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CRD Head Bolt Research Request: We need your data!
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Author:  geordi [ Sun Aug 24, 2014 7:55 pm ]
Post subject:  CRD Head Bolt Research Request: We need your data!

With the last few vehicles that have had their head bolts replaced with ARP studs, an interesting and distressing pattern has emerged. The bolts do not have the same torque from the factory, even within the same engine or location group in the engine.

I am asking anyone and everyone to assist in the collecting of data about the engines that you work on, so that a more complete picture can be created and predictions can be made.

Using the Factory Service Manual bolt numbering from page 9-197 and pictured here:
Image

PLEASE follow this pattern of numbering for consistency, and the following instructions to discover and report back about the breaking torque for each factory head bolt. This is very important, so thank you for doing this!

Measuring the force is fairly simple: Using your large click torque wrench (I use the $80 30 inch one from Home Depot - it clicks in both directions) set the torque to 80 lb-ft, and attempt to crack the bolt. If the wrench clicks (it should) increase the setting to 85, and try again. Continue increasing 5 lbs at a time. At the point that the bolt releases and the wrench does NOT click - that is the release torque. Make a chart of the bolt numbers according to the book's tightening sequence (I usually clean the head and write the numbers in sharpie directly on the head next to the bolt hole) and record the torque on that chart so that it can be shared in this thread with the board.

The critical ones to watch for are directly bordering the cylinders, on the exhaust side between or around cylinder #3. That seems to be the place that the torque is wildly different for some reason. I am curious to know the values on your engine because of this.

As for reporting: I would ask that you put the numbers into this thread in the following type of format, that I will quote in the next post for easy quote-and-edit pasting of the numbers.

CRD YEAR: xx
MILEAGE: xxx,xxx
BOLT TORQUE CENTER ROWS:
01: xxx
02: xxx
03: xxx
04: xxx
05: xxx
06: xxx
07: xxx
08: xxx
09: xxx
10: xxx

BOLT TORQUE OUTER ROWS:
11: xxx
12: xxx
13: xxx
14: xxx
15: xxx
16: xxx
17: xxx
18: xxx

Again, THANK YOU FOR HELPING THE GROUP!

Author:  geordi [ Sun Aug 24, 2014 7:55 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

CRD YEAR: xx
MILEAGE: xxx,xxx
BOLT TORQUE CENTER ROWS:
01: xxx
02: xxx
03: xxx
04: xxx
05: xxx
06: xxx
07: xxx
08: xxx
09: xxx
10: xxx

BOLT TORQUE OUTER ROWS:
11: xxx
12: xxx
13: xxx
14: xxx
15: xxx
16: xxx
17: xxx
18: xxx

Author:  geordi [ Sun Aug 24, 2014 7:59 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Reserved for future updates

Author:  geordi [ Sun Aug 24, 2014 8:11 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Reserved for future updates.

Author:  geordi [ Sun Aug 24, 2014 8:12 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Reserved for future updates.

Author:  tjkj2002 [ Mon Aug 25, 2014 6:28 am ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

What your looking for will not be constant,to many factors can lead to different "release" amounts.No 2 will be the same.

Author:  greiswig [ Mon Aug 25, 2014 11:27 am ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Looks like I may be doing mine, so I'll record this. It may be one of those cases where some data isn't better than none, but until we see whether there is consistency to the pattern we may not know. Doesn't hurt to track it and see.

Author:  cevans [ Mon Aug 25, 2014 4:09 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

tjkj2002 wrote:
What your looking for will not be constant,to many factors can lead to different "release" amounts.No 2 will be the same.


Exactly. It is impossible to get the installed torque spec once a bolt has been installed. Plus, a click-type torque wrench is NOT a precision instrument, so any data from a click-type is already invalid.

Author:  geordi [ Mon Aug 25, 2014 7:55 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

I have to disagree with both of you here.

Firstly, a click wrench has to be tested before getting sold. Whether it needs further testing or calibration after being in service for some time to remain accurate, I would admit that the cheaper consumer-grade would probably not hold their calibrations as long or as well as something from Snap-On.

But what I am looking to learn involves variations on release torque of greater than 40-50 lb-ft. This isn't a variable between engine #1 and engine #2, as much as between bolt #4 and bolt #3 or bolt #2 within the same engine. Doing the same job, on the same head, in the same engine for the same length of time... They should be within 10-15 lbs of each other. 50... Is right out.

I have done about 6 of these engines where I have observed MASSIVE differences in the release torque between bolts in the same section. The intake bolts on cylinder #3 should NOT be 50 lb-ft tighter than the exhaust bolts on the same cylinder! I would also suggest that they shouldn't be much different than ANY of the other bolts in the #1-#10 positions.

Yet they are.

This isn't a list to collect ultra-scientific double-blind 1% +/- results, as there wouldn't be any purpose. Why do that, so we can sue Chrysler and VM for putting out an engine with a massive flaw? No point, the bankruptcy judge gave them a free pass.

