Inlet manifolds

Technical MGB discussion
Ray Masters
Posts: 19
Joined: Wed Sep 19, 2018 11:22 am
Forename: Ray
Surname: Masters
Location: Stockport

Re: Inlet manifolds

Post by Ray Masters »

Hi Graham . Thank you for your reply . Any info you can give me , when convenient , will be useful and l will pass it onto my friend who originated the question. Ta , Ray.
Posts: 59
Joined: Wed Nov 21, 2018 9:37 pm
Forename: Graham
Surname: Moore

Re: Inlet manifolds

Post by ChargedAutoGT »

here you go....


Both manifolds are 12H2568
Flanges are 430 thou
except one which is 413

That's a big difference for an OEM part and whilst I cannot see signs of it, I do wonder if it's a DIY which I had not noticed before.
But, it's been done very well and must have had a pro milling machine.
Really not sure now.
Posts: 7
Joined: Sun Jul 19, 2020 3:05 pm
Forename: Brian
Surname: Bailey

Re: Inlet manifolds

Post by lightning »

Hi folks.
I came across this problem when converting and rebuilding my imported U.S.1972 B. The original carbs (and fuel emission setup ) were removed and replaced with HIF cabs. The flanges on the inlet manifold that came with them were thicker than the standard exhaust manifold. To overcome this the difference was built up by welding half a washer to the thick washer that secures both flanges to the head. Hope this helps. ATB
Posts: 2
Joined: Tue Jun 08, 2021 3:03 pm
Forename: Peter
Surname: Bonsall

Re: Inlet manifolds

Post by PeterB »

This is not an unusual situation. As been suggested you need three washers, cut one in half and use one and a half washers to give you the correct thickness on the two exhaust/inlet manifold studs. The half washer goes against the thin manifold as a packing piece and then the complete washer is placed on top. JB weld or a suitable glue is suggested to hold the washers together but once in place and tightened they are not going to drop out.
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