conquest30'

so i have a gen 5 502 that I upgraded to a roller cam. I had a problem with my crower retro-fit hyd. roller lifters. 4 of them were collasped. I had Bob madera make me a custom cam and went with the crower lifters because i already had them. Well anyways, when I found out they were bad I called Bob back and got some Morel/PBM lifters #931 that he recommended. The PBM lifters were longer so I had to get new pushrods, no big deal. Well the problem is, with the crowers that were bad I had 80psi cold oil pressure and 50psi hot. After swapping in the new lifters I have 40psi cold oil pressure and 20 psi hot throughout all the rpms. So my question is what gives? anybody have this problem. Im stumped. I put on a mechanical gauge and the pressure reads the same as my electric gauge. So again, can anybody help. Thanks

BillK

cq,
I have used the 931's on a couple of 502's and have not had any issues. I have a set at the shop I am getting ready to put in a 396 engine for a car. Only thing I can think of is if your new cam is ground on a smaller base circle or something unusual and is letting the oil hole of the lifter either come out of the bottom or the top of the lifter bore ? I will try to remember to look at the ones I have on Monday.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

conquest30'

thanks for the help. let me know? anybody else?

BillK

cq,
Just looked ata the RL931's that I have here at the shop and compared them to a set of Cranes. I do not see any reason that they should be causing an oil pressure problem. I also verified that they were the lifters we have used several times on 502's with cams in the .625" lift range.

Any possibility that something else is causing the problam ?

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

conquest30'

Well the pbm lifters are .300 longer than the crowers. Also are the pbm lifters the same as the isky 3970-hyrt?

endeavour32

iTrader: (4)

I'm using Morel Lifters from Bob, no problems at all with oil pressure. Call Bob and talk to him on this, if you stump him then use this forum. I've found out that if you go to Bob first you will save yourself a lot of time and headaches! JMHO

conquest30'

well i talked to bob and he thinks the lifter might be coming out of the lifter bore. He said he had this problem one time on "artic's" motor due to having a chamfer on the lifter bore. I noticed when I put the lifters in the bore, it had a chamber at the top of the bore. This is a stock GM block gen 5 non roller block. Is this normal for non roller gen 5 blocks? I believe factory roller motors have a squared off lifter bore. Any help would be great. If artic could respond with his experience that would also help. Thanks

ezstriper

maybe the engine was on the way out and thats why the 1st lifters collapsed ??

PatriYacht

I think Arctics problem was that the lifters' oil band dropped too low or lifted too high, exposing the oil gallery. You'll have to pull the intake and take a look.

conquest30'

so i talked to bob today and he said I should share my problem. Well I changed the fram oil filter to a new fram oil filter and now I am back to normal oil pressure of 80psi on the garden hose. Im going to the lake on thursday and I'll update you if I have any problems.