bottom end on my northstar has timecerts on the mains

it was done by a caddy lead mechanic

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Question wonder and be wierd
are you kind?

I've timeserted both head bolts and mains in my block. It's a '93 block.

quote Originally posted by Russ544:I've noticed CHRF uses head studs on many of their high HP northstars.

Well, slap my momma! I clean forgot about CHRFAB. Naturally, if anyone has head studs, or at least a source for them, it would be CHRFAB. Guess I'll add that to my list of things to buy from 'em ... Holley Commander, longer plug wires, head studs.

I also am at a loss in why AJ doesn't recommend studs in lieu of headbolts. I am hoping I will never have to pull one of these heads after my rebuild ... well, maybe not "never," but at least for another 150K miles ... but if or when I do, I'd much rather break a nut loose than 10mm headbolts. BTW, and IMHO, 10mm seems rather small. If there were five or six headbolts around each cylinder, I could see using a relatively small diamter headbolt, but with only four?

PS to AJ - I got your e-mail. Thanx!

[This message has been edited by WAWUZAT (edited 01-17-2007).]

Damn, there are so many engineers in this thread, you guys should just get together and build a real engine instead of trying to fix all the northstar's perceived flaws.

quote Originally posted by Zac88GT: I still dont see what your trying to say here. I was thinking useing headstuds would be a great idea because then you dont have to undo the bolt from the block, you just have to take the nut off the top of the stud. It would eliminate the possibility of haveing the threads in the block come out with the bolt.

With a properly installed timesert, this is not an issue.

From CHRF:

quote Pulled Head Bolts If you have pulled the head bolt threads, we install time serts. From 1 to 20. $500 labor for all 20. Now you can take the head off and on as many times as you want without the worry one will not torque properly.

If you have timeserts backing out, I would suspect they were not installed properly, or the threads were not cleaned of the tapping oil well enough for the loctite to do its job.

[This message has been edited by ryan.hess (edited 01-17-2007).]

I will take some other pictures of this lip or ridge that is not to be removed. My battery died in the camera.

It is close to the thickness of a razor blade

quote Originally posted by WAWUZAT: I'd much rather break a nut loose than 10mm headbolts. BTW, and IMHO, 10mm seems rather small. If there were five or six headbolts around each cylinder, I could see using a relatively small diamter headbolt, but with only four?

They are 11mm bolts.

quote Originally posted by ryan.hess: So.......... what's the outer thread on a northstar head bolt timesert?

11 x 1.5 STI.

quote Originally posted by AJxtcman: What makes a TIMESERT insert better than a good hole with out one? Why would you insert all the holes? We have all three engine support fixtures full right now. It isn't like we don't fix them. We are down to 8 Techs right now and we are the largest Cadillac dealer in the state.

Didn't you say you have a lot of timesert/headgasket repeat repairs? THAT's why you would insert all the holes.

With the cyclical heating/cooling of the heads and block, there are enormous pressures placed on the head bolt threads. Many times more than the force trying to blow the heads off coming from the in-cylinder pressures. Just because the aluminum threads look (and torque) okay, does not mean they are okay. Aluminum work hardens.

quote Originally posted by ryan.hess: Didn't you say you have a lot of timesert/headgasket repeat repairs? THAT's why you would insert all the holes. With the cyclical heating/cooling of the heads and block, there are enormous pressures placed on the head bolt threads. Many times more than the force trying to blow the heads off coming from the in-cylinder pressures. Just because the aluminum threads look (and torque) okay, does not mean they are okay. Aluminum work hardens.

The treads on the outside of a TIMESERT insert does not make an improvement! It is a band aid!!!! If you have done a few you would no that the grey powder that comes out when you drill the block is not a good sign and will not hold a TIMESERT. The blocks are no good in 95-99. This is a fact and GM now offers a short block for that application.

1995-1999 Cadillac Concours, Deville, Eldorado, Fleetwood, Seville 1999 Cadillac SLS,STS
A new short block assembly, part number 89018105, has been released to service 1995-99 Northstar LD8 and L37 applications

Another issue
4.0L L47 , 4.6L LD8 , L37 LH2 Engine Coolant or Oil Leak - kw back block cylinder drive head intake main manifold pan porosity rear #PI01771 - (02/23/2004)
Some vehicles equipped with the Northstar Engine may experience an engine coolant or engine oil leak.The coolant or oil may be appear to be leaking from the engine block at an area other than a gasket surface.

Recommendation/Instructions:
If all published diagnosis has been performed without success, then the engine block should be inspected for a condition of porosity. If the leak is found to be caused by porous engine block, the only GM validated repair procedure consists of the replacement of that engine assembly. No attempt should be made to repair the engine block (i.e. epoxy).

quote Originally posted by AJxtcman: .

