420A ARP & Eagle questions

[BLACK'98DSM]

I have a few questions about some ARP and Eagle performance parts for the 420a. Thanks

What are the torque specs for the ARP head studs? How about the nuts?

Which direction do the Eagle rods/rod bearings need to go on the crankshaft? Do the bearing slots need to be on the same side or opposite sides?

What are the torque specs for the ARP rod bolts that are included in the Eagle rod kit?

Also, does anybody know the torque specs for the skirt bolts? The torque spec sheet has a number, but there are 2 different bolt sizes holding the skirt on and I wouldn't think they have the same specs.

I probably will have more questions over the next couple months. I'll post them on this thread to keep the forums cleaned up a bit.

 

[VelocitàPaola]

What are the torque specs for the ARP head studs? How about the nuts?

I believe the studs are hand tightened. The nuts should be tightened to 85 ft-lbs with ARP "Ultra-Torque" assembly lube in three equal steps. See here: https://tech.arp-bolts.com/instructions/141-4202.pdf

Which direction do the Eagle rods/rod bearings need to go on the crankshaft? Do the bearing slots need to be on the same side or opposite sides

It's been a while since I rebuilt my engine, so you might want to double check this, but I don't remember the rods needing to be installed in a specific orientation. Corbin's guide doesn't address it, other than to say "some rods have oil squirters, so they must be installed a certain way", and I don't believe Eagle rods have oil squirters. The factory overhaul manual doesn't mention it either, as far as I can tell. If it were my engine, I'd just make sure they're all facing in the same direction.

What are the torque specs for the ARP rod bolts that are included in the Eagle rod kit?

43 ft-lbs. with ARP moly assembly lube on the threads. 28 ft-lbs for older design with 5/16" bolt (3/8" head). See here (search for "CRS5472N3D"): https://www.eaglerod.com/index.php?option=com_content&task=view&id=21&Itemid=32

Also, does anybody know the torque specs for the skirt bolts? The torque spec sheet has a number, but there are 2 different bolt sizes holding the skirt on and I wouldn't think they have the same specs.

20 and 55 ft-lbs. for the smaller and larger bolts, respectively. See here: https://2gnt.com/index.php?d=A_Proper_Rebuild

 

[BLACK'98DSM]

Perfect, that's just what I needed! (for now)

 

[BLACK'98DSM]

43 ft-lbs. with ARP moly assembly lube on the threads. See here (search for "CRS5472N3D"):

This depends on the head size of the bolts. If the head size is 3/8, then they should be torqued to 29 ft-lbs.

I tried to torque mine to 43 and one snapped long before then. So I did some research and found the Eagle instruction booklet. Ordered some new bolts and grease, and won't be making that mistake again.

 

[VelocitàPaola]

Yes, for future reference, per the page I linked:

NOTES: ... Older design used 5/16" bolt (3/8" head) - torque is 28 ftlbs with moly lube.

Updated above for clarity.