Cylinder head heat crossover?

[Jeff Stout]

Just to verify, the exhaust crossover can be plugged in head and intake gasket but cannot plug passage in intake manifold. Correct?

[Jeff Stout]

Read the rule several times. Says I can block on intake side of head. The rest of rules in head section and in intake section does not address plugging crossover in intake passage. I'm asking as I used lead to plug intake side on head. Pulled intake today because of having it be so hot along with carb and losing .2 ET. and found all the lead is gone from head. Yes it's gone with exception of a small nugget.
Want to plug at intake as I have no intention of pulling heads off.
I can make a plate to cover holes at intake surface, but dont know if its enough.

[Shadylane]

Jeff, some gasket sets come with the metal plate to block off the heat crossover. Tried the old Coke/Beer can cut up, burned right through. The cans are too thin now days.
Couldn't find a metal block off for my engine so I found a couple in my tool box from a Chebby that worked with a little modification. Never had a problem with them...yet.

Saw these gaskets that are already blocked.
https://www.summitracing.com/parts/s...ake/oldsmobile

Kelly

[Jeff Stout]

Thank you. But on Olds they have a steel valley pan/ intake gasket all in one
I might trim the steel valley pan to allow for these gaskets to work. That might be the ticket.
Also I was going to use stainless steel for blocking.

[Mark Yacavone]

A little lead is good for it. LOL
I can't remember if there are 1 or 2 exh. passages up to the intake side, but you want them completely filled and separated so the headers scavenge correctly. I've done many, many sets that are out there, using molten aluminum.
Also you want to mill the exh . side until the center ports are completely divided. Either that, or build up a dam on you header flanges.

[FED 387]

4 suggestions

1-Edelbrock #2733 plug ---about $12
2-Mondello #HR-351 insert---about $25
3- fill the cavity with liquid aluminum or maybe try JB weld
4- fabricate an aluminum plate to fit between the gasket and the cylinder head might have to resurface the manifold to compensate for the space

FED 387

[Jeff Stout]

Originally Posted by FED 387

4 suggestions

1-Edelbrock #2733 plug ---about $12
2-Mondello #HR-351 insert---about $25
3- fill the cavity with liquid aluminum or maybe try JB weld
4- fabricate an aluminum plate to fit between the gasket and the cylinder head might have to resurface the manifold to compensate for the space

FED 387

Thank you. I think the stainless insert will be the way..

[Mark Yacavone]

I don't know that you can't block the intake, if they let you fill the head all the way down to the port.
You could take a chunk of 1/4 " aluminum or steel and make a plug with tapered sides, and bang it in there.
No bubble packs here, unless we have to.

[Shadylane]

2020 Rule book: Stock Cars

Cylinder Heads
“Heat riser passage may be blocked from intake manifold side of cylinder head. Blocking passage down in the valve pocket prohibited.”

My interpretation: don’t block anywhere down into the head, but that’s just me. I would hate to get busted for plugging the head when a thin piece of stainless will be sufficient.

Kelly

[Mark Yacavone]

Originally Posted by Shadylane

2020 Rule book: Stock Cars

Cylinder Heads
“Heat riser passage may be blocked from intake manifold side of cylinder head. Blocking passage down in the valve pocket prohibited.”

My interpretation: don’t block anywhere down into the head, but that’s just me. I would hate to get busted for plugging the head when a thin piece of stainless will be sufficient.

Kelly

Kelly, As long as the plug is recessed a tad and not reshaping the port, it's fine. We've been doing them that way for year....Hettler /Kadar/ Watters , and others.