Thread: Bad Lifter

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I have a 350 SBC in my street rod and after it sits for a couple of days I get a real clattering from one lifter that goes flat. It goes away after a few minutes (3-5 minutes). I have changed the rocker nuts as one of them would not stay set and would loosen up and start the clattering again. There is really nothing else wrong with the motor. I run about 55lbs oil pressure when driving and about 30lbs at idle. My question is; is it feasible to change the lifters, push rods, rocker arms and nuts on a motor that you are not sure of the rest of the internals or the mileage on the motor. It burns no oil and does not leak.

If you have push in studs,that stud could be backing out.I had that happen to me.

I beleive the rest of the head is stock, so there would be press in studs. How would I go about checking them to see if one is pulling out? Just measure it and compare to the rest of the studs I suppose. Correct??

If they are stock they are push in studs.You should able to see if it is backing out just by looking close.On mine I would hit it back down with a soft blow hammer,not to damage the threads.If it is backing out a head shop can pen them in place.May not be your problem,but might be worth checking

I'm guessing these are flat tappet lifters (hydraulic)? You would get the same thing if a cam lobe is going flat or other damage to the lifter... check your oil and filter for steel shavings. I had a solid roller lifter go on me... only warning was that I had to keep relashing the same valve... I didn't figure it out until it was too late Check the stud first because it's easy then make sure you are getting the same max lift on that valve compared to the others.

Good luck

-Chris

Originally Posted by timkins

I have a 350 SBC in my street rod and after it sits for a couple of days I get a real clattering from one lifter that goes flat. It goes away after a few minutes (3-5 minutes). I have changed the rocker nuts as one of them would not stay set and would loosen up and start the clattering again. There is really nothing else wrong with the motor. I run about 55lbs oil pressure when driving and about 30lbs at idle. My question is; is it feasible to change the lifters, push rods, rocker arms and nuts on a motor that you are not sure of the rest of the internals or the mileage on the motor. It burns no oil and does not leak.

If it pumps back up after a starting, the oil pressure is bleeding down as the engine sits. Either the clearance is too great between the internal plunger and the main body; or the check valve at the bottom of the internal plunger is leaking. Add a quart of trans fluid to the oil and drive it for a bit. The trans fluid will sometimes free up sticking mechanisms in the lifter.

Lifters are cheap but you are taking a chance putting new lifters on an old cam. I'd try to narrow the one lifter down, pull it out and take it apart. It may be gummed up and just needs cleaning. You may be able to rebuild it using parts out of another lifter. Worst case, if you do change the lifter treat it like a new cam and "break it in".

try some CD2 VALVE MEDIC. just pour it in the oil.

I have had excellent results with it in the past.

Thanks to all for their suggestions and hints. I am taking the easy way out to start and have tried the valve medic and will let you know if it works.

I put a container of Valve Medic from GUNK (could not find the CD 2 Valve Medic) and it seems to have taken the noisy lifter noise away. Only time will tell now. Thanks for the suggestion!

Started the car yesterday after sitting for a couple of days and the noisy lifter is back. I guess it must be something a little deeper than what I thought. Time for a crate motor so I know what I got. Thanks to all who replied.