These type of self-locking nuts including factory style and almost all aftermarkets CANNOT be used on studs that have their threads formed by "rolling" instead of the old-fashioned "machined" method. This is especially true when using "ARP" brand of rocker studs. It's mentioned in their catalog. Most decent aftermarket studs have threads installed using the newer method. You have to go to some sort of positive lock. Thanks, Gary in N.Y.

 

It dawns on me I have long adopted a term that is possibly incorrect.

I am familiar with two types of r/a nuts: those with "jam type" or "interference" threads like on most stock non-shaft mounted factory stamped steel r/a's and those like I'm using now with a smaller set screw inside the r/a nut that you tighten down with an allen wrench after you set the nut to the desired place.

I have always referred to these latter type as "polylocks" - but is this correct? Is there even another type or have I botched the terms?

BTW, GoFast raised an excellent point if you are not using something like these locking nuts and are relying on interference threads on the nuts - as this will be dependant largely on the very type of thread you have on the stud (a smoother or different profile thread would not interfere or pinch as reliably.)

 

Now thats information i'm looking for. And i see a warning in the ARP catalog not to use their studs with stock type loc-nuts. But i don't know the difference between a machined thread and a rolled thread. And can't recall the mfr of studs.
I like those ARP Perma-loc rocker nuts and can see aquiring a set soon but looks like tall vlv covers required. But i want to give the double nuts a chance to prove themselves. Still have some tappet noise and will monitor for increase. Also may try 3/4 turn tight for pre-load as i'm thinking the Crane Hi-Intensity lifter may be a little soft at idle.
Any noise from your CC Mag rockers?
Thx again. cardo0

 

I recently bought a set of original style rocker arms (with new nuts) on Ebay. I'm going to install these to see if this annoying tapping (or better: ticking, clicking) noise is coming from my Comp roller tip rocker arms.

This clicking noise sounds like a loose rocker, however I checked them and all are fine. I verified that the pushrods are not hitting the guide plates (no evidence of contact on the rods), I set the valve lash several times..... I thought this noise was caused by a loose header (found three bolts loose) but that wasn't the problem...

This noise is only there when reving the engine up , it's not there at idle or under acceleration. Only when driving steady at roughly 45mph it's very noticeable, as soon as I push the pedal a little more and accelerate the noise is gone

I'll post the result of my rocker arm swap as soon as it's done.

 

I can't speak for the ARP perma-loc nuts, but I am using Crane Cool-nuts (thier version of poly-locs) with Magnum roller tips and I had to machine the upper diameter of the nut to insure they had clearance all through the lifters range of motion. There were a few that were to close for comfort out of the box. FWIW, you may want to use Comps own locking nuts, to make sure you don't have that issue (unless you have acces to a lathe, it's not that big a job).
I replaced the stock Comp nuts the first time I had the valve covers off to re-set the lash (solid flat-tappet). There were some that just didn't feel like they were locking as much as the rest when I put them in, but I didn't have any else to use at the time. I bought the cool-nuts to have on hand for the re-setting of the lash.

 

Red Bad: Thx for responding as my CC Mag rockers are ticking at idle and so begining to expect some noise from these. Used a sethiscope to listen and sounds more like just 1 or 2 rather than all.
How much pre-load do u use? I'm set at 1/2 turn tight and considering going to 1 full turn tight just to see what happens. I'll double check but i think 1 full turn is possible without overadjusting.
BTW what kind/mfr of lifter do u have?
Thx again. cardo0

68ragg: That's what we need to hear if youv'e had problems with those CC lock-nuts. Were urs just too easy to turn? Or any of the CC Mag rockers loose/making noise?
Man i had #3exh clacking away so bad the p-rod could hardly reach it. All less than 45 min run time after all brand new vlv train.
Thx for ur input. cardo0

 

I had them set at 1/2 turn, then I went to 3/4 turn when I thought they are too loose.... did not help...

At the time I installed these roller tip rockers I also installed a Edelbrock cam and hydraulic lifter kit (Performer).

I can only hope that this noise goes away when I install the original rockers - I am afraid of a wiped cam lobe or a messed up cam bearing...

