exh manifold to head heat transfer

[gtgt_bangbang]

if the exhaust manifold has anything to do wit the head gasket issues on the 3VZ, and I reasonably expect it does, heres a topic.

The driver side manifold has a bulge on the motor side down spout that brings the manifold and the head perilously close together, just below the bottom edge of the steel ex.gasket. There is just about a finger gap between bare aluminum and the hot iron, right freekin at the block/head parting line. Protect that line troops, and the battle is won. I bet this is the only hot spot to worry about, as the cross over, etc are nowhere near as close.

It would have been a quite simple matter to redesign the ex.gasket to put some radiation shielding right there at that hot post, but alas.

I have been cobbling some shields intended to fit there, using old ex gaskets , buts its proving to be a pain to shape and mount with the limited stuff I have for that.


Exhaust Wrapping is a first thought but as others have rightfully pointed out, that makes the manifold HOTTER and is probably not going to be doable at that vulnerable spot of closest approach.

Time to break out the old license plates to make a radiation shield, but the closest existing secure bolt holes are 1) unused threaded hole in the head, and 2) at the top motor mount bracket bolt.

You can't mount a shield UNDER the manifold using the ex.studs for hopefully obvious reasons ( wont be flat) although you might be able to bolt a shield OVER the stud nuts , under a second nut, but the threads are kind of short. Longer studs there might help.

That said, I will probably make a simple shield out of said license plates and pop rivet it to the standard ex manifold gasket.

There is a really thin part of the ex manifold web at the down spout that you can drill a hole to pass a stainless steel tie wrap thru, to secure a small shield , but I dont want to make an annoying rattle either.

pics later , comments welcome

 

[Hyde802]

I like your idea for a heat shield, interested to see what you come up with.

Thats another reason why headers do so much for this engine. People have also made their own by blocking off the back of the drivers manifold, and cutting the cross over pipe and using that flange to make the pass side down tube.

I agree with the pass on the heat wrap, but what about warping JUST the corner, not the whole thing. Maybe the y part too. I had heat wrap on mine for about a year, but cut it all off due to a pesky oil leak. And after I cut it off, I was thinking I should have left it right on the corner.

 

[gtgt_bangbang]

its too hard to get a secure wrap right at the exact problem point - the manifold is just too too complex right there , although there is a thin spot in the web to drill a hole thru that gives you a semi plane path run a stainless tiewrap around something. I made a groovy shield to rivet to the web of the gasket but now I wish it was an inch or so longer to shield the water line of the cooler