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Exhaust Gaskets??

Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC V8 Engine Repair and Modifications
Forum Description: AMC-made V8 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=98532
Printed Date: Mar/28/2024 at 1:35pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com


Topic: Exhaust Gaskets??
Posted By: 73amx
Subject: Exhaust Gaskets??
Date Posted: Feb/11/2019 at 3:12pm
Picked up my rebuilt engine from the builder.  I have had the stock exhaust manifolds cleaned and painted, and I am putting them on stock heads that have been rebuilt.  The builder tells me that I will not need to run exhaust gaskets (metal on metal) and I should be OK. In fact he recommended not putting them in. 
Has anyone heard of that before?
 
Mike



Replies:
Posted By: Ollie
Date Posted: Feb/11/2019 at 3:16pm
My 1983 258 came from Kenosha metal to metal. I put gaskets on during rebuild. Me personally I prefer gaskets.

Having AMC Fun,
Ollie


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1966 American Convertible -- "The Rambler"..SOLD
1974 Postal Jeep -- "Rapid Delivery"...SOLD
1969 Rambler 220 post car--"Road Warrior"
1989 Jeep Comanche Pioneer, 4.0L, auto, 2wd


Posted By: White70JavelinSST
Date Posted: Feb/11/2019 at 3:26pm
The White70JavelinSST V8 came from Kenosha without exhaust manifold to head gaskets. Over 50 years and 140K miles later, still no gaskets, still no trouble. I really don't see the need.  Just my two cents worth.


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70 Javelin SST, second owner, purchased 1972


Posted By: Bill Mitchell
Date Posted: Feb/11/2019 at 3:29pm
I have rebuilt several AMC's and have not used gaskets.  Works fine.  Personal choice I think.

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Bill Mitchell



Posted By: 73amx
Date Posted: Feb/11/2019 at 9:03pm
Thank you all.  I appreciate the feedback!

Mike


Posted By: one bad rambler
Date Posted: Feb/11/2019 at 9:28pm
A stiff board (Oak)and some 120 grit across the head surface and the same across the manifold if all is true your good to go

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68 AMX 390 4 Speed,68 American,64 American 2 Door Wagon Altered Wheelbase,78 Concord Build 360,727,8.8


Posted By: bigbad69
Date Posted: Feb/11/2019 at 10:24pm
Manufacturers (AMC was not the only one) did not use exhaust gaskets because the parts were new and true. Exhaust manifolds have a tendency to warp because of the excessive heat. The leaks manifest during the removal and replacement of the manifold. That is why gasket kits include exhaust gaskets. Do all manifolds warp? No. Can the manifolds be machined true again? Yes, but gaskets are cheaper.

The answer to the question about whether to use or not use the gaskets on your engine is simple. Don't use them. If you find there are exhaust leaks, then put the gaskets on. Some will argue there is better flow without the gaskets, and they are correct. However, on a street driven car using factory exhaust manifolds, the difference will be negligible.


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69 Javelin SST BBO 390 T10


Posted By: FSJunkie
Date Posted: Feb/11/2019 at 10:51pm
If a non-warped manifold that would seal without a gasket is used with a gasket, it will soon become warped or pitted and require a gasket forever.

Getting a machine shop to PROPERLY reface a manifold or head to not require gaskets is near impossible. They often screw things up worse.

The bad news is a warped manifold or head without a gasket will leak, but the leak won't usually get worse unlike a gasket blowing out.

I try to get away without gaskets if possible. Otherwise, Remflex gaskets. I blow out all other kinds of gaskets with my heavy right foot.

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1955 Packard
1966 Marlin
1972 Wagoneer
1973 Ambassador
1977 Hornet
1982 Concord D/L
1984 Eagle Limited


Posted By: MagentaMan
Date Posted: Feb/11/2019 at 11:07pm
Originally posted by FSJunkie FSJunkie wrote:


I try to get away without gaskets if possible. Otherwise, Remflex gaskets. I blow out all other kinds of gaskets with my heavy right foot.

Remflex are the BEST exhaust gaskets I have ever used!


Posted By: Trader
Date Posted: Feb/12/2019 at 6:31pm
One Bad Rambler, you must have good oak or a place with good humidity control. I find using a piece of float glass works very well for checking flat and lapping. An old large coffee table with a piece of 5/8" glass.  My buddy uses a piece of granite from a broken kitchen counter top.

DON"T bring car parts into the kitchen. Last time I was caught with pistons in the dishwasher it was pure heck!

If you take your time with a file and then grades of paper, you can get old manifolds flat yourself. I find some machine shops not very good at setting up properly to machine the faces and you get back worse then what you send out.


Posted By: WARBED
Date Posted: Mar/14/2019 at 8:30am
Finally after years of saying AMC didn't use exhaust manifold gaskets and since I had the Factory parts book and no gaskets were listed except in the group 19 section, I see that some are in agreement. AMC manifold very very rarely warp but once you run gaskets you will all ways have to use gaskets. Even on a good set of headers I have never ran gaskets, just made sure the flange was true and flat. Headmen don't fit into this category.

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59 American 2dr S/W. 70 390 AMX. 70 232 javelin. Kelvinator fridge ice cold beer storage.


Posted By: Steve_P
Date Posted: Mar/14/2019 at 1:42pm
I've never seen a used exhaust manifold from a virgin engine that was flat across the three planes. Once they heated up they stress and when they're first unbolted they move.

It's been pointed out many times here that there were no exhaust gaskets from the factory.


Posted By: WARBED
Date Posted: Mar/14/2019 at 3:39pm
Yea it's been a while maybe 15/20 years since I mentioned stock manifolds didn't use gaskets. I got hammered on that subject. I have had the log type warp especially the left bank off a v8 Pacer but so far I've been lucky on the freeflows. I just installed Hooker comp headers on a 69 Jav with a 72 360 and it was a nightmare. Had to right an article in the engine mod section about the ordeal.

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59 American 2dr S/W. 70 390 AMX. 70 232 javelin. Kelvinator fridge ice cold beer storage.



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