Packard Forum Index » Modification Discussion

I was hoping to get some input about my 1954 Packard. I'm in the process of putting the engine back together after being rebuilt. It's a 359 with a 288/327 head. I did not have the head "checked" but visually it looks fine.

I assembled the head with a new gasket, copper side up, onto the block using the original head bolts. I did have new washers made that are taller (about the height of three of the original washers since the cast head is shorter than the original aluminum) I torced the head to 62lbs with two different wrenches in case one was off in the pattern described in the manual.

With all that done I filled the engine with fluids and before I got around to trying to start it the head began to seep antifreeze around the perimeter of the block and at a few of the nuts on top. Instead of going any further I pulled everything back off revealing antifreeze in cylinders 4, 7 & 8.

So the antifreeze is cleaned up but any idea what I might need to do differently? A friend mentioned replacing the head bolts?

Thanks for your time.
Andy

Have you tried running a straight edge over the head to make sure it's truly flat? Also I believe some of the studs that go into the water jacket areas require a bit of sealant. Did you apply that?

I laid a straight edge down where I could though I did not remove the head bolts. Everything seems good.

I didn't use a sealant, what do you recommend?

Am assuming you verified the thick washers are tall enough to completely take up the space on all the studs and the nut is not bottoming out prematurely on any the stud threads leaving the head loose.

It is still a possibility the head is warped and has to be milled. If it does need milling, since you don't know if it has been done before be sure to check the valve clearance afterwards. Even new heads didn't leave a lot of space above the valves for much to be taken off. If it has been done before there may not be enough left to clear and the head may have to be junked or a bit of clearance ground out for the valve edges.

Before tightening the nuts again, lay the head on the gasket and rotate the engine thru a couple of turns. Watch for any movement of the head. You could get a bit more precise guess by using some modeling clay or similar above the valves in the recessed area. The amount of smash would verify exactly how much clearance there might be.

Many use the copper spray a gasket sealant on the gasket.

Thanks Howard, BigKev,
I'll look into these items.

I do know the nuts are not bottoming out on the studs.

Andy

G'day andymylin,
to PackardInfo, and I invite you to include your '54 Packard in the Packard Owner's Registry.

You should definitely use stud sealant, and use a quality one that stays 'soft' / doesn't harden. You don't want to lock the studs tightly into the block so you have trouble removing them in future. Also, use the copper spray when you reassemble with a new head gasket. I keep hearing reports about how good that stuff is.

Are you using the correct studs, which I believe have a taper? The stud holes cannot be 'cleaned' with a tap because they are a correct interference fit with the studs. You can carefully use a thread cleaner instead, which won't take any metal out of the stud hole.

Was this head originally on this block ?I would still have it carefully milled according to other's suggestion.

Quote:

JMHO, but I'd never consider a Packard I8 rebuilt unless the block and head mating surfaces had been milled.

Some have been able to get the two old pieces to seal up without it, but I'd not take the chance.

We put heads and blocks on the mill every day and it's a very rare piece which the first cut is even across the length and width, indicating it was flat as was.

Most have waves, dips or warps and it requires removing .005" to .015" to get them back flat.

jack vines

As Jack says, it's really essential to check the head; I've done more L8 headgasket jobs than I care to remember, never found an issue related to the block itself though he's right, a "thorough" rebuild would resurface that as well.

You should have no problems if the head has a simple warp of perhaps 0.010" or so, the nature of the head gasket and gasket cement should accommodate that much. Beyond that or for more than just a modest warp, the head should be resurfaced but before you do that, not knowing the prior history of the head, you really must first determine how much can be removed before you run into valve clearance problems. One way you can do this, and it's been often discussed here, is to use a dab of modeling clay on the highest edge (remember, they are not perpendicular to the block deck) of each valve. Then bolt the head down with a used headgasket (one that has already been compressed), rotate the engine thru several revolutions (more than 2), remove the head and check the thickness of the modeling clay remaining. Don't expect the same clearances from front to back!

For newly inserted studs, I do use a "hardening" Permatex or plain old simple gasket shellac (Indian Head); I know this is contrary to other advice but I've never had the least of a problem removing studs that used the hardening gasket cement. For the gasket, I hang it by a wire a spray both sides with a copperized head gasket cement.

Go to final torque in 3 more-or-less equal steps following a pattern starting in the center and spiraling end-to-end and side-to-side. Very important - retorque within a few minutes of initial startup, again within a few hours, and at least once more. Checking torque as part of your annual tune or check-over is always a good idea.

This is a bit dated and should be cleaned up a bit, but still might be worth your time to read:

packardclub.org/forum/viewtopic.php?f=14&t=863