Poly lock issue - Chevelle Tech
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post #1 of 26 (permalink) Old Jul 11th, 20, 9:33 AM Thread Starter
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Tyler
 
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Poly lock issue

Can one of you explain why this is happening?
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post #2 of 26 (permalink) Old Jul 11th, 20, 1:29 PM
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Mr Bill
 
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Re: Poly lock issue

How about a picture of the cylinder head with the polylocks on it ? Is the valve lash correct ? Almost looks like the rocker arm has been bouncing up and down and hitting the polylock ????


More details would help to. What engine ? Cam ? Spring pressures ?

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post #3 of 26 (permalink) Old Jul 11th, 20, 4:58 PM
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Eric
 
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Re: Poly lock issue

Installed with the round side of the roller bearing trunnion facing up, instead of down??

Someone on another board posted a lock that looked identical to that and he had put the roller trunnion on the stud upside down, so the poly lock wasn't on it's flat seat and was up against a curve surface....It looked just like that and had polluted the bearings in that rocker enough to make it stiff. to rotate.

Cheap grade of nuts without the proper hardening would be another possibility.

Look familiar?

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post #4 of 26 (permalink) Old Jul 11th, 20, 5:09 PM
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Re: Poly lock issue

Quote:
Originally Posted by Ericnova72 View Post
.....Cheap grade of nuts without the proper hardening would be another possibility.
That's what I was thinking too. I only use ARP brand for that reason.

70 Chevelle SS clone (632 CI powered).
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post #5 of 26 (permalink) Old Jul 11th, 20, 6:22 PM
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Re: Poly lock issue

If you have the trunions facing the correct way, side with the recess/flat surface up, then get a new set of knows quality locks. ARP.
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post #6 of 26 (permalink) Old Jul 12th, 20, 6:32 AM Thread Starter
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Tyler
 
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Thanks guys, yes they are correct with the flat surface up. These are a couple pictures I took just before it went in. Ironically it is right there (#2) that looks the worst. The studs should certainly be a little longer with less threaded area but anyway these are the pictures I have, didn’t take any of the assembly before I tore it apart.
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post #7 of 26 (permalink) Old Jul 12th, 20, 6:39 AM Thread Starter
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Tyler
 
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If memory serves open pressure is right about 320 pounds. Rpm performer cam, solid lifters. I had the lash set at .014 int/.016ex cold.
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post #8 of 26 (permalink) Old Jul 12th, 20, 6:54 AM
 
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Re: Poly lock issue

Quote:
Originally Posted by Chebell View Post
If memory serves open pressure is right about 320 pounds. Rpm performer cam, solid lifters. I had the lash set at .014 int/.016ex cold.
I thought the Edebrock performer rpm cam was a hyd cam? Damage may be due to using solid lifters on a hyd cam

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post #9 of 26 (permalink) Old Jul 12th, 20, 7:15 AM Thread Starter
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Tyler
 
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Yes, it is a hydraulic cam and I have solid lifters on it. If you have been seeing any of my posts you’ll see that I’ve had one hell of a time with Lunati cams......so long story short, after all the carnage, what I had laying around was this cam that was never ran and a new set of solid lifters. It was explained to me, and please correct the story if it’s wrong, that you can run solid lifters on a hydraulic cam but not so much the other way around due to the ramp profile. Just one issue would be a lash spec not being out there so I’ve been playing with that. I figured at this point I’ve spent so much it was worth a shot, if it blows apart I’ll just start over and go a totally different direction.
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post #10 of 26 (permalink) Old Jul 12th, 20, 7:18 AM
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rick
 
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Re: Poly lock issue

It looks like the rocker arm is touching the top of the spring & retainer or maybe I just cant blow the pic up enough but could that cause issues ?


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post #11 of 26 (permalink) Old Jul 12th, 20, 7:28 AM
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Re: Poly lock issue

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Originally Posted by shovelrick View Post
It looks like the rocker arm is touching the top of the spring & retainer or maybe I just cant blow the pic up enough but could that cause issues ?
Good catch. Yes it does look that way. Makes me wonder about those rocker arms, as well as the valve spring diameter used.

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post #12 of 26 (permalink) Old Jul 12th, 20, 7:32 AM
 
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Re: Poly lock issue

Quote:
Originally Posted by Chebell View Post
Yes, it is a hydraulic cam and I have solid lifters on it. If you have been seeing any of my posts you’ll see that I’ve had one hell of a time with Lunati cams......so long story short, after all the carnage, what I had laying around was this cam that was never ran and a new set of solid lifters. It was explained to me, and please correct the story if it’s wrong, that you can run solid lifters on a hydraulic cam but not so much the other way around due to the ramp profile. Just one issue would be a lash spec not being out there so I’ve been playing with that. I figured at this point I’ve spent so much it was worth a shot, if it blows apart I’ll just start over and go a totally different direction.
I thought that is only for using solid rollers on a hyd roller cam but I could be wrong

77 camaro,
400 build-up in progress
400 0.030 over, AFR 195 heads 68cc chambers, SRP 16cc dish pistons, Scat I-Beam rods 7/16 bolts, Scat 9000 cast crank, Crane 296 hyd roller cam, hooker 1 3/4 headers, Holley 750, Richmond 4.10:1 gears
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post #13 of 26 (permalink) Old Jul 12th, 20, 7:38 AM
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rick
 
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Re: Poly lock issue

I thought the same, solid rollers on hyd. roller cams, my engine builder (mach. work & rotating ass. only) wanted to do that with mine.


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post #14 of 26 (permalink) Old Jul 12th, 20, 8:04 AM Thread Starter
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Tyler
 
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No evidence of spring/rocker interference. I made sure to get the correct rockers so that wouldn’t happen, I’ve looked close and don’t see any witness marks. Maybe I got the solid/hydraulic thing backwards. What would have a slower “take up” ramp? I suppose it could be “pounding” them up as opposed to “pushing” them up.
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post #15 of 26 (permalink) Old Jul 12th, 20, 9:19 AM
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Re: Poly lock issue

I think when running solids on a hydraulic cam you typically run tight lash, like 0.006”-0.008” hot. If the rocker trunnion doesn’t have enough engagement on the shank or the stud it might be dancing around a bit.
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