rambling follow-up to my exhaust manifold removal problem, & a couple more questions

[DogBunny]

I got my passenger side exhaust manifold off. The manifold-to-exhaust pipe nut that was obstructed turned out to not be as obstructed as I thought it was. Using a 1/2" drive socket -- deep enough to clear the bolt threads, but not too deep -- and a 1/2" to 3/8" HF wobble adapter, and an extension, I was able to get the nut off. Working in my driveway, I had to hold everything in place under the car while a neighbor crouched in the wheel well and pulled on a 2' cheater on the ratchet handle. Not easy, but way less hard than I thought it would be.

When I pulled the 6 manifold-to-engine nuts, on the very last one, the whole stud came out. There was coolant behind that stud, so I was momentarily unnerved as anti-freeze started spilling on the ground. If it had been any nut other than the last one I might have been able to deal with it, but with the manifold now dangling, and all of my catch pans filthy, I just had to watch a gallon or more of perfectly good coolant go to waste.

The rear manifold-to-engine nuts were not very tight. Maybe the weight of the exhaust pipe on the rear of the manifold, and vibration of the pipe tends to loosen them? Gonna check the nuts on the other side.

The old exhaust manifold gasket was completely burned through in the middle.

Put a straightedge on the manifold, it is not very level and will be re-surfaced. Put a straightedge on the engine, a little bit hard to see with the engine in the car, but it appears straight -- I guess that surface never warps?

The exhaust manifold heat control valve shaft is frozen, and the plate has been removed. This really bothers me. I read in a couple of other threads where members asking about repairing the valve were told to just disable it. Am I the only one who thinks it's a good idea? Searched around and couldn't find the plate that I am missing or much else. If anyone knows of a source or happens to have parts, I am interested.

I am also interested in replacing the 2 exhaust manifold-to-exhaust pipe nuts and bolts, the 6 manifold-to-engine nuts, and the manifold stud that unscrewed from the engine. Any guidance on replacements is appreciated. Is stainless on the nuts and bolts a good or bad idea? If not stainless, then what grade and/or material fasteners am I looking for? As for the single stud that I need, can I just go to the dealer and get one? Do I need a part number? Maybe someone who bought a kit didn't use them all and will sell me one?

Any insight into any of the above is appreciated.

 

[Big_John]

I'll address the heat valve.

It does warm the manifold and that was great for cold weather (less than 32 degrees) driving with the gas the car was built to run. Now we have gas that boils out faster and do you really drive the car in the winter?

With the new gas you will have greater chance of vapor lock and to help prevent that, you will want your manifold to be cooler and therefore, you really don't want the hot gases running up under the carb. Eliminating the valve is good and blocking the crossover isn't a bad idea either.

 

[tallhair]

Concur with Big John.

FYI the magnum manifold bolts and nuts can be found new on ebay for magnum manifolds. Which ones do you have? Log or perf style?

I have a couple of magnum manifolds with the butterflys still in place but they are 67-69 manfolds and have 1 or 2 log type sets

 

[commando1]

The studs can be bought individually at a hardware store.

 

[DogBunny]

Thank you for the fast responses.
Big_John, great answer. I will quit worrying about it.

tallhair, thanks for concurring on not needing the heat control valve. Regarding magnum, log and perf, I have no idea what any of that means. I have the stock exhaust manifold.

There is a great fastener supply house close to me where I can get graded nuts and bolts cheap. Just need to know what grade. And curious if stainless is a good or bad idea.

commando1, excellent, thank you.

 

[BIGBARNEYCARS]

The Felpro valley pan gasket with the blockoff iz Fel-Pro#1215 if you wish to go that route and PAHLEEZZZ DON'T USE STAINLESS STEEL FOR STUDDZ, NUTZ, OR BOLTZ ON THOSE MANIFOLDEZ. IF YOU'VE EVER HEARD THE WORD "GAULING"? OR NOT? IT'S AH FUNNY LITTLE WORD THAT DESCRIBEZ WHAT HAPPENZ TO THE THREADZ ON THE NUTZ AND BOLTZ WHEN THEY PHYSICALLY MOVE AND DISTORT IN THE TIGHTENING PROCESS. HOPE YOU'RE READING THAT IT'S AH ONE WAY TRIP THAT YOU DON'T REALLY WANT TO TAKE, Jer

 

[DogBunny]

BIGBARNEYCARS, thanks for the warning and thanks for the gasket number. I suspected that there was a reason for not using stainless. What about on the two manifold-to-exhaust pipe nuts and bolts? If both the nut and bolt are stainless, is that okay, and is anything gained, or is it another bad idea?

 

[tallhair]

BIGBARNEYCARS, thanks for the warning and thanks for the gasket number. I suspected that there was a reason for not using stainless. What about on the two manifold-to-exhaust pipe nuts and bolts? If both the nut and bolt are stainless, is that okay, and is anything gained, or is it another bad idea?

I imagine you have the log type.

Magnum manifolds

Stainless have a rep for not staying tight. I'd go with hardened black hardware

You also need a thread sealer on the studs going though the water jacket when you go back together .. liquid teflon or teflon tapes works well

 

[DogBunny]

Yes, I have the log type. Teflon tape had not occured to me. Was going to use red Loc-Tite with the idea that maybe it would keep the stud from coming out next time, but now that I think about it, not sure how well that would work in a hole that is wet with anti-freeze. So, will use Teflon tape.