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Phoenix rod bolts
#1
A morsel of advice needed:

I'm assembling an engine with Phoenix 1 5/16" rods on a Phoenix crankshaft. The rods are metaled and the clamp screws or bolts look like this:

   


My instinct is to do them up to 30 ft/lbs with a drop of Loctite but does anyone have a definitive torque?

For what it's worth, the screws seem to be of North American origin, 5/16" UNF thread. One website has them listed with full specs but frustratingly, no tightening torque!

12 Point Flange Bolt Dimensions & Specs | AFT Fasteners

5/16"-24 x 1-1/4" 12 Point Flange Bolt | AFT Fasteners

AFT state that they're "made to Grade 9 specs". Comparing the figures, that's roughly equivalent to 12.9 metric spec; an M8 12.9 bolt would be 46.4 Nm or 34 ft/lbs.

Help!
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#2
Photo of conrod bolts used early bolt torque was 30 ft/lbs ARP bolt torque 35 ft/lbs, no locktite. Terry.    
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#3
Out of interest, here is the website for ARP  bolts: https://arp-bolts.com/.

The advice I was given is that they should only be re-used 3-4 times and they are very expensive. Last time I spoke to Alex Myall he was using an even higher spec bolt which could be used a greater number of times but even more costly! Remember they are designed to stretch to maintain load. John Barlow's version is just a normal boilt which I would be nervous of using.

Just for fun have a look at the Saenz conrod manufacturers website: https://saenzgroup.net/
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#4
I've never used them, but I seem to recall ARP promote the use of their assembly lubricant & I'd guess their specified torques assume this is used.
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#5
ARP rod bolts are correctly installed in elastic tension, so should be reusable.
If they’ve been over tightened, either by the use of a rubbish torque wrench or someone who incorrectly believes they have a calibrated wrist, then they should be replaced.
The ARP website says:

Are ARP bolts and studs re-usable?
Yes. As long as the fasteners have been installed and torqued correctly, and show no visible signs of damage, they can be re-used. If they show any signs of thread galling or corrosion, they should be replaced. In the case of rod bolts, if any of them have taken a permanent set and have stretched by .001” or longer, you should replace them immediately.
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#6
Turns out, they aren't Phoenix rods at all, although that was my understanding when they were passed on to me. They are actually remanufactured items from Tony Betts. 

Tony advises that they are torqued up to 35 ft/lbs, which I have done and they are fine.

Thanks for the advice guys.
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#7
Just checking if forum is working. No posts since yesterday!

Seems ok. Is everybody sleeping?
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#8
Nah, been out for a run in the sun...
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#9
(25-01-2024, 03:27 PM)Dave Wortley Wrote: Just checking if forum is working. No posts since yesterday!

Seems ok. Is everybody sleeping?

It does seem a bit quiet!
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#10
we're all outside, busy working on our cars... ;o)
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