Inlet manifold gasket problems

[JimMet]

Just recently i noticed that the inlet manifold gasket on my rv8 has bubbled up due to some unknown pressure (see picture). Also recently it's been loosing coolant but i cant work out from where??

Ever since i overhauled the top end i've noticed that occasionally there is a little bit of water sitting at the bottom of the valley. Till now i though it was due to a loose jubilee clip somewhere. The gasket i used was a tin one and i put it straight on with no sealant.

Why would the gasket do this and what do i need to do to stop it happening again?

[ChrisJC]

It probably is leaking water from somewhere on the inlet manifold, or where the manifold sits on the valley gasket.

It might be worth taking the manifold off, checking all the various water pipe connections, and refitting with a composite gasket.

Whenever I've used a tin gasket, I've always put a smear of instant gasket on both sides of the gasket at the waterways.

Chris.

[JimMet]

If i use a composite gasket do i still need to use some instant gasket as well?

[sidecar]

If i use a composite gasket do i still need to use some instant gasket as well?

You should be OK without the sealant if you use a composite gasket but make sure the manifold and heads are spotless on the gasket faces. Use acetone or something similar to clean them.

I use a tin gasket and the silicone sealent trick on both sides of the gasket on my lump and that worked OK. Use a very thin smear round all the ports, water and mixture inlet, then leave it to set of 30 mins before assembling everything. That way the sealent does not just get pushed out of the joints.

Regards,

Pete

[bodger]

Just recently i noticed that the inlet manifold gasket on my rv8 has bubbled up due to some unknown pressure (see picture). Also recently it's been loosing coolant but i cant work out from where??

Ever since i overhauled the top end i've noticed that occasionally there is a little bit of water sitting at the bottom of the valley. Till now i though it was due to a loose jubilee clip somewhere. The gasket i used was a tin one and i put it straight on with no sealant.

Why would the gasket do this and what do i need to do to stop it happening again?

its caused by blocked breather , if you have EFI , it's the hole breather hole in the plenum ... it's a because the crankcase pressure has no where to go