FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: BigBlueOvalFan on September 01, 2021, 10:00:59 PM
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Can anyone comment on a question I have about the factory LeMans rod bolts ? I was told today that the factory rod bolt is not round, but rather has an eccentric type thread, creating a locking type thread. I've never ran original LeMans rods prior, I've always purchased new but I'd like to run these for an original engine I'm building (the will be wet magged, checked for straight, shot peened and resized/rebushed).
I would also like to know how you guys feel about re-using ARP and/or factory rod bolts.
I have always bought brand new ARP as it's cheap insurance. I also have some rod bolts that don't shank down, black oxide in color, 12pt and they are .435 thick to the threads. I also have some older ARP bolts that shank down to .365 and some other no brand that shank down to .345 (these may be the original Ford bolts). All are 12pt. Any idea whose bolts these no names may be ? I'll post some pics of them tomorrow.
Any/all recommendations and info is appreciated.
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Not a fan of the factory LeMans rod bolts. They are necked down in the shank, plus they have a "Tri Lobe"threaded end, kinda like the threads are distorted , I assume as an attempt to make the bolts kinda a self locking bolts. The rods themselves are quite sturdy (but heavy), but I always replaced the rod bolts (capscrews, actually), with SPS or FPP non shanked, straight thread bolts many years ago, or ARPs later on.
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+1 on Rory's comment.
Throw away those tri-lobe bolts. A modern replacement will give you peace of mind. You will also have to chase out the rod threads with a tap to match.
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Thanks for your input. I think I may have some old FPP bolts with the washer that has been necked down for the shoulder of the bolt. You wouldn't happen to have any pics of the SPS or FPP bolts you have ? Just looking to match up what I have.
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+1 on Rory's comment.
Throw away those tri-lobe bolts. A modern replacement will give you peace of mind. You will also have to chase out the rod threads with a tap to match.
Thanks for confirming, that's what my gut told me. I guess that tri-lobe is a thing. Chasing the threads is no biggie and well worth the peace of mind with the new bolts.
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Thanks for your input. I think I may have some old FPP bolts with the washer that has been necked down for the shoulder of the bolt. You wouldn't happen to have any pics of the SPS or FPP bolts you have ? Just looking to match up what I have.
Here’s pictures of the SPS caps crews that were original to my Ford 427 NASCAR rods. I’m not sure if they would be the same part that would have been purchased back in the day to use in the LeMans rods.
(https://i.postimg.cc/BQfYxgCf/E0-AEA4-ED-0-E68-4023-B95-A-00173-F405404.jpg) (https://postimg.cc/14MrSDTv)
(https://i.postimg.cc/VL974C7r/FE322525-2-DE8-4038-A045-70-C612-C91-C1-F.jpg) (https://postimg.cc/1ftc3f1s)
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To use ANY aftermarket rod bolt other than the original tri lobe design , the threads MUST be "chased" to allow for the different thread design. Not doing so will give incorrect torque readings and eventual engine failure. Been there , done that.
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I just did this conversion to ARP bolts recently, as stated you have to chase the threads. I bought the bolts from POP as he specifies them as Lemans bolts and I wanted to ensure I had the right specs ARP 200-6001 https://stores.precisionoilpumps.com/ford-fe/?sort=featured&page=2.
Other note, it was discussed in the old FE forum by Barry I believe, but you have to ensure that the dowels are tight on Lemans rods. Mine needed to be replaced. https://stores.precisionoilpumps.com/ford-fe-390-427-428-lemans-rod-dowels/
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Thanks as always guys for all the feedback and info. I think I know the route I'm going now, thanks for all the help.