1. I've got a set of stock rods here that have been resized for aftermarket bolts. The problem is that I don't know much history on them. If I bought a new set of arp's do the rods have to (or can they even be) resized again?

2. Also have another set of rods with what I know are ARP's but a shop assembled the short block and I'm not sure what the stretch number should be on the bolts. Can they be re-used?

Thanks

 

there is no such thing as "resized for aftermarket bolts", the rods get resized with whatever bolts are in them. they may not need resized if you use ARP bolts, they will need rechecked to see if they need resized. check the specs on the bolts, liek at ARP web site for reuse and streach

 

i'm curious then, what is resizing? Is it just if the journal area is ovalized (or not perfect), and you enlarge it/bore it, (with bolts in it, to clamp it correctly), then put in bigger bearings?
And this has nothing to do with which bolts you use right?

 

To resize, the cap surfaces that mate with the rod are ground down slightly and precisely. The cap is then bolted on with whatever bolts you are going to use, torqued to spec, and the bearing mounting surface is honed out to the precise size required.

The thought is resizing is required whenever the rod bolts are disturbed, such as putting in aftermarket (ARP) rod bolts - the bolt shank is knurled to locate the cap precisely. As EDE said, it may not be required just because you're replacing the rod bolts. I replaced the bolts in the ZZ3 pink rods in the shortblock I rebuilt, the machinist checked out the rods afterwards and said no resizing required. So, I didn't bother spending that money.

 

If the hole is too small, it's honed to size.

If it's too large, the cap and bolts are removed and milled along the parting line to make it smaller before reassembling it and honing it back out to size. This may make the rod a few thousandths shorter, but it doesn't matter much.

The force required to press in the bolts can distort the shape of the cap, so the rods are resized if necessary when the bolts are changed.

 

Ugh, beat me to it... that's what I get for checking to see if I have a picture of it first.