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2004 Discovery II SE-7
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17 Posts
Discussion Starter · #1 ·
I've seen similar questions done to death but, maybe my situation/ findings will get someone to chime in with their experience.

My question is my head bolts are currently sitting @72 ft-lbs after the 1st 90° turn.
Am I safe to leave it at that?
All parts were purchased from Atlantic British. My heads weren't warped but I did have to get .007 taken off because the old head gasket wore a crescent gouge into it.

THE BACKSTORY:
I bought a D2 with a blown head gasket and shoddily repaired rust on the frame. Upon teardown I discovered Top hat liners already installed and the apparent cause of the failure were pulled threads in the block.
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When reinstalling the head the bolts were slipping at the 15-20 ft-lb mark. Pulled the head back off and installed some Timeserts.
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I did the upper and lower holes, put the head back on.. so far so good. 15 ft-lb followed by 90° and the threads to the left let go @58 ft-lb (my torque wrench does angle and tells you the end torque result). Head off... Again, Timeserts.. drilling.. cleaning up metal shavings.. and using my other head gasket since I'm not sure if this one is crushed now.
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At this point all the weak threads seem to have been sorted. But after the 15ft-lbs it took 68-82 ft-lbs to achieve a 90° turn. I don't think it would be wise turning these bolts another 90° and I'd appreciate if anyone has seen these these kind of numbers/ results before.
I've also double checked to be sure with a 2nd torque wrench.


Thanks all!
 

· Registered
2003 Discovery 2 SE7
Joined
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797 Posts
I've seen similar questions done to death but, maybe my situation/ findings will get someone to chime in with their experience.

My question is my head bolts are currently sitting @72 ft-lbs after the 1st 90° turn.
Am I safe to leave it at that?
All parts were purchased from Atlantic British. My heads weren't warped but I did have to get .007 taken off because the old head gasket wore a crescent gouge into it.

THE BACKSTORY:
I bought a D2 with a blown head gasket and shoddily repaired rust on the frame. Upon teardown I discovered Top hat liners already installed and the apparent cause of the failure were pulled threads in the block. View attachment 94985
View attachment 94984
When reinstalling the head the bolts were slipping at the 15-20 ft-lb mark. Pulled the head back off and installed some Timeserts.
View attachment 94986
I did the upper and lower holes, put the head back on.. so far so good. 15 ft-lb followed by 90° and the threads to the left let go @58 ft-lb (my torque wrench does angle and tells you the end torque result). Head off... Again, Timeserts.. drilling.. cleaning up metal shavings.. and using my other head gasket since I'm not sure if this one is crushed now. View attachment 94987
At this point all the weak threads seem to have been sorted. But after the 15ft-lbs it took 68-82 ft-lbs to achieve a 90° turn. I don't think it would be wise turning these bolts another 90° and I'd appreciate if anyone has seen these these kind of numbers/ results before.
I've also double checked to be sure with a 2nd torque wrench.


Thanks all!
I did mine based off what the RAVE states, which is 15 lb-ft + 90° + 90°. It gets them pretty tight. I had to get a jack handle on the end of my breaker bar to get the second 90°. I agree in your case I'd be worried about it though with the soft threads. If you feel confident in your repairs holding, I'd go at least another 75°, and evaluate from there - I think I went around 80 or 85° for the second degree tightening because I wasn't able to get the bar to move much further from the angle it was sitting at.
Also, I seem to remember that max allowable head machining is .004"? I could be wrong, it's been a while.
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· Registered
2003 Discovery 2 SE7
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797 Posts

· Registered
2004 Discovery II SE-7
Joined
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17 Posts
Discussion Starter · #4 ·
Thanks for the quick reply!
I've seen the Rave specs and AB included similar instructions with their kit. There's an optional torque spec of bolt 10 if it is a stud that got me wondering if going further would be too far.
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I'm also concerned about how much stretch the bolts have. At this point if I pull out more threads I'd probably have to buy another set of head bolts.

As for the resurfacing I recall the max to remove is .020 and max warp is .002
 

· Registered
2003 Discovery 2 SE7
Joined
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797 Posts
Thanks for the quick reply!
I've seen the Rave specs and AB included similar instructions with their kit. There's an optional torque spec of bolt 10 if it is a stud that got me wondering if going further would be too far.
View attachment 94989

I'm also concerned about how much stretch the bolts have. At this point if I pull out more threads I'd probably have to buy another set of head bolts.

As for the resurfacing I recall the max to remove is .020 and max warp is .002
Hopefully you have new head bolts in there. Since they are torque to yield (angle tighten) they should be replaced every time they are removed. I also don't remember seeing that note you highlighted in the RAVE documentation, although AB has some great videos on YouTube and they know their stuff. Did you fix all the bolt holes, or just the stripped out ones?
 

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2004 Discovery II SE-7
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17 Posts
Discussion Starter · #6 ·
I decided my toddler was sufficiently asleep and snuck back out to the garage. I'm no stranger to this job (first time on a LR) and I told myself this last time I felt confident in the "feel" of everything... Except bolt #1 in the sequence felt much stiffer than the rest. Decided if it's going to fail better to happen in the garage.

