Rod nuts

[carolinamudwalker]

In his book 4-bangers & me Jim Brierley recommends using ARP 12 point rod nuts. Are these to be used without lock washers and can they be re-used to adjust shims? When I dropped my pan the other day I found the carter pins so far down and loose they served no practical purpose. thanks Bob

[hardtimes]

Originally Posted by carolinamudwalker

In his book 4-bangers & me Jim Brierley recommends using ARP 12 point rod nuts. Are these to be used without lock washers and can they be re-used to adjust shims? When I dropped my pan the other day I found the carter pins so far down and loose they served no practical purpose. thanks Bob

Hey Bob,
'without washers'..yes.
Even though these arp nuts cost a few bucks, I wouldn't reuse them..myself. Don't know whether Jim B reuses same.

BTW...While visiting a Bville 4banger racer guy (still holds speed record) a while back, I was listening as fast as my old cells would absorb .

When I asked him about rod nuts, he handed me a new nut of the variety that he uses on rods in his race engines. His style nut is made a little 'mis shapened' /distorted (lack of proper term) a bit so that they lock onto the rod stud and not come lose. Point being that there is more than one nut that is strong /locking , to do the job better than Fords original equipment...i.e.-will not come lose and does not need cotter and/or washer.

[BILL WILLIAMSON]

While working on Jaguars, I used Chrysler rod nuts instead of dealing with cotter keys!
Jaguars were notorious for throwing off a cotter pin end, it would pass through the COARSE oil screen & end up STUCK under the oil pressure control valve & result in LOW OIL PRESSURE. One even locked up an oil pump & DESTROYED the bottom end!
Bill Limey

[Synchro909]

I use Nylocks. Now before the chorus of knockers start, I've done so for about 50,000 miles with no sign of issues.
As the nut goes on, I measure the amount of torque it takes to turn it on the bolt before it gets tight, then add that to the prescribed setting and tighten to that.

[Railcarmover]

The reason items are torqued is to put the fastener under tension. Using Nyloks and standard lock nuts even with adding the rolling torque of the lock nut still don't provide an accurate way of tensioning the rod stud..you'll probably get away with it,hardware available when the car was built is no where near the tolerances of today,metallurgy and consistency of steel designs have improved greatly.Actually,proper torquing of a designed fastener today requires no locking device,the tension the fastener is under holds the assembly.

[BILL WILLIAMSON]

Sponsored Links (Register now to hide all advertisements)

Most any nuts are better than castrated nuts with rinky dink cotter keys!
"Maybe" that was considered GOOD ENUFF, way back when??? BUT, not NOW.
Bill Fussy

[Synchro909]

Spot on, Fussy Bill!

[Railcarmover]

Cotter pins don't hold the assembly in tension...lock nuts do..and that's what your after,except you cant truly factor tension with them.8N rods have turn to torque nuts with no locks..

[BILL WILLIAMSON]

Not REALLY related, but interesting!
Friend, Ron, just put an M.G. engine together, upside down, no pan & on the engine stand. "POING"!--Something hit the ceiling like a SHOT!!!???---15 minutes later, "POING"!! again!!!
Long story short, the NEW RE-PRO rod bolts were snapping!!!-----Ron did some QUICK research, got 8 new Ford Falcon rod bolts & nuts & everything was A-OK!!!---You ALL would have LOVED Ron (RIP!) he was a Master at EVERYTHING Automotive, I could tell you STORIES & STORIES about what I learned from him. He was a MASTER with unexpected or unusual happenings. He worked on anything from a Fiat-500-2 Cyl air cooled to a Jaguar-V-12.
Thinking back, he DIDN'T do the Fiat-500! He boxed up all the engine pieces, dropped them off at MY HOUSE & when I had it together, he had a Tow Truck bring me the car! (THANKS, RON---+**+**#@#$^&+&%%)
I had NO Shop Manual or info on it, had to "guess" at the timing chain marks, valve clearances & timing, BUT that DUDE RAN!!!---I sat the engine on Cindys' step stool & "wiggled" it into the back end of the car & it had NO WATER leaks---LOL
Bill W.

[Jim Brierley]

Use without lock-washers, in fact never use lock-washers on mains or rods. I wouldn't hesitate to re-use the ARP nuts after adjusting the clearance.

[d.j. moordigian]

The ARP 12 point rod nuts are a VERY good product,..good for(best guess) 75 ft lbs of
torque. The "A" or "B" rod will distort at that torque,..it's just not that strong a rod.

Call ARP and ask them about issues,...or "half life" of the nuts? At 45-50 pounds of
torque there shouldn't be a problem,..PLUS no way to check "stretch" of the so-called
rod bolt,...that's why Ford put holes for cotter pins so the nut didn't fall off..

[katy]

it had NO WATER leaks

Probably because it was air cooled!

and can they be re-used to adjust shims?

Use plain nuts when adjusting the shims and put the "good" nuts on after you have the shims adjusted.

[redmodelt]

Rod bolt nuts, 35LBS dry threads.

[Ed H.]

Originally Posted by Synchro909

I use Nylocks. Now before the chorus of knockers start, I've done so for about 50,000 miles with no sign of issues.
As the nut goes on, I measure the amount of torque it takes to turn it on the bolt before it gets tight, then add that to the prescribed setting and tighten to that.

Just a question........would the oil eventually eat away at the plastic insert?

[Synchro909]

Originally Posted by Ed H.

Just a question........would the oil eventually eat away at the plastic insert?

As the name suggests, the insert is nylon and no, it doesn't.

[Bruce of MN]

Originally Posted by Synchro909

As the name suggests, the insert is nylon and no, it doesn't.

Are nyloks used on aero engines internally? I don't know, but it would be a good reference point.

This chart https://www.calpaclab.com/nylon-chem...ibility-chart/ says excellent for motor oil up to 120F. In reality, they are probably just fine at our oil temperatures.

[carolinamudwalker]

Thanks everyone, the collective advice usually provides a good answer. Bob

[updraught]

http://www.usfastener.com/insertlocknut.html

A bit about the thermal properties of nylon lock nuts here.

They come in nice colours.

[BILL WILLIAMSON]

I don't know if this fact even matters or not, but give us your thoughts about the ROD BOLT being FORGED as 1 piece, with the ROD itself??? AND, is NOT replaceable!!!
This sorta' "BOTHERS" me????---"Maybe" I "ponder" TOO MUCH????
Bill Nut

[redmodelt]

Re the fact the rod and studs are one piece, that is the best reason not to over torque the nuts or use a nut that might bind and deform the bolt/stud thread. Once the threads are pulled, new babbitt or not, they are junk. I tried as set of the nuts with the deformed tops on Model T rod bolts, which are replaceable and just a little smaller in diameter. Just putting them on as tight were just going on I was worried about pulling the threads and if I could get a true torque value.
Wonder if the nut is one use only and if maybe the bolt is too with some of these pinch nuts.