What's the rod bolt torque for a lunati crank and rods?
12-17-2005, 06:27 PM
#1
Found the rod bolt torque for lunati rods (and some damage) I bought a used engine, shortblock, it showed up Friday evening. Outside looks clean, but... One bank has a bunch of grit in the cylinders and there's gritty stuff up in the bottom too, on the crank throws, the bottom of the pistons, etc. Doesn't look like it was run with the grit, just got in there while the engine was open. I think I can clean it out by pulling the pistons, but leaving the crank in.
Not sure on the correct torque on these Lunati pieces though...
Not sure on the correct torque on these Lunati pieces though...
Last edited by John_D.; 12-19-2005 at 10:27 AM.
12-18-2005, 01:26 AM
#4
The torque for the Lunati rod bolts is not a torque spec. It is actually a bolt stretch guage reading of 5.5. I did some searching and this is about 73-75 lb-ft. It is much more accurate to use the bolt stretch gauge instead, because not all the bolts are going to be the same. Some might require more/less torque than others. Mine have already been stretched so I plan on using around 74 lb-ft and a torque wrench.
As for the mains, the are bolts stock or ARP? If they are stock you will need new bolts and torque them to yeild. Inside bolts go to 15 lb-ft then an additional 80 degrees, working inside to the outside. Outside bolts go to 15 lb-ft then an additional 53 degrees, working inside to the outside. Side bolts are torqued to 18 ft-lbs, again inside to the outside. Do one cap at a time.
For ARP studs, I believe the torque specs are 60 lb-ft on the inside, 50 lb-ft on the outside, and 18 lb-ft on the side bolts. There is probably a sequence drawing online somewhere.
Honestly, if its just a little dirt, do your best to clean it out without taking the motor apart.
As for the mains, the are bolts stock or ARP? If they are stock you will need new bolts and torque them to yeild. Inside bolts go to 15 lb-ft then an additional 80 degrees, working inside to the outside. Outside bolts go to 15 lb-ft then an additional 53 degrees, working inside to the outside. Side bolts are torqued to 18 ft-lbs, again inside to the outside. Do one cap at a time.
For ARP studs, I believe the torque specs are 60 lb-ft on the inside, 50 lb-ft on the outside, and 18 lb-ft on the side bolts. There is probably a sequence drawing online somewhere.
Honestly, if its just a little dirt, do your best to clean it out without taking the motor apart.
Last edited by Ferocity02; 12-18-2005 at 01:35 AM.
12-18-2005, 08:04 AM
#5
7 Second Club
iTrader: (42)
Join Date: Jun 2004
Location: paducah, ky
Posts: 4,558
Likes: 0
Received 0 Likes
on
0 Posts
i'm glad you found those specs cause torque can be off by several variables.
Originally Posted by Ferocity02
The torque for the Lunati rod bolts is not a torque spec. It is actually a bolt stretch guage reading of 5.5. I did some searching and this is about 73-75 lb-ft. It is much more accurate to use the bolt stretch gauge instead, because not all the bolts are going to be the same. Some might require more/less torque than others. Mine have already been stretched so I plan on using around 74 lb-ft and a torque wrench.
As for the mains, the are bolts stock or ARP? If they are stock you will need new bolts and torque them to yeild. Inside bolts go to 15 lb-ft then an additional 80 degrees, working inside to the outside. Outside bolts go to 15 lb-ft then an additional 53 degrees, working inside to the outside. Side bolts are torqued to 18 ft-lbs, again inside to the outside. Do one cap at a time.
For ARP studs, I believe the torque specs are 60 lb-ft on the inside, 50 lb-ft on the outside, and 18 lb-ft on the side bolts. There is probably a sequence drawing online somewhere.
Honestly, if its just a little dirt, do your best to clean it out without taking the motor apart.
As for the mains, the are bolts stock or ARP? If they are stock you will need new bolts and torque them to yeild. Inside bolts go to 15 lb-ft then an additional 80 degrees, working inside to the outside. Outside bolts go to 15 lb-ft then an additional 53 degrees, working inside to the outside. Side bolts are torqued to 18 ft-lbs, again inside to the outside. Do one cap at a time.
For ARP studs, I believe the torque specs are 60 lb-ft on the inside, 50 lb-ft on the outside, and 18 lb-ft on the side bolts. There is probably a sequence drawing online somewhere.
Honestly, if its just a little dirt, do your best to clean it out without taking the motor apart.
12-18-2005, 09:14 PM
#6
Thanks for the info.
I pulled one piston to see what I've got. I picked the one that had the piston rod over against one side of the piston, instead of centered on the pin. Bad rod bearing, scored crank... Good thing I dug a little deeper into this engine.
Here's a link to the Holley/Lunati page about the rod bolt torque procedure.
It says .0050-.0054 for the Pro-Mod rods and .0039-.0043 for the Street Race rods.
http://www.holley.com/data/TechServi...stallation.pdf
http://www.holley.com/TechService/Library.asp
I pulled one piston to see what I've got. I picked the one that had the piston rod over against one side of the piston, instead of centered on the pin. Bad rod bearing, scored crank... Good thing I dug a little deeper into this engine.
Here's a link to the Holley/Lunati page about the rod bolt torque procedure.
It says .0050-.0054 for the Pro-Mod rods and .0039-.0043 for the Street Race rods.
http://www.holley.com/data/TechServi...stallation.pdf
http://www.holley.com/TechService/Library.asp
