Rod Bolts

[JC]

Just gathering some thoughts. Arp 8740 Arp2000 Arp 3.5 Arp custom age 625. JC

[Krooser]

I've always used the basic ARP bolt without any problems. If I was turning the engine 9K that might change...

[JVMopar]

Ran stock bolts to 6500 rpm. About 2 seasons worth of races on it.

Put some ARP Pro Series Wave Loc bolts in a brand X. It ate a valve. So when rebuilding it I went to torque one rod and the threads pulled right off that bolt. Never even got tight enough to measure the stretch. ARP did replace the bolt. Sure was worried about it. Put a lot of dyno time on that motor never had a failure.

[JC]

Well the reason for the Question is I have seen the 3/8" ARP 2000 fail twice turning them a 7200-7400 at 5 or 6 races. ARP told me at PRI they were not made to turn that hard. The next step up in bolts goes to a 100 bucks per rod. I have been told it's a waste of money but I'm not so sure now. Two barrel lightweight stuff not running any junk. Crowers and Mahal. All my new builds have 7/16 bolts now just giving up the 100 grams of weight. I have not seen any failures below 6800 rpms. JC

[cageman]

I'm not sure what bolts my last 360 has that broke a rod bolt. But it wrecked a lot of good stuff. Arp something. 340king built it.

[JC]

Well I really just have never paid much attention to rod bolts in the past, just order ARP and ck for the 0.0055 to 0.0060 stretch and let it go. Same deal wrecking good parts starting to pay more attention to details now.

[340king]

They were the 8740 series 7/16" ARP fasteners. I haven't had any issues, save one Ford engine that had one fatigue and break.

The crazy thing is that they sometimes recommend stretch and other times don't. I had some Eagle rods that went too far on stretch and they said not to worry about it. I thought that was a little odd.

[B-Mod Dad]

Never had any problems with Eagle SIR rods or ARP bolts until last year. Had 1 rod bolt fall out and had 1 break. This year had an Eagle rod break up by the wrist pin, came around and broke at the rod end and took a big chunk out of the pan rail. Piston never even hit the spark plug. Piece left on crank will spin around with your fingers. Found 3 pieces of missing center section of rod in the pan. thinking about buying from someone else, but we run IMCA and have to use I-beam rods. Dont think many others make I-beam rods. Not wanting to use Scat rods either. Any ideas? This was on our 340.

[340king]

Chrysler 360
Sportsmaster® Rods

Part No. Center-to Big End Big End Crank Pin End Pin Avg. Gram
14139C-8 6.125" 2.250" .933" 2.125" 1.000" .9848" 555
Forged from aircraft quality 4340 material
Entire Sportsmaster® beam is profiled to remove stress risers and render the lightest possible rod
Shot peened after machining to MIL spec and 100% individually magnafluxed
Cap fasteners for 14139C-8 are 3/8" ARP 8740 cap screws
Premium Ampco pin bushings
Flywheel horsepower range for 14139C-8 rods is 550 HP

These are an option.

[Krooser]

Pankl 6.2... 540 grams... .827 pins... 2.08 big end (takes a narrow H series Clevite bearing). .890 big end width. $125.00 per set... one race old from Hendrick Motorsports.