Biggus

iTrader: (1)

Last weekend I had the opportunity to witness first hand what WILL result when running Competion Cams hydraulic roller lifters in a Gen 4 big block.

I am absolutlely floored over this design.It appears that the lifter bores on most big block Chevy`s are not exactly true, and if so,the tie bar rivet that joins the pair of lifters together eventually fails, the lifter spins and the roller flat spots and procedes to ruin the rest of the motor with all the shavings and loose parts involved when these things disintergrate.....this happened on Saturday. On Sunday, my buddy had the EXACT same problem happen to him. I had about 120 hrs, he had about 15 !!!

My block is junk, the axle for the roller went through a coolant passage, broke a piston and ruined one of the heads.

My question is this, is there a better alternative to the tie bar set up on a Gen 4 block? I really like the dog bone style retainer on the Gen 6. Is there a similar set up available for a Gen 4?

I`m leaning toward going back to a flat tappet hydraulic set up, they worked for years.

Looking forward to some experienced input.

Kurt.

formula31

Another reason, aside from the expense, why I stayed with flat tappet on my Mark 4's

bobby daniels

I've never known why they build them that way I've never had any of their lifters last due to that sam problem the rollers are fine its just the welded rivet

birdog

Anybody make a good roller lifter for mark 4 blocks ? or are they not worth the bother & cost ?

bobby daniels

The rollers are the way to go (boy thats hard to say )) but the isky lifters need to be used and I've had no problem with them
The factories have all switched to rollers due to how good they are ,you just have to be careful in the aftermarket and also know the hyd limitations

Adivanman

I used Isky (solid) rollers for several years on my 433" gen 4 with no problems. Big stick (RR-730B) and high RPM (8,000) - on street and at the track they were trouble free. Isky makes some of the best pieces available - i would take a look at their options.

my two cents

Biggus

iTrader: (1)

How does the Isky design differ from a Comp Cams roller lifter?

Could someone post a pic.

Bobby, It seems that the benefit of GREATLY increased longevity when running a flat tappet is far outweighed by any HP increase with the roller.

Thanks for the replies so quickly

Kurt

bobby daniels

I hate to say this with the trouble we both have had with rollers but the when installed right and the right good parts used will out last and make more power than a flat tappet period ,,, I've had more trouble with flats but maybe its just me !!!! the factories sure love then and they've proven they can last

The iskies are alot heavier duty and designed with out the rivet
I'll post a photo later

I do like solid rollers 100 times better than HYD rollers and if you have a good profile you only have to adjust the valves every 90 hrs or lmore depending on the cam ,,I'll give you some good numbers if needed

Infomaniac

I use the Isky pressure fed roller pin lifters. Red Zone.

Crower are good also.

Little Tommy

Hey guy, I feel your pain! I elected to keep mylate model GM 502 blocks due to the factory lifter set-up. They simply do not break, no tappet haging out in the valley. GM has spent countless hours testing this combination and it has definately proven itself.
The downfall is you are limited to cubic inch. I presently have a 502 block, 30 over/4.25 stroke crank = 540 cubic inch.

Little Tommy