Serving Professional Engine Builders & Rebuilders Since 1964




Survey Results
Do you utilize "green" strategies in your shop?












 
10/11/2012
Click on a thumbnail to see the full-size image

GM Cylinder Head Tightening Specification Clarification



This bulletin was issued to clarify GM 4.0L and 4.6L cylinder head tightening specifications found in previously published service manuals.

 

Affects:

1993 Cadillac Allante, Sixty Special (FWD)
1993-96 Cadillac Fleetwood
1993-99 Cadillac DeVille, Eldorado, Seville
1994-99 Cadillac Concours
1995-99 Oldsmobile Aurora
with 4.0 L or 4.6 L Engine (VINs C, Y, 9 - RPOs L47, LD8, L37)

Cylinder Head Installation

Torque specification and sequence for the cylinder head bolts (1-10) using a torque angle meter (J 36660-A):

1. First Pass - 30 ft.lbs. (40 N-m)

2. Second Pass - 70 Degrees

3. Third Pass - 60 Degrees

4. Fourth Pass - 60 Degrees (190 Degrees total)

The torque specification for the three front M6 cylinder head bolts is:

106 in.lbs. (12 N-m)

Some or all of this information was provided by the Automotive Parts Remanufacturers Association (APRA). For more information on technical bulletins available through APRA call 703-968-2772 or visit www.AutoBulletins.com.

Comments:

Thanks for the info for this Engine Blocks & Cylinder Heads specifications. This is a great guide for Cadillac owners.

by: engineman   5/17/2011
 
Oil Seepage from Cylinder Head on BMW E36 with M42 Engine
Oil seepage may occur from the left side of the cylinder head at the lower mounting bolt for the intake manifold support bracket due to a casting shrinkage issue....

Spiral-Reamed Valve Guide Misconceptions
There has been some confusion about the function of the threaded portion of the inside diameter of certain spiral reamed valve guides....













Babcox Media • www.babcox.com
3550 Embassy Parkway
Akron, OH 44333
330-670-1234 • (FAX) 330-670-0874