Go@$%^&$#am French Locks!

[Joe C.]

OKAY, so when I first put the exhaust manifolds on my '65 SB, I gave up trying to keep the locks from twisting during the final 1/4 turn of the bolts. So now I have the manifolds removed for a "freshening up", and this time I'm gonna try harder NOT to let them buckle during installation. Anybody have any ideas?

Joe

PS: No beers until the job's done.

[Joe L.]

Re: Go@$%^&$#am French Locks!

Joe-------

1) Use stainless french locks; the stainless steel material is a lot more resistant to "buckling". Plus, it won't rust;

2) Apply anti-sieze compound to the french lock (whether you use stainless or not) at the surface which contacts the bolt;

[Chris H.]

Re: Go@$%^&$#am French Locks!

I had no problem with twisting on non stainless locks. Are you using a torque wrench? The torque is pretty darn low.

chris

[James F.]

Re: Go@$%^&$#am French Locks!

Joe,
Know what you meam! Out of steel shim stock I stamped out thin washers. Can't remember shim thickness but probably under .010. The thin shim washers were not visiable and the french locks did not twist or rip. Also used the same idea for the 2 X 4 WCFB brass ident tags. Regards,

[Joe C.]

Re: Go@$%^&$#am French Locks!

Chris:

Yeah, I used a torque wrench. Torqued 'em to whatever the spec is (20-25 ft-lbs, I think, will check it before reinstall). Used all new bolts the first time, with some oil under the heads (I'll try Joe's suggestion of anti seize this time). The only other thing I'll try, is to very carefully check for burrs/nicks under the new bolts.

Joe

[Joe C.]

Joe And Jim

Thanks to both of you.
Joe. I'll try the antiseize. I used motor oil to lube on first install. Good thought on the SS locks, but, since they really don't do anything anyway, and are mostly for "show", I'll keep the mild steel ones, rust and all.

Jim. If I feel ambitious today, I'll carefully deburr/reprofile the undersides of the bolt heads, to minimize torque at the O.D. Good idea with the shim stock.

Joe

[dale edlund]

Re: Go@$%^&$#am French Locks!

Please tell me what a french lock is

[David W.]

Re: Go@$%^&$#am French Locks!

They are little devices that connect two of the exhaust manifold bolts to prevent the heads from turning and thus the bolts loosening. You can see a picture form the link below. The little tabs at each end are bent up ro surround the bolt head.




http://www.corvette-paragon.com/cata...5-F86776200879

[Chuck S.]

Increase The Coefficient of Friction...

Joe, you might try using some coarse sandpaper to slightly roughen the manifold contact surface just around the bolt hole(s), and the mating area on the french lock surface that contacts the manifold. If you are careful, the sanding marks shouldn't be visible, and the tendency of the lock to rotate on the manifold will be reduced. As I understood Joe's suggestion, anti-seize was to be used only under the bolt head to make it more slippery on the lock.

[Dennis C.]

OK - A check...

The first thing to hit the exhaust manifold is the thick round spacer washer. Next is the french lock on the front and rear exhaust outlets. Then the bolt, unless radio shielding brackets get involved. Usually, if I get the procedure correct, the locks don't twist on me. Go with the steel ones, not SS. Only set the one lock that best lines up with the hex of the bolt after torque. The AIM does provide some direction in this regard. Best, Dennis

[dale edlund]

Re: Go@$%^&$#am French Locks!

Thank you David for the explanation. Dale

[Joe C.]

UPDATE: Thanks Joe, And, Oh, Dale

First of all, Joe L's idea about the anti seize did the trick, using the plain old mild steel locks. The other good ideas were not necessary. Torqued all to 22 ft-lbs, twist free!

Dale, there was a lot of misunderstanding about these "French" locks. Seems that many folks believed that they had a sexual connotation. Specifically when someone sticks their tongue down their partner's throat during the throes of passion. These folks were later educated as to the difference between a "lip" lock, and a "French" lock.

Joe