The purpose of this is to see whether my observations track with other engines, and to allow people to see whether there IS a potential problem, and decide for themselves whether to go through the effort to install ARP studs to prevent a leak before one exists and maybe damages something on their engine.

If there was a chance that one or more head bolts in my engine were loose, there isn't any reason why I wouldn't want to have that information.


Sent from my iPad using Tapatalk HD

Author:  tjkj2002 [ Mon Aug 25, 2014 9:39 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

geordi wrote:
I have to disagree with both of you here.

Firstly, a click wrench has to be tested before getting sold. Whether it needs further testing or calibration after being in service for some time to remain accurate, I would admit that the cheaper consumer-grade would probably not hold their calibrations as long or as well as something from Snap-On.

But what I am looking to learn involves variations on release torque of greater than 40-50 lb-ft. This isn't a variable between engine #1 and engine #2, as much as between bolt #4 and bolt #3 or bolt #2 within the same engine. Doing the same job, on the same head, in the same engine for the same length of time... They should be within 10-15 lbs of each other. 50... Is right out.

I have done about 6 of these engines where I have observed MASSIVE differences in the release torque between bolts in the same section. The intake bolts on cylinder #3 should NOT be 50 lb-ft tighter than the exhaust bolts on the same cylinder! I would also suggest that they shouldn't be much different than ANY of the other bolts in the #1-#10 positions.

Yet they are.

This isn't a list to collect ultra-scientific double-blind 1% +/- results, as there wouldn't be any purpose. Why do that, so we can sue Chrysler and VM for putting out an engine with a massive flaw? No point, the bankruptcy judge gave them a free pass.

The purpose of this is to see whether my observations track with other engines, and to allow people to see whether there IS a potential problem, and decide for themselves whether to go through the effort to install ARP studs to prevent a leak before one exists and maybe damages something on their engine.

If there was a chance that one or more head bolts in my engine were loose, there isn't any reason why I wouldn't want to have that information.


Sent from my iPad using Tapatalk HD
The intake side bolts should be easier to release then the exhaust side on a engine that has say 100k on it.The intake side will have been subjected to less extreme heat then the exhaust side.


Oh and those no-name torque wrenches bought at HF and home depot are not accurate even when bought new,no QC at all.Seen it proved many times.Sorry but torque wrenches is 1 item that tops the list for "you get what you pay for".

Author:  ATXKJ [ Mon Aug 25, 2014 11:42 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

tjkj2002 wrote:
Oh and those no-name torque wrenches bought at HF and home depot are not accurate even when bought new,no QC at all.Seen it proved many times.Sorry but torque wrenches is 1 item that tops the list for "you get what you pay for".



Car Craft -tested them and they disagree.
http://www.carcraft.com/techarticles/ccrp_1304_torque_wrench_testing/

That said - I only use the Harbor freight for lugnuts - and use a Craftsman for anything on an engine.

and the caveat always remains with 'clicker' style - if you leave it with the preload on it looses accuracy fast
always zero them out after every use.

and to Geordi's research - if you get enough data - the problems will show in the Standard Deviation - you'll get a lot of noise.

Author:  geordi [ Tue Aug 26, 2014 12:40 am ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

TJKJ - I might agree with you, except my observations have been the exact OPPOSITE. The intake side and exhaust for most of the bolts were approximately the same, while the exhaust side were VERY loose on some bolts. Again, 50 lb-ft differences observed.

ATXKJ: I'm not looking so much for std deviations, and I agree that there will be a lot of noise between engines - more to the point of within a given engine, is there a wide deviation between bolts 1-10, where 8 of them are 125/130 lb-ft to release, and 2 are at 80/90? I think that will be conclusive enough WITHIN THAT ENGINE to override any potential variations. At the same time, the variations between wrenches is being accounted for, because each person having their own wrench will obviously render a different number from another wrench or CRD... But it is the deviation that I am interested in, not the specific numbers.

So even a wrench that thinks 120 (actual) is really 150... If the bolt next to it registers as 120 on that same wrench - that is a 30 point variation as measured on the same vehicle and by the same wrench - so the 30 lb difference should be a valid data point, regardless of the individual inaccuracy of the specific wrench.

Make sense yet?

On another note, comparing wrenches and leaving the torque on or off... Doc4444 believes as you do, that the wrench needs to be loosened after every use. I was unaware of this technique, and have had my big wrench set at 80 lb-ft for months, since I really only use it for CRDs. He was concerned about this, so we tested it against one of the head bolts on his CRD. Both wrenches clicked at the same point before the bolt released, and when it was reset with his wrench, mine clicked at the same point again. I'm not saying you are right or wrong, but it does seem that my wrench is holding its calibration even when I don't loosen it after every use.

Author:  flman [ Tue Aug 26, 2014 7:26 am ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Wow this is a sticky?

Well 2 of mine were looser but they were no where near the leak, my data is just looser.

And I must agree breaking torque will not always be the same and consistent like tightening torque.

Author:  greiswig [ Mon Sep 01, 2014 6:33 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Okay, I have the data from my head. There were at least two bolts where I think the bolt actually slipped a bit at 80 pounds, then clicked. And no, I don't think it as the flex in the wrench before it clicked: I was watching the socket. 1 and 7 seemed to do that.

