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NS300l Northstar Thread Kit


TheCaddyman

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Here is more info

http://www.huhnsolutions.com/

They make the following statement in italic in their FAQs. I disagree with it, the bolts are tightened to a point of stretching, they can not be re-used for that reason, in addition the bolts are coated

5. Can I re-use the original head bolts?

To insure an even torque when re-assembling the head, GM recommends new head bolts. Head bolts, over time, are put though many heat cycles, that could effect their elasticity, especially if the engine has been overheated

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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OH. I assumed you used Timeserts. That's what I get for multi-tasking lol

KIT_006.jpg

Interesting: What makes the NS300L™ Insert System more reliable than the GM-approved insert?

The NS300L™ is a high quality high-strength insert, with a much courser external thread, having over three times more thread engagement within the aluminum block than the GM-approved "first repair" insert and over two times that of the GM-approved "second repair" insert.

For sale on ebay: http://shop.ebay.com/i.html?_nkw=NS300L&am...from=&_ipg=

Bruce

2023 Cadillac CT4-V Blackwing

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The bolts do stretch. Torque to yield bolts. Plus there is a coating on the threads.

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I remember the guru stating the head bolds were not torque to yield bolts - the only reason they could not be reused was there was no way to apply the microencapsulated threadlocker on the threads and under the bolt head in the field. That's why new bolts are recommended.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I believe the following was posted by the Guru over at the other forum, this I believe is what Kevin recalls

The Northstar head bolts are not torque to yield fasteners. They are recommended to be used only once since they are coated with a microencapsulated thread locking agent that acts as a thread lubricant during assembly and a locking agent once the bolt is installed. There is no practical way to reapply these coatings on the threads and under the head of the bolt so new bolts are recommended when the head must be removed. Otherwise, the bolts themselves are fine.

Torque to yield bolts will stretch permanently when they are properly tensioned. If you measure the bolt, install it and then remove it you will find that it is now longer even when not under load. Those types of bolts cannot be reused as they keep stretching and then break. The Northstar head bolts are not like that despite common rumor.

The Northstar bolt tensioning is spec'd as a torque and angle. Torque and angle provides a much more accurate means of tensioning a fastener compared to a pure torque spec. Just because the fastener is spec'd for torque and angle does NOT mean that it is a torque to yield fastener.

Torque and angle specs even work great on studs as the torque and angle spec, once properly developed, is far more repeatable and accurate than pure torque. Ask ARP.

Any one who thinks that the Northstar head bolts stretched and caused the head gasket to fail is nuts. They didn't measure the bolts originally at the factory so how on earth could anyone suppose that the bolt "stretched" (since they didn't know how long it was originally...) I think they dreamed up this idea of the bolts stretching to explain something and posted it as fact

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The Northstar head bolts are not torque to yield fasteners. They are recommended to be used only once since they are coated with a microencapsulated thread locking agent that acts as a thread lubricant during assembly and a locking agent once the bolt is installed. There is no practical way to reapply these coatings on the threads and under the head of the bolt so new bolts are recommended when the head must be removed. Otherwise, the bolts themselves are fine.

I recall that as well.

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I dont know what made me think that those bolts were stretched when torqued, I wish knew where I got that idea.... it was not until today when Kevin posted that I realized that they are not stretched.

Kevin, read this article for me, I am especially interested in their opinion about studs. I want Jake to read the article also. They come to a conclusion about studs vs bolts and a tightening methodology. I found the article informative

http://www.pbase.com/stealthfti/hb

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Another thing to consider with "one size fits all" kits like these is that NorthStar head bolts are NOT one size fits all... As has been covered repetitively, NorthStar Head bolts come in three flavors...

The good, 2004 and newer blocks, long coarse thread bolts,

the bad 2000-2003 long fine thread and

the ugly 1993-1999 short fine threaded bolts.

From the Ebay add

"The NS300L™ Insert System is designed to work in the "93" through "2005 4.6L Cadillac Northstar engine, and the "95" through "99" 4.0L Oldsmobile Aurora Northstar engine"

I can't see how, since 2004 and 2005 head bolts require a different thread pitch and 2000-2003 head bolts require a different length.

The ebay add then adds

"Although the M11x1.5 is the preferred thread for torquing, in 2004 the Northstar went to a M11x2.0 head bolt thread in an attempt to fix the issue of the threads stripping from the block. The NS300L™ Insert System will work very well in the 2004-2005 4.6L engine, but must be used in conjunction with the head bolts made for a 2000 Northstar. The head bolts for the 2000 Northstar are the same length and diameter as the 2004-2005 head bolts, the difference is the 2000 Northstar has the M11x1.5 thread...the same as the NS300L™ insert. For this reason, the head bolts must be torqued to the latest specs required for the 2000 Northstar. "

So if you have a newer block you have the added expense of a set of head bolts too. I'm not sure how he deals with the "long/short" bolt problem of the pre/post 2000 blocks I suspect that this option might actually reduce the amount of bite that the longer bolts have in the block.

