Roller Lifter Question

[Bryan Broaddus]

We have used the Crowers for years in our Super Stock Big Blocks with very good luck. Ours are the .903 diameter and we spin them up to 8600 all the time.
If you change to the Isky you will have to change your pushrods too since they set up at a different height, from what I have seen.

[carl hinkson]

Originally Posted by Bryan Broaddus

We have used the Crowers for years in our Super Stock Big Blocks with very good luck. Ours are the .903 diameter and we spin them up to 8600 all the time.
If you change to the Isky you will have to change your pushrods too since they set up at a different height, from what I have seen.

They must send me and my customers all the junk .903 roller lifters LOL.

[nhramnl]

Thanks guys. From what I've learned here and through directly talking with lots of people, I'm leaning toward changing the Crowers for Morels. The biggest reason would be because the engine builder didn't open the lifter bores up (to a larger diameter) and I think the Crower might be marginal at .842. Thanks again to everybody who offered help. Mike Lyons

[Bryan Broaddus]

What I have found, and I am sure some of you guys have too, any time something is damaged in the valve train and the lifter runs uncontrolled on the cam, in other words the spring is not controlling the lifter and keeping it in contact with the ramp on the cam, the lifter will fail. It might not be on the next pass but given a few runs that lifter will fail. So if a rocker backs off or a pushrod tip is damaged, you lose a lash cap or anything in the system that allows excessive lash I will immediately pull that lifter pair and replace it. It may seem excessive but I really don't like the results of a broken lifter. The cost of a single pair of lifters is cheap compared to broken lifter and all the Crap it runs through the engine.

[nhramnl]

That's exactly the point that I keep hearing over and over again. Everyone I've talked to says that most currently available, true "race-quality" lifters will live if valve spring pressure is high enough to keep the valvetrain from going out of control and (to Brian's point) the lifter is replaced whenever there is an increase in lash observed. Once the lifter "bounces" on the lobe, you're pretty much done, because the roller bearing needles that were at the top and bottom of the wheel at the point where contact occured get "flat-spotted" and are doomed to ultimate failure.

[carl hinkson]

Originally Posted by nhramnl

Thanks guys. From what I've learned here and through directly talking with lots of people, I'm leaning toward changing the Crowers for Morels. The biggest reason would be because the engine builder didn't open the lifter bores up (to a larger diameter) and I think the Crower might be marginal at .842. Thanks again to everybody who offered help. Mike Lyons

Crower lifters run right a .841 and are usually to loose in a GM lifter bore that is right at .844

The Morels run right at .842 which is to GM spec and if the bore are at .844 you should be fine.

Lifter bores need to be checked for wear and roundness for sure. GM lifter are reamed and often don't have a very good finish for a roller lifter.

Most blocks I go to .904 and fit to the spec. recommended by the manufacturer

[Mike Taylor 3601]

I have customer w/.842 crowers severe dutys w hippo w/.180 offset has made a lot of passes, have 400lbs. seat 850-950 open (can't remember off top of my head exactly)
spins 8k w/24lbs boost.

One other tip is most .904 when offset are .210 offset ,alot of stuff that .030 straightens pushrods up alot,
.904's usaully run longer also
Mike Taylor 3601

[1320racer]

Been using Crower .842 Severe Duty roller lifters with HIPPO since 2000 without 1 issue. I've put 1000 passes on 2 different sets before retiring them from service in my stock block, 700+HP 468BB seeing 7200 RPM in the lights.

Been running them in my 900+HP, Dart big M block with stock lifter bores, 522 BB since 2008 that sees 8000 RPM in the lights and have retired 2 sets them from service at 500 passes.

My springs are Manley polished Nextek #221424 250/800.

[carl hinkson]

Originally Posted by 1320racer

Been using Crower .842 Severe Duty roller lifters with HIPPO since 2000 without 1 issue. I've put 1000 passes on 2 different sets before retiring them from service in my stock block, 700+HP 468BB seeing 7200 RPM in the lights.

Been running them in my 900+HP, Dart big M block with stock lifter bores, 522 BB since 2008 that sees 8000 RPM in the lights and have retired 2 sets them from service at 500 passes.

My springs are Manley polished Nextek #221424 250/800.

Never seen an .842 crower the ones I have seen been right at .841 same with ISKY, I know I have a set in the shop for a build for a customer and the Dart block the lifter bores are under size and Crowers should work fine for this build.

I don't let any block out the door t\with out fitting the bores to the lifters.

.903 Crower I was told by Carry Novak from Crower the best they could do for roundness was .0003 to .0005 Its hard to make oval lifter bores.

Most guys never measure lifters or bores for roundness or sizing and saying your crowers are .842 shows they were not measured for sure.

If you missed my earlier post look over this link.
http://www.yellowbullet.com/forum/sh...fter+roundness

Here is a link where crower told me that GM lifter bores were .8425 is why there lifter are .841
http://www.dartheads.com/dartboard/a...hp/t-2429.html