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Engine Specific Info and Questions => IDI Engine => Topic started by: TylerDurden on December 04, 2012, 01:57:01 pm

Title: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 04, 2012, 01:57:01 pm
I'm using new 12mm TTY bolts from AutohausAZ on a 1.6 TD.  (I did notice that some bolts were lighter/more-shiny than others.)

I read the threads on dry/oiled stretch bolts. I went dry, figuring the oil on the new bolts was to prevent rust.

No mention of oil in Bentley...

The block holes were cleaned and dry.

Only half of the bolts got to the yield-point, the others got up to ~100ft-lb and no yield.


All 12mm are TTY, yes?... Try again with oiled bolts?



Edit: revised title
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: 92EcoDiesel Jetta on December 04, 2012, 02:07:44 pm
How did you determine whether the bolts yielded or not? I also used head bolts from Autohausaz to do the head gasket on my 92 Eco and as I recall, I cleaned the block holes out with brake cleaner, blew out with compressed air but left the oil that came with the bolts (did not clean them)and followed the Bentley torque procedure and everything came out alright, no leaks of any kind so far in 20k miles.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: TylerDurden on December 04, 2012, 02:13:17 pm
Thanks for the reply.

With a beam type wrench you can see and feel the torque reach a plateau when the bolt yields... ~85ft-lbs.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: 92EcoDiesel Jetta on December 04, 2012, 02:32:27 pm
I used a click type torque wrench (Sears Craftsman) and I could not tell whether the bolts yielded or not during the initial torque. I think the final torque was by angle and the bolts did not all feel the same, most were smooth and quiet a about 3 of them squeaked. Not sure if the squeaking was an indication if the bolt yielded or not. I did not try to loosen and re-torque the squeaky bolts and left them and it seemed to have been OK.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: TylerDurden on December 04, 2012, 02:38:33 pm
Yeah the last bit is by angle, but I was watching the beam indicator too.  The ones that did not yield did not allow the angle turn... they were really stubborn and I didn't want to totally reef on em.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: 92EcoDiesel Jetta on December 04, 2012, 02:46:19 pm
Yeah the last bit is by angle, but I was watching the beam indicator too.  The ones that did not yield did not allow the angle turn... they were really stubborn and I didn't want to totally reef on em.

Did you mean on the bolts that did not angle turn, the torque wrench indicated they should have turned. What were the torque values on the ones that angle turned vs the ones that did not angle turn?
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: TylerDurden on December 04, 2012, 02:48:29 pm
The ones that angle turned went to ~85-90, IIRC. The stubborn ones were not budging at >100.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: 745 turbogreasel on December 05, 2012, 03:12:34 am
I always clean, dry and oil every fastener in an engine unless it specifies not to.
Going over 100lbs on a 12MM head is not abnormal.
If you stopped and chickened out, what are you going to do on the warm retorqes?
IMO, watching the torque is a waste of time, the bolts don't work that way, and if they break like the really cheap ones do, spin out the nub and put in another.
I'd back each  out, lightly oil it on the threads and the washer, tighten it to 35,  move to the next, then start over.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: TylerDurden on December 05, 2012, 04:23:13 am
Going over 100lbs on a 12MM head is not abnormal.
IMO, watching the torque is a waste of time, the bolts don't work that way,
Please explain.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: burn_your_money on December 05, 2012, 06:25:23 am
Personally I'm surprised that you only hit 85 ft-lbs. I don't use a torque wrench for the angle part of the procedure but by pulling on my 36" breaker bar, I know it's a lot more than 85.
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: 745 turbogreasel on December 05, 2012, 11:45:54 am
Going over 100lbs on a 12MM head is not abnormal. When I started with VW diesels, it seems I really had to reef on em, so i did a few with the clicker, and some were in the upper hundredandteens.
IMO, watching the torque is a waste of time, the bolts don't work that way, They are designed for an angle torque application , because doing it the old way wasn't good/consistent enough.  Therefor watching the  beam wrench does not  deliver useful information.
Please explain.
That answer your question?
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: R.O.R-2.0 on December 05, 2012, 11:47:59 am
Going over 100lbs on a 12MM head is not abnormal. When I started with VW diesels, it seems I really had to reef on em, so i did a few with the clicker, and some were in the upper hundredandteens.
IMO, watching the torque is a waste of time, the bolts don't work that way, They are designed for an angle torque application , because doing it the old way wasn't good/consistent enough.  Therefor watching the  beam wrench does not  deliver useful information.
Please explain.
That answer your question?

