Torque for Rod Caps with ARPs

[tpunx99GSX]

Ok, so i wanted to get an opinion on this. I havent dropped the pan yet but i have the feeling the bastard loosened again. or more-so, in the case that it has i would like to know what you all think.
The rods are Manley I Beam baller ass rods, they come with ARP 2000 rod bolts for the caps. Im using the moly lube on the bolts. When i built the motor i torqued it to the factory setting. Everything should have been perfect. I believe i was told it was 38 ft lbs. (if its not dont flame me, it was a while ago that i actually torqued them).
If the case is that the bolts came loose again, should i look into torquing it higher? I know the torque wrench is accurate, its a brand spanking new craftsman torque wrench.
Anyways, What do you guys think, Is this like the ARP Headstuds where i should be torqueing much higher than stock, or what?
Thanks in advance,
Tom

[Matt D.]

Did you not use Plastigauge? That will tell you what the torque spec is.

[asshanson]

I reused my ARP rod bolts and retorqued them to 42 ft-lbs I think. I doubt they came loose on you already, unless you forgot to torque a couple.

[tpunx99GSX]

I reused my ARP rod bolts and retorqued them to 42 ft-lbs I think. I doubt they came loose on you already, unless you forgot to torque a couple.

Yeah im absolutly positive i torqued all of them.

[tpunx99GSX]

Did you not use Plastigauge? That will tell you what the torque spec is.

How would a plastigage tell you what the torque spec is? It only tells you what the clearence is between the bearing and the shaft?

[Matt D.]

How would a plastigage tell you what the torque spec is? It only tells you what the clearence is between the bearing and the shaft?
The more torque there is holding the pieces together the less clearance there will be. Just because it says such and such a torque doesn't mean the clearance is correct, and improper clearance is what can make bearings fail.

[asshanson]

Tom, did you make sure you kept the same rods with the same rod caps? That is very important as well. And make sure you didn't put some on backwards?

For some reason I thought I heard someone say they didn't think matching the caps to rods was a big deal, and I'm almost positive you have to keep them the same, just like cam caps, they're machined to be a perfect fit for each other.

[tpunx99GSX]

Yes all of the rods were kept with their respecitve caps. And im sure the caps were placed correctly (notches on the oppisite side of each other.)
Im pretty sure one of the bearings just failed (i have a good idea which one). Ill just replace them.

[1ViciousGSX]

You need to know which bolts they came with.

http://www.arp-bolts.com/Tech/TechTorque.html

[blackrosenova400]

You only check bearing clearances using a plastigauge. Not for bolt torque.


The correct way of tightening rod bolts is using a stretch gauge or maybe a micrometer to check how much the studs have stretched. Also some rods come with differant studs/bolts so you have to figure out what bolts you have to figure out torque value if you choose to use that method.