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Am i adjusting my roller rockers right? Need advice ASAP

  • Thread starter Thread starter 85_SS_302_Coupe
  • Start date Start date Jul 7, 2008

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
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Jul 7, 2008
#1
  • Jul 7, 2008
  • #1
I've recently put roller rockers on my car (Comp Cams Pro Magnum 1.6's) and i'm worried that something isn't right. I've never done valve train so i had a buddy help. His way of adjusting them is to snug the nut down until you can just spin the pushrod with your fingers and then lock it down (at the bottom of the cam lobe). Not saying that's wrong, but is there a better way? We did that and they were NOISY. So i'm outside right now redoing them and some of them are so loose that the rod actually jiggles a little bit. I readjusted them to where they spin but not easy, just enough that they spin but aren't super easy to spin and they don't jiggle.

My other question is about how centered the roller tip is on the valve...i know that without shaft mount rockers you're gonna have a little bit of spin on the stud but a few of mine were just about on the sides of the rocker where the roller tips attach. Is that normal or could that be because the rockers were too loose?
 

ShortThrow50

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Oct 22, 2006
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#2
  • Jul 7, 2008
  • #2
You only tighten them down to you feel the SLIGHTEST resistance with your fingers while turning pushrod. then you turn 1/4 more turn and that is all. then lock the nut. Im assuming you using hydraulic lifters and not solids. that is the beuty of hydraulics becuase they adjust themselves and are quiet as hell becuase of this. DO NOT soak these hydraulics in oil either becuase you will experience what your experiencing now. Do one cyliner at a time starting with number one and going in firing order and turn the crank one quarter a turn in between
also, when you first start up after this procedure, the valve train will be noisy for about 20 seconds or so until the hydraulic lifters fill up with oil. basically they pump up
 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
6,945
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Northern KY
Jul 7, 2008
#3
  • Jul 7, 2008
  • #3
Well according to Comp's website they say tighten it until zero lash and then 1/2 turn past that and lock it down. Then i called my local speed shop and they said even 3/4 past that is ok. I tightened them until the rods were stiff but still spin and went 1/2 past that and lock'em down. I've already ran the engine for a good 100 miles, i just didn't like how loud the rockers were and i had a feeling they were loose.
 

67coupe

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Apr 5, 2002
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Huntsville, AL
Jul 7, 2008
#4
  • Jul 7, 2008
  • #4
Stud mount I assume?

As ShortThrow said: While tightening the nut, as soon you as feel resistance when turning the pushrod, this is zero lash. Tighten additional 1/2 turn and lock it. Just make sure your on the base of the cam lobe for the valve you're adjusting.

Your comment about the roller tips not being centered, was this before or after your adjustment? If they are still not centered after your adjustment, you may need to adjust the guide plates IF both roller tips on that cylinder are off center the same amount and in the same direction.
 

Foxfan88

My Grandpa has great wood.
Sep 13, 2004
2,487
4
0
Miami, Ok
Jul 7, 2008
#5
  • Jul 7, 2008
  • #5
easiest way i do them, if the lower is off it makes it much easier to find zero lash. if the lifters arent pumped up, it can be hard to tell what exactly is zero lash. hand tightening the nut will press the plunger down and you wont even know it and then you end up holding the valves open if you adjust with the lifter plungers bottomed out.

with the lower off you can see the lifter plunger move and it makes it much easier to find zero lash, i just handtighten until i see the lifter plunger barely move, then i go back and forth until i can nail zero lash exactly. you can also feel it after you do it alot.

then i set the preload which is usually .020-.030..... on a conventional 3/8-24 stud1/4 turn would be .010 so .020 would be a half turn etc etc.

as for roller tip location, to change that you need to change pushrods, with aftermarket parts and rockers and all the variables the best and most accurate way is to get a pushrod length checker and play around until you find the length that tracks around the center the best. you would need to use a checker spring because an adjustable pushrod isnt strong enough to push the springs down.

once you find the righ length pushrod you should notice with the valve shut the roller tip will be slightly on the intake side from center. once if opens up the tip moves in a radias in relation to the trunion of the rocker.
 

ShortThrow50

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Oct 22, 2006
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Jul 7, 2008
#6
  • Jul 7, 2008
  • #6
85_SS_302_Coupe said:
Well according to Comp's website they say tighten it until zero lash and then 1/2 turn past that and lock it down. Then i called my local speed shop and they said even 3/4 past that is ok. I tightened them until the rods were stiff but still spin and went 1/2 past that and lock'em down. I've already ran the engine for a good 100 miles, i just didn't like how loud the rockers were and i had a feeling they were loose.
Click to expand...

i dont know what i was thinking when i said 1/4 turn. yeah, i go half turn.
 
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