Alternative to Time Serts?

[joeb]

i would really be upset if i used studs and than the headgasket failed again. since its a new fix there is no history to go by. yes, studs are a known remedy but not used in a NS. you would really have to love the car to have the motor pulled again or even consider replacing the motor.

[MAC]

As most of you know, the head bolts get stretched after torgue is applied and are a one time use part.

WRONG. The head bolts do not get stretched nor are they a torque to yield bolt. The reason they are a one time use is die to the special threadlocker that is on the bolts. There is no practical method to apply this coating in the field so the procedures state to use new head bolts.

The Guru had a debate over what precisely was the likely reason why time-serts were needed after heads are removed. He stated that the impression of pulled head bolts was due to removing the bolts in the first place, which where locked into the block. When the bolts are removed the threads would strip and thus create the impression that they were deteriorating inside the block. He didn't state that this would be the case at all times, however, he did say that when a head gasket needed replacement the likely cause was deterioration of the head gasket rather than pulled head bolts. Again, he had quite an extensive debate over this issue and went into detail as far as what precautions GM took to coat the bolts and to create a protected pocket that would seal/shield them from antifreeze. He also stated that the most likely reason why head gaskets deteriorated was due to age, stress and/or neglected antifreeze. He also said that the more miles an engine has the greater likelihood that bolts would become even more difficult to pull as over time they actually become locked into place. Anyone who has done a head gasket job probably remembers that the head bolts are quite long, which is well beyond what would be required to withstand the maximum pressure that could be generated by the Northstar. The Guru stated that GM deliberately made the head bolts longer to insure they could withstand the maximum pressure and not pull, particularly in an aluminum block.

I wouldn't know if he would have changed his point of view since his original assessment of this issue, but I distinctly remember that he did state that head gasket failure was most likely caused by the head gasket itself and not pulled head bolts. I know that there are some that insist that anytime a head gasket blows it's due to pulled head bolts--however, chances are that pulled bolts is not the cause.

If anyone remembers something different, please let me know. However, I distinctly remember what the Guru said about this issue.

[dgaouette]

Good info guys! I do wish I knew you could reuse a partually torqued bolt and gasket as the last time I did one of these my son fell off his bike and by the time I get him cleaned up I had lost track of what bold was at what angle. I threw the bolts and gasket away and ordered a new one. That really hurt!! FOr what it's worth, I'll be sticking with the Time serts should I ever have the pleasure of doing another one of these motors. Untill then, I keep changing the heck out of that coolant on all three of my NS's. Other then oil burning and bolt pulling, you gotta love a North Star!!!!!!!!!!

[BodybyFisher]

Good info guys! I do wish I knew you could reuse a partually torqued bolt and gasket as the last time I did one of these my son fell off his bike and by the time I get him cleaned up I had lost track of what bold was at what angle. I threw the bolts and gasket away and ordered a new one. That really hurt!! FOr what it's worth, I'll be sticking with the Time serts should I ever have the pleasure of doing another one of these motors. Untill then, I keep changing the heck out of that coolant on all three of my NS's. Other then oil burning and bolt pulling, you gotta love a North Star!!!!!!!!!!

I agree, I was at a light before and just as the light turned green an impatient driver hit his horn and darted around me to the right giving me the finger, he had some sort of mini haha, with a road runner horn. I was like wait a minute, I didnt delay, I don't drive like a grandpa and this punk is on MY back giving me the finger? Luckily the road ahead was clear (Rt 347 Warren). I blew by him at about 90 still accelerating and let him hear my FOG HORN, that engine is amazing, I think he needed to change his shorts from the sheer noise of the NS

At 121,000 miles maybe I should treat her better, NOT!!!!

[NorthstarPerformance]

I am the man behind the SG102 stud kit. I developed this simply because I did not like the idea of inserts at all. I want to be able to give the engine WOT any time I feel like it without thinking "darn, better not, I don't want to blow the HG again"

There is way more thread area holding the head gasket down than anything else on the market. These will never pull up. Ever. Period.

If properly installed These studs will pass every torture test you can throw at them- you'll blow the piston through the oil pan before the threads will break loose and allow the studs to "pull up". Run a shot of nitrous if you like. And they will hold the correct torque on the head gasket through the heat cycles.

