Torque for Cylinder head/valve covers

[The_Handier_Man1]

From: Liv42dayOK  (Original Message)
Sent: 5/21/2003 9:17 PM

Ok!  Here's another babe in the mechanical woods question to chuckle at:  I need to replace my valve cover gasket.  When I read over the manual, there was no such creature.  I'm assuming what they called the cylinder head cover is the valve cover?  It also said that the torque on the bolts should be 40 lbs and it gave no torque sequence.  Any other manual I've seen always give a torque sequence and, the motor heads at work said that 40 lbs sounded high.  They work on much newer cars though.  It's a '74, 440-3.  Anybody want to save me from total embarassment? - Sob



From: Myk-dK
Sent: 5/21/2003 11:39 PM

that manual is wrong. no sequence in needed, just lightly snug them, then snug them more firmly,  then the 3rd time around I usualy thighten them with ONE HAND ON THE HEAD OF THE RATCHET, with only my thumb on the lever part of the handle.  More damage is done by over tightening than any thing else, as all you do is bend the thin near the bolt hole.

MYK



From: denison
Sent: 5/22/2003 6:27 AM

I looked in my service manual, and for the cylinder head cover bolts it says 40 in-lbs. That would be anout 3 ft-lbs. I have been overtightening mine; Im guessing I get them to 6 ft-lbs. ! I like to re-snug the bolts about one vacation later, and maybe again 6 months after that - not really tight, just taking up the settling of the gasket. I also call them rocker cover gaskets. On a motorhome v8 I would estimate they have a 10 to 15 year life before they might distort enough to begin leaking again - sitting for long periods lets them dry up. denison 



From: Cousin Eddie
Sent: 5/22/2003 7:58 PM

It is common for the big block Mopar engines that are not regularly used to leak a little from the valve covers. You may have noted a little smoke and burning oil smell when you first start the engine after sitting for awhile. The gaskets expand once they heat up preventing any more leakage...for awhile.

Over tightening the bolts compresses the gasket and also causes leaks. The bolts can also be easlliy wretched off if you torque' em  down too much.(deep vodoo here!) As pointed out in the previous post your looking at inch pounds rather than foot pounds.

As for sequence, if not noted in your book, just use common sense and remember to do it evenly, so you will not distort the cover (another cause of leaks).

When replacing the gasket, be sure all of the old gasket is removed from both surfaces, cover and head. Sounds fundamental, but it is often the cause of leakage after new gaskets are installed.

For a good selection of valve cover gaskets check:
www.manciniracing.com

Check parts under the RB engine series. 



From: Liv42dayOK
Sent: 5/22/2003 9:31 PM

Ahhhhh!  Great pickup, my dear Watson!  It would appear we've overlooked the obvious clue in the mystery!  No wonder they have that whole page or so of conversion tables.  I thought it was just stuff to impress us! -  Surelock Homes.



From: Liv42dayOK
Sent: 5/23/2003 7:18 PM

Thanks for the tips everybody!  I did get the standard cork replacements and sealant.  The PO couldn't remember when they were replaced last so, that'll tell you how old they are.  They seemed to have been plastic or maybe just oil saturated and cooked to well done.  The sides by the exhaust manifolds were cracked and very brittle.  The left side leaked a little but, the right side.... smoke like a hamburger on a grill!  Oil all over the place.  I got the covers off and cleaned up.  I'll be putting them back on tomorrow and taking the rig to the shop to check out the brakes. - Sob