BTW the fine threads might be better for torquing but the coarse bolts have proven themselves to be MUCH stronger on both NorthStars and the LS family of engines... I'm not crazy about a kit that requires people to move backward to weaker bolts.

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Easin' down the highway in a new Cadillac,

I had a fine fox in front, I had three more in the back

ZZTOP, I'm Bad I'm Nationwide

Greg

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I dont know what made me think that those bolts were stretched when torqued, I wish knew where I got that idea.... it was not until today when Kevin posted that I realized that they are not stretched.

Kevin, read this article for me, I am especially interested in their opinion about studs. I want Jake to read the article also. They come to a conclusion about studs vs bolts and a tightening methodology. I found the article informative

http://www.pbase.com/stealthfti/hb

Mike,

It was an interesting read. If I would have known about Northstar Performance 4 years ago, I might have considered studs when I repaired the STS I bought in North Carolina. The Timeserts are holding up just fine 46,000 miles later though...

Norm will need to revise his product to keep up with the engineering changes that have occured in the Northstar engine.

When are you planning on repairing your car?

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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  • 2 years later...

I will be using the NS300 kit over the timesert kit for two reasons. First as was mentioned there are two timesert kits the first and the second try. the second is not the bigsert but an oversized insert in case the original fails as quite a lot of them do. Those for the timesert say that it is GM certified but do not mention that over half of the dealers will not even repair the Northstar engin because the amount of repairs that don't work. Everyone agrees Norm's kit is too high priced but it is the best in my opinion.

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:welcomesmiley:

Oldwbuck, please let us know how your experience with your repair goes. I disagree with your assessment of Timeserts; the timesert is the proscribed thread repair solution by GM. However, I am interested in real world assessments of the Norm inserts and other solutions and I wish you well on your repair.

Please do share pics of the repair and let us know you progress in a new thread.

Bruce

2023 Cadillac CT4-V Blackwing

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I believe that the Northstar and most other modern all-aluminum production engines use torque-and-twist bolts. The initial torque bottoms the bolts and brings the head gasket to full contact. The total torque angle for all stages of tightening after that, with the thread pitch, give a stretch length for the bolts. The stretch length, along with the length of the bolts to the threads, the thickness of the bolts along that length, and the alloy give a spring constant. The spring constant times the stretch length gives the clamping force.

This does two things: the clamping force is very uniform across all the bolts of the same type, and the expansion differences between the engine and the bolts is taken up by changes in bolt stretch with no permanent change while maintaining good clamping force under the engine operating temperatures.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I believe that the Northstar and most other modern all-aluminum production engines use torque-and-twist bolts. The initial torque bottoms the bolts and brings the head gasket to full contact. The total torque angle for all stages of tightening after that, with the thread pitch, give a stretch length for the bolts. The stretch length, along with the length of the bolts to the threads, the thickness of the bolts along that length, and the alloy give a spring constant. The spring constant times the stretch length gives the clamping force.

This does two things: the clamping force is very uniform across all the bolts of the same type, and the expansion differences between the engine and the bolts is taken up by changes in bolt stretch with no permanent change while maintaining good clamping force under the engine operating temperatures.

Very nice summation of the attached article. Well said.

I would like to add that regardless of the type of bolt repair used on an all aluminum engine, if the bolts or studs are tightened to yield, they will also fail. The keys to a good repair is the spring action and the elimination of friction during the tightening process.

Never underestimate the amount of a persons greed.

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Thank you, JohnnyG. Of course, you are right about torque-to-yield and head bolts on all-aluminum engines. The problem with TTY is that, once the bolt has begun to yield, it will continue to yield as the engine warms up and the aluminum expands more than the bolt, repeatedly, with less clamping force each time.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I forgot to mention torque-and-twist studs, which work the same way as TAT bolts in terms of managing clamping force over the life of the engine.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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  • 5 years later...

Going to try my luck at head gasket repair on my 99 deville-I have a timesert kit for newer style engine with 2.0 thread pitch-can anyone tell me if the short bolts on the newer style engine are the same as the all short bolt block 99 engine except for the thread pitch-if so then I can use this kit and the newer style bolts-save me from buying the other kit

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There are three Northstar TimeSert kits, one for 1995-1999, one for 2000-2003, and one for 2004-up which you have.  The difference between the first two is the depths of the head bolt holes, which affects the guides for drilling and tapping, and I would not expect the head bolt hole depths for 2004-up to be the same as 1995-1999.

There are people here who can lend, rent or sell the kit for 1995-1999 minus the TimeSerts themselves, which are available separately.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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The kits are available as a rental. See: 

http://ledfix.com/j42385toolrental.html

We do not provide the inserts. The insert used on that era Northstar is the 11155. Those are easy to get on Amazon for $3.66 each. 

 

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Maybe you can sort it out with these...The Timesert instruction sheets. 

Be aware Timesert changes the link address almost weekly. Anyway..

1994-1999 J-42385-500 kit: http://www.timesert.com/html/northstar.pdf 

2004-newer J-42385-2030 kit: http://www.timesert.com/html/NORTHSTAR2004-PV8-headbolt.pdf

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