340 Manifold Heat Shield

[Rdchallenger]

Will the heat shield from a 273 work on the 340 manifold? I see the openings are slightly smaller but with the heat the manifolds produce I'd think that the thinness of that metal wouldn't stand a chance and would cause the openings to enlarge on their own. 

Anyone try this? Or have an opinion?

[Lunchbox]

Are you referring to this piece?

[Rdchallenger]

Are you referring to this piece?

Correct, except the two ends are squared on mine. Openings may be slightly smaller.

[Floyd]

I haven't tried, but I do not think there's enough material there to open it up.

[anlauto]

That's a great picture Floyd, I never knew the difference was that drastic 

[Lunchbox]

I have been trying to source one of these, looks like they are no longer reproducing them. Anyone have any other ideas?

[anlauto]

I need one too

[340challconvert]

Installed an NOS exhaust heat shield on the driver's side head studs, then installed the factory hp 1970 exhaust manifold. Finally started the newly rebuilt 340 and had a bad exhaust leak! Manifold is intact, in good condition with mating clean surface. Using new eddie aluminum heads specific for the hp340. Should I use sealer on the gasket? Right side installed w no gasket and just sealer; worked great!
Thoughts?

[mk]

Installed an NOS exhaust heat shield on the driver's side head studs, then installed the factory hp 1970 exhaust manifold. Finally started the newly rebuilt 340 and had a bad exhaust leak! Manifold is intact, in good condition with mating clean surface. Using new eddie aluminum heads specific for the hp340. Should I use sealer on the gasket? Right side installed w no gasket and just sealer; worked great!
Thoughts?

It almost looks like the exhaust manifold wasn't squeezing the bottom side of the gasket for some reason ? May be worth seeing if the manifold sits against the head tight with no gasket ..... and make sure it has no gap on the bottom side.

[340challconvert]

Installed an NOS exhaust heat shield on the driver's side head studs, then installed the factory hp 1970 exhaust manifold. Finally started the newly rebuilt 340 and had a bad exhaust leak! Manifold is intact, in good condition with mating clean surface. Using new eddie aluminum heads specific for the hp340. Should I use sealer on the gasket? Right side installed w no gasket and just sealer; worked great!
Thoughts?

It almost looks like the exhaust manifold wasn't squeezing the bottom side of the gasket for some reason ? May be worth seeing if the manifold sits against the head tight with no gasket ..... and make sure it has no gap on the bottom side.

Good thought; exhaust is all new Accurate. I will loosen the
Manifold to head pipe bolt for flexibility and check manifold alignment to head. It is obvious the problem is at the bottom. I think I will add sealer also!

[340challconvert]

Installed an NOS exhaust heat shield on the driver's side head studs, then installed the factory hp 1970 exhaust manifold. Finally started the newly rebuilt 340 and had a bad exhaust leak! Manifold is intact, in good condition with mating clean surface. Using new eddie aluminum heads specific for the hp340. Should I use sealer on the gasket? Right side installed w no gasket and just sealer; worked great!


Thoughts?

It almost looks like the exhaust manifold wasn't squeezing the bottom side of the gasket for some reason ? May be worth seeing if the manifold sits against the head tight with no gasket ..... and make sure it has no gap on the bottom side.

Good thought; exhaust is all new Accurate. I will loosen the
Manifold to head pipe bolt for flexibility and check manifold alignment to head. It is obvious the problem is at the bottom. I think I will add sealer also!

Thank you MK for your thought. Based on your suggestion, I took a look at the bottom of the exhaust manifold to look for problems with the bottom of the factory 340 gasket. After some further research (abodies) had a lot of information on small blocks with this issue; Edelbrock heads designed for the 340 have a larger flange on the bottom right side that does not allow the easy use of the factory hp left side manifold. It protrudes far out enough to interfere with the seating of the exhaust manifold. In fact edelbrock recommends the use of headers with their 60179 340 designed heads.I should have done additional research when I purchased the heads. There is a solution; to use  a header flange and gasket on the one side with some very prudent filing of either the head flange or the exhaust manifold.

[MoparLeo]

Exhaust gaskets were generally not installed by the factory for cast iron head/exhaust manifold applications.
Properly machined surfaces need no gasket.
Exhaust gaskets are only used to compensate for differing expansion and contraction rates of dissimilar materials,eg aluminum heads, iron block. Tubular header, any head material.
An exhaust gasket on factory iron head and exhaust manifold is usually a give away that someone has had the manifolf off since the car was new.