KJL

Just fired up my car after installing new com cam 256XE with comp cams hydrolic lifters and magnum roller tip rockers 1.52 on exhaust and 1.6 on intake. Also new Edelbrock RPM 64 cc heads. Rockers adjusted to zero plus 1/2 turn on nut. I am getting a clicking sound from the #6 cylinder area. I have check and rechecked push rod clearance and lash adjustment. On those heads in order to get the push rod at some locations far enough from the head wall the guide plates need to be pushed as far as they will go to one side. This causes the rocker to come in on the valve tip at a slight angle. Not sure if this can cause problem. All other valve locations sound good.
I am not sure if this is a lash issue ,sticky valve, bad lifter or a push rod issue.
I am going to buy a cheap valve cover, cut the top off and see what is going on in real time. Maybe adjust lash while engine is running. It seem after running the car a while it got a little better. Any thoughts on this one?? :confused: Thanks!!

45ACP

How long did you run it?

Smokehouse69

Have you checked to see if a rocker might be hitting a dripper on your rocker covers? MELVIN, had a problem like that one time, and that's what it turned out to be.

KJL

I ran it for the 30 minute cam break-in period. The rocker was hitting on the drip guard but I fixed that. The click is still there. It is not loud, doesn't really sound like lifter knock. I think it is either the valve or rocker. I hope it is not the valve. :confused:

SanDiegoPaul

It has roller rockers, right? They DO make noise ... they sound like solid lifters. If yours didn't make any clicking sounds, then I'd worry. :cheers:

lars

KJL -
I've had problems recently with CompCams lifters being noisy, and their Tech people are completely useless. Here's the deal: CompCams recommends that the lifter plunger be compressed .050" into the lifter body, or about a 1/2 turn on the adjuster. CompCams lifters will not run quiet at .050" compression. I have talked to the tech people at the factory that actually makes the lifters for CompCams and they tell me this: Rather than .050" preload, the plunger needs to be located about half-way in its travel range, or about .100" down in the lifter bore. This amounts to about a full turn compression on the adjuster nut beyond zero lash. This sounds like a lot, but the lifter will run well when adjusted on this range.

This all assumes, of course, that your valvetrain geometry is correct, and that you have the correct length pushrods with the correct relationship between the tip of the rocker arms and the end of the valve stems....

KJL

Thanks Lars, I will give that a try. I believe I have the correct geometry, the push rodes are per Edelbrock recommendation .01" over stock and the roller travel is centered over the valve tip. Can I just increase the loud lifter by 1/2 a turn or should I do them all regardless?

KJL

OK I have tried going the extra turn, didn't work..I tried re-adjusting the push rod guide...didn't work, I tried replacing the rocker arms...didn't work. So I figure at this point it is either a bad lifter or sticky valve. Being the heads are new, the valve is probably ok. I figure I would run the car with the cover off to be sure of the valve in question then I am going to attempt to replace the lifter through the distributor hole. The push rod slots in the Edelbrock head are quite large. I figure with some wire and a magnet it should be quite easy to do. How can I tell if it is a sticky valve? I thought that maybe a valve spring compressor may indicate if there is a problem.

cardo0

I am not sure if this is a lash issue ,sticky valve, bad lifter or a push rod issue.
I am going to buy a cheap valve cover, cut the top off and see what is going on in real time. Maybe adjust lash while engine is running.

Your on the right track with the open valve cover trick KJL. Once you have access to the rocker arm (without slinging oil all over your engine compartment) you can isolate the offending lifter/valve and start at zero lash and adjust it to full in steps. That open cover is a must have for any tool box.
Also have a stethoscope to locate noises - cheap and easy to use.
You could hold the valve with air and pop off the spring & retainer for inspection - much easier than removing intake (last resort to R&R lifter). :iagree: