Pioneer 3/8" rod bolts - Nova Tech
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  #1  
Old May 16th, 20, 04:52 PM
cw41 cw41 is offline
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Chuck
 
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Default Pioneer 3/8" rod bolts

On my 454, the machine shop resized the rods and used the HPerf type rod bolt from pioneer that use 60ft torque.
Putting the #1 together to check clearance I run the bolt down in 10lb incraments with 30w oil on threads and under nut and could never reach 60. Used my other torque wrench and same thing.
Took apart and nut threads were galled and a thread retore tap cleaned them up fairly easy( not that I would ever use again)! the rod bolt is a different story you cannot even start the restore die on it??
Never ran into this before using OEM rod bolts. these pioneer from about 10yrs ago are junk. First time I ever used them. and last
On a balanced assembly this really sucks. Thanks for any input.
chuck
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  #2  
Old May 16th, 20, 05:28 PM
Big Dave Big Dave is online now
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Default Re: Pioneer 3/8" rod bolts

When you replace the rod bolts you have to resize the rod. Since the combination of a good ARP rod bolt and machine shop labor is close to the price of a new rod with an ARP bolt installed in it; rods being reworked has become a lost art.

You can not rely upon a rod bolt that has been damaged. Retapping the thread is not an option. Those bolts are junk, and have to be replaced. By the way 3/8th bolts were only used on low performance engines (325 and 350 horse 396 and a 390 horse 427).

All High Performance big blocks used a 7/16th Boron alloy rod bolt on bigger stronger rods with a dimple in the webbing of the I-beam. Dimpled rods were not only forged, as are all Chevy rods, but they were shot peened and X-rayed before being sized.

Big Dave
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  #3  
Old May 16th, 20, 06:47 PM
cw41 cw41 is offline
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Default Re: Pioneer 3/8" rod bolts

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Originally Posted by Big Dave View Post
When you replace the rod bolts you have to resize the rod. Since the combination of a good ARP rod bolt and machine shop labor is close to the price of a new rod with an ARP bolt installed in it; rods being reworked has become a lost art.

You can not rely upon a rod bolt that has been damaged. Retapping the thread is not an option. Those bolts are junk, and have to be replaced. By the way 3/8th bolts were only used on low performance engines (325 and 350 horse 396 and a 390 horse 427).

All High Performance big blocks used a 7/16th Boron alloy rod bolt on bigger stronger rods with a dimple in the webbing of the I-beam. Dimpled rods were not only forged, as are all Chevy rods, but they were shot peened and X-rayed before being sized.

Big Dave

thanks again big dave, these bolts are junk. What about the rod though can I trust it on the machinist that installed the pioneer bolts and resized? This is a low perf build and sell thing just to make room in my shop. this was a balanced assembly done by king balancing in phoenix.
trying to find a machine shop is very hard. Do you have a recommdation in your area? Is it you thats in the tucson area?
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Old May 16th, 20, 08:30 PM
Big Dave Big Dave is online now
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Default Re: Pioneer 3/8" rod bolts

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Originally Posted by cw41 View Post
thanks again big dave, these bolts are junk. What about the rod though can I trust it on the machinist that installed the pioneer bolts and resized? This is a low perf build and sell thing just to make room in my shop. this was a balanced assembly done by king balancing in phoenix.
trying to find a machine shop is very hard.
The rod is fine but it will have to be resized again with new bolts.

Resizing shaves a bit off the big end and a new rod bearing bore is cut in the rod again every time you do that which lightens and shortens the overall length of the rod every time you do that.

I wouldn't worry about the balance depending upon how high you intend to spin it. Factory balance is to a half an ounce or 14.1748 grams. I rev the snot out of my motors so I balance them to 4 grams which will take a BBC to ten grand if it has a cam and valve train to support it.


Quote:
Do you have a recommdation in your area?
Yes I recommend my machinist very highly. Just going to be too far to drop off and pick up parts:

http://www.jandsmachineworks.com/

Quote:
Is it you thats in the tucson area?
No that is Philip our senior moderator. Unfortunately he has rediscovered his main love which is Chevelles. He spends most of his time on Team Chevelle.

