Cylinder head heat crossover?

[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.

[older racer]

hi, I found .015 stainless sheet works excellent. used same ones for last 10 years, has never burned out or blew a hole through it. mine are 2" by 2 1/2 "just food for thought.

[Rory McNeil]

On my 390/427/428 FE Fords, I have always blocked the exhaust crossover opening in the intake gaskets with a piece of an old butter knife, trimmed to fit inside the slot in the gasket. I have tried the gaskets with the unopened crossover holes, but they always burnt thru in short order. I always found it interesting that NHRA will not allow you to fill the head passage down into the bowl, yet the approved Edelbrock heads have no provisions for the crossover passages at all, but thats OK.

[Dwight Southerland]

Originally Posted by Rory McNeil

On my 390/427/428 FE Fords, I have always blocked the exhaust crossover opening in the intake gaskets with a piece of an old butter knife, trimmed to fit inside the slot in the gasket. I have tried the gaskets with the unopened crossover holes, but they always burnt thru in short order. I always found it interesting that NHRA will not allow you to fill the head passage down into the bowl, yet the approved Edelbrock heads have no provisions for the crossover passages at all, but thats OK.

NHRA will allow you to fill the passage as long as it does not extend into the bowl and make an extension of the port ceiling surface. I used Plaster of Paris poured into the crossover passage to within about 1/2" of the port. Usually wadded up tissue stuffed into the passage from the port side served as the boundary. Once it was heated, it was like ceramic. Never had a problem.

[Mike Taylor 3601]

I have always used zinc...that's what Mondello sold....
I buy a ingot of zinc alloy from Mc Master Carr industrial supply it is about 12'' long 3'' wide and 2'' thick will do 2-3 sets of SBC.
Olds might get 2 sets out it..
next set I do I may melt down some old pistons since I accumulate about 6-8 55 gallon drums a year that I scrap...
I have blocked off a SBC intake.. I filled all the heat riser and EGR passages...
intake was cracked under carb so I filled it to prevent vacuum leaks to EGR passages and it has been through teardown....
I think filling head is better to keep heat out of heads

[HP HUNTER]

Originally Posted by 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.

"No bubble packs here"



I could of sworn that was you standing in the window waiting for the UPS truck intently LOL

[Myron Piatek]

On applications that can use sheetmetal to block the crossover, I've had good luck with aluminum (thicker than cans) if glued & coated on the inside with a good hi-temp silicone to help insulate it.