120 ft lbs is not unheard of with yielded bolts...
Title: Re: TTY head bolts - some did not seem to yield. (?)
Post by: smutts on December 06, 2012, 04:36:17 am
I understand the theory of TTY bolts, but it still scares me to death doing it. On the brighter side, the last blown head gasket on my SB was a bit strange, Bought it for peanuts at 100k miles, ran like a scalded weasel but started to drip water at 170K, leaked for a while before it popped at 180k, weird thing was when dismantling, the head bolt at the blown corner was only finger tight. I've inherited someone elses bodge thinks I. But the gasket was the original Reinz with the same date stamp as when the car was built in 1991. It hasn't lost a drop in the 40k miles since. So did it leave the factory like that? That would be a very stiff head.

Back to the subject, I oil mine, as it depends on the angle the bolt is turned, so whatever makes life easy for those threads.
Title: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 06, 2012, 06:38:56 am
Thank you for the replies.  :)

My conclusion:
Bolts must be oiled.
Bentley Publishing has a serious omission by not mentioning this critical factor.



I did a little more reading on the subject. 
This was the most informative:
Engineering Fundamentals of Threaded Fastener Design and Analysis (https://docs.google.com/viewer?a=v&q=cache:cs-FkTcBCTMJ:www.hexagon.de/rs/engineering%2520fundamentals.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESiIKVkycT_x6dKOPGhBZFcvgGWJ6Iwi9aSGZEdOgKeTUM4Wq3lb-o3P0gK0msJiJpXsDJYPXkFp6pY_BM3NGfSV25jLBTsshNjzEfYs9Plf09LbptWGJnlxpG4hd-vToNvMwegE&sig=AHIEtbRbdnBr3t9YrdFVwCGfnY8w7WLqmg)

This is also a short but interesting read, regarding re-using stretch bolts:
Bolt Science: More Thoughts on Fastening (http://www.boltscience.com/pages/glorimermorethoughtsonfasteningarticle.htm)


The short story:


Some nuggets:
Quote
The torque applied to a fastener is absorbed in three main areas. First, there is underhead friction, which may absorb 50 percent or more of the total torque. Thread friction absorbs as much as 40 percent of the applied torque. The final 10 percent of the applied torque develops the clamping force that holds the components together. Thus an increase in either friction component of 5% can reduce tension by half.

*****

When torque-only control is used as the method for tightening a fastener, there is absolutely no way to be 100 percent certain that the desired tension will be created. Using installation torque alone to control the process always introduces an element of “statistical gambling” into the assembly process. Installation torque measurements that are not backed up with simultaneous angle-of-turn measurements cannot be totally relied upon to insure that proper fastener installation has been accomplished.

For bolted joints where safety and reliable performance are dependent upon proper initial tension, both torque and angle-of-turn must be monitored and controlled during the tightening process. As each fastener is installed, the torque-angle tightening signature of the bolted joint should be compared to established assembly process limits to insure that the specified assembly preload has been achieved.

The fundamental tightening procedure for Torque-Angle-Tension Control is simply defined as follows.
1. Torque is applied until a specified “threshold” level is attained.
2. An additional angle-of-turn is applied to finish the installation.


*****

The most general model of the fastener tightening process has four distinct zones as illustrated in Figure 19.

Zone 1 is the rundown or prevailing torque zone that occurs before the fastener or nut contacts the bearing surface. Prevailing torque due to thread locking features such as nylon inserts or deformed threads will show up in the rundown zone. Frictional drag on the shank or threads due to misalignment of parts, chips or foreign material in the threads as well as unintended interference due to out of tolerance threads are additional causes of prevailing torque in the rundown zone.

Zone 2, is the alignment or snugging zone, wherein the fastener and joint mating surfaces are drawn into alignment, or a stable, clamped condition. The nonlinear alignment zone is a complex function of the process of drawing together the mating parts, and bending of the fastener as a result of non-parallelism of the bearing surface to the fastener underhead surface. In addition to the macro effects related to alignment of parts, there are micro effects within the alignment zone. The micro effects include contact stress-induced deformations of plating and coatings as well as local surface roughness and thread deformations.

Zone 3, is the elastic clamping zone, wherein the slope of the torque-angle signature curve is constant. The elastic clamping zone torque-angle slope is a very important characteristic of each bolted joint. This slope can be projected backward to locate the elastic origin. Angle-of-turn from the elastic origin is multiplied by the angle-tension coefficient to calculate the tension that has been created by the tightening process.

Zone 4, as shown in Figure 19, is the post-yield zone, which begins with an inflection point at the end of the elastic clamping range. Yielding can occur in the bolt or in the joint assembly, as a result of underhead embedment or as thread strip in the bolt or mating threads. The yield point can be used to establish or verify the tension-angle coefficient for the torque-angle-tension tightening process.


