Rod bolts fell out!

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I’ve reused piles of rods where the bolts were barely snug in the bore(and would come out with a very light tap).

Never an issue.

On the other hand, I’ve often seen poor outcomes from resized rods with aftermarket bolts, where the skill of the person and/or the condition of the equipment doing that job wasn't up to par.
 
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I’ve reused piles of rods where the bolts were barely snug in the bore(and would come out with a very light tap).

Never an issue.



On the other hand, I’ve often seen poor outcomes from resized rods with aftermarket bolts, where the skill of the person and/or the condition of the equipment doing that job wasn't up to par.


I won’t use those ARP waveloc bolts either. No reason in the world to have that much press fit on the bolt. They distort the rod like crazy.
 
The old DC high strength rod bolts went in with barely any more noticeable press than the originals.
No “knurling” on them either...... just smooth like originals.

I checked the sizing after installing those bolts, and they often didn’t require any resizing.

Probably not even close to ARP quality....... but then again, I never encountered a broken one.
 
The old DC high strength rod bolts went in with barely any more noticeable press than the originals.
No “knurling” on them either...... just smooth like originals.

I checked the sizing after installing those bolts, and they often didn’t require any resizing.

Probably not even close to ARP quality....... but then again, I never encountered a broken one.


IIRC, those were the SPS bolts. They were very good. I used several sets of them.
 
The old DC high strength rod bolts went in with barely any more noticeable press than the originals.
No “knurling” on them either...... just smooth like originals.

I checked the sizing after installing those bolts, and they often didn’t require any resizing.

Probably not even close to ARP quality....... but then again, I never encountered a broken one.

The 426 hemi rod bolts had a fairly tite fit on the 2 that I had , took a hammer to move them .
 
Nothing wrong with stock 340 rods... I like Ma Mopar's metalurgy over over import rods any day I don't care if it cost's $300.00 to resize the stock rods. BTW Mine cost around $120.00 to resize, install new ARP bolts and balance plus the cost of the bolts.
 
Just to add more..

I was guiding a build on a 440 about 16 years ago and the guy didn't wanna spring for new rod bolts. It was a mancini rebuild kit with speed pros n such, anyways..
..so the rods were resized and that was that. Fast forward to assembly...as I put the P/R's in for him, he was special ed...the rod bolts on a couple...fell right out... no knurl or nothing. I told him I'd send this **** back for bolts...but he said fk it... so I bolted it togther and put it in and broke it in...
4.30's .533 lift. 6500 rpm shifts w/TA valve body and med 3800 stall 'too much'.
He didnt even have the heads rebuilt, so I took them and did the least...valve lap and proper spring setup.
Still running fine.
 
Ahhhhhhhh crap. Rookie mistake. Buttoning up my 5.9 Magnum short block. .030 over, new pistons installed on rods and in the block awaiting plastiguage check on rod tolerances with new ARP standard rod bolts. I did not resize rods. What now? Reuse old bolts or carry on? Engine had 100k on it. This is a street motor under 400hp. No track and no crazy revs.
 
So it is always advisable to resize the large ends when the bolts are replaced. This is due primarily to a possible mis-match on the caps to the rods, which (I think) can lead to spun bearings. That said, there have been those who have replaced rods and didnt resize and got away with it. Usually this is on engines with loose clearances on the rod journals.

The risk is yours to take.
 
Thanks JC. I am thinking I am better off with the new ARP bolts on my seasoned rods due to the duty cycle on the factory bolts. I will check my clearances but I suspect the fit will be somewhat loose but within spec. I did check the clearances before teardown and they were in spec. I am also replacing the rod bearings.
 
Ahhhhhhhh crap. Rookie mistake. Buttoning up my 5.9 Magnum short block. .030 over, new pistons installed on rods and in the block awaiting plastiguage check on rod tolerances with new ARP standard rod bolts. I did not resize rods. What now? Reuse old bolts or carry on? Engine had 100k on it. This is a street motor under 400hp. No track and no crazy revs.
Did you fit the new ARP bolts in the rods yet? If not, then keep the old ones in there; your use is not severe. If the ARP bolts are in already, then that is the potential issue if they had to be pushed or pulled in hard.

To be honest, I have never replaced a rod bolt in anything, including my Opel and Mitsubishi rally car engines that have been hammered on over and over. I suspect most of the failures come from come from poor install work (not torqured so too loose or overtightened and thus stretched) and from pushing the stock bolts beyond what they were designed for.
 
Ive never replaced bolts either, but I do replace the nuts with ARP parts, particularly if they look like the've been chewed on before.
 
Thanks guys. I removed the old bolts. They were in pretty tight so I had to tap them out with a hammer. The ARP bolts are in loosely right now. Not all the way yet.
 
I don't think tapping out the old bolts did anything bad, if you tapped them straight out. Seems like you could just put them back in. See post #26.

Since you have the pistons already on, then I can see trying to put in the old bolts. I would:
  • Put them back in and torque the rod nuts/bolts without bearing shells.
  • Measure the big end for roundness with a good dial caliper; if you are careful, you can get valid measurements of differences under .001"
  • Inspect the nuts as suggested above
 
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Ahhhhhhhh crap. Rookie mistake. Buttoning up my 5.9 Magnum short block. .030 over, new pistons installed on rods and in the block awaiting plastiguage check on rod tolerances with new ARP standard rod bolts. I did not resize rods. What now? Reuse old bolts or carry on? Engine had 100k on it. This is a street motor under 400hp. No track and no crazy revs.
If you didnt grind the grind the crank either and just honed for .030 pistons, fk it, you're fine. Enjoy
Its along the same lines as re ring and bearing deal. Sure they could be a hair oval by .00025+ ...everythings kinda worn together though, it's when you grind the crank, change rod bolts etc..or rod gauge them and they're oval that you need to re size them. Anything beyond a low mile or grocery getter re ring.. gets resized.
 
When you guys say resized, that means my new rod bearings would need replacing?
No, resized is probably not the right word. Rehoned would be better. What they do is trim (minimal) the caps mating surfaces and machine the insides to size the original size. The size of the bearings isnt dependent on the rods, just the crank.
 
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