Setting lifter preload??
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Joined: Sep 2002
Posts: 64
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From: Bay Area CA
Setting lifter preload??
Hey guys... I'm putting a new cam in my '71 BB and ran into a roadblock. The cam is in, chain is on, etc. I soaked the lifters in oil, dropped them in the bores, stuck in the pushrods, put on the rocker arms, and tightened down the locks. Well, I tried to. I ran out of thread!! With the locks bottomed, the pushrods still spin and the rocker arm still has play in it. So, for grins and giggles, I went ahead and stuck one of the old lifters in and everything worked fine. I was able to get it to tighten and still have room for the 1/4 turn.
Anyway, let me know what you think. The cam is Comp Cams part #XE284H. Even though it probably doesn't matter, these are the specs: 240/246 @ .050, .574/.578 110 LSA. The lifters are new part #858-16. And the rocker arms are the Pro-Magnum rollers.
I was thinking there might be an off chance the base circle might have been smaller on the new cam, but since the old lifters fit with the new cam, that idea gets tossed.
And one final stupid question just to make sure I am not being an idiot here. You set the preload when the valve is closed, right?? :confused:
Thanks!!
Anyway, let me know what you think. The cam is Comp Cams part #XE284H. Even though it probably doesn't matter, these are the specs: 240/246 @ .050, .574/.578 110 LSA. The lifters are new part #858-16. And the rocker arms are the Pro-Magnum rollers.
I was thinking there might be an off chance the base circle might have been smaller on the new cam, but since the old lifters fit with the new cam, that idea gets tossed.
And one final stupid question just to make sure I am not being an idiot here. You set the preload when the valve is closed, right?? :confused:
Thanks!!
Drifting
Joined: Jan 2002
Posts: 1,500
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From: N.Y
Re: Setting lifter preload?? (Black Magic)
Your last question is correct (yes closed) as far as the rocker bottoming out that doesn't sound right. do you have the right pushrods. Big Block use long and short. You may just need custom length push rods this happens with aftermarket stuff.
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Joined: Sep 2002
Posts: 64
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From: Bay Area CA
Re: Setting lifter preload?? (Black Magic)
Crap... Never mind. :crazy: I figured it out. I have the Comp Pro Magnum roller rockers. Even though I have seen numerous racers use them before, I have never played with them on my own cars. Anyway, you have to back the screw inside the lock off, set the lash, then tighten the allen screw back up. things sure go together a lot better when you know what the hell you;re doing... :) Hopefully I will someday! :smash: :smash: :smash:
Thanks anyway...
Thanks anyway...
