Preston99WS6

iTrader: (7)

The title pretty much somes it up need to know the rod bolt spec for arp 8740 bolts they have the 7/16 bolt heads and are 1.6" going into SCAT H Beams. Also do you have to use ARP moly or will the local store bought stuff work? Thanks

KCS

iTrader: (20)

What brand is the rod it goes in? You're better off calling the company that made them and see what they say. Chances are they will only have a spec for the ARP Moly lube or regular motor oil. If you use anything else, you may need to measure stretch instead.

Preston99WS6

iTrader: (7)

Rods are SCAT H beams. They have been run before I had to tear down due to an oil pressure issue. Turns out the builder never bolted the oil pump pickup to the oil pump. It was bolted to one of the studs. Ended up eating the Main bearings, and rod bearings so I had the crank turned to +10 and now I have all the parts bearings included. Just not sure on the torque spec. I know its different than factory though.

redbird555

iTrader: (14)

Did the motor originally have arp rod bolts? The reason being is that arp recommends line boring the rods to ensure they are perfectly round because the extra clamping force of the arp bolts will distort the rod bore from what it was before

Preston99WS6

iTrader: (7)

To answer the question they are the same bolts that came with the rods and have been in the LQ for about 20K miles before its oil pressure dropped and I pulled it. I just dont have the torque spec originally the spec would have come with the instructions in the box. I dont want to get it wrong when it goes back together. Guess I need to call SCAT and talk to a technician and see what they can dig up. Ill post up what I find.

chrisfrost

iTrader: (8)

That only pertains to OEM or equivalent rods .

suicidal racing

iTrader: (14)

arp has tq specs on there site

an you dont need to bore stock rods..they are not gen 1 sbc rods.

Xaviarrahl

iTrader: (3)

Right, with the cracked rods it seems like replacement without machine work is normal.... Hope so as I am planning this next week!

Are the aftermarket rods also a 'cracked' type?

Preston99WS6

iTrader: (7)

Got in touch with SCAT the other day this is what I found out

SCAT H Beams with ARP 2000 => 50 ft lbs
SCAT H beams with ARP 8740 => 63 ft lbs

Also spoke with a mechanic at texas speed and got the torque specs for ARP main studs

Inner => 60 ft lbs
outer => 50 ft lbs

bolts out side of block => 20 ft lbs

Hope this helps someone in the future.

Preston99WS6

iTrader: (7)

To answer my second question
ARP Brand Moly is not mandatory, store bought can be used just make sure you go back through the motor and retorque to ensure it didn't relax.

KCS

iTrader: (20)

Are you sure that is correct? The ARP 2000 bolts are a higher tensile strength than the 8740 bolts, so the torque should be higher for the ARP 2000's, not the other way around.

Also, is that for the 3/8" bolts or 7/16"?