How important is this manifold bolt?

[SouthBostonFJ40]

I am in the middle of replacing my manifold gasket. I have a used manifold from Cruiser Solutions and one of the three holes (the threaded one, closest to the head) that you use to bolt the exhaust manifold to the intake manifold is shot. I have the older F style exhaust manifold, so there is there is no opening between the two manifolds.I have a new gasket, but my question is how important is it to have a tight seal there if there isn't even an opening?

 

[Mr. Toad]

It's only important if you have issues with exhaust leaks where the intake and exhaust manifolds are joined.

 

[SouthBostonFJ40]

It's only important if you have issues with exhaust leaks where the intake and exhaust manifolds are joined.

Explain please...

Picture this...if I ran a header, there would be no connection between the intake and header. So if there is no opening between the two manifolds where would it leak?

 

[Pighead]

If you run a header, you don't need that bolt.

 

[SouthBostonFJ40]

If you run a header, you don't need that bolt.

I wouldn't?

 

[Mr. Toad]

Explain please...

Picture this...if I ran a header, there would be no connection between the intake and header. So if there is no opening between the two manifolds where would it leak?

Well, unless you have a type of exhaust manifold that I'm not familiar with, then the top of the exhaust manifold is wide open. The bottom of the intake manifold forms the top cap of the exhaust manifold. If the seal between them isn't tight, then it'll leak exhaust gas. You are right, however, in that there is no opening between them.

Picture's worth a thousand words:

Make sense now?

 

[SouthBostonFJ40]

Perfect sense now. I'm screwed.

 

[Degnol]

Is it the intake or the exhaust manifold that is fubar'd?

 

[SouthBostonFJ40]

It's the threaded hole in the exhaust manifold.

 

[Degnol]

It's the threaded hole in the exhaust manifold.

Woooo!!!!! How about a header?

 

[SouthBostonFJ40]

My truck runs so well the way it is and I really want to keep it stock so I do want to go the header route.

 

[Mr. Toad]

My truck runs so well the way it is and I really want to keep it stock so I do want to go the header route.

Re-tap it? Drill slightly larger hole and tap that bad boy. You might have to enlarge the bolt-hole in the intake too (to fit the larger bolt). On the other hand, if you screw up this job, then you're out both manifolds . . .

Good luck

Edit: That exhaust leak won't affect how well it runs. Just makes it stinky and eye-watery inside.

 

[Degnol]

Re-tap it? Drill slightly larger hole and tap that bad boy. You might have to enlarge the bolt-hole in the intake too (to fit the larger bolt). On the other hand, if you screw up this job, then you're out both manifolds . . .

Good luck

Good advice. If you try and f'ck it up, I'll send you a new intake, freebie. Sorry, **** help with the exhaust.


Ed

 

[SouthBostonFJ40]

Sorry, **** help with the exhaust.


Ed

Hey, this is a PG forum.

 

[handcannon]

Put a heli-coil in it.

 

[rsbcruiser]

SouthBoston, not real familiar with the cast iron exhaust, wondering if you can drill the hole deeper, or deeper and bigger,or maybe through, without entering the exhaust cavity, then bolt and nut it?

 

[bsevans]

Put a heli-coil in it.

X2 on the helicoil

 

[rsbcruiser]

Helicoils are an option, use the solid type if you can. The spring type not so good, but will work.

 

[gladly]

have you thought of using a helicoil?

 

[SouthBostonFJ40]

SouthBoston, not real familiar with the cast iron exhaust, wondering if you can drill the hole deeper, or deeper and bigger,or maybe through, without entering the exhaust cavity, then bolt and nut it?

This hole is outside the exhaust cavity so that may be an option.

In order to remove this screw and put in a larger one, I need to remove the carb, which I didn't want to do. Anybody know the part number for the gasket between the Aisin carb and the intake manifold?