i'm flabbergasted...

got my manley H-beams with arp bolts
went on to installing everything.

- measured and documented free length
- put in bearings
- greased up the rod bolts with arp-lube
- handtighten the bolts and look up stretch on the form
- it needed a ,0058-,0062" stretch
- stretched it to ,0058" (just to measure the bearing clearance)
- bearing clearance was a bit big at ,003 (ACL Race HX bearings)
- undid the bolts to install the normal ACL race bearings
- measured the free length of the bolts just to be sure (better safe then sorry)

free length increased by ,00275"!!! WTF???
you have to replace if free length increases more then ,001"!

WTF just happened? used the ARP lube to reach desired stretch and it overstretches? big time!

now scared to touch my other bolts..... anyone had this happen before?

now that i think of it, it needed quite a bit of force to stretch the required amount...probably more then 65lbs, i was'nt worried tough seeing i was using arp-lube + stretch gauge + multiple times torqueing and loosening before reaching required stretch......

anyone?

 

Check all your others first..its possble you got a bad bolt. That does sound weird as **** though lol..

 

update:

rod #2 with fresh bolts i tried another tactic.
instead of stretching the bolt to the specified value, i torqued it in multiple steps to 45ft/lbs (commonly accepted as the value to torque to with the ARP lube)
1. 27ft/lbs and loosen
2. 45ft/lbs and loosen
3. 45ft/lbs and measure

measured only ,002" stretch where ,006" is specified......?

 

I'ma say this.. maybe more steps inbetween?? Maybe add another one in there.

But i'ma say this, on alot of the geman cars that i torque stuff down on, they have a torque value, then they say do a 90Degree.. Try reaching the torque value , then set your wrench to where you go do a 90 degree pull from say 3 oclock to 6oclock and see if the strech changes.

 

done that and upped the torque a bit. so:

1. 27
2. 45
3. 45
4. 50

still only just ,0021" stretch

 

took the bolt out, applied some more lube and retorqued again at 45 so now it's;

1. 27
2. 45
3. 45 gave ,002" stretch
4. 51 gave ,0021"stretch
5. 45 gave ,002" stretch

i've gotten scared to apply more torque, don't want to ruin the next pair bolts.....

 

've gotten "bold"

retorqued at 55 and 60 ft/lbs, so now it's:

1. 27
2. 45
3. 45 gave ,002" stretch
4. 51 gave ,0021"stretch
5. 45 gave ,002" stretch
6. 55 gave ,0021" stretch
7. 60 gave ,0021" stretch

i'm flabbergasted, more torque ain't more stretch....... and i'm already at 60 ft/lbs on arp-lube in 7 times fastening and loosening.....

what's happening?????

 

65 ft/lbs on arp-lube gave it ,00236".....

woot woot, torqueing it to the value you would on 30w oil with arp-lube and only ,00236", only ,00364" to go and i'm already overtorqueing it...

 

reached 70ft/lbs and only got ,00283" loosened and retorqued for 9 times now and at max torque according to ARP on 30w oil with arp lube.

from 27ft/lbs (just closing the crush on the bearing) to 70ft/lbs is 45degrees....

clocking it 90 degrees from any torque value would severly stress the bolt
given the liniearity of the thread, the following should apply
1 x 45 degree = ,00283" stretch
1 x 90 degree = ,00566" stretch, wich is close to the required minimum of ,0058" tough

just scared the bolt won't return to it's normal state as torque is trough the roof.....

 

tried rod #3 in two steps without arp-lube (just the 30w the rods came with)

1. 27
2. 70

gotten ,00236" of stretch.....
keep getting flabbergasted

 

have a nice day

 

ARP bolts are not the best. I got one bad one straight from manley I called them up and then next day'd me one for free. Secondly I had the same results, I had to torque and loosen each bolt about 4 times before I had the required amount of stretch that matched the amount of torque applied.

 

i understand burnishing, and normally you don't need it when using a stretch gauge. after 9 torque cycles and 70ft/lbs (instead of the commonly excepted 45ft/lbs on the ARP-lube) the stretch still is'nt stable


i did just that and it seemed to overstretch the bolts seeing they don't return to within 0.001" of the original length

i'm not worried about overcycling, i'm worried about overstretching!

 

yes this sucks, i live in holland, so a new set of bolts takes a while....

i'm up to 9 times overtorqueing it and still not the required stretch achieved, damn ARP!!!!!!!!

the bolts i did not pay a whole lot of attention to total torque applied and just burnished them and stretched them by the book, i stretched them AAAARRRGGHHHHH!!!!