Torque to yield on a 429?

[Bruce Nunnally]

RJGuyser writes:

Anyone know if there are any torque to yield fasteners on the '67 Cadillac 429? Gonna disassemble & check clearances.

[KHE]

Not sure if torque to yield fasteners were used that long ago. It might be a good idea to obtain a copy of the shop manual which can often be found on ebay.

Try this forum: http://forums.500cid.com/

They deal with the big-block Cadillac engines and may be able to help out.

[growe3]

RJGuyser writes:

Anyone know if there are any torque to yield fasteners on the '67 Cadillac 429? Gonna disassemble & check clearances.

1967 Cadillac 429 Cu-In engines were normal turn to foot-pound torque type bolts.

Typically values of 60 Ft-Lb or more are done in three stages, less than 60 Ft-Lbs can be done in two stages.

I don't know of any automotive torque to "yield" bolts, they are torque to "angle" bolts.

In structural building design, torque to "yield" bolts may be used at certain types of connections.

All values are Ft-Lbs

Head Bolts = 70-80

Rod Bearing Bolts = 40-45

Main Bearing Bolts = 90-100

Crankshaft Balancer Bolts = 65-70

Flywheel to Crankshaft Bolts = 75-80

Intake Manifold bolts = 25-30

Exhaust Manifold bolts = 25-30

Cylinder Head Tightening Sequence

8 4 1 5 9

7 3 2 6 10

-George

[KHE]

I don't know of any automotive torque to "yield" bolts, they are torque to "angle" bolts.

In structural building design, torque to "yield" bolts may be used at certain types of connections.

-George

George,

The rod cap bolts in the Northstar engine are torque to yield bolts. There is an initial torque then an angular sequence. The service manual states to replace the rod cap bolts when they are removed. The head bolts are a different story. The head bolts are not torque to yield - they are only replaced due to the microencapsulated loctite threadlocker.