Setting valve lash
Setting valve lash Ok, i have a SB 332 that i just put a new comp cam with hydraulic magnum comp lifters. I have profrom 1.5 roller rockers with the locking nut and everything. Whats the proper way for adjusting the valve lash on this beast?
is your hydraulic lifters pumped up with oil yet?if not i would adjust so pushrod still turns easily because you need to break in the cam.when final adjustment we would loosen the rocker arm when the motor is running until you hear it clicking and then tighten it back down 1/4 to 1/2 turn.there are different ways but that worked the best for me.it would probably be best to squirt the lifters full of oil to begin with.good luck.
It says in the directions to avoid lifter pre pump during first fire due to it will cause the valves to open incorrectly. I soaked them in oil first. When i go through the adjusting procedure, ill get almost done and then ill get to a hard spot on turning the motor and i cant turn it anymore by hand.
is your spark plugs in yet?it will get hard to turn over by hand when pressure builds in a couple of cylinders.if it is completely locking up i have no idea unless a valve is tagging a piston.
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Joined: Jan 2003
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From: AUSTIN TX
I would do it the same way you would a solid cam xcept using different lash amounts. First off, are you using a type R lifter or just the regular hydraulic roller. In any event, turn the motor over in the direction of rotation, when the exhaust valve starts to open, adjust the intake valve on that cylinder. then turn the motor over some more in the direction of rotation (clock wise) until the intake valve has opened, and is almost closed, then adjust the exhaust valve. This method will ensure you are udjusting the lifter in the correct spot no matter how big the cam is. As far as how to adjust it, that will depend on the type of lifter used. All hydraulic lifters (pumped up or not) have the plunger in the lifter pressed up by a spring. The biggest problem is some people mistake "zero lash" for when they can not turn the push rod or it becomes hard to turn, this is usually the point they have bottomed out the plunger. Zero lash is when the pushrod first contacts the plunger. The easiest way to find it is to tighten down the rocker adjusting nut (careful not to be touching the pivot ball or trunion, while turning the pushrod by hand. all you want to do is take out all of the slack between the pushrod cups in the rocker and lifter. This is usually felt by a SLIGHT resistance to the twisting of the pushrod (not that you can not turn it anymore). This should be "ZERO" lash. Typical hydraulic lifters like between 1/2 and 1 turn of additional rotation of the adjusting nut to give the required lash while a type R lifter will usually prefer to run at zero lash. A solid would actually require additional clearance that would be measured with a feeler gauge. Hope this helps.
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Joined: Jan 2003
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From: AUSTIN TX
Originally Posted by Unaffiliated Racing
First thing lash and preload are two different things. Lash is only for solid cams. Preload is for all hydraulic cams. On the Pro Magnum lifters you need .002"- .004" of preload (hot setting). I would suggest .008"- .010" for a cold setting. The Pro Mag lifter is also know as the "R" series.
It includes lifter adjusting instructions, and Unaffiliated Racing is correct, the Pro Magnum lifters are the same as the old Comp R's and require very little Preload (or adjustment past zero lash). I am talking like a 1/16 to 1/8 of a turn past zero lash. I used to run them at zero on circle track cars all the time and never had a problem other than they make a little noise.
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