CI exhaust manifold gasket with stock manifold?

[65fback]

My car leaks.....


at the siamese ports!


Big shock (now). It took me awhile browsing the classic inlines site, but I finally read up on their exhaust gaskets and discovered it's a common problem.

I'm not ready to throw money at the car (yet). Well, OK, I am, but safety first. Seatbelts, brakes, better lights, etc.

But I would like to get rid of that pesky exhaust leak.

Is it worth putting the beefier gasket on with the stock manifold? Or will the stock manifold not have enough square footage around the siamese ports to make a difference? I'm *really* getting sick of listening to the exhaust sound coming from the engine bay.

 

[CobraSix]

I ran an Autozone exhaust gasket without any problems. I just used high temp permatex to seal around it. That was with a stock exhaust manifold.

 

[Frankenstang]

Is it worth putting the beefier gasket on with the stock manifold? Or will the stock manifold not have enough square footage around the siamese ports to make a difference?

It might!? Problem with most the stock exhaust manifolds is they eventually succomb to the fate Fordconvert pictured here...
viewtopic.php?f=1&t=43577

Blown up choke passage. Believe the thinner area of casting in this locale and the hot cold exchange eventually leads to this end, but initally they'll start out bulginging in that area. So you may want to look/examine it closely to make sure (if it is not 'blown up') that bulging is not interfering with solid contact across that large manifold gasket mating surface of the siamese ports. If it has started to bulge, then hopefully it would not be more than a little grinding and a good gasket can overcome. The CI gaskets are very good qualilty with compound material in the middle, sistered on both sides with metal (read 'forgiving')...and very, very reasonable (~$10 IIRC...reminds me I need to order a couple).

And if the choke passage has only bulged and cracked then you still may be able to perform a temporary fix by tapping&plugging the top and bottom fresh air openings for the passage (top one is actually smaller to receive the tube...the bottom one is large and gets pretty thin at the gasket surface, but plugs still might make do). Good luck

EDIT: PS And as Cobrasix mentioned high temp gasket sealer may be necessary for good measure. These efforts are still only a temporary fix but may get you by...and I have seen decent stock manifolds go on ebay for a reasonable price, as well as new repops.