6.4 cracked block, ARP stud specs?

Yotadzl

New member
Joined
Feb 13, 2016
Messages
234
I recently had a block crack between 6 and 8 after assembling with ARP studs. I torqued them to ARP spec of 275. No that the block is replaced I am beginning assembly. Is anyone using a different torque spec or method to help prevent this from happening? I am seeing a lot of mixed information.
 
Common issue. It is an inherent design flaw as the casting is the thinnest there. Don't listen to all the guys that say the holes were dirty, or the studs bottomed out, or moved a quarter turn when torquing.

Yes, a different torque is the answer. I'm trying to find the actual spec as the one who figured out the issue as well as the solution passed almost two years ago. I personally ran an engine built by him that had the torque reduced on the back two cylinders. They way he put it to me was that even with the reduced torque, it still had more clamping force than a top fuel engine so it should be ok lol
I'm thinking ARP spec is 235, and he reduced to 210 on those particular studs...
 
Morgan told me 230 ft lbs on the 2nd and 4th stud in the top row, all the others get 275 ft lbs.
 
Back
Top