stock heads
Thread Starter
Burning Brakes
Joined: Mar 2011
Posts: 969
Likes: 1
From: NJ
stock heads
This might be a silly question but on my 1970 L46 are the stock heads cast iron or aluminum?
I am putting in a new exhaust and was going to go with headers but after seeing the manifold bolts and the very rusted bolt heads along with reading how hard it could be to get them off and possibly breaking/twisting them off ... I am slowly considering leaving the stock manifolds on the car....especially if the stock heads are iron and the bolts could be rusted throughout.
I am putting in a new exhaust and was going to go with headers but after seeing the manifold bolts and the very rusted bolt heads along with reading how hard it could be to get them off and possibly breaking/twisting them off ... I am slowly considering leaving the stock manifolds on the car....especially if the stock heads are iron and the bolts could be rusted throughout.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Unless someone has swapped them, they are cast iron.
On the bright side, I've found it's odd the bolts seize in the heads. May take some heat and effort, and I have had some break, but for the most part they will come out. Again, not always, but they do come out. If you are looking at removal, soak everything with your favorite penetrating oil for a few days before. I like Hoppes #9 Gun Solvent, but others like different stuff.
On the bright side, I've found it's odd the bolts seize in the heads. May take some heat and effort, and I have had some break, but for the most part they will come out. Again, not always, but they do come out. If you are looking at removal, soak everything with your favorite penetrating oil for a few days before. I like Hoppes #9 Gun Solvent, but others like different stuff.
Thread Starter
Burning Brakes
Joined: Mar 2011
Posts: 969
Likes: 1
From: NJ
Unless someone has swapped them, they are cast iron.
On the bright side, I've found it's odd the bolts seize in the heads. May take some heat and effort, and I have had some break, but for the most part they will come out. Again, not always, but they do come out. If you are looking at removal, soak everything with your favorite penetrating oil for a few days before. I like Hoppes #9 Gun Solvent, but others like different stuff.
On the bright side, I've found it's odd the bolts seize in the heads. May take some heat and effort, and I have had some break, but for the most part they will come out. Again, not always, but they do come out. If you are looking at removal, soak everything with your favorite penetrating oil for a few days before. I like Hoppes #9 Gun Solvent, but others like different stuff.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Broken off, and in the car, some of them you won't be able to get to. Just not enough room. I've got a really short right angle drill (aircraft stuff) that has a head that's only 1/2" in diameter and it won't even make it. Pulling the head would be about the only option. Plus, if you're drilling out a broken bolt, drilling it off-center does not help.
Some bolts snap right under the bolt head too. Even if that happens, you can't get the manifold off far enough to get to the bolt without a lot of hassle. I've had a few (been messing with this stuff for close to 40 years), that I've had to get the manifold away from the head, and then cut the bolt leaving the stub in the head.
Some bolts snap right under the bolt head too. Even if that happens, you can't get the manifold off far enough to get to the bolt without a lot of hassle. I've had a few (been messing with this stuff for close to 40 years), that I've had to get the manifold away from the head, and then cut the bolt leaving the stub in the head.
Melting Slicks
Joined: Jun 2006
Posts: 2,071
Likes: 147
From: S Nevada
Broken off, and in the car, some of them you won't be able to get to. Just not enough room. I've got a really short right angle drill (aircraft stuff) that has a head that's only 1/2" in diameter and it won't even make it. Pulling the head would be about the only option. Plus, if you're drilling out a broken bolt, drilling it off-center does not help.
Some bolts snap right under the bolt head too. Even if that happens, you can't get the manifold off far enough to get to the bolt without a lot of hassle. I've had a few (been messing with this stuff for close to 40 years), that I've had to get the manifold away from the head, and then cut the bolt leaving the stub in the head.
Some bolts snap right under the bolt head too. Even if that happens, you can't get the manifold off far enough to get to the bolt without a lot of hassle. I've had a few (been messing with this stuff for close to 40 years), that I've had to get the manifold away from the head, and then cut the bolt leaving the stub in the head.
I totally agree. You may try spraying the bolts with Kano kroil a few times a day for a day or so, then trying to break them free. But if you snap the bolt, see post above.
Melting Slicks
Joined: Oct 2002
Posts: 2,865
Likes: 1
From: I may be getting old but I refuse to grow up
Broken off, and in the car, some of them you won't be able to get to. Just not enough room. I've got a really short right angle drill (aircraft stuff) that has a head that's only 1/2" in diameter and it won't even make it. Pulling the head would be about the only option. Plus, if you're drilling out a broken bolt, drilling it off-center does not help.
Some bolts snap right under the bolt head too. Even if that happens, you can't get the manifold off far enough to get to the bolt without a lot of hassle. I've had a few (been messing with this stuff for close to 40 years), that I've had to get the manifold away from the head, and then cut the bolt leaving the stub in the head.
Some bolts snap right under the bolt head too. Even if that happens, you can't get the manifold off far enough to get to the bolt without a lot of hassle. I've had a few (been messing with this stuff for close to 40 years), that I've had to get the manifold away from the head, and then cut the bolt leaving the stub in the head.