Big Dave
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  #5  
Old May 16th, 20, 08:42 PM
cw41 cw41 is offline
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Default Re: Pioneer 3/8" rod bolts

too bad he is not closer. the guy I used in phoenix changed his phone number maybe went out of business?? thanks again!!
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  #6  
Old May 16th, 20, 08:59 PM
62 NovaWagon 62 NovaWagon is offline
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Default Re: Pioneer 3/8" rod bolts

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Originally Posted by cw41 View Post
too bad he is not closer. the guy I used in phoenix changed his phone number maybe went out of business?? thanks again!!
If you're in Phoenix call Mike, great guy and really knows his $hit, he done stuff for me and always right on the way I wanted it, can't beat him reasonable prices too..


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  #7  
Old May 22nd, 20, 04:29 PM
Dave Ray Dave Ray is offline
 
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Default Re: Pioneer 3/8" rod bolts

On this type of thread, the threads themselves have "rolled" edges, and a regular tap has sharp ends, not compatible. NEVER run a regular tao through a rolled threaded hole, it destroys the threading. Same goes for a bolt like for rodfs, heads, etc.

There is another way to properly tighten bolts, it is to use a stretch meter to show the stretch of the bolt to get it to the proper holding tension. torque alone can sometimes not allow the attainment of correct stretch tension.

If you look on the ends of good rod bolts, there will be a dimple in the bolt center, these are where the stretch meter sits while being tightened to the correct bolt stretch.

Bolt stretch is far more accurate than torquing.
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Old May 22nd, 20, 04:50 PM
cottonwood green cottonwood green is offline
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Default Re: Pioneer 3/8" rod bolts

I can't believe that a shop wouldn't just install at the very least, ARP 8740 bolts when reconditioning rods!
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  #9  
Old May 23rd, 20, 08:57 AM
cw41 cw41 is offline
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Default Re: Pioneer 3/8" rod bolts

Quote:
Originally Posted by 62 NovaWagon View Post
If you're in Phoenix call Mike, great guy and really knows his $hit, he done stuff for me and always right on the way I wanted it, can't beat him reasonable prices too..


https://www.facebook.com/Zimmerman-R...7308924137928/

thank you for the tip on the machinist in phoenix as I've had lots of work done there over the last 40yrs. Most all are closed now. Never had an issues with rod bolts even years ago reusing the original old ones was ok. I never threw a rod and god knows I should have thrown many!! thanks
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  #10  
Old May 23rd, 20, 08:59 AM
cw41 cw41 is offline
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Default Re: Pioneer 3/8" rod bolts

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Originally Posted by cottonwood green View Post
I can't believe that a shop wouldn't just install at the very least, ARP 8740 bolts when reconditioning rods!
when I had these rods redone, pioneer was very competive with arp and the shop recommended them. Now have a pile of junk needing redone. thanks
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  #11  
Old May 23rd, 20, 09:09 AM
cw41 cw41 is offline
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Default Re: Pioneer 3/8" rod bolts

Quote:
Originally Posted by Dave Ray View Post
On this type of thread, the threads themselves have "rolled" edges, and a regular tap has sharp ends, not compatible. NEVER run a regular tao through a rolled threaded hole, it destroys the threading. Same goes for a bolt like for rodfs, heads, etc.

There is another way to properly tighten bolts, it is to use a stretch meter to show the stretch of the bolt to get it to the proper holding tension. torque alone can sometimes not allow the attainment of correct stretch tension.

If you look on the ends of good rod bolts, there will be a dimple in the bolt center, these are where the stretch meter sits while being tightened to the correct bolt stretch.

Bolt stretch is far more accurate than torquing.
thanks I have a stretch meter but the dimple isn't there on these. but to gall a rod bolt thead just is unheard of in my life especially in my bro's life as he is a retired mechanic and done hundreds of motors of every kind!
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