hi

who here has used mls head gaskets on their alu head iron block hemi and had oil seeping out between head and block ?

i think mine are leaking oil ?

is there a sealer to put on the gaskets to stop this ?

thank you !

I use MLS Cometics on my hemi. I don't have any leaking with the gaskets. I coated both sides of the gasket with copper coat spray sealant before installation. I thought I had a leak between the gasket and the head or block once, but that turned out to be a leak where the intake seals against the block and head. I re-sealed the intake and it's been dry since. This is a common issue with Hemis. I also have aluminum heads on an iron block.

No leaks with my MLS gaskets on my Hemi. Also sprayed with copper coat.

One other thing. If you haven't retorqued the heads bolt/studs after it was built, you should do that after it's seen a few heat cycles and it may help seal a small leak if the torque is off.

MLS head gaskets require extremely smooth surface finishes ... there should be specs with the new gaskets.... and your local machine shop should spend the time to get to those specs (heads and block deck).... otherwise, fluid leakage can possibly occur.

From Tim Banning at FHO, smear a little of the Right Stuff gasket maker around the oil drain back holes. front and back, both sides of gasket.

On the Cometic MLS head gaskets for Hemiriod motors I have had to cut the rivets off so the heads would not try and pinch them between the heads and block. I learn also that the Cometic MLS head gaskets need a lot smoother head and deck surface than other composition head gaskets need to seal properly. Call them to get the correct RA number for the deck and head surfaces I can't remember if it is 35 or 50 RA

It's 50

I've heard this from a few known hemi engine builders. Silicone works also. Works for me.