COMP Cams Pro-Magnum 1.60 RR replacement PolyLock 7/16" part number help

[mpcv2000]

I have a set of 1.60 Roller Rocker from COMP Cams on my stoked LT4 using a 7/16" stud and this weekend a nut came lose making some nasty noises.
I have no damage because I've stopped the car right away.
I've try to re-tork it using the the Shbox write up and even before applying any pressure on the PolyLock it broke right off.

I'll suspect it cracked and came lose but anyway , I've been driving the car for 17,000 KM and this is the first issue I have had with the new motor so far.


Since I'm not too sure of the exact part number of the Roller Rocker and studs I have I ask you guys to give me your inputs.


Here's what I found out when I've removed the valve covers :







It was holding there by 2 or 3 threads.









I was barely starting to tight the Polylock ( 1/8 to 1/4 turn procedure ) and it broke .



















I'd like to order 1st thing tomorrow morning what I need to get me back on the road but I'm not too sure if the replacement part I've found is the right one.


I think I need 1401B-1 (..PolyLock search on CompCams web site ..) .

Am I right ?

Thanks.

[digitalsolo]

I'd call Comp, they might just send you a new one.

[mpcv2000]

I will give them a call tomorrow.


Someone on LS1Tech found the part number I'm looking for .


Part number needed 4603-16 .






Rocker Arm Nuts, Magnum, Roller Rockers, 7/16 in.-20 Thread, .6752 in. Outside Diameter, Set of 16

[mpcv2000]

Thursday evening .
I'm getting ready to re-assemble my top end ( if I can say ) and I've ordered the wrong PolyLocks .

Maybe I have a older sets of 1.6 Roller Rockers and the PolyLock are different ?

Anyway here's what I've got :













Right is the new one ( obvious ) 














Now left is the new one....




























I was hoping my car will be running tonight but looks like it won't happen.

I have also someone at CompCams that is aware of what I'm looking for so I hope I'll get the right part number before noon tomorrow so I can get the part on Friday.

 

[mpcv2000]

With what I know now I went back on COMPcams web site and found the right one I think :








Rocker Arm Style                      : Full roller
Rocker Arm Nut Style              : Polylock
Rocker Stud Thread Diameter           : 7/16-20 in.
Overall Height (in)                      : 1.000 in.
Outside Diameter (in)              : 0.600 in.
For Use with Stud Girdle                   :No


This time I've mesured the nut and they matches what's above.

I should have done that yesterday......

[bikedad]

Wow. Good thing it broke while you were tightening it.
I had a rocker stud snap at 7000 RPM and caused "Bikedad Go Boom" thread.

My engine having solid lifters has me adjusting them every 2000 miles or so. I don't mind it though. I like tinkering around in the engine and this way I find the weak points before they happen. (Hopefully  )

[mpcv2000]

Wow. Good thing it broke while you were tightening it.
I had a rocker stud snap at 7000 RPM and caused "Bikedad Go Boom" thread.

It broke at the track ( around 6,000RPM ) my guess  .
I traillered the car back home.

I realized it was broken when I've tried to torque it.
1st I thought it just got lose somehow.

My guess is I have no motor damage but I haven't started the car since it is still not fixed.

[bikedad]

You're probably fine with your motor.
When my rocker stud snapped the car backfired and blew the intake manifold gasket out at the water jacket. I was just coming into the traps when it happened.
It flooded cylinder 3 and hydro-locked it. Lot's of smoke and noise when it went.
That's when I decided to go the stroker route.
Comp Cams sent me new improved rocker studs. That's what I have now.

[mpcv2000]

Got the kit today 4600-16 .













They are not the right one again.

I need to have the machined end to fit the 1.6 Roller Rocker grove.

















Like you can see the old one fits into the grove perfectly .












The new one are a too big .












I said fuk it I'm not going to wait another week so I grinded it down....











Now it fits perfectly. ( not nice but....)

















Back together.















I've started the motor and it runs perfectly , like before.

I'm very happy I haven't broke anything.