Pistons and Callies H beams are ready to install. The rods have L19 arp bolts and Callies spec is 92 lbft using Callies #3 extreme pressure lube. Seems high, but i'm curious to what you guys have been torquing the L19 bolt to with good results?

I use the stretch method, but I end up right at 92-95 lb-ft.


Joe

I have dabbled with a stretch gauge in the past with not so good results. The gauge would never repeat each time it was removed and my numbers where all over the place. I prefer to torque and forget. Callies suggest torque to 25lbft then to final spec. Was this your method? I like to torque in three even steps if possible. Not sure it really matters.

Stretch & Torque Values
Stretch: 0.0065 - 0.0070 in.
Bolt Torque Value: 80 ft-lbs (108 Nm) with ARP Ultra-Torque Fastener Assembly Lubricant

saw this on there website for that particular bolt

https://www.dragzine.com/tech-stori...rocess-of-fastening-rod-caps-is-crucial/

https://www.enginelabs.com/engine-t...ing-rod-bolt-stretch-vs-torque-with-arp/

https://www.dragzine.com/tech-stori...-all-those-bolt-alloys-and-numbers-mean/

This may help understanding of today's engine building techniques...torque is an approximation, bolt stretch is what's required with today's fastners...

Make sure you don't handle L 19 bolts with your hands. They are very suseptible to corosion. I'd read up on them.
Doug

I feel your pain as that was pretty much my experience as I attempted to do this for the very first time. After a few tries I discovered that the gauge tension needed to be much higher to make it less susceptible to even the tiniest movement. Replacing the dial indicator spring helped greatly. Still, I would have a steady reading that all of a sudden would jump by like 0.005" or so...ugh???

Well, the 2nd part was to make sure that the rod bolt ends and my gauge and dial indicator locating pin/foot left no room for the bolt to move around. Off shopping I went, picked up a set of these attachments with different shapes and found one that would mate very well.

These two steps were key to getting repeatable results.

Having said that...my Eagle H-beam rods had the Eagle ARP S2000 bolts, spec'ed for 0.0064-8" stretch at 75 ft-lbs. I went through 3 ON/OFF cycles, in the proper connecting rod vise, using the ARP lube, eventually got them to 85 ft-lbs and stopped there. The numbers were repeatable but I could not get them to that 0.0064-8 stretch.

Yes, the tip style does matter and it seemed like the measuring surface in the bolt head was not very uniform on the Molnar 2000 bolts. I gave up and just torque them using torque to yield method Molnar suggested. Rods are still in the block 5 years later. Callies included an instruction card with torque suggested torque method, torque to 25lbft then to 92. I just question that as that is not my method of torquing a bolt and the final spec seems very high for that size of bolt, but then again i have never dealt with L19 bolts. Thanks for the info. I might check stretch on all them if the numbers look trustworthy.

Here’s what they gave me.

I would, and have and do, call ARP for the straight scoop to make sure I get it done correctly

torqued the rod bolts to 92lbft and measuring bolt stretch along to way netted the same results as last time i tried that. numbers all over the place, but i did average .004-.0045 on stretch. I dont put alot of clout into those numbers because zeroing the gauge and moving the upper locater the smallest bit resulted in .002-.004 differences. ARP needs to put accurate locating divits into both ends of the bolts. I measured .003 to .005 between the different bolts. My spec was .005-.006 or 92lbft.

Glad I'm not the only one who's had trouble with the rod bolt stretch measurement. I tried to do that w/ my hemi when I built it in 2006 w/ Oliver rods. Had a heck of a time getting consistent measurements...real sensitive. Ended up just torqueing them to Oliver's spec. That was 2006 and I've beat on this motor pretty good w/ no issues. That stretch gauge hasn't left my toolbox since.

Glad i'm not the only one having trouble with that as well. If ARP would just machine a divit into each end of the bolt to positively locate the gauge, problem solved.

All the ARP 8640 (I think that is the correct number for the cheaper ARP rod bolts) and all the ARP 2000 bolts I've used had nice machine recesses, divots, in both ends for the rod bolt stretch dial indicator ends
I do remember reading on the stock 440 and 383 ARP replacement rod bolts with nuts to stretch them and release them three times before using them with their stretch methods a long time ago
IHTHs

The best thing you can do with L19 bolts is to toss them in the trash. Those bolts have cause more rod failures than any other bolt ever has.

They are so strong to the point the are brittle and will snap off. Call Tom Molnar who has 41 years in the rod business start at Oliver, then K-1, and now his own company Molnar Technologies we will tell you many

horror stories of rods failing with L19 bolts.

Tom

This is the first I have heard of this issue on those bolts My understanding on the ranking of strengths on ARP after market race rod bolt is ARP 8740 7/16 depending on he under head length is the cheapest and on the bottom of the strength charts, the ARP 2000 are in the middle and the L19 and SPS bolts are the strongest and the best
I will say this on the ARP 2000 7/16 bolts Tom uses is they are all custom made to his design and manufacturing specs and they are the only ARP 2000 rod bolt I have had any issue with on the strength when using the bolt stretch method of tightening them: work :
ARP will not stand behind them whiney: He has to cover his custom made products warrantee

Molnar will not and does not use any L19 bolts in their products. Just for fun call Tom and talk to him about it. I myself have no interest in blowing up an engine from bad rod bolts.

Tom

Interesting. I sent my Oliver rods back to Oliver 3 years ago to be rebuilt. They installed new rod bolts, which are ARP L19.

Google L-19 bolt corosion.
Doug

I also read up on L19 bolts, contamination if handled without gloves, hydrogen embrittlement….definitely not a bolt I would use. I decided to run Custom Age 625