There will always be skeptics out there, I knew that when I put it on the market. The bottom line is, there is now a permanent and reliable repair for the Northstar engine. A custom CNC machined stud, that is the bolt and insert all in one. Not everyone will approve of it, but that's OK- I don't expect everyone to. But the ones that do approve, and use them or have me install them, will never have to worry about their HG's blowing due to failed bolts again.

I have done 48 Northstars to date, with ZERO failures. All engines were useable, even though some already had the first repair "timeserts" in them. Not one engine could not be used. I have great feedback from all of my customers. They love being able to WOT their engines at will. And I encourage this too- test them out.

One of my customers came to pick up his car. I took it for the first test drive after repair with him in it. He was nervous about the car overheating again (not trusting my work) so during the test drive I said "let me show you how nervous I am"- I gave it 10 shots of WOT all the way up to 70 or 80 MPH- then I had him convinced. The temp guage was right at 12:00 the whole time. (A '98 STS)

I used to make these on my lathe. Now they're machined in a fastener manufacturing shop- professionally done on a CNC machine and heat treated in a state of the art facility. I want accurate, precision studs- and that's what I use myself, and sell to N* owners. There is nothing cheap about these studs- if anyone knew what it costed me to have these studs machined they'd say I should charge more. I'm working with pricing but the bottom line is I want to offer a permanent, AFFORDABLE repair for the N* engine. It's all I do, 7 days per week. $549 USD, shipping included.

The only thing I'm still working on is a more precise drill fixture, and I'm working with another shop to develop a CNC plasma cut drill fixture.

I've got thousands of dollars invested in R&D on the N* and it's not limited to studs, but that's the base of my business.

I am confident in the product I sell. I know it will work and it will last.

To each his own. Whoever has confidence in my product will not be sorry.

[Bruce Nunnally]

and thanks for posting.

I hope you continue to have good success with the approach; I like to see new products for Cadillacs.

[NorthstarPerformance]

Thanks Bruce! Cadillac needs a good aftermarket parts line. The aftermarket is not big enough.

[OynxSTS]

The Guru had a debate over what precisely was the likely reason why time-serts were needed after heads are removed. He stated that the impression of pulled head bolts was due to removing the bolts in the first place, which where locked into the block. When the bolts are removed the threads would strip and thus create the impression that they were deteriorating inside the block. He didn't state that this would be the case at all times, however, he did say that when a head gasket needed replacement the likely cause was deterioration of the head gasket rather than pulled head bolts. Again, he had quite an extensive debate over this issue and went into detail as far as what precautions GM took to coat the bolts and to create a protected pocket that would seal/shield them from antifreeze. He also stated that the most likely reason why head gaskets deteriorated was due to age, stress and/or neglected antifreeze. He also said that the more miles an engine has the greater likelihood that bolts would become even more difficult to pull as over time they actually become locked into place. Anyone who has done a head gasket job probably remembers that the head bolts are quite long, which is well beyond what would be required to withstand the maximum pressure that could be generated by the Northstar. The Guru stated that GM deliberately made the head bolts longer to insure they could withstand the maximum pressure and not pull, particularly in an aluminum block.

I wouldn't know if he would have changed his point of view since his original assessment of this issue, but I distinctly remember that he did state that head gasket failure was most likely caused by the head gasket itself and not pulled head bolts. I know that there are some that insist that anytime a head gasket blows it's due to pulled head bolts--however, chances are that pulled bolts is not the cause.

If anyone remembers something different, please let me know. However, I distinctly remember what the Guru said about this issue.

That is pretty much exactly what the Guru said... I wish he was still around to discuss and debate this further... Some interesting empirical data around Northstar head gasket problem is starting to come in:

1) About 75% of the problem occur in the tight span of 1997/98 and 99 model years. The frequency drops DRAMATICALLY in 2000 when GM switched to longer head bolts and it drops to zilch in 2004 when GM switched to LS1 style "long and coarse" head bolts.

2) Who has ever heard of an LS1 head bolt or headmaster fail? Why? These engines have been out there almost as long as the Northstars and yet the coarse head bolts on these motors seem to tolerate one torquing after another into aluminum blocks without pulled threads...

3) Older Northstars (93-96) seem to be almost as good as the 2000-present units... if this is a coolant issue these should be the worst of the bunch... but they aren't.

