Rod bolts
02-16-2003, 07:42 PM
#1
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Rod bolts
Can I change them myself? What is the procedure and equipment required. I will be changing stock 3/8" to ARP 3/8". Never done it myself before. Oh, engines apart.
02-17-2003, 11:22 AM
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Take to a shop
If they are bolts (assuming nut & bolt, not a cap screw), you need to press the old ones out, and the new ones in...........then the rods should be re-conned with the new bolts.
I'd recommend taking them in if you haven't done them & don't have the equipment.
RJ
I'd recommend taking them in if you haven't done them & don't have the equipment.
RJ
02-17-2003, 11:35 AM
#3
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Right Ratchet!!
When you change the rod bolts, the rods deform slightly and are no longer round. You need to have the big end reconditioned by a competent machine shop. Changing those bolts in your rods is a very good idea. Just knocking the old ones out and the new ones in is asking for big trouble!!
When you change the rod bolts, the rods deform slightly and are no longer round. You need to have the big end reconditioned by a competent machine shop. Changing those bolts in your rods is a very good idea. Just knocking the old ones out and the new ones in is asking for big trouble!!
02-17-2003, 11:35 AM
#4
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You can press the old ones out and the new ones in, but then the bearing hole won't be round anymore (we're talking teeeeeny little bit here). Besides, the rod is used and could stand a new hone anyhow. What they do is they knock a few thou off the cap surface and bolt them down with the new bolts. They run a hone thru and resize it back to standard.
While you're at it, you could polish the sides of the beams with a sanding roll to take the rough edges off the forging line.
And you could have them shot-peened.
Your best bet is to get pricing for the above services. It is not really expensive. If you are handy with a die grinder and sanding roll then you can do that part yourself (remember, you're just taking any crosswise marks out of the forge line).
While you're at it, you could polish the sides of the beams with a sanding roll to take the rough edges off the forging line.
And you could have them shot-peened.
Your best bet is to get pricing for the above services. It is not really expensive. If you are handy with a die grinder and sanding roll then you can do that part yourself (remember, you're just taking any crosswise marks out of the forge line).
02-17-2003, 01:25 PM
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Originally posted by mcollinstn
You can press the old ones out and the new ones in, but then the bearing hole won't be round anymore (we're talking teeeeeny little bit here). Besides, the rod is used and could stand a new hone anyhow. What they do is they knock a few thou off the cap surface and bolt them down with the new bolts. They run a hone thru and resize it back to standard.
While you're at it, you could polish the sides of the beams with a sanding roll to take the rough edges off the forging line.
And you could have them shot-peened.
Your best bet is to get pricing for the above services. It is not really expensive. If you are handy with a die grinder and sanding roll then you can do that part yourself (remember, you're just taking any crosswise marks out of the forge line).
You can press the old ones out and the new ones in, but then the bearing hole won't be round anymore (we're talking teeeeeny little bit here). Besides, the rod is used and could stand a new hone anyhow. What they do is they knock a few thou off the cap surface and bolt them down with the new bolts. They run a hone thru and resize it back to standard.
While you're at it, you could polish the sides of the beams with a sanding roll to take the rough edges off the forging line.
And you could have them shot-peened.
Your best bet is to get pricing for the above services. It is not really expensive. If you are handy with a die grinder and sanding roll then you can do that part yourself (remember, you're just taking any crosswise marks out of the forge line).
Blown,
Actually, Ideally, you really do not want the rods truly round do you ? If you think about it (and spin one around on a sun indicator), you'd want the rod to be just an ever so slightly amount larger from side to side, as opposed to the measurement along the centerline of the rod to allow for a bit of stretch (which causes the sides to pull closer) over time, right ?
Chit..........I'm thinkin about this a bit much huh ?
Guess that's what happens when it snows out.RJ
02-17-2003, 02:38 PM
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Naw, you want them round.
While there are reasons for wanting NON-round bearings for the big end of a rod, there are no easy ways to manufacture the rods to be rebuildable with cam-ground ends. The cost to do that on a refurb basis would make all rods throwaway units. Besides, the eccentricity you mention varies for different applications. A station wagon motor would require a different spec than a top fuel motor. The easy (and current) way of doing what you describe is to have different bearings for different applications.
Any eccentricity is designed into the bearing itself.
I polish my own rods so that part is free.
Shot peening is about $30 for a set if you know somebody (any aircraft service facility will have a shotpeener).
R & R on the rod ends is the same price whether you do the above or not.
While there are reasons for wanting NON-round bearings for the big end of a rod, there are no easy ways to manufacture the rods to be rebuildable with cam-ground ends. The cost to do that on a refurb basis would make all rods throwaway units. Besides, the eccentricity you mention varies for different applications. A station wagon motor would require a different spec than a top fuel motor. The easy (and current) way of doing what you describe is to have different bearings for different applications.
Any eccentricity is designed into the bearing itself.
I polish my own rods so that part is free.
Shot peening is about $30 for a set if you know somebody (any aircraft service facility will have a shotpeener).
R & R on the rod ends is the same price whether you do the above or not.
02-17-2003, 02:53 PM
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Originally posted by mcollinstn
Naw, you want them round.
While there are reasons for wanting NON-round bearings for the big end of a rod, there are no easy ways to manufacture the rods to be rebuildable with cam-ground ends. The cost to do that on a refurb basis would make all rods throwaway units. Besides, the eccentricity you mention varies for different applications. A station wagon motor would require a different spec than a top fuel motor. The easy (and current) way of doing what you describe is to have different bearings for different applications.
Any eccentricity is designed into the bearing itself.
I polish my own rods so that part is free.
Shot peening is about $30 for a set if you know somebody (any aircraft service facility will have a shotpeener).
R & R on the rod ends is the same price whether you do the above or not.
Naw, you want them round.
While there are reasons for wanting NON-round bearings for the big end of a rod, there are no easy ways to manufacture the rods to be rebuildable with cam-ground ends. The cost to do that on a refurb basis would make all rods throwaway units. Besides, the eccentricity you mention varies for different applications. A station wagon motor would require a different spec than a top fuel motor. The easy (and current) way of doing what you describe is to have different bearings for different applications.
Any eccentricity is designed into the bearing itself.
I polish my own rods so that part is free.
Shot peening is about $30 for a set if you know somebody (any aircraft service facility will have a shotpeener).
R & R on the rod ends is the same price whether you do the above or not.
I was just suggesting the aftermarket rods, because a couple of times it was close, when doing everything you mentioned to a stock set (or at least having it done by someone else).
RJ
02-17-2003, 09:18 PM
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Everything Ive ever seen in aftermarket rods required them to be worked on anyway, especially Eagle. If I cant get the bolts out and new in without reworking them, Ill just leave them alone. Thanks for all the info. $300 to recon them is just too much for what I need. Bearings looked perfect.