*****

For this process to work reliably, it is necessary that the threshold torque level for starting angle counting be set at a level which is above the alignment zone of the tightening process.




The range of final torque values on the engine I'm working on ranged from 108ft-lb to 140ft-lb.

Following the Bentley sequence, torque values at the end of angle-tightening (in ft-lbs):
Bolt #12345678910
First 1/4 turn:901159095908510080115100
Second 1/4 turn: 108115100115120120120100140110


I don't think using a bolt with relief cuts is adequate to chase threads, the ones I tried were too loose to address corrosion. A tap would be better, methinks.
Title: Re: TTY head bolts - more than you might want to know.
Post by: JFettig on December 06, 2012, 10:48:28 am
NO, you do NOT oil stock head bolts!

There is a reason you angle tighten them and not torque them to a certain number. Torquing them to only 44ft-lbs then angle tightening eliminates most of the friction error. DO NOT OIL

If you oil head bolts you'll only get about 80-110ft-lbs out of them, if you try for more you'll just stretch the hell out of them... My haynes manual says to oil them, Bentley says DRY! Bentley is correct.

I am experimenting with something new, I use 12.9 SHCS, M12x1.75 by 110mm long, 115-125ft-lbs OILED(30w oil).  pick your torque and use the same torque for all of them. Make sure to clean the holes out very well, sucking out any fluid that is in them to prevent cracking the block.

http://www.mcmaster.com/nav/enter.asp?partnum=91290A642
http://www.mcmaster.com/#98035A107
Title: Re: TTY head bolts - more than you might want to know.
Post by: burn_your_money on December 06, 2012, 12:08:19 pm
Because it is an angle torque it does not really matter if you oil them or not. 180 degrees is 180 degrees whether the threads are dry, coated in 30w or coated in peanut butter. This is the exact reason why most OEMs spec angle torques for critical areas. It eliminates a lot of potential error.
Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 06, 2012, 12:23:41 pm
NO, you do NOT oil stock head bolts!

There is a reason you angle tighten them and not torque them to a certain number. Torquing them to only 44ft-lbs then angle tightening eliminates most of the friction error. DO NOT OIL
Un oiled threads like to gall up.

If you oil head bolts you'll only get about 80-110ft-lbs out of them, if you try for more you'll just stretch the hell out of them... My haynes manual says to oil them, Bentley says DRY! Bentley is correct. Bolts with oiled threads stretch more easily?

I am experimenting with something new, I use 12.9 SHCS, M12x1.75 by 110mm long, 115-125ft-lbs OILED(30w oil).  pick your torque and use the same torque for all of them. Make sure to clean the holes out very well, sucking out any fluid that is in them to prevent cracking the block.


It eliminates a lot of potential error.
Or sells a lot of one use bolts.

That said, buy studs once, your head wont lift regardless of torque, and you will never have to buy another one.
Title: Re: TTY head bolts - more than you might want to know.
Post by: burn_your_money on December 06, 2012, 12:48:18 pm
Just because a bolt has an angle torque does not mean it is 1 time use. In the case of our headbolts, it most certainly does mean 1 time use however.

You have to blow a lot of headgaskets to make studs financially worthwhile.
Title: Re: TTY head bolts - more than you might want to know.
Post by: libbydiesel on December 06, 2012, 01:37:53 pm
Just because a bolt has an angle torque does not mean it is 1 time use. In the case of our headbolts, it most certainly does mean 1 time use however.

You have to blow a lot of headgaskets to make studs financially worthwhile.

Well, that depends on whether or not the headgasket is more or less likely to blow with studs.  If the head gaskets lasted the exact same amount of time with studs vs stock bolts it would take 10 blown gaskets to pay for the studs (never gonna happen unless you are really abusing your engine).  If, on the other hand, the studs double the lifetime of the gasket, they will be more cost effective on the first gasket as the labor to swap the gasket is more than the initial cost of the studs. 
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 06, 2012, 01:44:16 pm
If you read the lit, you will see that friction error is not reduced by torquing into the elastic range. In the case of these headbolts, the two torque stages bring the fastener past the alignment-range and ensure that the bolt gets near or past the elastic range; usually into the plastic range (yield).

(https://lh6.googleusercontent.com/-UHEsE48bE_k/UMERVSSrkwI/AAAAAAAAA1A/MGNuArvTlK8/s800/TorqueSlope1.jpg)


The critical issue is clamping force, you can be reasonably certain that the clamping force is adequate when friction losses are minimized. Quite the contrary, if friction is increased.

(https://lh4.googleusercontent.com/-XaPL7OVSCLU/UMEQmz1rmdI/AAAAAAAAA04/1WDzEBmu09Y/s640/Where-Torque-Goes.jpg)


The Haynes and Bentley manuals I have here (two mk2, four mk1) do not say bolts should be "dry", only that the block threads should be chased and free of debris.

