BBC solid roller lifter failures - a root cause analysis

[Rommel Racing]

How many miles to date, Steve?

Bill,

I wish I could say I had alot of miles on these's,but honestly so far not that many. (hence, why I say knock on wood)LOL

So far,I have 6 dyno pulls, 23 quarter mile passes,and around 300-400 miles on the street. Although,this may not sound like much,the valves have not needed any adjusting yet.

I really hope these EZX lifters work out, I'm running 265lbs on the seat and around 800lbs on the nose.

Oh, I also know what it like to loose a roller lifter I had a Crane Pro- series lifter fail with only 40 passes on a brand new motor!(failed on the street) made a real nice mess!

Anyhow,time will tell if these new lifters are the ticket or not.

[MadBill]

Thanks Steve. Keep us posted as time goes by!
Meantime, Mike's input is encouraging but jimivice's and kirkwoodken's musing are disturbing. How can anyone possibly make an axle soft enough to swage/rivet into place, yet hard enough to withstand brinelling/spalling? Seems like a better retention method is called for...

[Unkl Ian]

In the bearing manufacturers catalogs, they give a minimum
hardness spec for the shaft that needle bearings are to be riding on.

[kirkwoodken]

Minimum hardness for a roller surface is 55 R-c. Swaging should be out of the question at that hardness. (Have you ever tried swaging a dowel pin?)

Again, as others have said, it seems we are limited by the size constraints we have to work with. I think all we can do is accept the reality of occasional breakage. We take a calculated risk and hope for the best. I think the manufacturers are doing a good job of supplying a good product. I'm running a roller with a rev kit, and try to keep the oil clean. If it breaks, it breaks. I don't feel that I can do anything else that will guarantee more life, and if it does break, I won't feel like the manufacturer screwed me.

At some point, you have to realize if the lifters were made from diamond and indestructible, no one could afford them. There must be some balance between material cost, R and D, complexity, etc., and the price the market will bear. I've never talked to Ron I., but I'll bet he has answers to most of the questions.

[kirkwoodken]

Quote: kirkwoodken's musing are disturbing. How can anyone possibly make an axle soft enough to swage/rivet into place, yet hard enough to withstand brinelling/spalling? Seems like a better retention method is called for... Unquote

????? I don't think I mentioned anything about axle retention.

[Scott H]

Thanks Steve. Keep us posted as time goes by!
How can anyone possibly make an axle soft enough to swage/rivet into place, yet hard enough to withstand brinelling/spalling? Seems like a better retention method is called for...

Perhaps the solution would be to make the axle as hard as needed, and stake or swage the lifter body instead.

[TheEngineWorks.com]

Perhaps the solution would be to make the axle as hard as needed, and stake or swage the lifter body instead.

Wait a second... I think a number of rollers have a clip to retain the axle. I use Comps in my combo and I believe they have a tiny clip in them, I am about to send them out for rebuild on Monday.

[robert1]

The problem with roller lifters is there ain't no problem! If you call any of the manufacturers they are going to tell you they don't have a problem or they have very few complaints. I have seen the axle fail in most every brand out there. I still use a good number of the Iskys with the internal race. These would be a problem for drag race application because of the diameter of the axle itself being to small to sustain the pressures being exerted. I have for the last year or so been converting over to Redzones in these, I guess, because I thought they are somehow better than the older style. I just looked at an older style Isky that apparently had the inner race seize because the race itself has the same wear pattern as an axle displays. I can see this because there is no longer a wheel around it.

At least one company does retain the axle with circlips but then you run the risk of scratching the axle while pressing it in.

As far as the axles being too hard to swage, all you have to do is look at them. All of the brands I have used are swagged in with the exception of the Comps.

I bought a few sets of the Crower Hippos because the pressurized oiling looked good to me. As of now I have had no problem with these. But then I have 3 of the tall offset Crowers that the axles failed with about 700 laps on. 250 lbs seat 700 open. So this goes right back to the axles.

As I started out if you call any of these companies they will tell you there is no problem. If I was an engineer at any of them it would be my main objective to build a better mouse trap. IMO if the axle is soft enough to brad it's too soft to survive in this environment. But who's to say if they replaced the axle with one hard enough that it would then be too brittle to absorb the shock and then shear off.

I can't really buy into the oiling theory because two stroke engines run needle bearings at way higher rpms than a lifter could every experience and they have virtually no problems. And for years this oil was diluted in the gas. One of the main features of a roller bearing is requireing less oil. Roller cam bearings are splash only as well as rocker arms.

I guess the main trouble is trying to contain costs and package an acceptable bearing assembly in less than 1 inch that can abosrb this much impact. Unfortunely I'm not the one with the answer.

[pleonard]

I just checked a set of Morel lifters and they too have an axle retained by a round wire clip. The axles are hardened too. I do not have access to a Rockwell hardness tester but the tip on an automatic center punch was flattened out and didn't make any visible mark to the end of the axle.

[AA Performance]

Has anyone pulled apart the Crower hippo lifters apart. I have used then thinking that they are the ones to use but after seeing their high pressure oiling direct to the shaft, I aint as impressed any more. I think that the Crane are a better lifter as they have a similar oiling to the roller only they haven't advertised the fact & have been doing it for longer than Crower. Crower has the hole on one side about 2/3 the way up the roller from the shaft. I thought the hole was at the base of the shaft that would squirt the oil along the shaft. The Crane is just as effective in my opinion & have treated shafts & rollers as well as an option.

[btnhra]

I had issues with roller lifters in my oem bbc's for years. I got a merlin ll block to make a better motor and after 100 runs I had the same issue. I removed the oil restrictors to the top of the motor. All problem wen t away. I now change them every 300 runs or so just to be safe.

[540 RAT]

I had issues with roller lifters in my oem bbc's for years. I got a merlin ll block to make a better motor and after 100 runs I had the same issue. I removed the oil restrictors to the top of the motor. All problem wen t away. I now change them every 300 runs or so just to be safe.

You will almost certainly endup disappointed it you expect frequent oil changes will save you. If only it were that simple. Every failed lifter I examined matched what some others have reported seeing also, and that is pitting and flaking on the bad surfaces of the failed lifters. And this failure is a textbook case of metal fatigue failure. No amount of oil changing will have any affect at all on metal fatigue. Only the psi loading and the number of pressure cycles can affect fatigue life for a given metal.

OOPS, I just reread what you wrote and you weren't talking about oil changes, sorry. Even so, the comment about oil changes is still worth repeating.