Head Bolt, Stud Torque Tech Tip - Importance of a proper washer - Interesting

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Sounds like ARP didnt keep up with quality control or random engineering checks/tests !

If their production process changed they should have rechecked stretch/torque ratings !
 
That is a good article, thanks. I will say this though. I've reused probably hundreds of sets of OEM head bolts through the years and had not one problem. No washers. Used a good bit of ARP bolts, too. With washers. I think it all depends on the type of metal involved, both in the head and bolts.
 
Thanks RRR. I'm reusing the head bolts on my low mileage magnum build. Not to hijack but what are the thoughts on reusing con rod bolts?
 
JoePole1 said:
Thanks RRR. I'm reusing the head bolts on my low mileage magnum build. Not to hijack but what are the thoughts on reusing con rod bolts?
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I draw the line there. Good rod bolts and rod resizing is not a huge expense. A lot of people don't realize what the rod bolts go through.....................Let me splain.

As engine RPM increases, the piston tries to pull the piston and the connecting rod off of the rod cap every time it reaches TDC. The rod bolts actually go through momentary stretch cycles at high RPM, AND When the engine is revved high off idle. Imagine how many times the rod bolts stretch and relax over the life of an engine. When you think of that, it makes no since to reuse old rod bolts.
 
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you the original owner?
if not has the motor been apart before- NO- you are good to go no spun rod bearings or similar...
yes
how many times have they been torqued up
put the cap (s) on a piece of glass or a steel plate and make sure the flats are flat
if there is an angle it means that the caps have sometime in the past been cut on an angle for a chepie reguild
have to cut them a lot to get them fixed- most likely rods are junk
as for the bolts
MP used to sell the MP SPS rod bolts inexpensive and there are other choices besides ARP for a rebuild
 
IMHO, the 'unintended consequences' of the smooth washers referred to the article are not 100% unintended by ARP. They make the washers smooth and flat on the bolt head/nut side so that they present a lower and more consistent friction when the bolt/nut turns, and so you get a better read on the what the friction is at the threads.

But the info on the surfaces being too smooth on both side is pretty good info. My hat is off the the guys who noticed the final torque increase not behaving as it should, and catching this. And it's a clever solution to sand the bottom of the washers and not lube them; good stuff.

Rod bolts? Depends on how hard you will use them and the specific conditions. American V8 stuff, with longer strokes and heavier pistons/rods, sees a lot more rod bolt stress/strain than some other engines, and just seem to need more attention there. FWIW: In contrast, I always reused them on my 1.9L Opel engines (pretty much the same sizing as for SBM rod bolts) and revved the crap out of them to 8K repeatedly in racing; nary a problem. But, the pistons/rods are a ton lighter that your standard V8 stuff and the stroke is only 2.75" so the acceleration forces on the rod bolts are lower for multiple reasons.
 
I've got a set of used aluminum heads and notice that the bolt seats on the holes that are under the valve cover have a very distinct depression in the aluminum from the washer or bolt the previous owner used. The other row of holes on the outside don't show this deformation. Is this common or was there a screw up? I was going to try and face the bolt seat off and use a little wider thin hard washer under the nuts and washers (SM stud kit) when I install them to help spread the load. Not sure if this is normal or those had the washer catch and turn, or what happened.
 
Hard to say for sure without knowing what was actually used. I would wonder if a washer was NOT used and the area got ground down. Or, if those upper bolt seats are not surrounded by metal at the same level, then the AL would seem to be subject to distortion and 'flowing' out. (AL has about half the shear strength of cast iron.) And the Edelbrock heads' upper seats are like that... isolated towers; IDK on others.

Any washer under the bolt head needs to be thick like an ARP washer, not thin. A thin washer will just bend and distort, and not be effective in spreading the loading around. So maybe you need wider thick washers than your kit....
 
nm9stheham said:
Hard to say for sure without knowing what was actually used. I would wonder if a washer was NOT used and the area got ground down. Or, if those upper bolt seats are not surrounded by metal at the same level, then the AL would seem to be subject to distortion and 'flowing' out. (AL has about half the shear strength of cast iron.) And the Edelbrock heads' upper seats are like that... isolated towers; IDK on others.

Any washer under the bolt head needs to be thick like an ARP washer, not thin. A thin washer will just bend and distort, and not be effective in spreading the loading around. So maybe you need wider thick washers than your kit....
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I don't know what was used but there is marked difference in the result. I disagree on the thin washer of proper heat treated steel. It would provide the extra surface area that will prevent damage to the aluminum at reasonable force/torque levels. On the other hand a wider thick washer would be better and after I correct the bolt seats. I'll turn some up on the lathe and heat treat them in my oven if the ones in the new kit aren't satisfactory. I have a feeling that no washer was used or it was locked to the bolt and turning based on the markings I remember. I don't see how it is from compression only.

I'll try to post a pic or two if I have time tonight.
 