Lube selection is more critical with studs, as they have no yield to prevent over-tightening.


I spoke with a guy yesterday who has done a couple hundred heads, who concurs bolts should be lubed.
Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 06, 2012, 02:42:53 pm
Just because a bolt has an angle torque does not mean it is 1 time use. In the case of our headbolts, it most certainly does mean 1 time use however.

You have to blow a lot of headgaskets to make studs financially worthwhile.

Well, that depends on whether or not the headgasket is more or less likely to blow with studs.  If the head gaskets lasted the exact same amount of time with studs vs stock bolts it would take 10 blown gaskets to pay for the studs (never gonna happen unless you are really abusing your engine).  If, on the other hand, the studs double the lifetime of the gasket, they will be more cost effective on the first gasket as the labor to swap the gasket is more than the initial cost of the studs. 
Also if you are the kind of person who might remove the head for another reason before the gasket blows.
Title: Re: TTY head bolts - more than you might want to know.
Post by: theman53 on December 06, 2012, 06:32:23 pm

If you oil head bolts you'll only get about 80-110ft-lbs out of them, if you try for more you'll just stretch the hell out of them... My haynes manual says to oil them, Bentley says DRY! Bentley is correct.


80 to 110 is about all you get when you angle them. FWIW you are wrong, if you oil the bolts the coefficient of friction is reduced and you will torque the bolts more not less. Your torque wrench will click later as it will be going off more the clamping force than friction, then you will go off angle from there. It won't be much as you are only talking 44 lbs, but still.

Watch out how long your SHCS are. You can crack a block if they are too long and I thought the one guy from Kansas said 105mm was the limit. Also, I sell bolts for a living and McMaster is competition...most all of the SHCS they sell are from China or Taiwan.
Title: Re: TTY head bolts - more than you might want to know.
Post by: JFettig on December 07, 2012, 08:27:29 am
Wow, lots of misinformation.

I'm wrong about something you interpreted different then intended? oh well.

As a mechanical engineer who designs bolted connections on a regular basis, I have a little bit of an idea whats going on here ;) Oiling the bolts increases the load on the bolt at 44ft-lbs torque, thus increasing the load on the bolt at +180 degrees. For these bolts, it runs them farther into yield and closer to ultimate, maybe even past it where clamping force drops off.


If they gave you a spec for oiled bolts, it would be the correct way to torque them, they gave us a torque spec for DRY bolts, torque them dry.

I didn't willy-nilly grab 12.9 bolts from McMaster. FWIW, I used these on TDI's, I dunno if its any different than TD's, but with thick hardened washers it brings it up to about 107mm.

Not all Chinese stuff is garbage. Maybe these are lesser quality than your product, maybe not. They're working great so far at 200hp/300ft-lbs. Moving up to ~220/350 soon.
Title: Re: TTY head bolts - more than you might want to know.
Post by: burn_your_money on December 07, 2012, 08:54:17 am
80 to 110 is about all you get when you angle them. FWIW you are wrong, if you oil the bolts the coefficient of friction is reduced and you will torque the bolts more not less. Your torque wrench will click later as it will be going off more the clamping force than friction, then you will go off angle from there. It won't be much as you are only talking 44 lbs, but still.

Oiling the bolts increases the load on the bolt at 44ft-lbs torque, thus increasing the load on the bolt at +180 degrees. For these bolts, it runs them farther into yield and closer to ultimate, maybe even past it where clamping force drops off.

Pretty sure you guys are saying the exact same thing  ???
Title: Re: TTY head bolts - more than you might want to know.
Post by: 92EcoDiesel Jetta on December 07, 2012, 08:55:15 am
I agree oiling the bolts will result in advancing the bolts further than if they were dry during the torque wrench sequence (30, 44, 55 ft lbs), and will end up with higher torqued bolts after angle torque. The Bentley I have does not state (or I have not found it yet) whether the head bolts should be oiled or dry. If anyone find it, please post the section and page.

JFettig, which McMaster 12.9 bolts did you use?
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 07, 2012, 08:56:21 am
... they gave us a torque spec for DRY bolts, torque them dry.
No mention of dry bolts in any Haynes or Bentley i own.

Victor Reinz specs lightly oiled.
(https://lh3.googleusercontent.com/-fG5spxTfZL0/UMIfOe8nWSI/AAAAAAAAA1Q/mfHexbUy6QQ/s800/VictorReinz-headboltsScreengrab.jpg)

http://www.reinz.com/pictures/39-00129-10_PI_2_Bolts-low-e.pdf
Title: Re: TTY head bolts - more than you might want to know.
Post by: JFettig on December 07, 2012, 09:23:51 am
Bentley doesn't say TO oil them, Every TDI mechanic I've talked to says DRY DRY DRY. This is including Franko6 and others.