I'm always facinated by the user names people use. let me guess: AJ (your initials) xtc (extacy) man ?

hope I'm wrong, as MDMA will cook you.
Russ544

I am almost 40. The name has been with me for some time. At a few shops I have been called Pint-stine. I am a little height impaired and about 10 years ago I could rattle of all sort of TSB#, spec and part #. The other Half is for Einstein. My memory isn't as good as it used to be. Mostly from when I bounced my head off the pavement at about 80MPH "CBR600F". The XTC MAN is something else.

Well, now I'm worried!
My 97 Northstar smoked a bit in the doner car and the plugs showed some oil burn, so before the exercise of installation I had a local shop "fix" it. They installed new rings and had the heads done at a local head shop. The valves were ground and new seals and guides were installed. Despite reading about the headbolt issue on other threads and questioning the shop, they insisted that the block threads were good after inspection and none required inserts. I was also advised that they measured the bolts for stretch and they were also good, so the original bolts were reused. None of the headbolts pulled during torquing, and I was reluctantly convinced to accept all was good. My acceptance of this is still very reluctant, and I am nervous about a head leak.
I have not fired the engine yet, and have a good portion of the install to complete before I do. Mabe in the spring if I'm lucky.
QUESTION: Does informed opinion support my concern or am I likely OK? I’d hate to have to pull the heads again.
Dave

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Daviero - 88 N* GT

As long as that's the only time the heads have been off, you're probably fine.

I see that Will said that it was not esential to change the head bolt. I have always and thought that that statement was alittle goofy. I have a training booklet from 95 for the 4.0L and 4.6L in front of me. It says to discard the bolts. Then it has a ! IMPORTANT "note" That states do not reuse bolts because of a special coating for bolt retention "threadlocker". No mention of streching. I just looked up the service proceedure for a 97. In red it states do not reuse head bolts. Then in red it says do not reuse head gasket. Then in red it states You must clean the thread sealant material from the cylinder head bolt holes in the cylinder block. Failure to do so could cause false torque readings during reassembly. I replace them because they come in GM kits and I would not like to clean them or take a chance on having a bad one. Sometimes they are rusted. I recently rebuilt a 3.6L high feature engine. Ok they updated the info. IT was a note on a set of bolts. Important: The side main cap bolts originally have a sealant on the flange of the bolt head. NEW bolts must be used. If OLD bolts are used thead sealer must be used. I ordered new bolts and they had NO sealer on them. I have always and will always replace them. I feel that Will is correct and they can be used two times.

My understanding was that the manual said replace the bolts because of the coating. The bolts themselves are not torque to yield.

The question though, is how do you know it's torqued properly without using the threadlock/lubricant?

And don't new head bolts come with the head gasket kit?

So I'm safe if I don't timesert the block and use new headbolts and gaskets?

quote Originally posted by ryan.hess: The question though, is how do you know it's torqued properly without using the threadlock/lubricant? And don't new head bolts come with the head gasket kit?

Nowadays, a lot of manufacturers have gone to a low initial torque value for the first pass through the tightening sequence. Then that's followed by one or two more passes that turn the fasteners a specified number of degrees. The final tightening is NOT to a torque value. This makes lubricant on the threads a non-issue, and provides more uniform tension among the bolts or studs. Anytime I've purchased head gaskets, or a complete upper-end gasket kit, head bolts were never included ... and I'm sure vice versa is true, too.

i'm pretty sure the bolts that you tighten up to whatever torque spec and then 90* or 1/2 turn or whatever they specify are torque to yeild bolts. They're supposed to be replaced after 2.-3 torqueings i think. But it was said earlier that the northstar bolts aren't torque to yeild and the reason they have to be replaced is because of the threadlocker?

quote Originally posted by Zac88GT: But it was said earlier that the northstar bolts aren't torque to yeild and the reason they have to be replaced is because of the threadlocker?

Correct.

And I don't know about aftermarket sets, but the GM set comes with head bolts.

quote Originally posted by AJxtcman: I will take some other pictures of this lip or ridge that is not to be removed. My battery died in the camera. It is close to the thickness of a razor blade

Do you know if the 93-95 engines pistons are at 0 zero deck or in or out the hole?

