Thread: Lifter Mystery

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I have finished most of the build on my coupe and decided to take it out on the expressway to get a feel as to how it would drive and perform.I got up to 55 mph.and suddendly a click,click.I reduced speed and limped back to the house.To my surprise I had a loose valve adjusting nut(roller rockers) also some smoke was coming from the driver side.I called the individual that I purchased the engine from to get the particulars on the valve adjustment and he said just torque the valves to "0" lash while running I thought the valves needed lash to perform properly.He said he did not have the cam card that came with the engine but that it was a no load type lifter.The cam is a comp cam with a full roller rocker system(scorpion).The lifters are not hydraulic.I thought you either have solid or hydraulic and adjust accordingly.I don't want to do any damage to the engine as it is a performance engine at about 450 HP. any suggestions appreciated.

Don in Austin

Originally Posted by DennyW

Any chance of getting the cam number ? If they are solids, they do need some clearance, not zero.

Denny I have all the engine specs.but no cam #'s comp cam stamps the number on the back end of the cam ,which says i'll need to tear down and after just getting it up and running I am trying to avoid tear down.have you ever heard of a no load lifter? If so what are the lash #'s.

Don in Austin

If the engine builder said to zero lash the lifters, then they have to be hydraulics. With the motor warmed up and running, loosen each adjuster nut, one at a time until it clatters, then tighten it down 1/2 to 3/4 of a turn.

Any solid lifter needs some "play" or lash so that the valve will be on the seat for a little while to transfer heat to the seat. Otherwise, so much heat will build up in the valve that it will warp and presto....you have a burned valve and zero compression. If you find out these are solids, lash 'em at 0.025" cold as a starting point.

Originally Posted by DennyW

Pro Magnum Lifter™ Instructions for Part #’s 858-12, 858-16, 862-12, 862-16, 863-16, 865-12, 865-16, 867-12, and 867-16
All Pro Magnum Lifters™ require an adjustable valve train for proper operation. Lifter preload should be set to .002”-.004” (hot settings). These adjustments should be made similar to the adjustment for a
hydraulic lifter camshaft.
Care and Inspection:
Remember, when using solid roller lifters, the only oiling the lifters receive is from windage created by the rotating assembly. Excessive idling or very low RPM usage may cause lack of oil supply to the lifters and cause premature wear to the axles, bearings or roller wheels. This can result in extensive engine damage.
Roller lifters should be inspected periodically for wear to the wheels and or bearings. If valve lash has to be corrected more often than normal, this could be an indication of accelerated lifter wear. Periodic checks are beneficial in determining if your roller lifters need to be rebuilt.
COMP Cams® offers a rebuild program for our solid roller lifters. This procedure includes magnafluxing and polishing the lifter bodies, replacing the axles, bearings, wheels and lock rings for a very nominal charge.
If you have any questions regarding our roller lifters, our rebuild program or any other COMP Cams® products, please feel free to contact us Monday through Friday, 7am-8pm CST via our CAM HELP® line toll free at 1-800-999-0853.

The (scorpion) rockers are rated very high as being one of the best. Every where I checked said that about them.

DennyW :
Thanks for the research.I think what you have stated is what I needed to know. The engine I purchased was built some time ago by a Tony Sizemore in Nashville Tn. for the person I purchased it from. He had no cam card to furnish me and that left me in the dark.all I have are the engine specs.and mfgr.names.I may give comp cam a call tomorrow and see if they have any record of the engine builder.I tried the white and yellow pages but struck out on finding the builder.Thanks again for the help.

Don In Austin