#10, IF the manufacture specifies....

92EcoDiesel Jetta - previous page, last post.
Title: Re: TTY head bolts - more than you might want to know.
Post by: 92EcoDiesel Jetta on December 07, 2012, 10:53:03 am
NO, you do NOT oil stock head bolts!

There is a reason you angle tighten them and not torque them to a certain number. Torquing them to only 44ft-lbs then angle tightening eliminates most of the friction error. DO NOT OIL

If you oil head bolts you'll only get about 80-110ft-lbs out of them, if you try for more you'll just stretch the hell out of them... My haynes manual says to oil them, Bentley says DRY! Bentley is correct.

I am experimenting with something new, I use 12.9 SHCS, M12x1.75 by 110mm long, 115-125ft-lbs OILED(30w oil).  pick your torque and use the same torque for all of them. Make sure to clean the holes out very well, sucking out any fluid that is in them to prevent cracking the block.

http://www.mcmaster.com/nav/enter.asp?partnum=91290A642
http://www.mcmaster.com/#98035A107

Are these Mcmaster bolts multi-use? They're not listed as TTY so I assume they are not one time use. Not bad, $20 for a set of bolts and washers! They are Allen, not XZN?
Title: Re: TTY head bolts - more than you might want to know.
Post by: JFettig on December 07, 2012, 11:47:33 am
At that price I'd replace them. they are 10mm allen.
Title: Re: TTY head bolts - more than you might want to know.
Post by: libbydiesel on December 07, 2012, 01:45:22 pm
That's like $130 for the hardware that you still consider single use.  I'd just buy the stock bolts or the ARP studs. and not mess with an experiment that costs 10 times what the stock bolts cost.
Title: Re: TTY head bolts - more than you might want to know.
Post by: theman53 on December 07, 2012, 02:10:39 pm
That's like $130 for the hardware that you still consider single use.  I'd just buy the stock bolts or the ARP studs. and not mess with an experiment that costs 10 times what the stock bolts cost.

I thought so too, but it is 7....ish per pack of 5, so it is only around 20.00. Which for import is still high as can be. I could sell the American made or SPS Unbrako for close to that now.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 07, 2012, 02:47:16 pm
From Bill McKnight, Director of Training for MAHLE Clevite:

" Unless specified otherwise, 30W motor oil is the standard lubricant for automotive fasteners. If we want to achieve loads similar to the OEMs. we need to lubricate our fasteners with 30W oil. Don’t forget that underhead and thread friction both need to be controlled, so lubricate both areas. In the case of head bolts going into the water jacket, the sealer on the threads will provide the lubrication needed, so just apply oil to the underside of the head of the bolt. Super lubricants may actually get you in trouble by relieving too much friction, leading to over-tightening."

http://www.enginebuildermag.com/Article/2343/threaded_fasteners_torquetoyield_and_torquetoangle.aspx
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 07, 2012, 03:03:19 pm
From Fel-Pro Torque Guide:

"Lightly coat bolt threads and the underside of the bolt heads with motor oil. When they enter the water jackets of an engine, bolt threads should be coated with a non-hardening automotive sealer to prevent leakage."

http://www.felpro-only.com/tec_notes/Fel-Pro_Torque-Guide.pdf
Title: Re: TTY head bolts - more than you might want to know.
Post by: JFettig on December 07, 2012, 04:08:03 pm
Do whatever you want man. Its your motor.

If you look through the bentley, it says to oil certain bolts... it doesn't specify for others, probably a reason for that ;)
Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 07, 2012, 09:41:03 pm
The reason being they mistakenly assume you know it?
My 84 factory manual is pretty specific:
Quote
Tightening torques
Apply to lightly oiled nuts and bolts.
Degreased (washed) parts must be oiled prior to assembly.
Cylinder head--tighten in stages
sequence[pic]
Tighten cylinder head bolts in stages
Remove oil and dirt from bolt holes.  Oil and dirt left in holes will reduce  the pressure on cylinder head gasket.

Bolt threads and washers must however be oiled, otherwise frictional forces will be too large.

Use new bolts.  The washers need not be replaced.

Tighten in six stages:
stage 1=30ft/lbs.
stage 2=44ft/lbs.
stage 3=55ft/lbs.
stage 4=tighten 180* Note this should be in one movement without stopping.
stage 5=Run engine till oil temperature is at least 112F.
stage 6=tighten 90* Note this should be in one movement without stopping.

Retorquing of cylinder head bolts

Retorque after 600-1200 miles.  The engine should be cold or almost cold.