 

CC Magnum roller tipped rockers here with the supplied nuts. No problems at all with them loosening after 3 years use. Installed with 1/2 turn extra & later checked them - all fine.
I've not seen a polylock but am guessing that it's what we call "Nyloc"? It's like a normal nut but on top there is some extra metal that contains a nylon (or some sort of polyblurb) material. The thread cuts/deforms this when the nut is tightened & it then grips the thread to stop any movement of the nut. Is this what a polylock is, or is it something else?
Post on the rolled vs cut threads is a good point.

 

cardo0, When I put the rocker arms in and set the initial lash cold (solid lifters) I felt a few of the Comp Cam nuts were just a little to easy to turn while adjusting. I went ahead and broke in my XS268S cam with them and re-set the lash hot, the same nuts still felt to easy to turn for comfort. I figured I would get something to replace them when I checked the lash the next time. I ended up running that way all last year and put about 2000 miles on them. When I went to back the nuts off for the winter, I checked the lash to see if they had changed, and there was no difference from the first hot setting. So, they did not move in my case anyway.
I did replace them with the Crane nuts just for piece of mind anyways.

UKPaul, Comp Cams Poly-locks and Crane Kool-nuts are the type with a hex for adjusting lash and a set screw in the top that is tightened against the stud afterwards, to "lock" the nut adjustment in place.

Dave

 

Got it! Thanks Dave

 

Sorry for the late reply all, finaly got the chance to post again and need to follow this up.

Red Bad: Ok ur CC lock-nuts sounded like a problem so thats a mark against CC rocker nuts. Good luck with R&R rockers. I think you may have saved me a try at 3/4 turn tight preload. BTW my rockers are 1.6 ratio - may have a significance. How 'bout urs? 1.5? 1.6?
Your situation is similar to mine and i appreciate the input.

Thx for your honesty ragg: I don't know how to count the solid cam's lock nuts since a possible bad set of hyd lifters dosn't apply here. But shall consider them a good set of lock-nuts if adjusment held for 2,000mi.

UK Paul thx for input and 3 yrs is a good point for CC. I will look elsewhere now and leave my lifter adjustment alone. Now my list (suspicions) of questions is qrowing. Interested now in type of lifter you have. What ratio CC rocker are u using? 1.6? 1.5?

Totals time: So lets say 'bout 5 good sets to only 2 bad sets of CC Mag lock-nuts.
I really can't include the Poly type locks as i'm not running those (yet).

Miss match with type of threads on studs a possible cause.

Good night. cardo0

 

Cardo0
I'm running 1.52:1 rockers with Crane hyd lifters that were supplied with the cam.
It's definitely worth investigating

 

A couple of days ago it seemed you were rather stressed and a little short with me when I asked a few simple questions. You basically told me all the information was in your profile, and to some degree it is. If you are so concerned with the compatibility of your nuts with your studs call the head manufacturer and the rocker arm manufacturer on three-way and hash it out. Taking a poll like you are trying to do is not a definitive answer to anything, there are entirely too many variables most of which is the person installing and adjusting the rocker arms. Kind of like the person that tried to install your GM mini starter that couldn't get it too fit because that person obviously didn't know there is more than one size flywheel.

ltlevil

 

Hey ur a big help. Its just that i'm low on cash right now and can't afford the longdistance air time for that 3-way call - need to buy some good new lock nuts instead. But maybe you could get CC and WP engineering on the phone to ask for me. With ur mental powers of investigation i'm sure u'll get those big guys straightned out.

Sorry starters where on another post. Hey try your own post on starters and then i'll get to study that. But for now i'll continue with this poll/post.

Have a nice day. cardo0

 

Well just got off the phone with Comp Cams (rockers) and Edelbrock (heads) used Edelbrock because that is what is on a motor I just built for someone. I talked to both reps at the same time and it didn't cost me anything. After I called the 800 number (CC) and explained the same problem you described, I suggested CC get Edelbrock on the phone at the same time to discuss a possible problem with the studs or nuts-simple as that he said good idea and then all three of us were talking on there dime. On top of this CC is willing to send a new set of nuts and Edelbrock will send a new set of studs. I told them I will give it another try to see if I just didn't set them right. As far as the starter reference, that was a nice way of me saying, "If the same person that tried to install the starter (and didn't know there were different flywheels, or to move the starter over), is the same person working on the rocker arms and trying to set the valves- I believe I would look a little closer at their technical abilities and the craftsmanship before I blamed your trouble on a mechanical problem. " If this person is you Now you can say what you want or tap your toe or any of those other comments you made before, but I truly was trying to help you, sorry I didn't realize you didn't want help fixing the problem just wanted to have something/somebody other than yourself to blame it on.

ltlevil

 

Ok folks its time to just ignore lurkers that can't identify themselfs (in thier profile) and move on with this post/poll. We don't give in to nonsense makers do we guys? Does anyone here care about Edelbrock studs or starters? Best method is just to put'm on ur ignore list.

