Intake Manifold Bolt Torque Spec

[jdwarns]

Location: Annapolis, MD
Boat: 2006 Tahoe 215 I/O
Engine: V6 Mercruiser 4.3l TKS
Engine Serial: OW344165

I'm bolting everything back together after a longblock rebuild and had a question on the torque spec for the intake manifold.
Service Manual #25 indicates 11 lb-ft in the table on page 3A-2:

and then later indicates 35 lb-ft on page 3A-25:


Any assistance in getting the correct torque spec will be greatly appreciated.

~ Jesse

 

[dubs283]

Re: Intake Manifold Bolt Torque Spec

35 lb/ft

needs to be torqued in a specific pattern too

 

[jdwarns]

Re: Intake Manifold Bolt Torque Spec

Thanks dubs283. 11 lb-ft did seem a little low. Think it was a typo in the table?

 

[Don S]

Re: Intake Manifold Bolt Torque Spec

DO NOT torque to 35 ft lbs. You will rip the threads out.

For that manifold 11 ft lbs is correct.

Here is the Mercruiser service bulletin explaining it.

View attachment Intake torque.pdf

 

[jdwarns]

Re: Intake Manifold Bolt Torque Spec

DO NOT torque to 35 ft lbs. You will rip the threads out.

For that manifold 11 ft lbs is correct.

Here is the Mercruiser service bulletin explaining it.

View attachment 142680

Can't thank you enough, Don. Glad I waited for you to chime in.

 

[dubs283]

Re: Intake Manifold Bolt Torque Spec

shows what i know!!

thought all gm intakes were 35 lb/ft like the older ones

 

[johnslade]

I apologize in advance for resurrecting and old post. I searched through the forum and this was the closest to my search.
I am wondering if the torque specs and toque sequence is the same for a 4.3L Carb Alpha/Bravo SN 0W638447. I appreciate any and all insight on this.

 

[Lou C]

The 35 ft lbs is for the Pre Vortec engines (intake has 12 bolts; up to 1995). The 11 ft lbs is for the Vortec engines (intake has 8 bolts; 1996 and up).