Question about comp roller rockers
#1
Staging Lane
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Question about comp roller rockers
My 383 ls1 has comp roller rockers on it, and the comp instructions say to tighten them 1/2 turn past zero lash. Does anyone have any experience with these things? They just seem noisy and I was wondering if that wasnt enough preload. I checked the pushrod length when I put the motor together and the wipe pattern looked good. Thanks for your help
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yeah they are adjustable. There isnt a pedestal with a bolt like the stock rockers, theres a stud the rockers ride on. Oh and a word of advice to those that buy comp roller rockers, they didnt fit under my valve covers, I had to buy spacers.
#6
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If they are stud mounted/adjustable they are like the old SBC engines. As one valve starts to open adjust the other one. Spin the pushrod between your fingers and slowly tighten the nut. When the pushrod stops spinning freely that's zero lash. Anything after that is preload. I use 3/4-1 turn for years and that seems to be a good spot. Make sure you tighten down the jamb nut so it won't back off. Turn the engine over till that valve starts to open and adjust the other. Repeat this for the rest of the engine.
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#8
Google EO/IC valve adjustment method. Preload is determined by the threads per inch (pitch) of the adjustment bolt or poly lock. Figure out what that is, divide 1 by the pitch, and that gives you what 1 turn (1 thread) equals. I also use .080-.100 on standard hyd. lifters.
FWIW, typical sizes are 3/8-24 UNF and 7/16-20 UNF. That translates to .050"/turn for 20TPI and .042"/turn for 24TPI.
FWIW, typical sizes are 3/8-24 UNF and 7/16-20 UNF. That translates to .050"/turn for 20TPI and .042"/turn for 24TPI.
#9
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This is the way i adjust my comp rocker arms on my LS1, Read the hydraulic lifter adjustment procedure.
Do one cylinder at a time.
http://www.cpgnation.com/forum/comp-...ment-2076.html
Do one cylinder at a time.
http://www.cpgnation.com/forum/comp-...ment-2076.html
Last edited by Randy WS6; 09-07-2011 at 11:44 AM.
#11
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Google EO/IC valve adjustment method. Preload is determined by the threads per inch (pitch) of the adjustment bolt or poly lock. Figure out what that is, divide 1 by the pitch, and that gives you what 1 turn (1 thread) equals. I also use .080-.100 on standard hyd. lifters.
FWIW, typical sizes are 3/8-24 UNF and 7/16-20 UNF. That translates to .050"/turn for 20TPI and .042"/turn for 24TPI.
FWIW, typical sizes are 3/8-24 UNF and 7/16-20 UNF. That translates to .050"/turn for 20TPI and .042"/turn for 24TPI.
#12
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Good info. I'll have to try and check the thread pitch on those things saturday. so if I'm looking for around .060 to .080 I'd need at least a good turn, turn and a half depending on the thread pitch. I actually used those instructions randy ws6 posted and comp only recommends half a turn. Seems like that would only be .020 to .025 or so, maybe thats why my valvetrain is noisy. Thanks for the help guys, I'll update with my findings
#13
Ive been using this method 1/2" turn and my engine is quite, but it might be because i use Mobil-1 15W/50 performance oil. Isn't the .080" depth for a stock style engines ? I just figured that were i'm running Comp rockers and performance lifters that they would know what the reload would need to be. And a stock engine usually don't rev past 5500rpm's , were I rev at 7400rpm's. So Comp my be setting the lifter reload for high performance engines that rev high for extra clearance and spring pressures & rpm's.
#14
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I don't have the time to go into the differences between a shorter vs. longer preload at the moment. But from extensive testing, there is absolutely no reason to have .100+ travel in high RPM applications. Even at .080" preload, LS7's will still have .100"-.120" travel. Your setup and shift point would love some short travels
#15
Depends on your lifters. But that post was referring to standard lifters and your comment about high RPM and .020"-.025" preload. Standard meaning LS7 or even aftermarkets keeping roughly .200 available travel. I like keeping .125 travel on standard lifters, always has shown stability in my tests vs. running shallower or deeper. Subsequently that is where a lifter will quiet up sometimes when set shallow. Might be 1 or all 16. Which happens when the leakdown rate on a certain lifter in the set is on the low side, on top of a shallow preload. Thus you always hear the fix, more preload.
Last edited by Havoc40; 09-08-2011 at 09:23 PM.