I still would enjoy to hear from anyone with CC Mag rockers having vlv train noise or not. I'm greatly interested in this due to all the recent posting of wiped cams from CC and having 2 nuts loosen up my rockers right at break-in.

I appreciate all your tolerance here with some real nonsense. cardo0

 

before either. It stabilized, unlike the other, deeper, originating problems on this "Rosemary's Engine". This isn't fake or a result of incredible idiocy on the part of enthusiasts.

I don't see a great use for the personal engagements on this thread (or on a couple of others.) If any respondee is bored or annoyed by the starter of a thread - make that clear once, then move on. What possible purpose does it serve to engage someone over and over you just don't like or regard as foolish?

On the other side, if you do have the huevos to post something you are having a problem with that might cause ridicule, it doesn't seem a posted conversation is enough to expect reps of manufacturers or other overly interested parties to jump in and attempt to sabotage this complaint - it's probably a legitimate disgreement, even if personally based. It doesn't follow that such a disagreeing party is necessarily wrong either.

(I really don't accept to many excuses or disparaging remarks from manufacturers' sales staffs either. The bubba car parts industry is not really known for customer support.)

These CC ProMags are now the staple of best valvetrain equipment, like the original Harland Sharp's used to be. There may, nonetheless, be something going on that didn't used to with aluminum bodied rockers. Having put them on in place of cheapy ProForm $100 Sharp knock-offs, I doubt there really is much impact under 8K.

I know I learned something here may involve different thread types, which I had never considered - so something concrete came out of this dialog. Think I was going to learn that from a factory rep right out in the open?

I know a similar "current best" product - the MSD ProBillet distributor -has a bad tendency to leak - and leak badly - at the slip collar until you RTV it in place, which is hardly emphasized in their literature. Few mechanics were familiar with it. (Personally, I think they should redesign that slip collar to be a continous piece - spiral, tongued-in, whatever.)

What a shame it would be if such dialogs became repressed from either excess personal criticism or dismissal out of hand of those who don't agree as being trolls.

 

Thank you for your response and I welcome your comments Wayne. I also am a believer in the CC Mag rockers and expect they will prove thier great performance reputation.
So i reviewed this poll/post again for another look and found my acounting off by 1 bad set of Poly-locs that finaly worked out. So the revised results are: 2 bad sets - myself (cardo0), Redbad79 (curious not at idle for Redbad)
5 good sets - Page 62, Stingr69, Ragg (but using solids), Yellow73 and PaulUK

From this short list the bad sets are over 25% Not good!
But the Polyloc users are 100% good sets and only 1 set with inital problems that recovered - WayneLB (with initial poly-loc problems).
GoFast deserves an honnorable mention here with some great insight on threads.

I need more data. And would like to run this poll to 100 responses looking at CC May self-locking nuts. But i'll feel lucky if we hear from 50 in a reasonal time.

Well anyways i need time to shop for taller vlv covers and new gaskets (can't recall brand, using the 1/4" or 5/16" thick cork set now and they really work great) and of course a set of Perma-locks.

Your responses will only help other vette owners in the future avoid this problem. I have to say this is really one of the great benifits of this forum. And i'll verify we have brainstormed other problems here before with good results. cardo0

Please forgive my previous math errors (spelling too). :o cardo0

 

Bought Crane Kool-Nuts from Summit for $26. They were a few more bucks than Poly-locs but 1/2 the price of ARP Perma-locks. Crane advertizes better oiling and heat sinking with thiers so thought i'd try'm. Have used the Ploy-locks before with good results but the Kool-Nuts seemed to have some improvements. And look like great quality.

Now i just have to put them on and adjust the vlvs for the 4th time.

cardo0

 

If I recall, you are using magnum rockers. As I posted earlier, you should check that the nuts don't hit the rocker arms (up at the top). The 1.7 ratio on my BB needed the top diameter turned for clearance.