Tighen each bolt separately and in correct sequence(see pic).

Tighten bolt 90* Note this should be in one movement without stopping.

Bolts should not be slackened first.

Emphasis is all as per the book. I left out the metric specs, and pic, cause I type slow.
book 760-03, section 2, Page 40.


There is a revision for 85+, bolts have captive washers, do not reuse.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 08, 2012, 06:24:16 am
The 1980 and 1981 editions of Bentley spec using anti-seize on headbolt threads and washers, plus changing from hex to 12pt bolts.
Title: Re: TTY head bolts - more than you might want to know.
Post by: 8v-of-fury on December 08, 2012, 03:14:18 pm
As a mechanical engineer who designs bolted connections on a regular basis, I have a little bit of an idea whats going on here ;)

I would think that because this man has a degree and literal hands on experience with the exact matter at hand, maybe he does actually know what he is talking about?

Just because it is written in the "Bentley" does not mean it is written as matter-of-fact, or that it was even right in the first place when published.
Title: Re: TTY head bolts - more than you might want to know.
Post by: ORCoaster on December 08, 2012, 04:32:44 pm
Just because it is written in the "Bentley" does not mean it is written as matter-of-fact, or that it was even right in the first place when published.

And how many misstated things do we already know about in the "Bentley"?  Plenty if I can think about it a bit.  Not all is as it should be.  Publishers do make mistakes.  Like we don't?
Title: Re: TTY head bolts - more than you might want to know.
Post by: shorttimer on December 08, 2012, 06:28:55 pm
To heck with all the bickering about bolts. Even with my paltry income, I find the ARP bolts to be a good value. I've never blown a head gasket, but i don't want to take any chances after all the work I've done. I can easily go without movies, eating out & other consumables to have good hard parts.
Title: Re: TTY head bolts - more than you might want to know.
Post by: burn_your_money on December 08, 2012, 06:59:17 pm
Considering how many people have oiled their bolts and had success, and how many have not oiled them and had success I think it's safe to say that in this application it doesn't really matter.
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 08, 2012, 07:16:41 pm
most of the head bolts i get have anti-seize with them (in seperate packet) so i use it, (not the anti-seize that comes w/bolts either).
might i point out using OIL on head bolts can cause you to crack your block, and i find anti-seize to be better.
i saw at least 1 post of using brake clean and compressed air.++.
Title: Re: TTY head bolts - more than you might want to know.
Post by: R.O.R-2.0 on December 09, 2012, 11:41:22 am
most of the head bolts i get have anti-seize with them (in seperate packet) so i use it, (not the anti-seize that comes w/bolts either).
might i point out using OIL on head bolts can cause you to crack your block, and i find anti-seize to be better.
i saw at least 1 post of using brake clean and compressed air.++.

its when you leave a PUDDLE of oil in a hole.. like to the top of the hole, and the bolt comes down on top.. hydraulic pressure pushes the oil down, and the only place it has to go, is thru the block..
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 09, 2012, 12:57:51 pm
not so BIG of a puddle is necessary to push thru block, theres not alot of space between bottom of bolt and block, and bolt seals at block if even 1 thread up the bolt, you wont need a lot of LIQUID to do it.
in any case the main thing is cleaning holes w/brake clean everytime. And make sure all brake clean is dry too.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 09, 2012, 01:36:36 pm
Quote from: myself in another thread
New bolt length = 110.4mm (Tip to washer)

Block-Hole depth = 43.5mm
Head-hole depth = 78.8
Gasket = 1mm
Combined hole depth = 123.3mm
Remaining threads in block after threading head and bolts = 11mm (corrected from 13mm)


Bolt threads below head/gasket = 32mm
Head recess before threads begin = 13mm
Thread engaged during fastening = 19mm
Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 09, 2012, 01:43:06 pm
Also, the bolt is stretched one full turn or 1.75MM, leaving 9.25MM
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 09, 2012, 01:49:58 pm
Also, the bolt is stretched one full turn or 1.75MM, leaving 9.25MM

FWIW, The "original" bolts I pulled from my '91 were only stretched .875mm. Not even 1/2turn.

Which correlates, if the first turn to angle is 180 (or two 90s). Some folks don't bother with the followup turn after a heat/cool cycle.



- edit to include quote -
Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 09, 2012, 02:41:31 pm
Were you able to measure them with the head installed? or is this after they had relaxed again?
Some of that will be in compression of the head gasket  rather than bolt stretch I suppose.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 09, 2012, 03:57:27 pm
Lol, the bolts were out.

But a fair question... how much do they contract... I would say the tension was off after turning them out 1/4turn (some much less). What percentage of that was gasket and how much was the elasticity of the bolt,  how much was loosening over time... who knows.