RustyRatRod said:
That is a good article, thanks. I will say this though. I've reused probably hundreds of sets of OEM head bolts through the years and had not one problem. No washers. Used a good bit of ARP bolts, too. With washers. I think it all depends on the type of metal involved, both in the head and bolts.
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Same here. Motor oil on threads when torqued.
Over n over. Main bolts too.
 
gzig5 said:
I don't know what was used but there is marked difference in the result. I disagree on the thin washer of proper heat treated steel. It would provide the extra surface area that will prevent damage to the aluminum at reasonable force/torque levels. On the other hand a wider thick washer would be better and after I correct the bolt seats. I'll turn some up on the lathe and heat treat them in my oven if the ones in the new kit aren't satisfactory. I have a feeling that no washer was used or it was locked to the bolt and turning based on the markings I remember. I don't see how it is from compression only.

I'll try to post a pic or two if I have time tonight.
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Well, look at the washer under the bolt for the damper... it is as thick as it is for one reason only: To not distort when you put that 135 ft lbs of torque on the bolt. You can only do so much in terms of strength increase with hardening.

You're probably right....I'd think any compression problems would show up in how the material is distorted nearby. Seems like the 'pad' would become shaped something like the top of a glass soda-pop bottle if is did.

Having that lathe is great... I hope I can follow you soon. I'll see your lathe and raise you a mill LOL
 
nm9stheham said:
Well, look at the washer under the bolt for the damper... it is as thick as it is for one reason only: To not distort when you put that 135 ft lbs of torque on the bolt. You can only do so much in terms of strength increase with hardening.

You're probably right....I'd think any compression problems would show up in how the material is distorted nearby. Seems like the 'pad' would become shaped something like the top of a glass soda-pop bottle if is did.

Having that lathe is great... I hope I can follow you soon. I'll see your lathe and raise you a mill LOL
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I always just lightly hit it with an impact or a couple swings of a 2lb sledge on the braker bar. Never come off till they're told to.
 
nm9stheham said:
Having that lathe is great... I hope I can follow you soon. I'll see your lathe and raise you a mill LOL
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You may not want to keep betting. I had to sell two South Bend 10L lathes, a Sheldon horizontal, and an EMCO vertical lathe (among other stuff) to make room in the garage for my Cuda. But, I'm still sitting on four lathes and 3 1/2 milling machines. OK, two of the lathes are little desktop jobs and two of the mills are counting the mill head attachments on the EMCO lathes, but they still count. :D
Part of my machining hobby is rebuilding and scraping the ways on the machines. Keeps me out of the bars in the evenings.
 
pics as promised. I think I'll just knock the burr off and live with it. The SM stud kit washers are just over the diameter of the indentation. Just seemed odd that the ones on the outside didn't show the marks. But now that I think about it, the orange paint that was on the head (which I removed) must have provided cushion under the fasteners. Obviously the ones under the valve covers weren't painted. Mystery solved?

IMG_3129.JPG


IMG_3132.JPG


IMG_3133.JPG
 
gzig5 said:
You may not want to keep betting. I had to sell two South Bend 10L lathes, a Sheldon horizontal, and an EMCO vertical lathe (among other stuff) to make room in the garage for my Cuda. But, I'm still sitting on four lathes and 3 1/2 milling machines. OK, two of the lathes are little desktop jobs and two of the mills are counting the mill head attachments on the EMCO lathes, but they still count. :D
Part of my machining hobby is rebuilding and scraping the ways on the machines. Keeps me out of the bars in the evenings.
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LOL! That is good stuff. So do you do this for other shops, or do you just restore and turn stuff around and resell it?

And yes on the paint.... I looked at your pix and the indentation looks the same, just that the washers' anodizing got transferred to the head on the upper ones. Obvioulsy, the AL material is getting a bit brinnelled or maybe even crushed. Looks like the washers were not there, or maybe like the original article here, the washers spun some with the bolts/nuts. I guess you get to try sanding the bottom sides down and not lubing them, like the article recommended.

Thanks for sharing the info.
 
MOPAROFFICIAL said:
I always just lightly hit it with an impact or a couple swings of a 2lb sledge on the braker bar. Never come off till they're told to.
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But the 135 ft lbs is not to keep it on... it's to make sure the crank's internal vibrations couple to the damper hub.
 
nm9stheham said:
LOL! That is good stuff. So do you do this for other shops, or do you just restore and turn stuff around and resell it?

And yes on the paint.... I looked at your pix and the indentation looks the same, just that the washers' anodizing got transferred to the head on the upper ones. Obvioulsy, the AL material is getting a bit brinnelled or maybe even crushed. Looks like the washers were not there, or maybe like the original article here, the washers spun some with the bolts/nuts. I guess you get to try sanding the bottom sides down and not lubing them, like the article recommended.

Thanks for sharing the info.
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I just do the rebuild stuff for me and for resale if I come across a machine at the right price. I have a two car garage in which my side was a machine/work shop for the last 17 years. I had to move/sell/give away a lot of stuff to be able to get a car in on my side. Wife won't give up her side during winter and the lot layout won't allow me to expand. Getting close to retirement and hoping to come up with a few widgets to make and sell to keep me busy. I've been repairing BMW E39 M5 oil pans for several years because parts for those cars are crazy expensive.
 
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