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Does anyone know the torque for the head on a 8 cylinder 34 pierce?
it’s hard for me to believe that nobody in the PAS knows how much torque to put on some head bolts.
Greg,
8 cylinder head torque has been documented in several of the PAS Service Bulletins, 95-2, page 2, for example. If you don’t have a copy, let me know and I will e-mail it to you.
The torque should be 65-70 ft-lb, however:
1. The bolts should be tightned following the recommended sequence in the PASB.
2. The bolts should be tightened in stages, don’t just take them right to the 65-70 ft-lb limit.
3. Head bolts should be tightened on a cold engine.
4. After the engine has been run, the gasket compressed, and everything stabilized, the head bolts will again need to be re-torqued.
Chris Diekman
Greg and Chris,
One caution that has often been offered by Eric Rosenau (our immediate past Chief Judge and who restores Pierces for a living) is to NOT RE-torque a head while the engine is hot.
On my cars, I let the engine cool for 60-90 minutes (but not overnight) before re-torque.
As to pattern, there is no specific pattern recommended other than to start at the center and work your way evenly out to both ends.
To clarify Chris’s information, I make one pass at 35, another at 50, and a 3rd at 65-70, then a final also at 65-70. Don’t be tempted to overtighten!
Greg, this is a very busy time of year for a lot of us. Frankly, when I saw your post, I thought "I really don’t have time to reply right now–if someone else doesn’t respond in a couple of days, I will." Perhaps others have been in the same boat. For everyone with a question like this, may I suggest that if there is no message board response to your tech question in a couple of days, e-mail it to Fay Butler (link to ‘ask Tech Committee’), who — if he’s not comfortable answering it himself — will send it to one of us who has experience with that year and model.
Best wishes to all for a happy holiday season!
George
Greg,
George is right about the time of year. But anytime you want a REALLY QUICK answer to a question like this, I’d suggest that there is another alternative that can often get you on the correct path.
The Society has 30 years of PAS Service Bulletins on three CD’s that are available through the Company Store. Most factory technical bulletins have been included in the club Service Bulletins. The advantage of the CD’s is that you can search by keyword, year or model number for almost any question you’ll ever have and have an instant display of relevant files. They are a fantastic tool!
After I obtained the set of CD’s, I seldom refer to the huge collection of paper copies that I had assembled in a 3 ring binder unless I break down on the road. It is almost always quicker and easier to go to the CD, print out the info I need right then and proceed to the car. As you do this you can put important info in a book to keep in the car when traveling.
If you don’t have them, you should get the CD’s. Then if you still need experienced advice like Chris or George offered, do a posting on the message board. But bear in mind that not many of us check the message board every day in the best of times. And unfortunately when dealing with Pierce-Arrows, there aren’t that many of us to begin with.
Happy Holidays!