Let’s discuss the ins and outs of torqueing head studs. What are the best practices to address these issues? I attempted to state the issues immediately below, but more details and background in the numbered lines that follow.
I’ve encountered variation in the torqueing process and several subtle issues as follows.
A. Uneven torque run-in. Sometimes the running torque while turning torque-wrench will get easier as you are turning. Is the coarse thread fighting with the fine thread? The course thread portion of the stud is only hand tight.
B. What torque? What sequence? Specifically what sequence when using different torque settings for long (110 ft-lbs) vs. short studs (100 ft-lbs). Logically you should follow the torque sequence to even out pressure and stresses?
C. If you get out of sequence (mistake), do you loosen and re-torque (start over)?
D. Should you follow the Barry R?? Procedure to loosen and re-torque to better seat the Felpro gaskets? Or not?
E. Do you re-torque again after torqueing to the final torque values….back through the torque sequence again? How many times? I went back through torque sequence with final torque settings and was able to tighten up some of the nuts further.
Background: I’m assembling my FE 427 back-up from a short block. The engine includes a Robert Pond aluminum block, Edelbrock heads, ARP Studs (nuts and washers).
1. I used the ARP thread lub. I used a reversible drill motor to work the lub back and forth into the fine thread ends and the nuts. All threaded connections were easily threaded in and out by hand (i.e. minimized running-torque).
2. Opinion varies on final torque. I initially torqued to 65 ft-lbs and then to 95 ft-lbs (per the FE 427 Build thread on the Factory Five website by “Fifty-Two”). I used the recommended torque sequence (apparently for ARP bolts, not studs)
3. I let the engine rest overnight. Followed the Barry R. procedure to loosen all nuts in reverse torque sequence and re-torque the heads (I assume this is the Barry from Survival Motorsports). I noticed when loosening the nuts, some of the studs backed out slightly. I made sure to finger tighten again before re-tightening. Is this normal for studs to back out?
4. After more reading more that night on the topic of torque, I ended up following Edelbrock instructions: 110 ft-lbs long studs, 100 ft-lbs short studs. Using the correct torque sequence, I re-tightened in 3 stages; 65 ft-lbs, then 85 ft-lbs, then following the torque sequence, I torqued to 110 and 100 ft-lbs. I wasn’t sure if I should torque all to 100 ft-lbs, then only torque long studs (inside studs) to 110 ft-lbs (this violated the torque sequence). I ended up following the torque sequence and bouncing back and forth between 110 and 100. I did the best I could to use continuous sweeping motion until final torque wrench “click” was obtained.
More background: This build was heavily referencing the FE 427 Build thread on the Factory Five website by “Fifty-Two”: Here is the blow by blow so far:
I removed each stud from the block. I found they were all easy to remove. Some of the thread holes were saturated with
oil. I drained
oil and cleaned out and was able to hand thread all back in. Removed all the studs again to clean gasket surfaces.
I cleaned up the block and head surfaces.
Re-installed all studs in the same hole they removed. All finger tight.
Bought the Ford Racing head gaskets (repackaged Felpro two per package). Installed per above. Correct FRONT orientation.
Thoughts? I did a lot of small block engine work in my youth, mostly stock engines. I read as much as I could find. I used as much logical reasoning to work through the torqueing, yet I want to make sure y final build-up is solid!
Your feedback appreciated