: 97 N* Crank Pulley / Oil Pump Torque setting



ToMuchWork
03-15-12, 02:39 PM
I am rebuilding a N* out of a 97 STS. I have installed the Head studs from northstarperformance. Thank you northstarperformance for your kit. I feel confident that I wont have to worry about any HG issues with this motor.
I would like to feel confident that I am not going to have other issues also and one of the things I am worried about is the oiling system on this motor. Not sure why Cadillac went with the torgue type oil pump drive system knowing that gear driven oil pumps have been used successfully for decades. Their engineers are smarter then I am and it is what it is and I just have to deal with it and make it work so I dont have any oil related issues. With that said I have a question about the CORRECT TORGUE on the crankshaft pully bolt that gives the oil pump its needed torgue.
I was reading a old post on cadillacforums and the guy that was working on his N* was having a problem getting the crank bolt off. One of the posts by "Ranger" on the 1st page is posted below and states that he thinks the bolt is held on with "300lbs" of torgue.

This is the link to the old post - http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/126253-97-etc-n-head-gasket-project.html

Below is the reference by Ranger

Ranger (http://www.cadillacforums.com/forums/member.php?u=12088)

http://www.cadillacforums.com/forums/images/statusicon/user-offline.png Cadillac Owners Member http://www.cadillacforums.com/forums/images/ranks/platsupport.gif
http://www.cadillacforums.com/forums/images/ranks/cadillac-m.gif



Re: 97 Etc N* Head Gasket Project


If I remember correctly, that bolt has 300+ lb/ft of torque. Even more important than removal is the proper installation torque. Under torque it and you'll have oil pressure problems. This may not need saying, but better now than later.

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The instructions that I have from ALLDATA is to Crank the bolt down to 37 ft. lbs then a additional 120 degrees. It would seem to me that this may give the bolt about 100-125 ft. lbs or so "just guessing" but not 300 ft. lbs. So is this the correct procedure for a 97 N*? I definitely dont want to have a problem with the oiling system on a new rebuild!! Any info would be much appreciated.

Thanks,

Submariner409
03-15-12, 03:04 PM
The instructions you have for harmonic balancer bolt torque are correct. You'll become a believer when you apply that 120 degrees of additional rotation - and you must lock the engine, using the flexplate toothed ring, to get even close to that 120 degree mark.

ToMuchWork
03-15-12, 07:00 PM
submariner409,

Thanks for the info. I have a 1/2 inch breaker bar that is about 2 1/2 foot long. Think that will get the job done?

Ranger
03-15-12, 09:31 PM
I would not swear to that 300, but it is very high. Don't worry about torque. Just follow the torque and degrees you have.

A 2 1/2' breaker bar should do it. You can always add a pipe to it if you need more.

maeng9981
03-15-12, 10:57 PM
:yeah: 100-125 ft lbs won't do it. Follow the factory spec and it will have no problems.

ToMuchWork
03-16-12, 12:43 AM
Ranger,

Thanks for chiming in on this, really appreciate your opinion. It was your reference in the older thread about getting the torgue correct that really made me think that I better ask questions and be sure I had the right procedure or I may be throwing alot of time and money down the drain. I have been looking at the flywheel holder J 39411. I have seen one on ebay for $89. They look like something that I may be able to make for a few bucks but I am not sure how it mounts on the block. Looks like they have 2 holes that line up with holes on the block that are probably transmission bolt holes. Does anyone know which holes these are so I can use the correct holes when making this tool? I sure dont want to take a chance of breaking the block by using the wrong holes. Thanks. BTW I have attached a pic of my N*. The studs look pretty cool. Kind of wish I didnt have to cover them up with the heads ~lol

88278

ToMuchWork
03-16-12, 01:21 AM
Well noticed that my engine pic didnt upload, darn :o Lets try it again and hopefully it works.

Ranger
03-16-12, 09:55 AM
Having never done the job I am not exactly sure where the holder attaches. There are several people who have and I'm sure will chime in.

vincentm
03-16-12, 10:13 AM
Newly studded Northstar blocks are such a beauty to look at

Submariner409
03-16-12, 10:51 AM
The flexplate locking tool goes in place of the starter motor.

ToMuchWork
03-17-12, 10:17 AM
Thanks submariner409 for the info