Hemi Rocker Assembly

[jayfire]

I have an oil leak on my Hemi. I believe it’s coming from the oil return hole in the rear, on both heads. I have replaced heads and gaskets on SBC and BBC, but never on a Hemi. I can pull everything apart, but when I do, I need to re-install the o-ring that was done to the block and reinstall the rocker assembly. Should I try this myself or find a shop that can do it? Is there any special tricks to installing the copper o-ring? How do you set up a Hemi rocker assembly? Thanks

 

[snakeoil24]

Is it a copper o ring around cylinder bores?

 

[jayfire]

Is it a copper o ring around cylinder bores?

Yes, I assume so. The PO had it o-ringed in the late 80’s due to the blower installation. I have the roll of copper wire and new Cometic copper gaskets. Just unsure if I should attempt it or does it need a pro?

 

[pnora]

What heads? Iron or aluminum?

 

[snakeoil24]

If thing is rocker bases have to go back in same place as before. The reason I’d 2 of bases per side feed oil up from the block thru specific rocker stands been so long since I did mine. Secondly you need a dog bone wrench for the studs in valley which is 9/1/ by three eights square for torque wrench. Then you need really good head gaskets which is multi layer from cometic, but you need to call cometic to find out which set works with o ringed configuration. Also remember to apply extra silicone around cooling ports and have your heads checked for cracks.

 

[jayfire]

What heads? Iron or aluminum?

Aluminum Stage V heads

 

[jayfire]

If thing is rocker bases have to go back in same place as before. The reason I’d 2 of bases per side feed oil up from the block thru specific rocker stands been so long since I did mine. Secondly you need a dog bone wrench for the studs in valley which is 9/1/ by three eights square for torque wrench. Then you need really good head gaskets which is multi layer from cometic, but you need to call cometic to find out which set works with o ringed configuration. Also remember to apply extra silicone around cooling ports and have your heads checked for cracks.

I’ve been looking up videos, and I saw what you mean about the oil passages and tool to get to the valley stud. I’m meticulous about pulling something apart and taking lots of pics and having everything go back in the same location. I need to know how to adjust the rockers to spec. Chevys were easy with valve cover removed. Don’t think that works on a Hemi!

 

[pnora]

Adjusting valves on a Hemi is no different than any other solid lifter motor. Its not any easier or harder. The only extra tool is the inner head stud nuts in the valley.

 

[69 hemibee]

If thing is rocker bases have to go back in same place as before. The reason I’d 2 of bases per side feed oil up from the block thru specific rocker stands been so long since I did mine. Secondly you need a dog bone wrench for the studs in valley which is 9/1/ by three eights square for torque wrench. Then you need really good head gaskets which is multi layer from cometic, but you need to call cometic to find out which set works with o ringed configuration. Also remember to apply extra silicone around cooling ports and have your heads checked for cracks.

I thought they same and called Cometic to make sure. They advised me not to use any lubricant with their gaskets as they have lubricants (black rings) already built into the gaskets. I'm not talking about reusing the gasket where copper spray is warranted. I installed my dry and she hasn't had any leaks.

 

[jayfire]

I thought they same and called Cometic to make sure. They advised me not to use any lubricant with their gaskets as they have lubricants (black rings) already built into the gaskets. I'm not talking about reusing the gasket where copper spray is warranted. I installed my dry and she hasn't had any leaks.

Is your block o-ringed? I wonder if that has anything to do with why my copper gasket doesn’t seal well enough to have a leak around the oil return holes in the rear.

 

[69 hemibee]

Is your block o-ringed? I wonder if that has anything to do with why my copper gasket doesn’t seal well enough to have a leak around the oil return holes in the rear.

No orings

 

[snakeoil24]

Is your block o-ringed? I wonder if that has anything to do with why my copper gasket doesn’t seal well enough to have a leak around the oil return holes in the rear.

Hemi blocks have had issues a long time sealing if your using steel shim gaskets cometic should solve it

 

[Hemirunner]

Yes, I assume so. The PO had it o-ringed in the late 80’s due to the blower installation. I have the roll of copper wire and new Cometic copper gaskets. Just unsure if I should attempt it or does it need a pro?

Make sure you anneal those gaskets... or get the Clarks that are already done.

 

[jayfire]

Make sure you anneal those gaskets... or get the Clarks that are already done.

Ok, you lost me at anneal! Are Clarks a brand?

 

[69 hemibee]

Ok, you lost me at anneal! Are Clarks a brand?

Annealing is a process of heating metal and cooling it to soften its atomic structure. It changes the property of the metal gasket to give you a better seal.

 

[Hemirunner]

Ok, you lost me at anneal! Are Clarks a brand?

https://www.clarkcoppergaskets.com/

See the link, and as already mentioned, it’s a heating process to soften the gasket.

 

[Hemirunner]

The oil returns are a pain to seal as they’re subject to any crankcase pressure that might be present at any time and often, the holes don’t even line up well. I run cometic MLS gaskets and my plan is to order them with an oversized oil return hole and I’ll put an o-ring in there before dropping the head on.

 

[pnora]

There are two areas of concern. Pressure and return. Both can allow oil to wick out. Pressure is at the head to block where pressurized oil is fed to the rocker stand along side the head stud or bolt. Return is at both lower block to head areas. I put a sealant on all 4 areas on both sides of the gasket.

 

[pnora]

I have an oil leak on my Hemi. I believe it’s coming from the oil return hole in the rear, on both heads. I have replaced heads and gaskets on SBC and BBC, but never on a Hemi. I can pull everything apart, but when I do, I need to re-install the o-ring that was done to the block and reinstall the rocker assembly. Should I try this myself or find a shop that can do it? Is there any special tricks to installing the copper o-ring? How do you set up a Hemi rocker assembly? Thanks

Double check that leak and make sure it is not the rear of the intake leaking. Or a sending unit or line. Clean it well and get a mirror back there.

 

[jayfire]

Double check that leak and make sure it is not the rear of the intake leaking. Or a sending unit or line. Clean it well and get a mirror back there.

I did that several times. Definitely leaking from head.