Bolts Instead of Studs For Exhaust

[Azrael]

Would heli-coiling be recommended? I don't see why not as almost everything on aircraft engines are.

[fastback4]

That is sound advise. I believe I'll use the studs and nuts....Thanks 96

Let me add a little warning about removing studs and using bolts in a aluminum head...I don't advise this swap...with a soft material like aluminum the stud is screwed in and stable while the nut does all the force to cinch the manifold against the head...if you remove the stud and use a bolt you are now going to rely on using the threads in the softer aluminum head to tighten the manifold against the head...what this will do is gull the threads and eventually it will strip out...you might say that the first time it worked fine, but in reality you probably already did the damage and don't know it yet...this is why all aluminum heads have studs, it is the most effective way to hold parts together but if you do use the bolts, then best of luck to you and don't say I didn't warn you not to do this swap...I don't advise it!

if you must have the bolt look then what I would do is cut your studs to length and use some of those SS nuts that are domed to cover the stud this will give you a cleaner look and you will keep your studs...I believe there is a kit that has a center allen head to install the stud...but this is the only safe way of not damaging your head.

[96lumina]

Let me add a little warning about removing studs and using bolts in a aluminum head...I don't advise this swap...with a soft material like aluminum the stud is screwed in and stable while the nut does all the force to cinch the manifold against the head...if you remove the stud and use a bolt you are now going to rely on using the threads in the softer aluminum head to tighten the manifold against the head...what this will do is gull the threads and eventually it will strip out...you might say that the first time it worked fine, but in reality you probably already did the damage and don't know it yet...this is why all aluminum heads have studs, it is the most effective way to hold parts together but if you do use the bolts, then best of luck to you and don't say I didn't warn you not to do this swap...I don't advise it!

if you must have the bolt look then what I would do is cut your studs to length and use some of those SS nuts that are domed to cover the stud this will give you a cleaner look and you will keep your studs...I believe there is a kit that has a center allen head to install the stud...but this is the only safe way of not damaging your head.

[geoffinbc]

Yea they work well too.

[pocket-rocket]

The 4.3 TBI I changed in a 4x4 Jimmy had bolts. It also had these little flimsy sheet metal hoops that went over the top of the manifold ports between the two bolts. It also had ears on it that got bent over the sides of the bolts once they were honked down on to keep them from rotating out.

[geoffinbc]

Lock washers wont to anything for exhaust bolts. It's too hot and they loose their temper. They wont prevent the bolts from backing off. The best way to prevent exhaust bolts from backing off is to drill a small hole through the side of the bolt head and wire them in place.

[Azrael]

My local dealership was asking $20 per stud. They obviously didn't need anyones business. If you do use bolts, make sure you use those split lock-washers.

[geoffinbc]

Your auto parts store should have a selection of studs. At least the ones around here do. Or have you tried a GM dealer to get stock replacements? I bought all new ones for my engine and they were cheap.

Try gmpartsdirect or rockauto also

[fastback4]

I've thought about this swap also. Can't say i remember anyone talking of doing the swap. I know the nuts used on the exhaust studs that are on the heads are locking type nuts, so i suppose alot of exspantion/contraction is going on between the aluminum head and the cast exhaust. I have some metric bolts ( M8x1.50) i may use but i'll apply some thread locker to them first......

[eckoxl]

Anyone use bolts instead of studs for exhaust manifolds? Just asking because I can't find any studs locally, but I can find bolts. If so, how long should they be? I know the thread is M8x1.25.