Intake Manifold Skimming

[Sondar]

The heads on my 4.6 have been skimmed to such a point that it's almost impossible to get a proper seal on the intake manifold because it's sitting too high in the vee.

I had to use a significant amount of anaerobic gasket sealant on the manifold to get a seal on it and I'm concerned that some of this may get inside the engine. I'd guess that the gas flow into the heads will be affected too because the ports don't line up properly.

I can't think of any way around this other than buying new heads (I'm not keen on that one) or skimming the faces of the inlet manifold.

I'm a bit nervous about skimming the manifold because if the angles aren't properly maintained, it's still going to need loads of sealant & may end up worse than it is now.

Anybody have any opinions on this?

[ChrisJC]

I skimmed my inlet manifold. The seating faces are exactly 90 degrees from each other, so it's quite easy to set up.

And the maths show that however much you take off the heads you have to take the same amount of each side of the inlet manifold.

The complicating factor is that the valley gasket will be too wide, so I had to cut & shut one to fit.

Chris.

[katanaman]

If your heads are still off then skim the inlets of the heads. That way your inlet manifold is still standard and will still fit anything.

[ppyvabw]

wont that create a step where the heads join the web thingamies in the valley where the valley gasket seals at the front and back. Is that bad?

[katanaman]

you need the trim the rubber gasket thing slightly which is no big deal

[Sondar]

Thanks for the help. I'll get the manifold faces machined to fit.

I can see the point on skimming the inlet faces on the head, but there's a lot of work involved in removing heads & I'd be concerned about getting the gaskets to fit properly.

Manifolds aren't that expensive, so I'll risk that rather than anything else.