How do I block the exhaust cross-over?

If my valley pan has the full opening for the heat cross-over can I block it somehow (without buying a new valley pan)?

SOME have suggested that you melt some old pistons and fill the crossover in the intake with the molten aluminum.

NEVER done that me-self ...I am a fan of a crossover at least a LITTLE open.

Yeah I hear ya but I have a very old Torker 383 intake that has a crossover (didn't think they had them...) that I want to close up.

This intake has a hole in the bottom of the plenum that goes into the heat cross over and there is, what appears to be, a provision for a choke or something directly behind the carb. I wanted to close it up.

Just find some thin sheet metal and cut out a couple rectangles bigger than the crossover opening in the head. I get a lttle more extragevent and have a tiny tab on the end of the plate i bend to 90 degrees so it holds in place better while putting the intake gaskets on. Just use a little silicon to hold them onto the head, and put your intake gaskets over that. Done. I do this to any engine I do that wont see any cold weather use. If you email me, I can send you a pic when I cut a set for a 383 and 440 I am getting ready to button up here.

If your after just filling the hole in the bottom of the intake, A little JB weld will hold just fine there if the surface is clean--i would get some aluminum cleaner---BUT, you still need to block it off at the heads as it will blow the JB weld back out eventually.

Cut a couple of pieces from a old valley pan and make some block offs and secure them with ultra copper rtv.

It has GOT TO BE some real thin sheet metal. If not .. it can screw-up the seal of the intake to head. I have heard of some people having good-luck with some hi-quality stainless steel.

I did have some of FelPro block offs laying aroud here.Dont know if I can find them but if I do Ill send them to you.I always just buy the pan with the blocks.Rocky

I use roof flashing, very thin and seems to hold up.

i cut out some sheet aluminum and welded it into openings in the aluminum manifold.

then milled the welds down flush

a roll of aluminum foil. tear of sheets of it and pack it in..keep going until your satisfied with it.

it works btw and is a older way of doing it....



steve

At one time I used stainless shim stock. Don't remember the thickness, but months later it was same as when it when in. I don't know how to tune an engine very good and I couldn't make my engine run right with it blocked (I'm sure because the temps and mixture didn't get along) so I unblocked it.

Thanks to all for the good tips.

Rocky- Thanks for the offer to send the block offs!

I think I'll just cut some thin stock and lay them in there. Or maybe's Steve's idea of tin foil

Quote:

---

Thanks to all for the good tips.

Rocky- Thanks for the offer to send the block offs!

I think I'll just cut some thin stock and lay them in there. Or maybe's Steve's idea of tin foil

---

Why not just buy the $20.00 block off vally pan.

To do any other block off option , you will have to remove the intake anyways and want a new pan gasket.


The Tin foil plug is a old school idea. I did that back in 1976 It didnt last though

Maybe I didnt cram the tin foil balls in there hard enough. After a year, when I took the intake off, all of the tin foil was gone

The forces of exhuast pressures and heat were enough to remove the tin foil restriction over time.