just did a rebuild on an early 302 (68) and installed a CompCams high energy cam and lifters...it runs fine and pulls good, has about 500 miles on it now, but the lifters clatter at idle..it has good oil pressure and lots of oil to the rockers..I had pumped up the lifters before installing..there was nothing in the instuctions that said not to!!! then I found on their website it says not to pump them up....( I love this aftermarket crap). it also says to adjust them at 1/2 turn..they clatter, so I adjust them to 3/4 turn like I do normaly on smallblocks, they clatter!! I had Ford Racing roller rockers on it, so I changed them, back to stock rockers, they still clatter at idle..I've adjusted them 3 times..anyone with a suggestion or experienced this with their high energy lifters? thanks Jim

 

I had the same thing happen...I tried everything in the book to stop the lifter noise. It was on a 68 build with D0OE heads......

Let me ask you a few questions....

Are you running the recommended valve springs at the recommended heigth?

and what cam is this..........

 

what heads are on it and what kind of rockers....are they rail type.

 

the heads are stock C8OE 4V...the heads were done about 2 yrs ago ( hardened seats new valves and springs) and had low milage so they weren't touched when we rebuilt the bottom end..and there was no problem with lifter noise before the rebuild running a more aggressive cam and stock lifters..the Compcam is a FS 260H-10..supposidly an RV/towing cam

 

Ok you should start looking at the valve tips if you are still using the rail type rockers that came on those heads. If the stem or rocker is worn the rocker will hit the retainer before it hits the valve stem.... making all kinds of noise.

are you using rail type or have you converted to studs and guide plates.

 

Also a good chance you wiped out the cam, happens a lot if your not real careful when braking them in.

check all the valves when it's idleing make sure they are all opening about the same...I mark the push rod with a screwdriver or something then measure the mark. That will give you cam lift.....

 

I have screw in studs and and have tried both standard( non rail) and roller rockers, no difference, checked all the clearances, no interference with the valve springs, I think the break in went well, ran it at 2000rpm for 30mins, it has 500 miles on it and I had the covers off this Sunday after a 200 mile trip Sat and all is well, the noise isn't any worst than when I first fired it..its not excessive, you cant hear it from inside the car and barely from outside, but when the hoods up I hear them, maybe this is normal for this type of lifter and I'm just being too critical..just above idle all sounds good

 

there should be no noise with that set up.

Lets make sure we are on the same page ...are your rockers like the ones below........

 

no they don't look like that...I would take a picture tonight when the wife gets home with the camera, but I have never had any luck posting pictures here, my computor skills are limited..yours look like what I refer to as rail rockers?

 

ok ....... do you have the valves made for rail type rockers...the extra long tips...or are they just over the retainers?

sorry about all the ? just trying to get a better pic of what you have.

 

I have the short tip valves, In fact they are CHEBBY valves..I still think the problem is the lifters, I never had any problem with this rocker/pushrod/valve combo on the other cam and lifters

 

is it all of them or just a few...if it's just a few might be the cam.....

pull it and see......

 

held my share of junk cams.......sucks.....

 

it sounds like all of them, its really not that loud, If I didn't know better I would say it had solid lifters.......LOL

 

If you have chance read about these High Energy lifters...have you ever used Rhoades lifters?? thats what these things remind me of, at this point I'll just run it till it blows..I've emptied the valve cover gasket inventory at the parts store