# Does this POLY LOCK look right to you?



## Red Skeleton (Jul 2, 2019)

Hi,

I installed the first poly lock on my 68 400 and I see the base of the lock contacts a much smaller area on the pivot ball. Is this right? I like the way the old nuts hold the rocker much more securely. Pictures aren't great, one is with a flash but the lock is significantly smaller at its base.:surprise:


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## bigD (Jul 21, 2016)

There are poly-locks with different diameter bodies. But, I don't know that any of 'em will have as much pivot ball contact as a stock nut.

I suppose you could use a hardened washer, under the poly-lock, if you think that more contact would somehow be better. 

I've never read of a problem, because of using thin wall poly-locks. I assume the pivot balls are kept from rocking, by their contact with the rocker stud. So, I don't think the diameter of the hold down nut would change anything. The only function of the nut is to hold the pivot ball down, when the pushrod comes up.


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## PontiacJim (Dec 29, 2012)

*bigD*: "There are poly-locks with different diameter bodies. But, I don't know that any of 'em will have as much pivot ball contact as a stock nut."

*PJ*: Red contacted me via PM and was trying to decide which poly lock. When you do a search, it becomes confusing real fast due to the descriptions. Yep, all kinds of different diameter bodies and then they say for roller rockers, and nothing about use on a standard stamped steel rocker - which you can see now that most any diameter body poly lock would work on factory stamped rocker arms. They also come in different lengths (excluding the longer stud girdle style) to add more to the confusion. Seemed to me that back in the "old days," you just ordered the poly lock for your application and were done with it. Of course the "tech" on the other side of the email or phone can't help because all they can do is read off a manufacturers card.

The poly locks should be fine as long as you have enough thread at the top of them to insert the set screw to lock them into place. This is where body length comes into play. If for some chance the poly lock is too short, do as *bigD* suggested and you can insert a Grade 8/hardened washers under the poly lock and on top of the rocker arm ball to raise the poly lock up to give you more threads so you can tighten down the set screw and not pull/strip it out.


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## Red Skeleton (Jul 2, 2019)

PontiacJim said:


> *bigD*: "There are poly-locks with different diameter bodies. But, I don't know that any of 'em will have as much pivot ball contact as a stock nut."
> 
> *PJ*: Red contacted me via PM and was trying to decide which poly lock. When you do a search, it becomes confusing real fast due to the descriptions. Yep, all kinds of different diameter bodies and then they say for roller rockers, and nothing about use on a standard stamped steel rocker - which you can see now that most any diameter body poly lock would work on factory stamped rocker arms. They also come in different lengths (excluding the longer stud girdle style) to add more to the confusion. Seemed to me that back in the "old days," you just ordered the poly lock for your application and were done with it. Of course the "tech" on the other side of the email or phone can't help because all they can do is read off a manufacturers card.
> 
> The poly locks should be fine as long as you have enough thread at the top of them to insert the set screw to lock them into place. This is where body length comes into play. If for some chance the poly lock is too short, do as *bigD* suggested and you can insert a Grade 8/hardened washers under the poly lock and on top of the rocker arm ball to raise the poly lock up to give you more threads so you can tighten down the set screw and not pull/strip it out.


Thank you guys, I installed them and adjusted twice, and gave them a 1/2-3/4 more. Oil deflectors were great. Clicking is less but still there so must just be the nature of the beast. Still lurches at low speeds so it's hard to make a good shift between first and second. I did notice that the rockers were able to move side to side a little on top of the valve. I would assume this is normal. I've got to say again, on a straight away this thing is impressive. It just keeps on pulling making me wonder what it top speed is? Whew!


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## geeteeohguy (Feb 2, 2008)

It shouldn't click with hydraulic lifters. The rockers need to be tight enough so there is no noise, but the pushrod is still spinning freely when the engine is running. If the pushrod stops spinning, you are too tight. You should be able to grab the rocker (careful!) with the engine running (or use an open end wrench) and move it from side to side over the top of the valve. If you can't, you are too tight. If it moves all over, and is clicking, you are too loose.


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## BearGFR (Aug 25, 2008)

Red Skeleton said:


> Hi,
> 
> I installed the first poly lock on my 68 400 and I see the base of the lock contacts a much smaller area on the pivot ball. Is this right? I like the way the old nuts hold the rocker much more securely. Pictures aren't great, one is with a flash but the lock is significantly smaller at its base.:surprise:


Hey Red,
I tried to take a really close look at your photos, at the rocker nut on the front (right side in the photo) of the engine. It does look like a poly-lock body but what I'm not seeing in the photo is the set screw that's supposed to be inside it. Perhaps it's there and just not showing up in the photo? Just in case, the way you adjust these things is to set them where you want them, then tighten the set screw inside down against the top of the rocker stud to "lock" that adjustment in (see the photo). Without the set screw, they will not hold their adjustment and definitely will back off. 









Bear


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## Red Skeleton (Jul 2, 2019)

Thank you Bear, 

yes the allen lock screw is inside. What you didn't notice is the oil deflector is on the wrong end of the rocker. I figured that out later. 

I now have a dilema that my valve seals need replacing (the car sat for 10 years) so I thing they've gone bad and may be fouling my plugs. The outer threaded part of the plugs are wet looking as is the tops of the pistons. Next on my list..........


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