for what it is worth, bushed vs needle roller lifters

[Dragsinger]

With the original build, we installed a bushed roller lifter. With the rocker arms removed the engine assembly would rotate easily and smoothly with an 18" bar on the damper bolt. As the rockers were installed, it required turning the engine with the starter to assemble and adjust the rockers. The rotation effort was very high.

After a tear down to make some changes we installed to a needle roller lifter. Now, the completed assembly, including rockers can easily be rotated with the 18" bar.

The rotation effort by hand is significantly reduced. This is an unscientific observation and may not make any difference once the engine is spinning.

[user-612937456]

Different rings and pistons? Difference in ring tension?

[Dragsinger]

no, heads were not removed, same main & rod bearings.

[cjperformance]

Yes the bushed lifters have way more drag when turning at hand speed (no hydrodynamic lube condition at this speed) compared to needle rollers. I havnt had to resort to using the starter motor though. Spark plugs out the difference is quite noticable but yours sounds extreme.

[In-Tech]

Since I have no experience with bushed lifters, I asked a question in another thread regarding a rev kit and bushed lifters as to wear. No response.

The only thing I can offer is a LS test where we had stock needle fulcrum bearing rockers on the hyd roller engine and ran to 7100 rpm, then with no other changes, installed bushed rockers and the engine fell off like a stone at 6800 rpm. I have no idea what the clearances were in the rocker. I'm still not sold on anything bushed that isn't pressure fed and/or cyclic on pressure like a piston pin. JMO

[cjperformance]

Anything to keep the roller in contact with the cam (like a rev kit) will help life of roller or bushed type, keeping the lifter wheel rotating at libe surface speed is a massive key to lifespan, needle or bushed.
In your bushed v needle rocker scenario, first up was the geometry of each rocker near identical?

[In-Tech]

Anything to keep the roller in contact with the cam (like a rev kit) will help life of roller or bushed type, keeping the lifter wheel rotating at libe surface speed is a massive key to lifespan, needle or bushed.
In your bushed v needle rocker scenario, first up was the geometry of each rocker near identical?

I was just flown in to tune and I did not build the engine so I do not know if the geometry was correct to start with. Both were GM LS stock rockers, one set with roller fulcrum and other with bushing fulcrum.

[hoodeng]

Probably drifting from the original intent of the post but relevant to the comment on roller rockers. I work on V twin engines that all use roller cam followers that give excellent service life if not contaminated . A good few years back a noted performance valve train manufacturer produced roller tip rockers that also had roller bearings installed to run on the rocker pivot shafts ,sensational!!!,,no friction anywhere!!,,, until ,,they racked up a bunch of miles , and we started to get top end noise ,on disassembly we found the pivot shaft rollers had cut roller tracks into the bottom area of the shaft and after cutting the bearing open found the same in the bearing housing at the load points. The shafts are not very large in Ø .555" .What was happening was with a .500"lift cam the rollers in the bearing were not traveling over the path of the rollers either side of it so eventually cut a groove , if the cam was .600" lift the problem was not as pronounced .
The manufacturer on notification offered a bearing with considerably more smaller rollers or a bush kit , both fix's were good.

Cheers,

[F-BIRD'88]

A small amount of moly additive will help reduce high force "EP" metal on metal wear
when that "oil wedge" is not there.

Some kind of a sonic/acoustic sensor on the engine should be able to detect abnormal
sound signature of the running engine. A data log of the sound of the running engine could be
compared to a "normal" baseline data set in either real time or for later diagnostic analysis
to detect faults,,, impending failure by the change in the acoustic signature of the running valvetrain.
Find the failing part and replace before it finds you wallet.
Roller bearings and bushing type bearings are great up until they start to get loose
lashy. Thats when you want to detect that and change them.
This is true in any mechanical system using roller bearings, not just automotive valvetrains.
it is the CHANGE in the acoustic signature of that running mechanical system that you want to detect. Not rocket science. Need not be real costly.

