I'm in the process of building a original aluminum GM block and 074 Head engine. And I am in need of the proper Fastener torque specs. Most important are the Mains and Heads. If possible I would like specs for Bolts and Studs. Because I may use both. Also what do you guys like for Main bearing clearance with this Aluminum block? spinning 7800 RPMS.
Thanks you.
1969 427 ZL1 Bolt Torque Specs
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Re: 1969 427 ZL1 Bolt Torque Specs
wasn't that a special bolt???? I did one years ago and I think it had some sort of special bolt...
does the bolt have a neck down and a raised rib in the center of the bolt????
I think that if I remember correct that was a carr bolt and was to replaced as it was a 1 time use only...
I am talking rod bolts....
I think the mains were stock bolts with the stand off for the windage tray....
does the bolt have a neck down and a raised rib in the center of the bolt????
I think that if I remember correct that was a carr bolt and was to replaced as it was a 1 time use only...
I am talking rod bolts....
I think the mains were stock bolts with the stand off for the windage tray....
Re: 1969 427 ZL1 Bolt Torque Specs
Hi Ken, here's some numbers:Kenny M wrote: ↑Thu Dec 07, 2017 12:04 pm I'm in the process of building a original aluminum GM block and 074 Head engine. And I am in need of the proper Fastener torque specs. Most important are the Mains and Heads. If possible I would like specs for Bolts and Studs. Because I may use both. Also what do you guys like for Main bearing clearance with this Aluminum block? spinning 7800 RPMS.
Thanks you.
Mains=
studs- 100# (oil)
bolts (inner) - 100# (moly) / (outer) - 100# (moly)
Heads=
bolts- 70# (long) / 60# (short) (sealant on both)
studs- (7/16" fine) / 65# (long) / 55# (short) (oil on both)
If you are using aftermarket fasteners (ARP, etc) follow their directions, they will "override" what I show here?
Thanks, Gary in N.Y.
P.S. Strongly recommend "pinning" the front 4 lower main shells to the caps! We do all aluminum plaform builds this way for insurance!
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Re: 1969 427 ZL1 Bolt Torque Specs
On my all-aluminum FE engines, with a 2.750" main diameter, I will aim for .0018-.002" clearance "cold".
I've never pinned a main bearing, but I do green Loctite the cam bearings in.
I've never pinned a main bearing, but I do green Loctite the cam bearings in.
Lykins Motorsports
brent@lykinsmotorsports.com
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Custom Ford Windsor, Cleveland, and FE Street/Race Engines
brent@lykinsmotorsports.com
www.lykinsmotorsports.com
www.customfordcams.com
Custom Ford Windsor, Cleveland, and FE Street/Race Engines