I read some threads about arp rod bolt installation, you need to resize the big bore end of the rod since it may get off aligned or egg-shaped. I also read that some did not resize the rod and were fine. I know that it is recommended to do so.

I don't have a machine shop in my area or near my area that could resize the rod.

I am rebuilding a brand new B18C5 short block, replacing stock 10.6:1 Type R pistons to Toda pistons, changing to Toda oil gear, adding ARP head studs and flywheel bolt.

Was also planning on changing to ARP rod bolts and main studs, but instructions said that rod needs to be resized and block need align hone for use of main studs.

This is a brand new short block, if I use the rod bolts and get the rods resized, can I still use the new bearings that came with the short block or will I need to plastigauge and get new bearings if necessary.

Or would I be able to change the rod bolts and main studs without resizing rods and align honing the block?

What is actually done when resizing the rod?

 

You can just use the ARP main studs without any machine shop work! There is a dowel that aligns up the caps and you wouldn't be changing them.

As for the rod bolts, if you get the correct size ones they should be a direct replacement. Plan on having to use a press to remove the old bolts and then again to press in the new ones.

As for "re-sizing" a rod, here is what happens; When a rod gets beaten on a lot, it's the top and bottom that go out of round. Think of it this way, the rod only sees a pulling and pushing force at the crank bearing.

In order to make the hole round again, a machine shop removes some of the material where the cap and rod bolt together. This makes the hole smaller if measured from top to bottom. (the width of the hole is unchanged) Then they can machine the hole round again.

You WILL need to figure out the size required for new bearings unless the machine shop magically manages to make the hole exactly the same size as what it originally was. (DON'T COUNT ON IT)

Wes

 

Thanks for the info.

 

when i used the arp main studs i had too get my block align bored because the mains were way too tight