I'm trying to rase the compression of my engine.
Thanks,
JG

When I rebuilt my Quad 4, nearly every bolt is torque to yield. Even the main caps. My enigne was put together using a 3/8 torque wrench, because my dads 1/2 doesnt go low enough for 75% of the bolts. I think the main caps were like 20lb-ft, then 180º. The only bolts I replaced were the head bolts. I work at a parts store, and there is no listings for the other bolts. Other bolts that were torque to yield were: Cam tower bolts (very low torque, like 5 ft/lbs, then 90º), flywheel bolts, crank pulley bolt (we didnt tty that bolt, kind of hard to do that when the engine is off the engine stand, on a hoist, and you are turning a bolt on the end of the crank 270º from like 50lb,ft), I also think the connecting rod nuts were tty.

Forgot to add, Quad 4 is a cast iron block, the only bolts that went into aluminum were the cam tower bolts, all 20 of them.

[This message has been edited by befarrer (edited 01-19-2007).]

My headgaskets were GM and did not come with new bolts. The block threads were chased prior to reassembly. I don't know if locktite was used upon assembly. What's that addage about wanting something done right, so researching and doing it yourself is often the best alternative?.........
I hope you're right Will, but I've no way of knowing if the heads have been off already - the doner car was a rearended wreck when I bought it. We see upon fire up I suppose...
Dave.

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Daviero - 88 N* GT

quote Originally posted by AJxtcman: A new short block assembly, part number 89018105, has been released to service 1995-99 Northstar LD8 and L37 applications

AJ, do you happen to know how much that short block costs?

Joe

I know that the cost was under $4000. I can not remember if that was Cost or List price.

quote Originally posted by AJxtcman: I know that the cost was under $4000. I can not remember if that was Cost or List price.

http://www.gmpartsdirect.com/results.cfm
GM PART # 89018105
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00
GM LIST: $5,208.66
OUR PRICE: $3,118.96
S&H $686.17
TOTAL $3,805.13

quote Originally posted by Zac88GT: i'm pretty sure the bolts that you tighten up to whatever torque spec and then 90* or 1/2 turn or whatever they specify are torque to yeild bolts.

This is not correct.
Torque + Angle is NOT THE SAME AS Torque to Yield.

Torque + Angle is a procedure to apply a very precise tension to a fastener.
Torque to Yield involves precisely applying to a fastener a tension greater than its elastic yield stress. This allows bolts to be smaller to do the same job, as long as the metallurgy is very consistent.

The ONLY bolts I have seen with T+A specs that are TTY are the Northstar rod bolts. The main bolts are over 6 inches long, tighten 90 degrees and are NOT TTY. The rod bolts are 2.5 inches long and tighten something like 120 degrees... a LOT more strain on the fastener. Using the smallest possible fastener in a conrod is important because smaller fasteners are lighter and reduce recip weight.

quote Originally posted by AJxtcman: http://www.gmpartsdirect.com/results.cfm GM PART # 89018105 CATEGORY: All PACK QTY: 1 CORE CHARGE: $0.00 GM LIST: $5,208.66 OUR PRICE: $3,118.96 S&H $686.17 TOTAL $3,805.13

Thanks AJ, at that price I think I'll take my chances with Timeserts.

Joe

You should read this thread. TIMESERT inserts do not work 100% of the time. The blocks are not very good from 96-99. If you drill out the block and find the metal to be grey, dull, powdery, chunky, NOT shiny then a TIMESERT will not hold. You can get a very good quality insert from Norm. They are listed on E-bay and are at the beginning of this thread.
Norm HUHN
Week days after 4:30 EST or weekends at 717-880-1888: or a message can be left on my toll free voice mail number 1-866-302-2762 and I will return the call. Voice mail is checked often.
I was just curious if we have done business before, I didn't recognize your name.
Thanks.
Norm

OK for all you non believers. Last night they gave me a head gasket job. I pulled it in my stall and heard the horn going off all the way in the shop. It was the radiator cap blowing the exhaust out. I raised the hood to find coolant in the valley. Needs an engine. last night I pulled the intake and pressurised the cooling system. This morning coolant was leaking from the head gasket into the valley. Needs an engine. I pulled the engine out and pulled the heads off for my manager. The rear head had 1 tight head bolt the three on the top towards the bell housing felt like the threads were gone. Needs an engine. I have lots of pics.

The one good hole on the bottom! Note the shininess


This is one of the top three. hard to see the pits



This is the worst hole. This is the start just for you guys. NEEDS AN ENGINE!


This points out the pits


More Pitts


Grey drill filings


The pick is in the pits after it was drilled


The pits marked out


another shot


filings of the tap. a couple of shinny pieces

so the 00+ n*s are the better engines to get? What kind of engine management can handle them? Sorry for the hijack, but I figure that most n* geniuses are gonna be in this thread and why start a new thread for 1 question. Thanks, Drew