92 LT1 Intake Torque

[Mark L.]

I'm doing the infamous gasket replacement on the 92 and I've seen several different intake bolt torque spec's. Perhaps it changed from 92 to 96? Anyone have a value they feel confident in? Thanks

[Terry M.]

Re: 92 LT1 Intake Torque

I have changed gaskets and RTV on the intake of both Caprices. My recollection is I used the torque published in the FSM for the B-body. I'll look when I get home and post what it is -- it has been a few years since I did the job.

Be sure you use a good quality RTV at the back. The heat from the exhaust tube to the EGR will toast the RTV back there resulting in the dreaded oil leak from he!!.

[Robert Z.]

Re: 92 LT1 Intake Torque

Mark,

Here it is right from Chevy's SM for the '92 LT-1 : Apply a 3/16" bead of RTV to front and rear of cylinder block extending 1/2" up each cylinder head to seal and retain the gaskets.

On the first pass, tighten the intake bolts to 8 N.m (71 in lbs.). Follow a circular sequence starting in the center and working out (according to the tightening sequence diagram).

On the second pass tighten to 26 N.m (19 ft. lbs.). Will I see you in Kissimmee?

Bob Z.

[Mark L.]

Re: 92 LT1 Intake Torque

Hi Bob,
Thanks for the reply. What you quote is one of the spec's that I have from my manual. I also saw a tech article that stated 35 ft/lbs, thus the question. It made me wonder if the spec was changed after 92. Hopefully Terry will have more to contribute and perhaps someone who has a later manual will take a look.
I will see you in Florida, in fact I think we are on the same C4 Team. It's always a pleasure to go south this time of year!
Mark

[Robert Z.]

Re: 92 LT1 Intake Torque

Mark,

There may well be a tech article on the topic. The Impala SS guys have a website (lost it from my bookmarks) that offer a world of info on the LT-1 engines, upgrades, mods etc. Perhaps Terry McManmon will have something on the topic. I did check the Corvette Action Center for any possible TSB's and did not uncover any that would supercede what the SM stated. The TSB's are current to at least 2005.

Bob

p.s. Looking forward to seeing you in Kissimmee

[Terry M.]

Re: 92 LT1 Intake Torque

There are three or four Impala SS sites. IMO the main one is www.impalass.com

I don't recall anything from there. There is a F-body site with a good how-to on the LT1 intake gasket change, but I don't have that link here at work. Google or some other search engine may turn it up if you try. I have to get back to work.

In thinking about Bob's posts it occurs to me that the 1994-1996 B-body LT1 has iron heads, but the Y-body (Corvette) and F-body (Camaro/Firebird) have aluminum heads. That material difference may, or may not, make a difference in the torque values given in the FSM. We will see when I get home.

[Mark L.]

Re: 92 LT1 Intake Torque

I looked at a few posts in the F Body LT1 arena and they state 35 ft-lbs for a 94. If anyone has a 94 or 95 Corvette SM take a look and let us know what you see. Thanks!
Mark

[Joe L.]

Re: 92 LT1 Intake Torque

I looked at a few posts in the F Body LT1 arena and they state 35 ft-lbs for a 94. If anyone has a 94 or 95 Corvette SM take a look and let us know what you see. Thanks!
Mark

Mark-----


The specifications in the 1992 Corvette Service Manual call for an initial pass of intake manifold bolt torque of 71 in/lbs. The second pass is specified to go to 35 lb/ft which is the traditional and long-standing torque value used for Chevrolet small block intake manifold bolts. This information can be found on pages 6A1A-28, 6A1B-37 and 6A1B-38, of the 1992 manual. The reference on page 6A1A-5 to a final torque value of 19 lb/ft is INCORRECT. The same intake manifold torque values apply to 93-97 LT-1 engines used in Corvettes and other GM cars.

For the end seals, I recommend using Permatex Ultra Copper RTV. This is a very high temperature RTV which also has excellent oil sealing qualities. The GM #1052366 specified in the service manual is no longer available, having been discontinued without supercession in August, 2000. However, even if it were available, I would not recommend its use for this application.

[Mark L.]

Re: 92 LT1 Intake Torque

Joe,
Again you provide the information to solve the mysteries!
As luck would have it I was looking at the page with the 19 ft-lb spec. I wonder if they corrected this in later year SM's. Thanks for the recommendation on the sealer.
Mark

[Terry M.]

Re: 92 LT1 Intake Torque

The 1995 B-body FSM gives the same intake manifold torque values as Joe listed above:
First pass torque to 71 in/lbs.
Final pass to 35 lb/ft

The torque chart at the end of the engine chapter shows the same values as above. It also lists the GM #1052366 for use on the ends of the manifold.

When I changed mine I did some research and found recommendations of 12345739 as of 11-21-02
12346141 as of 8-29-03.
The internet sources I found at the time, 2004 or 2005, were recommending the Ultra Copper Joe favors. Some individuals were reporting good results with "The Right Stuff."

The only comment I would offer is if you intend to have the car judged the color of the sealant might be of concern to you. My best recollection is that the original material on my end rails was light gray. If judging is a concern to you consider doing some more research.

The link to the how-to I was thinking of was to a Trans-Am site that is no longer on the net.