head bolt torque 41ft. lb. + 90deg.?

[fastback4]

1997 3100 Monte. 41 ft. lb. doesn't seem like very much torque for a head bolt, but adding 90 degree's more to the bolt on the second pass seems like a lot. So whats the final torque? Do you mark the head bolt, call that 0 degrees, and turn 90 more degrees from that point?............Tom

[geldartb]

off on your numbers a bit but here are the correct specs.

Tighten the NEW cylinder head bolts to 60 Nm (44 lb ft) in the order shown. Use the J 36660-A torque angle meter in order to rotate the cylinder head bolts an additional 95 degrees .

[fastback4]

Here's what this site's home page under engine specifications has for bolt torque sequence and foot pounds applied.
First Pass 55n 41ft.
Final Pass Add 90 degrees

*Manifold Side*
6 2 3 7
Notice the circular torque sequence versus your staggered sequence?
5 1 4 8
* Outer Side *

[geldartb]

the torque sequence was revised so depending on when that was written on here it most likely was written before the specs were revised.

date on this article for the revision say 08 so most likely the stuff on this site was written before that.

INFORMATION

Bulletin No.: 02-06-01-003B

Date: April 15, 2008
Subject:
Revised Cylinder Head Bolt Torque Specification and Tightening Sequence

Models:
1994-1998 Buick Skylark
1994-2002 Buick Century, Regal
2002 Buick Rendezvous
1994-1996 Chevrolet Beretta, Corsica, Lumina APV
1994-2000 Chevrolet Camaro, Lumina
1994-2002 Chevrolet Monte Carlo
1997-2002 Chevrolet Malibu, Venture
2000-2002 Chevrolet Impala
1993-1996 Oldsmobile Ciera
1993-1997 Oldsmobile Cutlass Supreme
1994-2002 Oldsmobile Silhouette
1996-1999 Oldsmobile Cutlass
1998 Oldsmobile Achieva
1999-2002 Oldsmobile Alero
1994-2000 Pontiac Firebird, TransSport
1994-2002 Pontiac Grand Am, Grand Prix
1999-2002 Pontiac Montana
2001-2002 Pontiac Aztek

with 3.1L or 3.4L Engine (VINs J, E - RPOs LG8, LA)

Supercede:

This bulletin is being revised to include a Notice advising that the cylinder head bolts are NOT to be re-used. Please discard Corporate Bulletin Number 02-06-01-003A (Section 06 - Engine).
Notice: This component uses torque-to-yield bolts. When servicing this component do not re-use the bolts. New torque-to-yield bolts must be installed. Re-using used torque-to-yield bolts will not provide proper bolt torque and clamp load. Failure to install NEW torque-to-yield bolts may lead to engine damage.

The cylinder head bolt torque and tightening sequence have been revised. This revision has been made in the SI. If you are using a paper version of this Service Manual please make a reference to this bulletin on the affected page.

The revised specification is as follows:

this and the specs i posted were pulled from my alldata subscription

[fastback4]

Thanks........Tom
By the way. I used your new numbers for torquing the heads + 95 deg. I used a dial foot pound torque wrench and after adding the 90 degrees, final torque was at around 97 foot pounds...This number is what i got. Please do not use it for a replacement of actual bolt degreeing.

[Jcdew67]

I realize this is a very old post but I have the same question but I have a 1996 3.1 engine with a (M) code.
The link geldartb posted only says
"with 3.1L or 3.4L Engine (VINs J, E - RPOs LG8, LA)" but it does not say (M)

I keep seeing 33ft lbs +90 degrees for my engine.

Aren't the heads basically the same outside of intake locator holes and size? So why would the torque be different?

I am putting redone heads on my 96 Monte(engine actually came out of a 94 Buick) so I have ball and stud rockers.

Checking Rock Auto the head bolt numbers from Fel-Pro are different BUT if you examine cylinder head replacements while the heads look the same the numbers are different.(I have the 10154743 heads btw)

Do the new torque specs apply to the (M) also?
Thank You

[3400-95-Modified]

Might just be revised torque that they found would work better. It would probably work out fine since that number sounds familiar to what I've done in the past.

[Jcdew67]

Ordered new Felpro head bolts,I ordered them for a 1996 Monte Carlo ,On that box it said

ES72892
3.1L Vin-J 2000
3.4L Vin-E 1996-00

Now it seems that set is given for even a 1996 Monte Carlo Vin-M it seems so I am going to go with the revised specs,part of me is scared cause I read on some forums a guy had his break doing revision.I can't see how that happened as these bolts look the same as the ones I took out.

I know I am just being nitpicky

[3400-95-Modified]

The bolts are probably all the same. I highly doubt you will break them. Just send her in!

[robertisaar]

i just did the 44+95* on my 95 3100 a couple weeks ago, didn't kill any bolts. using fel-pro permatorque severe duty headgaskets.

[Jcdew67]

Good to hear that someone has done this on a 95.
I went with the Felpro 9957 PT due to a tight budget,I would have loved to get the Severe Duty but you know the drill.
Even the FelPro ES72892 Head Bolts I bought have a instruction sheet with the 44+95*

The revision is a little confusing.
A lot of cars on the list only offered the "M" 3.1.
I have read several websites that are saying it only applies to (VINs J and E) but that obviously is wrong and it does also apply to "M" VINs otherwise 85% of the cars listed would be wrong.

Does this mean that they were wrong when they made the old torque values and it wasn't stretching the tty bolts enough so they revised it?
The same with the tightening sequence?

[Jcdew67]

I am back yet again,I am one of those people that keep thinking of things too much.lol

If the new bolt specs are (44 ft lbs then 95 degrees) but someone only does what the manual says(33 ft lbs then 90 degrees) wouldn't they be under torquing and thus not stretching it? This would make the gasket/head more prone to failure I assume and possibly why they revised it.

I always assumed stretch doesn't happen until you went the +degrees,when does a tty bolt start the point of no reuse?

[robertisaar]

how old is your manual? none of the info I'm pulling up on alldata is showing that 33+90* was ever used on a gen3 60V6.

[Jcdew67]

One of them is a Haynes manual revision 2005.
The Felpro website also lists 33ft +90. http://www.fme-cat.com/
Several websites out there also list the same.

Now,I used the revision of (44ft lbs +90*) and revised torque pattern since every place I go to and order Felpro head bolts I get the choice for the same exact ones and I would think those specific bolts are made to start stretch at or after 44 ft lbs.
I believe that tty head bolt stretch doesn't happen until you go the +degrees after the initial torque of course I could be wrong.

If someone went by what Felpro has posted then they would be under torquing the head and more prone to failure I would think.

[robertisaar]

the gen2(87ish-94ish) engines list 33+90*, but all of the gen3 applications I'm looking up are showing 41+90* or 44+95*, depending on year and/or TSB revision.

I think somebody carried over torque specs without updating them.