Having vlv train problems and suspect my rocker arm self-locking nuts are backing out - brand new along with my CC Magnum rockers. So i bought a set of Crane Kool Nuts and they have a flange at the top that hits my rocker arms!
Don't see how they could work for anyone. Don't want to grind off that flange either. I liked the quality but man what a bumbled design. I always expected better of Crane than that.

BTW talking to an engine builder said its not uncommon to have rocker nuts loosen. He also said using the backup nuts like i'm trying has much more clamping force than any set screw design. Wouldn't even sell me a set of poly-locks reasoning that if the double nutting don't hold then problem lies elsewhere.

Anyone able to use Cranes Kool-Nuts?? cardo0

engine has WP torquers with screw-in studs and Crane Eneregizer 266.
measure p-rod length again and right on with my Manley checker
can sb Chevy vlvs rotate - found wear pattern on vlv tip at different angles though right accross tip center??

 

I am using Kool nuts with WP Sportsman II heads. My rockers are 1.6. No problem with fit, but they DO come loose.

 

Using Kool Nuts on my TF 23* heads, CC roller tip rockers, and a XE274 cam. No problems.

 

Desi, i just took 1 look/trial fit and didn't measure for clearance as they looked like they made contact. Do u have CC Magnum rockers? Or stamped rockers? Thx for the warning they too loosen. I'm battling that problem with the self-locking CC nuts. Makes me suspect other vlv train parts.

Glen good to read ur set up is working. Are u running 1.6 rockers or 1.5? How does ur Kool-Nut to rocker clearance look? Close? Maybe i was mistaken by the view.

Well maybe i should have made a run with those Kool-Nuts but it looked like they would produce some damage to rockers/vlv train. I'm 'bout to send them back but maybe should give them a try. I still believe in Crane products. Maybe its just my setup with 1.6 Magnum rockers - but no way do i want to reduce to 1.5s.

Anyone else running Crane nuts? cardo0

 

I am using them on a pretty stock suburban, no problems...

 

1.5 CC Magnum rockers. No clearance problems. BTW, have not loosened up during my 1st 500 miles on new engine.

 

I have stamped 1.6 rockers with 700 miles, solid lifters.

 

I am using them on my motor. I have a .525 lift solid cam with 1.5 CC roller tips. I did turn down the "flange" slightly because the clearance was to small. They did not hit but it was very tight. I have never had one loosen in about 3000 miles of driving. They get adjusted or checked about every 1000 miles. No problems at all.

 

I'm wondering if it is actually a stud or studs backing out on you? I had a problem initially with my Crane Gold Race rockers. Their instructions call for using lock-tite on the studs and torqing to 22 ft/lbs., letting the lock-tite cure for 6 hours before attempting installing the rockers and setting the valve lash. For some reason if I went to high rpms, I'd have a stud back out with a loose rocker arm. I was lucky because once the set screw on the rocker with a backed out stud came off and fell inside the valve cover. I had to go back and repeat the installation setting the lash all over again. The way I resolved this from happening again was once I had it all adjusted again, I went back and gave each adjusting nut with the set screw in place some additional torque. This provided the clamping force on the studs and locked the setscrew in place without upsetting the preload. I've never had a rocker come loose since. Cranes valve lash adjustment procedure leaves alot for interpretation. The Magnum rockers may be very similar for the adjustment. I found a website that helped me alot more than Cranes instructions. I'll post the link here. I may be completely off base here with your problem, but I hope this helps. http://www.vincihighperformance.com/...TRUCTIONS.HTML
The adjustment may be similar to your rockers even if it isn't an LS1/LS6 getting the rockers to stay in place.

 

Thx for posting Gordon. I was starting to double guess my first impression/trail fit. I bet 1.6 CC magnum rockers will contact.

zo6 i checked all my studs still tight at 50ft-lbs - no change.

I hate to just throw money at the problem and now looking at a couple cheap fixes.
1 - more lifer prelode - 3/4 to 1 full turn?
2 - maybe run 1.5 stamped rockers with those Kool-Nuts. Thinking is maybe some vlv train clearance i overlooked. Gude plates? Summit has roller tip 1.5 rockers for $100 (Crane wants $200 for roller tip rocker for some reason). Or maybe even plain Jane 1.5 stamped rockers - $50 (Crane $80). Or pay-up for CC 1.5 magnum rockers.

Oh well, just 1 change at a time. cardo0

 

Cardo, I read this thread and wondered if those kool nuts worked out for you?
I got bluing on my magnums, trying to get more oil to them. Running the 1.6rr as well.