1962 Exhaust Manifold Problem

[wjw1741]

Ok, so I am driving my '62 with a rebuilt .327 this weekend and notice it seems alot louder than normal. Well, an investigation under the hood, I determined that the drivers side exhaust manifold has cracked where the thread bolts connect to exhaust pipe and has separated from each other causing the unusually loud exhaust.

Is there a way to repair the original one? Or do I just go and buy a new pair? Any suggestions as to which company/catalog I should purchase them from? Any idea how much labor would be involved in replacing them, I do not do my own work?

And last but not least, I have a feeling that the car should not be driven. It seems to me that I heard along time ago that there is something to do with 'back' pressure when something like this happens. Is there any truth to it, and could someone explain whether or not I should be driving the car until it is repaired.

Thanks,

Warrenhnoes

 

[Tom Bryant]

Hi Warren,

First off you aren't going to hurt anything running the engine with an exhaust leak. It just sounds bad. I have always heard that you don't want to run an engine without the exhaust manifold on it as the valves can cool down too fast and warp when you turn it off but you don't have that problem.

It could be that the packing donut is just burnt out which is the most common occurrence at this connection. Can you see where it is cracked? If one of the ears that the studs go in has cracked off it could possibly be welded by a professional and never cause any problem again. It all depends on how good the weld is.

If you need to replace the manifold Paragon has it. There is a casting number on your manifold you can use to go by when looking up a new one. You will need to know if it is a 2 inch outlet (250 and 300 horse) or a 2 1/2 inch outlet (340 and 360 horse).

You will also need to buy the studs, nuts, exhaust donut and maybe the donut alignment sleeve if yours isn't reusable. The good news is that you don't need to replace both sides, just the left side.

Tom

 

[wjw1741]

The good news is that you don't need to replace both sides, just the left side.

Tom[/QUOTE]

Shouldnt I replace both now anyway? I think it would look strange with one new one and one old one. Perhaps its just a vanity issue.

I can see the crack, and yes it starts near the thread and goes towards the engine, its about an inch or so.

So, I can drive it, and the only problem would be the noise, which I kinda like, it makes it sound like a big block.

Thanks,

Warren

 

[Tom Bryant]

I guess I'm just cheap but I wouldn't. If appearance is really important then by all means do it. You could just have the right side one bead blasted to clean it up also.

If you are going to take both sides apart check that the heat riser valve on the right side is working freely. You may need to order one of these too plus a donut, flat gasket, studs, nuts, and donut sleeve for this side.

The studs will more than likely twist off unless they are fairly new. If replacing the manifold it's no big deal but if you are reusing the right side then be prepared to have to remove the remnants of the old studs.

Tom

 

[wjw1741]

Tom,

Good advice, and thanks for your help. One more thing, so there is a heat riser, but its only on the passenger side?

Warren

 

[Tom Bryant]

Yes. When you push down on the weight (cold) it should move freely and spring back closed.

Tom