I can say with certainty that the first try with DRY bolts, three yielded on the first 1/4 turn. They were the ones I remarked were shinier than the others... maybe the threads were rolled after the oxide coating was applied.  The rest were identical length to new.

(https://lh5.googleusercontent.com/-5eElQ-5pF6g/UMUk7l7hP4I/AAAAAAAAA2Y/69aKXBYr9nw/s640/IMG_9166.JPG)

IIRC, they were longer by... 1/4 turn.

Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 09, 2012, 04:36:29 pm
As a casual observation, steel will spring back about half way from bending in plastic range...straightening body and frame panels is an easy place to see this.
Taking this as a general rule, 1/4 thread of stretch would be perfectly consistent with your having skipped half of the tightening procedure.
Title: Re: TTY head bolts - more than you might want to know.
Post by: bbob203 on December 09, 2012, 04:43:25 pm
* note to self buy head studs...?
Title: Re: TTY head bolts - more than you might want to know.
Post by: 92EcoDiesel Jetta on December 09, 2012, 05:02:11 pm
As I recall when I did the head gasket on my 92 Eco more than a year ago, I tried to measure the old bolt's stretch compared to a new bolt (from bottom of bolt head to tip of bolt) and the difference was so small it was not measurable with a vernier caliper. The only way to tell if there was bolt stretch was to place the threads of an old bolt against threads of a new bolt, held up to sunlight so you can observe the slight uneven meshing of the threads.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 09, 2012, 05:13:50 pm
Ja, that's how I did it too... not even a half thread difference on the old bolts compared to a new.
Title: Re: TTY head bolts - more than you might want to know.
Post by: R.O.R-2.0 on December 09, 2012, 05:20:35 pm
not so BIG of a puddle is necessary to push thru block, theres not alot of space between bottom of bolt and block, and bolt seals at block if even 1 thread up the bolt, you wont need a lot of LIQUID to do it.
in any case the main thing is cleaning holes w/brake clean everytime. And make sure all brake clean is dry too.

1.5D and 1.6D head bolts dont come anywheres close to bottoming out in the block with the head, gasket, and OEM bolts in place..

 ???

wtf you talking about?

you need a visible puddle of liquid at the bottom of the threaded hole.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 09, 2012, 05:49:28 pm
* note to self buy head studs...?

I'll pass on studs. This is a one-shot. (I hope)

Plus, I'm pretty sure the dings in the head surface were from the PO using cut-down bolts when replacing the head, but struggling to line it up with the manifolds on.  Certainly wasn't wood dowels that marked up a freshly machined head.
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 09, 2012, 07:51:58 pm
not so BIG of a puddle is necessary to push thru block, theres not alot of space between bottom of bolt and block, and bolt seals at block if even 1 thread up the bolt, you wont need a lot of LIQUID to do it.
in any case the main thing is cleaning holes w/brake clean everytime. And make sure all brake clean is dry too.

1.5D and 1.6D head bolts dont come anywheres close to bottoming out in the block with the head, gasket, and OEM bolts in place..

 ???

wtf you talking about?

you need a visible puddle of liquid at the bottom of the threaded hole.
who are you in the first place, and i dont understand why you would take this for granted, its not bad advice in anyway. if you pull your head you need to be aware of this, it cannt hurt in anyway; and might i say IS on topic
Title: Re: TTY head bolts - more than you might want to know.
Post by: R.O.R-2.0 on December 09, 2012, 08:00:56 pm
not so BIG of a puddle is necessary to push thru block, theres not alot of space between bottom of bolt and block, and bolt seals at block if even 1 thread up the bolt, you wont need a lot of LIQUID to do it.
in any case the main thing is cleaning holes w/brake clean everytime. And make sure all brake clean is dry too.

1.5D and 1.6D head bolts dont come anywheres close to bottoming out in the block with the head, gasket, and OEM bolts in place..

 ???

wtf you talking about?

you need a visible puddle of liquid at the bottom of the threaded hole.
who are you in the first place, and i dont understand why you would take this for granted, its not bad advice in anyway. if you pull your head you need to be aware of this, it cannt hurt in anyway; and might i say IS on topic

does it matter who i am?

i DO know that you give BS advice over at the whoretex all the time..

you should never install or torque your head bolts DRY..

i know my VW engines.. and how far the head bolts thread into the block..
Title: Re: TTY head bolts - more than you might want to know.
Post by: 8v-of-fury on December 09, 2012, 10:11:40 pm
Language and Aggression check please. Leave it at the door, it need not apply here.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 17, 2012, 05:58:32 am
I got a reply from Victor Reinz - GmbH. 


