Author Topic: Exhasut Manifold bolt washers  (Read 756 times)

sixt9x33rs

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Exhasut Manifold bolt washers
« on: November 08, 2011, 02:17:21 PM »
Why do some of the bolts for Small blocks have lock washers and others have rather fat flat washers?

Thanks

Lawrence
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firstgenaddict

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Re: Exhasut Manifold bolt washers
« Reply #1 on: November 08, 2011, 02:58:39 PM »
Lock washers will not retain their "lock" with the heat cycling on exhaust manifolds.
James
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sixt9x33rs

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Re: Exhasut Manifold bolt washers
« Reply #2 on: November 08, 2011, 04:54:53 PM »
Lock washers will not retain their "lock" with the heat cycling on exhaust manifolds.
So they are not used on exhaust manifolds?
'69 RS Z/28 Olympic Gold, 711
Flat hood no spoiler, black top, endura, 4:10
POP 39,000
69 X77 Z/28 69 711 Original Paint Unrestored
'69 X66 Convertible Cortez Silver 712 black top Endura, auto, bumper guards, am/fm rear speaker 44k miles

Petes L48

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Re: Exhasut Manifold bolt washers
« Reply #3 on: November 09, 2011, 12:29:49 AM »
The middle ports did not have washers under the bolts.  The outer/end ports of the manifolds got the thick spacer washer, then a french lock, then the bolt.  The tabs on the french lock were bent over the bolt hex head to prevent loosening.  The order is important because you cannot properly bend the locks if the washer is in between it and the hex bolt head.

Here's pics of both the thick washers and french locks for SBC and BBs.  Factory locks were steel, most repops are stainless.
http://www.licorvette.com/french_locks_Corvette.htm

I can't recall exactly, but if you start adding a/c brackets etc to the manifolds you need to check your AIM to see if the french lock was still used or left off.

sixt9x33rs

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Re: Exhasut Manifold bolt washers
« Reply #4 on: November 09, 2011, 02:07:53 AM »
Thanks for the info Pete.
'69 RS Z/28 Olympic Gold, 711
Flat hood no spoiler, black top, endura, 4:10
POP 39,000
69 X77 Z/28 69 711 Original Paint Unrestored
'69 X66 Convertible Cortez Silver 712 black top Endura, auto, bumper guards, am/fm rear speaker 44k miles