4) There are lost of "over" maintained coolant systems out there with failed head bolts too... my 2002 hasn't failed... But my car gets new Dex every other year REGARDLESS of miles... If the head bolts let go it won't be the coolant on my car.

5) There are even more Northstars that are just fine still running on the 10 year old factory coolant (One is a friend of mine)

6) The locker that is used to "glue" in the timeserts is also proving to be problematic and there is lots of data around serts that come unstuck and fail. The sert has two clamping surfaces (inside and outside) and is an additional failure point.

I really like the idea of these studs... as I understand them they use a thread pitch that is at least as course as the "better" LS1 bolts PLUS they are longer and have a greater diameter. (win win win!)

The only down side is that you can't remove the heads in the car anymore... but you can't do that anyway...

I can't see any down side to this product.

Stronger, Better, Faster... Smarter!

[BodybyFisher]

Greg you said this

The only down side is that you can't remove the heads in the car anymore... but you can't do that anyway...

You lost me what do you mean, by, but you can't do that anyway

[NorthstarPerformance]

I think what he means is that it's near impossible to remove the heads in the car in the first place, although some with more patience than I have done this. It is very difficult and personally, I find it less time-consuming and easier to just pull the engine. I've done them all (48 cars) through the top, although if I have to pull another 2000+ Deville, I'm lowering the cradle. Too much crowding.

[BodybyFisher]

Ahh that is what confused me, we have had a bunch of members do the timesert job from the top, both in an out of the car. These studs cause you to have to get the engine out. But, if the studs are as effective as you say, you need only do this job once

By the way are you using OEM head gaskets?

[NorthstarPerformance]

I use Fel-Pro gaskets. Always have, and probably always will.

[BodybyFisher]

I use Fel-Pro gaskets. Always have, and probably always will.

Any reason in particular? I have used Fel-Pro in the past but with such a critical application (NS head gasket) I don't know. As a noted in my PM to you, we tend to be OEM types here. I am interested in your thoughts. Jim bought a rebuilt and they used an aftermarket gasket, Ill try to direct him here

[Cadillac Jim]

I got a Jasper remanufactured Northstar in July, 2006. I quizzed Jasper about different parts, specifically Timeserts, head gaskets, rings, etc. The head gaskets that they said they use are the same type that Cadillac sells as replacement types and uses in new Northstars, and are a change from the OEM; I don't recall precisely what type they are, but they are probably MLS.

Jasper Timeserts all Nortstar blocks. The head bolts on the new engine are noticeably larger than the OEM head bolts. The heads on Jasper engines are installed using clamping force instead of torque-and-twist for more accurate head clamping forces, like the GM factory engines.

All modern aluminum engines use torque-and-twist bolts for the cylinder heads. Torque-and-twist bolts are actually tension springs. The tension on each bolt is adjusted by turning the bolt a specified angle after the bolt head contacts the cylinder head; the angle with the thread pitch gives the stretch distance, and the bolt alloy and thickness with the stretch distance gives the clamping force.

The big advantage of torque-and-twist is that the clamping force remains within a specific range selected in the design over the temperature range of the head and block. The first aluminum engines, used by Rambler in the 1960's, would pull the threads if the egine overheated; the longer bolts used in torque-and-twist allow some stretching without the clamping forces becoming high enough to pull the threads.

[NorthstarPerformance]

I use Fel-Pro, because that's what I've always used and never had problems. Fel-Pro is a big company (headed by Federal Mogul) and they know their stuff when it comes to sealing technology. I trust them, I have had good experiences with their products, so I have no reason to switch to a different gasket manufacturer.

[NorthstarPerformance]

Here's a photo of a studded block with the CNC studs:

[OynxSTS]

Greg you said this

The only down side is that you can't remove the heads in the car anymore... but you can't do that anyway...

You lost me what do you mean, by, but you can't do that anyway

Yes technically you can remove the heads without pulling the engine or dropping the cradle. But once you pull a head you need to "sert" the block and while one or two brave soles have done this almost everyone agrees that it is easier to drop the cradle.

Plus head studs are just plain COOL...

Every racer will tell you that you cannot beat the pure clamping force that studs provide..

More clamping force with less stress on the block.

[ted tcb]

I've gotta say it ... that studded block looks awesome.

With the robust bottom end on that motor, a studded block could go

for 300k?

