Shimming an exhaust manifold

Speterson64

Member
Local time
7:34 AM
Joined
Jun 22, 2015
Messages
19
Reaction score
4
Location
Michigan
Hey all! I have a little dilemma. I’m putting together an max wedge clone. (493”)
My issue is I’m going with the factory style MW headers and the passenger side is hitting my valve cover. Due to them being taller mopar performance cast aluminum. I couldn’t go with the shorter factory style cover due to them hit the rockers. So my question is, has anyone ever put shims on their exhaust to gain some clearance? If I shim the header out 1/16” and double gasket it, it’ll clear my valve cover just enough. thoughts??!!
My only thought is it’d be easier to blow the gaskets out!
 

eldubb440

more miracles than Jesus
FBBO Gold Member
Local time
7:34 AM
Joined
Jul 17, 2008
Messages
11,417
Reaction score
27,630
Location
South Jersey USA
how about just clearance the valve cover a little? you stated they are cast aluminum
 

Curiousyellow71

Well-Known Member
Local time
6:34 AM
Joined
Jun 18, 2019
Messages
1,247
Reaction score
1,356
Location
Nebraska
I recall making shims to turn exhaust manifolds upside down for a turbo application. Some engines don't even use gaskets. Just finely machined surfaces. I've known guys 2 stack gaskets too, but usually short lived.
 
Last edited:

MIKESPOLARA

Well-Known Member
Local time
4:34 AM
Joined
Jun 16, 2021
Messages
709
Reaction score
739
Location
CALIF
how about just clearance the valve cover a little? you stated they are cast aluminum


Depending on where and how much needed the cover can be nicely done if you do it on a vertical mill so it comes out smooth, even and shiny
 

33 IMP

FBBO Gold Member
FBBO Gold Member
Local time
4:34 AM
Joined
Dec 21, 2017
Messages
7,666
Reaction score
10,753
Location
taxifornia,soon 2b Arizona.
If they are real max exhausts, I would leave them alone and try double gasket.
If they are repops, I would have the one hitting the cover angle milled a few degrees.
Cook that valve cover, and you won't be able to keep paint on it, or gaskets under it.
Pictures of the interference would help.
 

Dodge Bros

Well-Known Member
Local time
6:34 AM
Joined
Mar 23, 2020
Messages
88
Reaction score
75
Location
Nebraska
Might be some other options out there. Remflex gaskets start out .125” thick, irc they can take up almost half their thickness though, not sure what the clamped thickness is.

Could possibly use MLS gaskets and add layers until they clear. Would get pricey though, they start out .030”.

Spacers are doable to, we made spacers on this turbo set up to flip a manifold upside down. Could just use a cheaper header flange. I think this photo is what curiousyellow71 is recalling.. Been sitting awhile and needs a bath… But if the shim and double gasket can hold on this thing…lol

1ED642E1-0BDD-4E59-A47E-86996281951A.jpeg
 
Last edited:

Speterson64

Member
Local time
7:34 AM
Joined
Jun 22, 2015
Messages
19
Reaction score
4
Location
Michigan
I recall making shims to turn exhaust manifolds upside down for a turbo application. Some engines don't even use gaskets. Just finely machined surfaces. I've known guys 2 stack gaskets too, but usually short lived.
I think shims will work best. Thanks for the advice
 

Speterson64

Member
Local time
7:34 AM
Joined
Jun 22, 2015
Messages
19
Reaction score
4
Location
Michigan
If they are real max exhausts, I would leave them alone and try double gasket.
If they are repops, I would have the one hitting the cover angle milled a few degrees.
Cook that valve cover, and you won't be able to keep paint on it, or gaskets under it.
Pictures of the interference would help.
This is an excellent idea!! Thanks
They are repops. So no worries there
 

33 IMP

FBBO Gold Member
FBBO Gold Member
Local time
4:34 AM
Joined
Dec 21, 2017
Messages
7,666
Reaction score
10,753
Location
taxifornia,soon 2b Arizona.
Search 440 Chrysler header flange at summit. Found two from patriot, one even has the big exhaust opening for max heads. $53, I think, might even come with gaskets.
 

Don Frelier

FBBO Gold Member
FBBO Gold Member
Local time
7:34 AM
Joined
Oct 11, 2016
Messages
5,747
Reaction score
7,364
Location
Ionia, NY
If you plan to put an H-pipe on it it will likley cause problems.
 
Top