What is the best head gasket

[Onewickedchallenger]

I just bought a 528 Hemi that was overhauled a year ago. We put it on a stand to break in cam. 5 minutes into run water started leaking from the back of head. We pulled off valve cover and checked tork. At 80lbs. All were tight. Going to change head gasket. Been reading a lot and now confused. What is the best one to get, and why?


Thanks

[cudabob496]

some alumaseal in the coolant is always a good thing
Fel-pros have always done me well.
maybe block and head surfaces aren't matching correctly. Might
want to check gaps when heads off.

[Chryco Psycho]

Alum head ?
 the only gasket that wll live with a iron block / alum head combo is a MLS [multi layer steel] to allow for different expansion rates , I use Cometic 

[cudabob496]

Alum head ?
 the only gasket that wll live with a iron block / alum head combo is a MLS [multi layer steel] to allow for different expansion rates , I use Cometic 

Chryco, I'm sure you've forgotten more than I know, but I've never heard of a problem with the Felpros for an alum head/iron block combo?

[HP_Cuda]

Felpro MLS worked like a charm and hit almost the exact sizing I needed.

[72cudamaan]

Chryco, I'm sure you've forgotten more than I know, but I've never heard of a problem with the Felpros for an alum head/iron block combo?

Even the big 3 had humongous problems with aluminum/iron combo's before they learned from the
Europeans and Japanese. I believe Neil was saying that a mls gasket is necessary to make the combo live. Just
not necessarily Cometic. I believe that Mr. Gasket mls head gaskets are made by Cometic.

[jnjdragracing]

No nothing about a hemi, but we use cometic on our twin turbo and no issues. Used to use felpro but with boost we switched. Back in the old days I would use copper with the block o ringed along with the head being o ringed also.

John

[cudabob496]

I would think that the design head bolt torque, for an aluminum head, would give the necessary clamping force, so
that differences in alum and iron behavior would be negated.  Also, the new alum heads these days have lots of head bolts.
If there's water leakage, I would suspect surfaces have not been machined properly, or perhaps the torquing of the head
did not occur in the proper/necessary manner, for that particular head design.

Also, if coolant system not vented properly, some serious head hot spots could occur, causing warpage.

[73restomod]

Could even be debris, or a dowel pin that is too long/seized, aluminium expands more than iron, but takes longer to reach temperature due to its thermal conductivity. I had a bit of rag lodged on a dowel pin once, it was enough to cause a leak.

Sent from my DROID RAZR using Tapatalk 2

[cudabob496]

since it could be something minor, I would add some alumaseal to the coolant,
and see if that stops it, before I'd tear down the motor.

also make sure its not a header bolt leaking. I had that, and alumaseal stopped
it easily. No new leaks in the last 10 years.

[Chryco Psycho]

Alum expands at almost 2x the rate of steel , so the fibers in the gasket will tear , especially in -40 which was common where I used to live

[73EStroker]

If you want to do it once then please take CPs advice - MLS! I used those and even had one head off to seal the valley cover and simply bolted it back on as they are reusable. My heads are aluminum Indy's. one thing though is that some alloy heads have rough machine surfaces. These can tear apart MLS gaskets so ensure you check the head surface before you install.

[Onewickedchallenger]

Thanks, I do have aluminum heads that were gone through. I ordered the cometic gaskets. Thanks again a great help.

[tvacuda340]

 

Alum head ?
 the only gasket that wll live with a iron block / alum head combo is a MLS [multi layer steel] to allow for different expansion rates , I use Cometic 

I agreed

[ireland383]

No need for those high dollar gaskets unless you need a custom one below .039. The Felpro 8519 has served me well for years without issue.