[Belgian1979]

Since I have no experience with bushed lifters, I asked a question in another thread regarding a rev kit and bushed lifters as to wear. No response.

The only thing I can offer is a LS test where we had stock needle fulcrum bearing rockers on the hyd roller engine and ran to 7100 rpm, then with no other changes, installed bushed rockers and the engine fell off like a stone at 6800 rpm. I have no idea what the clearances were in the rocker. I'm still not sold on anything bushed that isn't pressure fed and/or cyclic on pressure like a piston pin. JMO

That was in my thread about morel lifters.

I think the rev kit does increase life and prevents the lifter coming off the lobe and hitting the cam under speed.
So far I do not had to adjust the valve lash much from where I left them last, time, indicating that the lifters have not worn.

[Belgian1979]

A small amount of moly additive will help reduce high force "EP" metal on metal wear
when that "oil wedge" is not there.

Some kind of a sonic/acoustic sensor on the engine should be able to detect abnormal
sound signature of the running engine. A data log of the sound of the running engine could be
compared to a "normal" baseline data set in either real time or for later diagnostic analysis
to detect faults,,, impending failure by the change in the acoustic signature of the running valvetrain.
Find the failing part and replace before it finds you wallet.
Roller bearings and bushing type bearings are great up until they start to get loose
lashy. Thats when you want to detect that and change them.
This is true in any mechanical system using roller bearings, not just automotive valvetrains.
it is the CHANGE in the acoustic signature of that running mechanical system that you want to detect. Not rocket science. Need not be real costly.

I personally do not see how an oil wedge is kept up constantly in the lifter. I mean, you have lifters going up and down all the time, more or less cutting of the flow of oil. For an oil wedge to form, you need pretty much a constant pressurized flow of oil. But I'm no expert on the subject.

As for sound yes. Very simple to do with a knock sensor. However analysing the sound characteristics is a sience in itself and certainly not easy.

[pamotorman]

Bushing lifters are insurance against catastrophic failure. My advise is.....if you have a good ear for engine noise and do regular spot maintenance they use a needle bearings lifter. If you don't have a good ear for engine noise then use a bushing lifter.

The bushing lifter was developed for the Buick Indy series back in the late 80's. Morel developed it for McLaren/Buick. Morel's patent is from 1991.

The latest is the Morel Mamba lifter, no needles no bearings. An oil wedge is developed between wheel and axle.

I believe that was how the schubeck solid ceramic roller lifters worked in the oil wedge.

[In-Tech]

Thank you for the reply. The lash is a great way to keep track of wear. Just so I'm clear...you are using bushed lifters AND a rev kit???

I am quite aware of the advantage of a rev kit and needle lifters, I am interested if there are wear issues with bushed lifters and rev kits or is that brand dependant, the bushed morels that Chris Straub posted look promising. Are the Isky and Crowers pressure fed as well?

Thanks, trying to learn what has been tried and proven.

[F-BIRD'88]

Someone should develop a tool that checks the valve lash when the engine is running.
Possible by lazer/optical analysis of the running rocker arm/valve tip interface.

If you are checking the valve lash ACCURATELY with the lifter on the back side of the cam lobe, each time at the same temperature, then theoretically if the valve lash does change, then something is or did bend/deflect beyond yield point or something is wearing, something has moved or.... something....$$$

"much" is a relative, subjective term.

[Belgian1979]

Thank you for the reply. The lash is a great way to keep track of wear. Just so I'm clear...you are using bushed lifters AND a rev kit???

I am quite aware of the advantage of a rev kit and needle lifters, I am interested if there are wear issues with bushed lifters and rev kits or is that brand dependant, the bushed morels that Chris Straub posted look promising. Are the Isky and Crowers pressure fed as well?

Thanks, trying to learn what has been tried and proven.

I still use the needle bearing lifters. No experience with bushed rollers and a rev kit. Personally I think these do not match well.