Author Topic: Looking for recommendations for poly locks for use with 302  (Read 5769 times)

Bryan302

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Looking for recommendations for poly locks for use with 302
« on: October 20, 2014, 04:21:35 AM »
Due to the fact that they don't make things like they use to, and most cam companies have been bought out.  I ask for 69 Z owners to recommend a good poly lock that is reliable and will keep the adjustment well, and with a good quality overall.  I will be using a 140 cam and 3927142 springs and O rockers.  Please give your suggestions on a good brand and the part number.

Thanks,
Bryan
Bryan S.
1968 RS Z/28, 12E, PNT R2, TR 749
1969 Z/28 X33, 05A, PNT 52 52, TR 719, endura bumper

CNorton

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Re: Looking for recommendations for poly locks for use with 302
« Reply #1 on: October 20, 2014, 12:58:13 PM »
I've had good success with ARP 12-point Perma-Loc hardware (part # 8241 for 3/8-24 thread studs or # 8242 for 7/16-20 thread studs).   Any poly-lock will work better if the stud ends are trued for a flat surface. the way ARP studs are finished.  A dimpled stud end does not provide a solid seat for the set screw.

c

69Z28-RS

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Re: Looking for recommendations for poly locks for use with 302
« Reply #2 on: October 20, 2014, 01:44:10 PM »
I've had BAD LUCK with two different types of poly-locks many years apart; left me stranded both times!   so my recommendation is STOCK CHEVY FRICTION NUTS...  new ones....  they won't move much, and if they do the movement is so slow that you have LOTS of warning, when the 'poly unlockers' come off, they do so VERY quickly.... with no warning whatsoever.. maybe a couple of seconds!

IMO:  poly locks are worse than worthless!
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Kelley W King

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Re: Looking for recommendations for poly locks for use with 302
« Reply #3 on: October 20, 2014, 03:08:04 PM »
ditto on the friction nuts. My Z is down now with a nasty click. Have gotten the cover off but I kind of know what to look for.
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69Z28-RS

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Re: Looking for recommendations for poly locks for use with 302
« Reply #4 on: October 20, 2014, 04:52:29 PM »
I don't have pictorial evidence of the first time I had a 'poly locks' failure, as I was driving my '70 Z28 and one came off suddenly.. leaving me stranded until another '70 Z28 stopped to help me (what's the chances of that?).. :)

But pictured below is the last time I got stranded, my son in law and I were headed to the Good Guys Nostalgia meet in Bowling green KY in 2008 I think it was..  when one of his backed off.. leaving us stranded along I-65.   Fortunately we had chairs in the truck, which made it a bit easier while we waited for the truck/trailer to come get us... and take us back home to get a different vehicle...  :)

first photo:  It looked good when we started out.. :)
2nd photo:  After only 35 miles up I-65.... :(
3rd photo:  .. waiting glumly....
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
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motorman

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Re: Looking for recommendations for poly locks for use with 302
« Reply #5 on: October 20, 2014, 10:07:04 PM »
I have used "PAL"nuts as a lock nut on the std GM nuts
new Camaros owned 68 and 69 Z-28. new Corvettes owned 59,62,63,64,65,66,97,99 02,05 and 08. retired race engine builder, former NASCAR tech inspector

Bryan302

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Re: Looking for recommendations for poly locks for use with 302
« Reply #6 on: October 21, 2014, 05:43:06 AM »
Thanks all, for the suggestions and help!

Bryan
Bryan S.
1968 RS Z/28, 12E, PNT R2, TR 749
1969 Z/28 X33, 05A, PNT 52 52, TR 719, endura bumper

motorman

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Re: Looking for recommendations for poly locks for use with 302
« Reply #7 on: October 21, 2014, 04:37:49 PM »
Thanks all, for the suggestions and help!

Bryan
also if you do use poly locks set the lash .003 loose ,tighten the locking set screw and then use the adjustment nut to tighten to the correct lash. this wall tighten then poly lock in place. just snugging up the allen lock screw does not do it
new Camaros owned 68 and 69 Z-28. new Corvettes owned 59,62,63,64,65,66,97,99 02,05 and 08. retired race engine builder, former NASCAR tech inspector

L78 steve

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Re: Looking for recommendations for poly locks for use with 302
« Reply #8 on: October 23, 2014, 09:54:36 PM »
Poly locks wont come loose if the studs are spot faced as mentioned above. They can be ground flat in an old Sioux valve grinder on the valve stem fixture. If you have valve cover drippers they will have to be shortened also.
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z28z11

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Re: Looking for recommendations for poly locks for use with 302
« Reply #9 on: October 24, 2014, 04:58:51 PM »

[/quote]
But pictured below is the last time I got stranded, my son in law and I were headed to the Good Guys Nostalgia meet in Bowling green KY in 2008 I think it was..  when one of his backed off.. leaving us stranded along I-65.   Fortunately we had chairs in the truck, which made it a bit easier while we waited for the truck/trailer to come get us... and take us back home to get a different vehicle...  :)

Looks like somewhere near Ardmore or Lynnville. Glad you made it out in one piece -  ;D
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69Z28-RS

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Re: Looking for recommendations for poly locks for use with 302
« Reply #10 on: October 24, 2014, 06:54:25 PM »
*L*..  Yes, but even worse...  it was just north of the Elkton exit.. :)     
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan