I'll be installing new heads with new ARP head bolts in the near future (using ARP sealant and/or lube). ARP recommends torquing new bolts 5 times before applying final torque (see below). That is a LOT of wrench turning. What are folks' experience with this? I'll do it if I should (I only want to install heads ONCE and get it right the first time).

From ARP:
The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP® lubricants are used, five cycles are required before final torquing.

Thanks,
Rob
95 Z28

 

For heads, I've always just done 30-50-70 ft.-lbs., then re-torqued after breaking in the engine.

 

Thanks cASe SenSiTive. Anybody else have suggestions or real world methods/results?

 

Well my 93 factory service manual just says to tighten them up to 65lb/ft in 3 passes.

IMHO loosening them and retorqueing them 5 times sounds a little excessive. It sounds like that would be pretty hard on the threads in the block not to mention it would take forever.

17 bolts per head x 5 cycles = 85 cycles per head

85 x 2 heads = 170 cycles for both heads?!?

I probably would call ARP for a clarification...

 

Called ARP and they verified:

5 cycles of loosening and re-torquing before applying final torque. Using the sequence and torque-stepping in the manual.

My arms hurt just thinking about it!

 

I torqued them 3 times as the manual said... after done I went and got a pointer and a hammer and hit each screw slightly twice...

Then retorqued them to 65ftpds... some even went 3/4 of a turn more with this... DOnt think I will need to retorque but I'll do again anyways.

 

I'll be using the ARP bolts too.

Where did you buy the ARP sealant and lube?

 

I got the sealant and lube from Summit. I think the p/n were:

ARP-100-9903
ARP-100-9904

 

Boy, that's news to me. I never heard of that procedure of tightening and loosening?! I just put a set of Edelbrock alum heads on a BBC. I had the APR bolt set that Edel specifically recommends. I read the instruction sheet carefully. Edel's approach was the traditional three steps of increased TQ in the proper bolt sequence. I wonder why it would be so different for LT1 alum heads?

 

I don't think it's specific to LT1 heads as it's not in my instruction sheet either. I found the information in the ARP catalog and they recommended that method for any new ARP bolt. Page 11 in the catalog under TECH section, "Proper Fastener Retention".

 

I have done around 4-5 head installs with ARP bolts w/ Teflon thread sealant and I used the 20/40/65lb method....No problems at all...Thats crzy to loosen them then retorque

Cody

 

sounds like you are asking for head gasket sealing problems doing it that way.

just throw some thread sealant on them, torque to 20, then 40, then 65. no need to retorque them from what i have seen

BTW i have some arp head bolts with 200 miles on them if anyone needs some

 

Does anyone have a diagram of the torque pattern for the head? Thanks.....

 

This thread is really old... but I want to bring it to the top. I have to re-do head gaskets over spring and I want to be 100% sure whether or not I need to torque multiple times. This is the first time I've seen this mentioned and I want to make sure I fix my car the right way.

Thanks.

 

It has nothing to do with the factory manual torque values, but rather what ARP's position is on use of the fastener. Friction can affect the torque value so the iterations of tightening and loosening with the lube makes it even out to a point where it may stay more uniform.