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Omega Help Area => Omega General Help => Topic started by: Spireite on 27 April 2015, 22:59:03

Title: Fitting 3.2 manifolds
Post by: Spireite on 27 April 2015, 22:59:03
Im starting to strip the engine to tackle fitting 3.2 manifolds.

I've bought 3.0 head to manifold studs and copper washers, looking at replacing the studs and nuts on the 3.2 manifold to downpipe, what do i use - 3.0 or 3.2 studs and nuts?

I'm mating the 3.2 manifolds to jetex downpipes with sports cats, I'll still need to remove part of the pipe where it protrudes above the flange face, do I need to maintain a certain dimension?

Or is it I need to accomodate 2 x 3.0 downpipe gaskets stacked on top of on another, and the clamping effect and the pipe itself slotting into the manifold recess?

So to recap, what studs and nuts do I need for the 3.2 manifold to downpipe or 3.0 type?

And is it I need 4x 3.2 or 3.0 manifold to downpipe gaskets?

Also can anyone confirm a dimension, Im an engineer by trade so work to accurate dimensions if I can.

Cheers in advance

Dean
Title: Re: Fitting 3.2 manifolds
Post by: Nick W on 28 April 2015, 07:02:04
Dean, it doesn't matter which manifolds you use; the fittings are the same. You do need to use appropriate head to manifold gasket: it needs to match the manifold. 3.2 gaskets are about 3 times the price of the earlier ones.

The type of downpipe to manifold gasket doesn't really matter. Mine have two different generic ones per side; one ring against the manifold, and a larger one with stud holes against the downpipe.

Trimming the pipe into the manifold isn't a precision job. I stacked the gaskets on mine, drew around the pipe with a marker so there was a small protrusion and used an angle grinder to remove the excess.
Title: Re: Fitting 3.2 manifolds
Post by: biggriffin on 28 April 2015, 07:28:09
Don't need to replace studs,just run them down.
Manifold to down pipe gaskets use 2 or 1 an appropriate amount of high temp sealent(Halfords)
Drill out flanges on downpipes and exhaust flanges to take m8 nuts n bolts,easier than the threaded flange that's standard.
You need about 5mm protruding from 3.0L downpipes,just cut with angle grinder
Check exhaust hangers(rubbers) in good condition  :y
Title: Re: Fitting 3.2 manifolds
Post by: Spireite on 28 April 2015, 12:21:25
I already have the metal 3.2 manifold to head gaskets, genuine vauxhall.

I was thinking of the pipe protrusion where it drops down into the recess of the manifold and its sealing face?  I also thought the sealing was done with the gaskets of course, but if I cut too little off, the clamping process of the 2 did you say? Gaskets wont be created, thats why i thought the height was critical?

You say you use 2 types, which types do you mean?

Dean