Exhaust manifold Merc BBC stainless bolts from ARP
03-30-2011, 09:57 PM
#11
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HOLD OFF on SS Bolts !
It seems that I made a mistake on the 1.75 inch long bolts- I did not account for the possibility that the holes in the head are not threaded all the way to the bottom. I recieved my bolts today, and in test fitting them to a BBC head in my garage, I find that they are about 1/8 inch too long. I could probably grind them down to size but I am not sure how this would affect the heat treatment/hardness/toughness of the bolts. Considering they are about $35-40 for the set, I am not sure if I am going to grind down or return them for exchange.
I am also going to try chasing the threads with a tap and see if that cleans them up further to the bottom of the hole- but if you are going to order the 3/8-16 bolts for your exhaust manifolds, then I would probably advise getting the 1.5 inch instead of the 1.75 inch lengths.
I am also going to try chasing the threads with a tap and see if that cleans them up further to the bottom of the hole- but if you are going to order the 3/8-16 bolts for your exhaust manifolds, then I would probably advise getting the 1.5 inch instead of the 1.75 inch lengths.
01-05-2017, 09:32 PM
#12
AT Cult Member #3
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If you buy off-the-shelf 18-8 or 316 stainless bolts, they are not as strong as grade 8 bolts. ARP bolts, however, are made of a special material that's actually rated stronger than grade 8 bolts (170,000 psi vs 150,000 psi).
For what it's worth, I've had no problems using the off-the shelf 316 bolts from McMaster-Carr to hold my Eickert manifolds on.
For what it's worth, I've had no problems using the off-the shelf 316 bolts from McMaster-Carr to hold my Eickert manifolds on.
01-05-2017, 10:46 PM
#13
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I hear what you are doing but .....
I've found each hole in the heads are not always drilled to the same depth. Maybe it is crap in the bottom, they didn't tap it deep enough or drill deep enough but there is always one. I do use SS out of Ace Hardware which is plenty strong for exhaust manifolds. Never a issue with breakage or backing out. I never use anything on them like anti seize or thread locker but after running it the first time I will give all the bolts a extra 1/8 turn while still warm. Never had an issue getting one back out. As for length. Never found the right size so I just buy the longer size and cut them to length.
I've found each hole in the heads are not always drilled to the same depth. Maybe it is crap in the bottom, they didn't tap it deep enough or drill deep enough but there is always one. I do use SS out of Ace Hardware which is plenty strong for exhaust manifolds. Never a issue with breakage or backing out. I never use anything on them like anti seize or thread locker but after running it the first time I will give all the bolts a extra 1/8 turn while still warm. Never had an issue getting one back out. As for length. Never found the right size so I just buy the longer size and cut them to length.
01-06-2017, 08:22 PM
#14
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We switched from the ARP bolts to the ARP studs for the exhaust. It is so much easier to install the CMI exhaust using studs vs. bolts. It seems like it would be the same with the Eickert manifolds. A lower cost option with be to use 2 studs per manifold and hand tighten with nuts. You could then use bolts on the rest as the manifolds and gaskets would then be in alignment.
01-06-2017, 10:05 PM
#15
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We switched from the ARP bolts to the ARP studs for the exhaust. It is so much easier to install the CMI exhaust using studs vs. bolts. It seems like it would be the same with the Eickert manifolds. A lower cost option with be to use 2 studs per manifold and hand tighten with nuts. You could then use bolts on the rest as the manifolds and gaskets would then be in alignment.