[NorthstarPerformance]

The studded blocks will last darn near forever. The bottom ends are strong. If good oil is used and proper maintenance is done, I believe a Northstar could see a million miles on the original build. Mileage is not a factor. Age is, and with new studs and gaskets, I honestly don't think you'd have another HG problem for over 10+ years, depending on how the cooling system is maintained.

[adallak]

Well....you could be describing two different situations.

One, that I suspect you are thinking of, is a thru bolt with a nut on the other end. Given the geometry of the engine block and the necessity to get bolts in the center of the vee of the engine this is very very improbalbe. I suppose that an engine could be designed to use this approach but it would be very cumbersome and difficult to assemble. And for what?? Remember that you would have to get to the nut end to tighten the joint properly so this would really make assembly difficult.

The other approach is to install studs into the block holes and then use nuts to hold the heads down on the other end of the studs. This approach is common in racing engines that are torn down frequently. It is a very strong way of making the joint as the stud does not have to be turned in the aluminum threads under load as the stud is tensioned when the nut is tightened. The stud approach makes assembly of the engine very difficult as it is hard to align the studs into the head holes and very easy to damage the aluminum surface of the head with the studs so it would be very rare to see this approach on a high volume engine.

The engine , as designed, with head bolts into blind holes works extremely well and is easily repairable when problems occur. Why change it.

Any idea whos comment is this? I made a suggestion to see whether it was viable a few years ago...

[OynxSTS]

The other approach is to install studs into the block holes and then use nuts to hold the heads down on the other end of the studs. This approach is common in racing engines that are torn down frequently. It is a very strong way of making the joint as the stud does not have to be turned in the aluminum threads under load as the stud is tensioned when the nut is tightened. The stud approach makes assembly of the engine very difficult as it is hard to align the studs into the head holes and very easy to damage the aluminum surface of the head with the studs so it would be very rare to see this approach on a high volume engine.

The engine , as designed, with head bolts into blind holes works extremely well and is easily repairable when problems occur. Why change it.

Sounds like the 'ol guru again... and he is/was right... Using studs in a factory engine would be very costly and would be over kill...He said the same thing about using steel inserts too... Of course while he was posting that, GM was very busy redesigned and then redesigning the redesigned the head bolts... First making them longer in 2000 and then making them longer and coarser in 2004. He was wrong that on a Northstar our head bolts are "easily repairable". Sadly, they have proven to be the death of many a fine Cadillac.

These studs enable you to bring your pre-2004 block up to (an better then) the new standards that GM uses on their current Northstars... Yes you would never use studs on an assembly line... But the majority of the cost of a Northstar head gasket job is NOT in the parts... It is in the cost of dropping the cradle and the cost to remachine the block for serts... If you are going to do all of this anyway... why not take your block to the next level and build a completely bullet proof top end.

I bet if the guru was still here he would be all over this product... In a good way... It is one of those... "I wish I had thought of this first"

[cessnatech]

after getting things disconnected I've come to the conclusion I'm better off getting rid of this problem. I've put all back together and I'm car shopping now. After 40 years of owning cars this is by far the worst I've ever owned. I never did get the engine out. But I did enjoy the car for 10 years. Cessnatech.

[joeb]

Its great that there seems to be fixes available that makes the motor bulletproof. the downside is what will the rest of a 97 STS look like in 20yrs time? a 95-97 STS may have cost 38k new and in 10 yrs no one wants to touch one if it needs a 5k motor replacement. a 10yr old car might still look nice but if the motor is shot, it ends up in the junkyard. now add 5 or more years and it gets to be an even tougher prospect.

[BodybyFisher]

I never disagreed with the Guru, you couldn't he always had the facts. But I felt they should have cast in steel inserts into the block and said so. My justification was, you billed this engine as the engine that could go 50 miles with NO COOLANT, you are coming back from the ashes and competing with MB and BMW. To build an engine to JUST last 100,000 miles or LESS and potentially damage your reputation with the NEW and especially the USED car crowd, the ones that MIGHT just buy a NEW car one day by saving a few dollars on each engine is shortsighted and foolish.

Does anyone think there were ANY shortcuts on the 429, 472 or 500 cu in monsters?

[Cadillac Jim]

I just got a Jasper in 2006, service my transmission every 30,000 miles or so, and have a very reliable 1997 model year Cadillac that is the object of envy of all that see it.