Studs holding head instead of Bolts

Unknown

Have a 49 Commodore with a straight 8. I have seepage on the drivers side rear of the cylinder head. Oil mostly, but I think I can see a hint of anti-freeze in the small amount of seepage. Recommendations have been to re-torque the head. Instructions say to re-torque using the correct sequence ( got that from an old addition of WTN ). BUT, my engine has studs instead of head bolts. Is this normal for the 8??? I think the torque spec for studs is around 35 ft lbs versus the head bolt specs of around 75 ft lbs. There was a LARGE warning about going higher than 35 ft lbs on studs. Should or can I change to head bolts by pulling the studs? If so, what are the sources for head bolts for the 254 CI 8? I understand that re-torquing the head might not fix the seepage and I might have to pull the head and replace the head gasket. Still would like to understand the stud versus head bolt issue before I replace the head gasket.



BST RGDS

GARY ( happychris )

Uncle Josh

Stay with the studs on the 8. Take the head off, clean things up, spray both sides of the gasket with high temp aluminum paint if it's still in one piece, and re-assemble while tacky. Correct torque is 45-50 in the 41-47 manual and in the stepdown manual. Sequence is from center to sides toward ends. Run up to temp and re-torque. Iron head HOT, Aluminum head COLD.



I replaced the studs in my 212 truck head with bolts. So far so good but tricky since some of them go in farther than others and have to watch the length. Also, you take a chance on disturbing the seal since the bolts go into the water jacket. Also on the 6, you have to pull 2 bolts to remove the distributor. Not a problem on the 8 but there are several brackets etc up on top of the head that you don't want to be disturbing the bolts to get to.

Unknown

Uncle Josh,



THANKS for that input - guess I will stick with the studs and give your recommendation a try. I bet I can tell if I have an aluminum head once I take it off - but is there a easy way to tell with the head on the engine? Do I just scratch the head to determine which I have? Any suggestions - or just wait till I pull it?



BST RGDS & THANKS

GARY ( happychris )

Geoff

IMPORTANT - do not tighten the head nuts down tighter than 50 lbs. If you do so you are likely to stretch the block and cause radial cracks around the base of the studs. The 8's all had studs, not bolts. Just try sticking a magnet to the head, you can pretty soon tell if you have an alloy or iron one that way. It is a good idea to slightly countersink the holes in the head, so that there is no danger of the head and gasket bottoming on a slight upraising around the base of the studs, which can cause the leakage you describe.

Geoff

Uncle Josh

The 8 cyl iron head had HUDSON cast in the top. The Aluminum did not.

Unknown

Uncle Josh wrote:

The 8 cyl iron head had HUDSON cast in the top. The Aluminum did not.

Guess I have an aluminum head then - no HUDSON cast in the top. I know you have to torque the aluminum head cold. Anything else to worry about? Is having a aluminum head a good or bad thing?



BST RGDS

GARY ( happychris )

Unknown

Gary,



It depends on who you talk to. Many of those who have had problems with aluminum heads will be negative while those of us who have never had a problem will tend to be positive. Many cars had and still have aluminum heads. The problems with them tends to result from improper installation and/or lack of cooling system maintenance. On the up side, they dissipate heat quicker than cast iron. I would like to believe that the aluminum heads Hudson used were designed to be as reliable as the cars themselves. On my 53 Hornet, time has proven this to be true.

Unknown

HOw can I tell if a material is aluminum or iron?

Find a magnet and drop it on the head. It it doesn't stick, the head is aluminum.



-Chris

Uncle Josh

My eight came to me with an aluminum head. I did what I posted earlier to make sure I got rid of all the nut shucks and installed the motor in my 52 Hornet, thus creating the only Hornadore I know of and ran it 2 years. No problems, no leaks.



When I rebuilt the 308, I removed the 254 and am putting it in my 46PU. I like the looks of the iron head better so traded the aluminum off, but it worked good for me. BTW, it is higher compression and gives you 138HP vs 128 for the iron head.