Quote
07.12.2012 20:44

Hello,

Should new headbolts be lightly oiled, specifically, for Volkswagen  TDI and IDI engines?

The Robert Bentley manuals for Volkswagen  TDI and IDI vehicles are unclear regarding whether new headbolts should be oiled (or dry) for installation.

The Victor Reinz literature indicates generally they should be oiled (but also indicates to follow manufacturers' directions).

Any help to clear this ambiguity is appreciated.


Thank You,

T. Durden

(https://lh3.googleusercontent.com/-gwkSfQmM8jo/UM8is9WwazI/AAAAAAAAA4A/80lFFA1P-Uk/s800/VictorReinz-Reply.jpg)
Title: Re: TTY head bolts - more than you might want to know.
Post by: R.O.R-2.0 on December 17, 2012, 10:44:34 am
i rest my case... ^^^

NEVER install bolts DRY..

i go one step further, i use copper anti-seize, or pipe thread sealant on ALL the head bolts i re-install..

if the bolt goes into the water jacket, then it gets PTFE compound just for extra help. ive had toyotas leak from the head bolt holes.
Title: Re: TTY head bolts - more than you might want to know.
Post by: burn_your_money on December 17, 2012, 10:52:14 am
i go one step further, i use copper anti-seize, or pipe thread sealant on ALL the head bolts i re-install..

You re-install headbolts? Dude, this whole thread is about replacing them ;D :P
Title: Re: TTY head bolts - more than you might want to know.
Post by: R.O.R-2.0 on December 17, 2012, 10:53:36 am
i go one step further, i use copper anti-seize, or pipe thread sealant on ALL the head bolts i re-install..

You re-install headbolts? Dude, this whole thread is about replacing them ;D :P

Tyler, not all engines on this planet use TTY bolts..

yes, i DO re-use TTY head bolts ONE TIME, after measuring them..
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 27, 2012, 07:26:29 am

wtf you talking about?



does it matter who i am?

i DO know that you give BS advice over at the whoretex all the time..

you should never install or torque your head bolts DRY..
i never commented on oiling bolts, i did say i use copper anti-sieze if you'd bother to read what i posted, and that the head bolts i've recently bought have some sort of copper anti-sieze with them.
i'll say this (rather like again) cleaning the bolt holes in the block is important, esp if you do use (light) oil on head bolts.(or any other bolt like this situation, ie encased.)
....edit....leave it to PM's if need be, but never on the board.
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 27, 2012, 04:28:22 pm
also its very smart to get most dirt and gum out of holes too, and its not uncommon to have some, esp if someone else owned car. and considering your taking the head off and some is going to go down in those holes...
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 28, 2012, 12:04:02 pm
i saw at least 1 post of using brake clean and compressed air.++.
i take this statement back; if you use compressed air the cleaner dirt, etc. mix is going down the water jackets and oil holes.
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 28, 2012, 12:27:33 pm
Advice in another topic suggested solvents & compressed air - but covering the blowback with a rag to collect the debris and dirty solvents and to protect one's eyes (and ears).  That rag also kept stuff out of other passages and the bores when I did it that way.

It is a fairly trivial matter when the engine is on a stand  - simply turn the block on its side to have the schmutz blow out the hole and away from the block, with or without the rag. (Oil may seep from the main gallery, so a small plug can be useful.)

Title: Re: TTY head bolts - more than you might want to know.
Post by: 745 turbogreasel on December 28, 2012, 02:26:26 pm
i saw at least 1 post of using brake clean and compressed air.++.
i take this statement back; if you use compressed air the cleaner dirt, etc. mix is going down the water jackets and oil holes.
(http://www.battlefieldhome.com/forum/images/smilies/facepalm2.gif)
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 28, 2012, 06:42:35 pm
Advice in another topic suggested solvents & compressed air - but covering the blowback with a rag to collect the debris and dirty solvents and to protect one's eyes (and ears).  That rag also kept stuff out of other passages and the bores when I did it that way.
using a rag is all i wanted to know, that clarifies that
Title: Re: TTY head bolts - more than you might want to know.
Post by: air-cooled or diesel on December 28, 2012, 07:41:50 pm
this one is just for you, im not trying anything more than to clarify this
as seeing what just happened im just saying 1 thing.
i never said I put x,xxxk miles on my cars, but they do have that(apx).
Title: Re: TTY head bolts - more than you might want to know.
Post by: TylerDurden on December 29, 2012, 11:00:59 am

Got the TD fired up for the first heat cycle and subsequent 90o re-torque.

FWIW, all the bolts (TTY) topped in the region of 140 ft-lb.

While the final torque is itself not the most important issue (clamping force is), it may be helpful to others to know what can be expected.



(edit: text for superscript)