never had a problem unless the head was screwed up. no sealer either.

68c10airstream 04-15-2018 10:41 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Worked at a gmc dealer for years and i swear we got all of the motorhome manifold leaks in town. One guy would fix then all and the same way. He said the only thing that lasts is machined flat manifolds, with high temp silicone small bead and tighten down and no comebacks.

I do the same on all old school engines because thick composition gaskets don't retain the torque because they continue to squish thinner with time and now are loose. Multi layer steel (mls) are a very good one time install, as many newer engines are this way.

I refused to deal with those god awful 3 bolt flanges on my ls headers. Sliced them off and tig welded on v band clamps. No leaks.

special-K 04-15-2018 11:09 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Well, that's what a guy who likes headers gets for answering. I've had plenty of these trucks that never had a bolt cracked since new but I guess it's been so long I don't remember. I use gaskets with headers and don't see why what works so well for them would be any worse with manifolds. It's not the whopping twenty bucks I'm sure, because what does it cost to plane the surfaces? I don't have a way to do that, so I use gaskets...and never had them blow out. This was a good question to ask

stsalvage 04-15-2018 11:54 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Headers are completely different animal Steel to cast iron.You can Plain cast iron Never seen it done on steel.But if there is a will there is a way.The Sanders are hard to come by.You need one that the whole exhaust manifold can lay on.If not it wont work.Then cheap sanders you buy at your thrift stores or harbor fright stores will not work.For one there not long or wide enough.I've been looking for one for 10 years.I have over 20 sets of Ram horns and Big block manifolds That i like to get them done and sell them.But with warped manifolds people will just say there defective.But that me.I got 14 sets of the 1965 396 car and trucks ones and ones after that have some cool date codes

BCOWANWHEELS 04-16-2018 05:26 AM

Re: Should I Run Exhaust Manifold Gaskets?
 
you have to run them

jocko 04-16-2018 08:59 AM

Re: Should I Run Exhaust Manifold Gaskets?
 
Quote:

Originally Posted by LockDoc (Post 8237396)
I have always used the stock GM gaskets with no problems, just make sure that the flanges are nice and clean, and smooth....

LockDoc

ditto

special-K 04-16-2018 03:12 PM

Re: Should I Run Exhaust Manifold Gaskets?
 
Quote:

Originally Posted by stsalvage (Post 8239420)
Headers are completely different animal Steel to cast iron.You can Plain cast iron Never seen it done on steel.But if there is a blah blah blah :lol:

Save your breath. I appreciate the education but who doesn't know all that? I was just saying that although the best, right, or GM way is iron to iron using gaskets will not hurt a thing, is a good idea, especially if you don't have that special sander or the time to send them out. I hear there are people with piles on manifolds laying around just because they have no way to plane them. I'm saying it makes sense to me to go ahead and sell them to people who have enough sense to so simply run gaskets...quality gaskets. They work. Yeah, one might get loose and burn out. But it's no big deal to fix that. And there are cases where the exhaust has sawn through the cast when less than snug. What do you do then? Too late for gaskets. I'd rather blow a gasket.


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