Note also that a lot of these let loose at 80 pounds, which is the starting setting. So I don't know how far below that they were torqued to.

Symptoms were stumbling starts with smoke, and finally a clear hydro lock. Hopefully I avoided bending anything. Rockers look great.

Data is listed below.

CRD YEAR: 2005
BOLT TORQUE CENTER ROWS:
01: 90*
02: 124
03: 80
04: 96
05: 86
06: 96
07: 90*
08: 100
09: 90
10: 94

BOLT TORQUE OUTER ROWS:
11: 80
12: 86
13: 80
14: 80
15: 86
16: 80
17: 80
18: 96

geordi wrote:
Again, THANK YOU FOR HELPING THE GROUP!


Least we can do to help this fantastic community.

HTH,

Author:  LMWatBullRun [ Fri Sep 05, 2014 11:45 am ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

As you Install the studs at 2 and 8, please note how much rotation is required to acheive required torque at each step. You may find, as I did, that at certain torque levels, the arp nut will rotate more than others. Most of mine were consistent, but some took more rotation to get to final torque. I attribute this to slight warping of the head; the studs flattened it out.

Author:  flman [ Fri Sep 05, 2014 5:15 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

LMWatBullRun wrote:
As you Install the studs at 2 and 8, please note how much rotation is required to acheive required torque at each step. You may find, as I did, that at certain torque levels, the arp nut will rotate more than others. Most of mine were consistent, but some took more rotation to get to final torque. I attribute this to slight warping of the head; the studs flattened it out.


Most of them leak and warp on the exhaust side of the engine, mine did and most of the pics I saw hear was on the exhaust side. When I did my HG, I starting torquing where the leakage was out of sequence, in order to pull the head down in that area first.

Author:  Tony P. [ Mon Sep 15, 2014 9:09 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

CRD YEAR: 2006
BOLT TORQUE CENTER ROWS:
01: 120
02: 150
03: 160
04: 155
05: 150
06: 160++stripped the head round and still in place.
07: 155
08: 155
09: 140
10: 140

BOLT TORQUE OUTER ROWS:
11: 120
12: 130
13: 120
14: 140
15: 140
16: 130
17: 125
18: 140

Author:  spoon [ Thu Oct 02, 2014 11:38 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

I did the head because I was down to the rockers. The head gasket was showing signs of corrosion on the exhaust side of #3. There was quite a bit of what I would call frettiing corrosion in some areas which indicated movement between the head and block. I used a beam torque wrench. As tight as the bolts were I don't know how long the gasket would last, 20,000 or another 100,000.

CRD YEAR: 2005, 108,000
BOLT TORQUE CENTER ROWS:
01: 125
02: 150
03: 150
04: 155
05: 155
06: 145
07: 155
08: 145
09: 145
10: 200

BOLT TORQUE OUTER ROWS:
11: 140
12: 120
13: 130
14: 115
15: 135
16: 135
17: 140
18: 130

Author:  geordi [ Fri Oct 03, 2014 2:42 am ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

Thank you for your data points!

Leakage / blow-through on the gasket on the exhaust side of #3 seems to be the common location - yours makes about #7 that I have heard about or seen personally with the failure in this spot.

I agree with you - hard to tell whether the gasket would last another 20k or 100k... HOWEVER - Ours is a laminated steel gasket. I'm beginning to wonder if the gasket itself is salvageable if the bolts weaken, just by cleaning it and using studs.

I agree that the cost probably isn't worth the effort, but it is just a thought at this point. What are the gaskets in other (more normal) engines like? It seems much of this engine is unique only to itself...

Author:  greiswig [ Fri Oct 03, 2014 1:52 pm ]
Post subject:  Re: CRD Head Bolt Research Request: We need your data!

geordi wrote:
Thank you for your data points!

Leakage / blow-through on the gasket on the exhaust side of #3 seems to be the common location - yours makes about #7 that I have heard about or seen personally with the failure in this spot.

I agree with you - hard to tell whether the gasket would last another 20k or 100k... HOWEVER - Ours is a laminated steel gasket. I'm beginning to wonder if the gasket itself is salvageable if the bolts weaken, just by cleaning it and using studs.

I agree that the cost probably isn't worth the effort, but it is just a thought at this point. What are the gaskets in other (more normal) engines like? It seems much of this engine is unique only to itself...


Only other diesel head gasket I have extensive experience with is from my Benz OM352. It is definitely not multilayer steel. Composite with copper crimp rings around high pressure galleys, steel cylinder rings, silicone bead around other areas. Pretty complex.

I talked quite awhile with the head of the shop that is working on my cylinder head. According to him, he used to put together racing engines with MLS head gaskets, and they would weep about 75% of the time. He started using a thin coating of copper spray gasket seal on each surface, and has not had any problem since. But I don't think I would ever re-use an old gasket unless I was trapped in the backwoods of the Yukon territory and had no other way out.

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