Mr Gadgets

I had the same problems with solid roller lifters.. too many wheels stopped turning. I was using Isky lifters, but not the model you linked to Bobby.. very interesting.
My alternative was to go to a flat tappet .904 lifter from Schubeck. So far so good.. quick where is the wood.. Anyway about 60-70hrs so far and all is well.
I thought I would be in a pickle with the larger lifter bores if I want to throw my roller cam back it. but it seems I could go with the red zone and do well.. Hmmm back up plans always in place.

Good luck with your choice Biggus..

Oh yeah the place that bushed my block at .904 uses Jessel lifters with a tab on it.. and a slot in the bushing, but they do drag cars, so I didnt invest..

Dick

tomcat

Hi Kurt:

Sorry to hear of your trouble. Lucky you had a Gen 4 in the pipeline...now our test with NEVRENUFF is going to be even more interesting.

Tom

Infomaniac

I had these pics on the net already. Just remembered. Isky Red Zone. These are actually the solids that have the longer body for Dart blocks or Gen VI blocks

Part of one of my projects. How to find exact TDC and degree the cam.

Project Link *** CLICK HERE ***

Biggus

Tomcat,

Yes, NEVRENUFF`s new motor should make a very interesting platform for your new Supercooler. I had really enjoyed working with you last winter and I`m looking forward to the next dyno session!

Kurt.

klaw

Biggus,

I am in the process of two 500 hp builds so as you know with twins the cost is double when you change on one you ussually change on two.
If you really feel that the comp cam is prone to failure why would you use them again. If they give you a free one put it in e-bay and gos with the isky and at the same time change the one on the starbord moyor as well because if it was the same build lot it will just fail also and it is much cheaper to do it now.

I find it interesting that there has been so many negatived about comp and no one has chimmed in that the have had similar problems with a isky

My hp500s are soon to be normakklty asperated 575 (dyno will tell)
we are using Isky.

Looks like me and Birdog will be bidding against one another if you ever seel the Gun.

Good luck,

Klaw

JOHN G

I HAVE HAD REPEATED PROBLEMS WITH LIFTER FAILURE IN GM BIG BLOCK APPLICATIONS. THE MOST RECENT FAILURE WAS A CAM FAILURE PRIOR TO LIFTER DESTRUCTION. THERE HAVE BEEN SEVERAL QUESTIONS RAISED AS TO VALVE GEOMETRY, END PLAY TOLLERANCES AT THE CAM BUTTON, BELT OR GEAR DRIVEN CAM, AS WELL AS LIFTER SIZE AND BORE. HAS ANYBODY LIVED THIS LEARNING CURVE AND SUCCESSFULLY SOLVED THE PROBLEM?
I HAVE GM TALL DECKS BORED TO 592 CUBIC INCHES. WE USE JESSEL ROCKER ASSEMBLIES. THE REED CAM IS CURRENTLY DRIVEN BY GEAR. THE VALVES HAVE A LIFT OF .709 INCHES. WE USE DART BIG CHIEF ALUMINUM HEADS AND THE MOTORS ARE LUBRICATED FROM A DRY SUMP APPLICATION. THE ROCKER ARM RATIO IS 1.7. WE INSTALLED OIL SHOWERS OVER THE VALVES AS WELL AS THE CAM. THE CURRENT SPRING PRESSURE IS 240 LBS. THE CAM BUTTON WAS PRESSED AGAINST THE GEAR CASE AND CAUSED WEAR ON THE CASE. WE RUN APPROXIMATELY 6200 RPM. WE ARE USING ISKY 372-96L0180 LIFTERS.

THE LAST FAILURE HAPPENED AFTER 8 HOURS OF USE THE LIFTERS TOOK LARGE SECTIONS OF THE CAM LOBES OFF. THE LIFTERS REMAINED WHAT SEEMS TO BE OK BUT THE CAM IS GONE.

bobby daniels

that would be a tough one to help with the geomrty most likly did it as with jessels it has to be perfect or the springs seem light to keep the lifter on the cam at 6200 its most likly one of those but its a complucated system to do on here but great one for sure . its designed great ,you did use the good jessels I've not been able to make the sportsman jessels to live !!

birdog

C'MON Klaw !!!!! Don't do that to me !!!
did you get my E-mail?...Hope it was some help

Jersey Tom

I think everyone is focusing on the lifters and not the problem The problem is that the lifter bores in the block are not right. They can be bored out and bushed to realign them with the cam. The poor bore quality is not a problem until you start to increase spring tension and valve train geometry. This causes the lifter to push more against the sidesof the out of aligned bores and eventually leads to lifter/cam failure. Any lifter will fail depending on how bad the lifter bores are out of whack. 502's are notorious for this problem.(made in Mexico?)

Biggus

In this case, the cam failed because the tie bar on the lifters let go at the rivet.

Do the lifter bores need to be bushed to get the lifters to last?