Vintage Mustang Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
187 Posts
Discussion Starter #1
In the process of removing dammed roller tipped rockers to reinstall stock ones i have one rocker adjusted down as far as it will go and still have not attained zero lash, the stud is not pulled out and the pushrods are all the same length, turning over the motor the pushrod moves but does not seem to go as far as the others, does this sound like a collapsed lifter? any easy fix, the car has been in storage all winter and driven about 30 miles and was running for sh--, this motor has about 200 miles since rebuild
 

·
Registered
Joined
·
1,712 Posts
Not many words of encouragement here, but a collapsed lifter is better than a flattened cam lobe which is the other possibility that comes to mind.

I am very interested in your roller tip experience; there seems to be a great divide in the group. There seem to be two groups; one that says they are very noisy, and a second group that claims they are quiet. Of course a collapsed lifter or a flat lobe will make a lot of noise too, so I really don't know which group you fall into!

Good luck
 

·
Registered
Joined
·
187 Posts
Discussion Starter #3
I could not quiet down the roller tipped rockers, i even changed out the hyd lifters after complaining to Comp Cams who told me there was dirt in the new lifters, i have to friends who had there motors one 289 and one chevy 350 rebuilt by the same guy with the same Comp Cams cam and lifters with no problems and no noise, at least i have a spare set of lifters so a little labor will be all i lose.
 

·
Registered
Joined
·
1,079 Posts
Could be a collapsed lifter. I don't mean to be questioning your skills, but do you know how to adjust roller rockers properly? I can't tell you how many people I sold rockers to who complained that they were too noisey, only to find that they tried to adjust all of them at the same time. They are naturally a little louder than stock ones, as part of them having less friction, that means less contact to absorb the sound.
 

·
Registered
Joined
·
607 Posts
Do you know it won't pump up under oil pressure?

You can perform a rough test of cam lobe lift with a dial indicator on the push rod end, and compare it to another rod.

Yeah, damn roller lifters are simply noisier than stock!
 

·
Registered
Joined
·
187 Posts
Discussion Starter #6
I turned the motor over till the battery went down and all the others pumped up fine, i added a 1/2 qt of Rislone to the oil recharged the battery and turned it over again till the battery went down and will check it out tonight to see if it loosened up that lifter. As per the other post about adjusting the valves i go one cylinder at a time turning the motor over so that the exhaust is open and adjust the intake and so on, i go in steps zero lash first then back and do the whole process at 1/2 turn and once again at 1/4 turn for a total of 3/4 past zero, if this sounds wrong please let me know the secret.
 

·
Registered
Joined
·
607 Posts
The process is:
One valve at a time, (can be done in sets if you know the combinations)
when you know the lifter is on the low/flat part of the cam, adjust down the rocker with your fingers until there is zero endplay, a slight resistance to rotation of the rod. Then turn the nut 1/2-3/4 (mfg. instructions) farther and hold it steady while setting the locknut. That's it. On a pumped up lifter this pushes the piston on the lifter around half way through its range. There is no need to go around the sequence again.

You can start the engine with that questionable lifter at zero end play, and go by sound. If it rattles on you, it probably isn't pumping up and will have to be replaced. If too tight, the valve will not be closing fully.

Helps if you have an old valve cover, top cut open, to catch oil when you start the engine without a cover tightened in place. Some people set their valves by sound with it running. Hope this helps.
 
1 - 7 of 7 Posts
Top