I put another 90° on 9/10 of the bolts and they seemed to plateau around here
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I set the angle to 25° and monitored how much force I had to apply getting there (did this 3x), then finished off with a final 15° to reach 90.

Bolt #1 in the pattern I left at 75° because it felt much tighter than the rest... Since it was
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In total I put in 3 Timeserts around the "failed" cylinder, initially I did 2 but the threads of the 3rd pulled @58ft-lbs on the 90° swing.
The bolts are new from AB.
My first go around I was using my standard Craftsman torque wrench I use at work. The next 2x I bought a digital one and being able to see the force you're applying when doing and angle definitely made this job easier on my nerves.

To answer my own question after doing 15-90°-90° you'll end up averaging 88-97 ft-lbs.
 

· Registered
2003 Discovery 2 SE7
Joined
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797 Posts
I decided my toddler was sufficiently asleep and snuck back out to the garage. I'm no stranger to this job (first time on a LR) and I told myself this last time I felt confident in the "feel" of everything... Except bolt #1 in the sequence felt much stiffer than the rest. Decided if it's going to fail better to happen in the garage.

I put another 90° on 9/10 of the bolts and they seemed to plateau around here
View attachment 94990

I set the angle to 25° and monitored how much force I had to apply getting there (did this 3x), then finished off with a final 15° to reach 90.

Bolt #1 in the pattern I left at 75° because it felt much tighter than the rest... Since it was
View attachment 94991

In total I put in 3 Timeserts around the "failed" cylinder, initially I did 2 but the threads of the 3rd pulled @58ft-lbs on the 90° swing.
The bolts are new from AB.
My first go around I was using my standard Craftsman torque wrench I use at work. The next 2x I bought a digital one and being able to see the force you're applying when doing and angle definitely made this job easier on my nerves.

To answer my own question after doing 15-90°-90° you'll end up averaging 88-97 ft-lbs.
Nice - glad you were able to get them tight. That torque plateau is the bolt stretching as it should
 

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78 Posts
I've seen similar questions done to death but, maybe my situation/ findings will get someone to chime in with their experience.

My question is my head bolts are currently sitting @72 ft-lbs after the 1st 90° turn.
Am I safe to leave it at that?
All parts were purchased from Atlantic British. My heads weren't warped but I did have to get .007 taken off because the old head gasket wore a crescent gouge into it.

THE BACKSTORY:
I bought a D2 with a blown head gasket and shoddily repaired rust on the frame. Upon teardown I discovered Top hat liners already installed and the apparent cause of the failure were pulled threads in the block. View attachment 94985
View attachment 94984
When reinstalling the head the bolts were slipping at the 15-20 ft-lb mark. Pulled the head back off and installed some Timeserts.
View attachment 94986
I did the upper and lower holes, put the head back on.. so far so good. 15 ft-lb followed by 90° and the threads to the left let go @58 ft-lb (my torque wrench does angle and tells you the end torque result). Head off... Again, Timeserts.. drilling.. cleaning up metal shavings.. and using my other head gasket since I'm not sure if this one is crushed now. View attachment 94987
At this point all the weak threads seem to have been sorted. But after the 15ft-lbs it took 68-82 ft-lbs to achieve a 90° turn. I don't think it would be wise turning these bolts another 90° and I'd appreciate if anyone has seen these these kind of numbers/ results before.
I've also double checked to be sure with a 2nd torque wrench.


Thanks all!
Just use ARP studs next time. after 8 sets of head gaskets on different rigs, I know they are superior both in terms of more accurate torques being achieved, and in less stress to the block threads since they are not turning in the block while torquing. You can also reuse them again and again. they are superior in every way. That is one dirty engine, since it has top hat liners, that would mean it was clean in there when they did that machining. It also indicates that this is at least the second head gasket that has failed and now your putting on at least the third. all that contributes to the condition of the threads. With ARP studs the final torque on the instructions says 100 ft pounds! I did that a couple times but settled on 85 foot pounds and have never had any trouble or blown head gaskets again. Also when using the studs I advise to torque them to the second torque setting and leave them over night then check that the torque is still at the 2nd stage as there is often one or two that are no longer the torque you set them at. After that I do the final torque to 85 ft lbs. I have not had any failures to this point.
 

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2004 Discovery II SE-7
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Discussion Starter · #9 ·
I was really tempted to use them. I think what made me decide on the bolts was that they would put a little extra stress on the threads. Since I was already putting the timeserts in if there were any other threads about to fail I'd rather it happen in the garage.

Also yes! My thoughts exactly. The engine is very sludged considering it was clean at the machine shop. I don't have a history on her so I can only assume there's been two owners since this engine was rebuilt (before I got her). The person I got it from bought it for their daughter and the head gasket blew after 500 mi.
I mean me personally if I went through the trouble of doing liners, rings, etc.. I'd keep up on oil changes..
 
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