Quick question. I am replacing my rod bolts with ARP and I have a stretch gauge so I am all good from that stand point. My question is, when I am measuring bearing clearances, I know i need to torque down the bolts to get accurate measurements. Should I use the ARP bolts when torquing them down for measuring or should I use the stock bolts? If i use the ARP bolts, can I re-use them when I do the final build (ie can they be used multiple times or once they are stretched, they are done)?

Craig - Who has a lot to learn

 

Arp bolts and the stock rod bolts are not torque to yield aka stretch bolts. They will be fine to retorque many times.

 

The bolts are not torque-to-yield however there is a stretch method involved.

OP, set the rod up as you intend on running it. If you plan to run ARP bolts measure with them installed.

 

You have to re-size the rods after you install the arp's so yes, you are going to want to measure bearing clearance after the arp's are installed and the rods have been re-sized. The arp rod bolts for these cars are not torque to yield so you are fine to torque and re-torque as you need to when it comes time to measure for clearances. As mentioned, it is recommended to use the rod bolt stretch gauge as opposed to a generic torque spec when it comes to the arp bolts. Also make sure you use the arp lube that came with the bolts.

 

As many times as I've used ARP rod bolts, never have I seen a rod big end distort from the different rod bolts. This test wasn't done with PLASTIGAGE either.

 

When you say re-size the rod end, you are talking about re-checking the bearing size or actually having it honed/bored? I do have some dial bore gages that i can use to check roundness down to the .0001".

The question is, since this is a mild (sub 250hp) build, should i just forgo the ARP bolts and re-use the stock ones?
Based on the comments above, the stock rod bolts can be re-stretch/re-torqued multiple times as well.

I do need to take the block in to a machine shop, so having them re-size the rods should be pretty simple.

Craig - Who already purchased arp bolts

 

Then do what I did. Leave the stock bolts in , torque the caps down without any bearings and use the dial bore gauge and check for distortion. Record your finding.

Swap the stock rod bolts for the ARP and do the same procedure as before. Measure, record and compare. You are looking to see if the any of the previously recorded measuemts with the stock bolts have changed when switching to the ARP

 

Thanks for the tip Jimbo. That will work perfectly. If they are out of round or different, I'll just drop them off with the block and have them re-sized.

Craig - Who hopes to hit the machine shop in 2 weeks.

 

While I don't disagree with you completely, I have seen a few distort, but only slightly at that. If you have the proper precision equipment to measure big end distortion then by all means, it isn't necessary to to re-size if there is no measurable distortion. However, most weekend mechanics don't have said equipment so best practice is to spend $40 and get the rods re-sized when changing over to arp bolts.

Craig, if you already bought the arp's then use them. Just go via the method jimbo explained and if any of the big ends go out of round after you put the new bolts in, take them with the block and let the machine shop hone them back into round. Yes, by re-size I mean the machine shop will actually hone the big end back into round.

 

Out of curiosity, how much distortion have you seen and where in the big end was it distorting? I have seen rods that had .0002-.0003 deviation toward the parting line, and that number did not increase when switching to the ARP bolts.

 

Its not so much the added torque from the ARP bolts that cause the rods to oblong its the fact that the shoulder that gets pressed in is slightly larger than stock. Once the ARP bolts are pressed in the clearance on the sides tightens up. When I did my d-series they were out of round by 0.0008"-0.001", needless to say I had them re-sized.

My current build will just have the pistons and rods dropped off with the new pistons and ARP rod bolts for a straight re-re and re-size.

 

Boost Ben , were the big ends distorted before the ARP's were swapped in?

 

I wish I would have measured...Sadly I popped them out before hand. From what I've seen mine were on the bad side compared to others. I always recommend having them re-sized but, I think most people in this thread are using dial bore gauges and mics not plastique gauge so if you can measure out of round then you should be fine.

There was a thread on here years ago where the rods were so badly distorted you could see it with your eye. The guy found out during assembly when the crank wouldn't even spin...

 

I use the ARP 2000 rod bolts which distorted the rod almost .0005". Not a honda engine though.

 

I know you work with engines and machine work all day, have you ever witnessed a Honda rod distorting with ARP replacement bolts?