Early Tripower on 6x Heads
 

My buddy is putting an early tripower (66?) on a 455 with 6X heads. Problem is the center coolant passage in the head over the exhaust crossover is exposed (see pics). Any suggestions how to deal with this?

use this link http://www.wallaceracing.com/intakesearch.htm

and save the page for future reference. tons of info there.
Good luck!

Thanks for the suggestion, but I don't see how this solves the issue. Using a larger gasket will simply be unsupported and coolant under 15psi will surely leak. Was wondering if anyone has done this with maybe an epoxy plug or other creative idea without resorting to welding/milling onto an original iron manifold.

That is not a coolant passage. You can use Fel-pro 1233 gaskets and solve your issue.

Thanks for the reply! So is that exhaust? I don't have the heads in front of me, I'm just going from my buddy's pic and his inspection, silly me.

So that Felpro gasket will seal without being supported by the manifold?

Its a blind hole that simply provides space between hot exhaust crossover gases and engine oil splashing around from the valvetrain. You can fill it with molten aluminum, furnace cement and there are some ultra high temp epoxies out there too.

Thank you. Sounds like no critical reason for a super tight seal.

Just use a 1972 and later intake gasket set and a stainless shim on passenger side to cover the blind hole above crossover channel.

Appreciate all the feedback on the correct gaskets, seems like problem solved.

Having not used these later model heads before, I'm now pretty curious if there's anything more to learn about the purpose of this cavity and what problem it solved from the earlier heads, aside from Android211's note of reducing oil heating, which makes sense. If that's it then apparently the only reason to cover it is to avoid collection of water and debris.

The space may have been to prevent a concern of any extra heating of the oil beneath the valve cover there. The blank passage eliminates the crossover heat from cooking the oil under the valve cover...May have been put there because of the center 2 exhaust ports together there, maybe some minor cooling effect...

Yes the Fel-pro gaskets will seal just fine. The hole isolates heat from the crossover from reaching oil under the valve covers.

This is the crude but functional method. Remove the area on the gasket, replace it with 18ga sheet metal, coat with a thin layer of high temp silicone.

https://img.photobucket.com/albums/v...takegasket.jpg

It's ghetto, but it works.

-Abone.

Iron mopar heads have the same blind hole above there Exh crossover passage for that same reason, to keep oil temps down and to stop the oil from burning into a hard Carbon that flows thru the oil and creates more ware!

Interesting. I have had Chevy's that cooked the oil so much in that location that the push rods were impacted with the burned oil remnants that were like cement.