Has anybody flat spotted roller lifters w/synthetic oil?
 

I've heard rumors of roller lifters not turning due to synthetic oils lower coefficient of friction, causing flat spots on the rollers, cam, even on the needle bearings (how would they wear flat?). If the friction is lower than the force needed to make the roller turn, how could it cause any wear? The cam/roller is designed for a higher level of friction than that if all this is true. Teague (whom I think knows his stuff) wrote a long reply to this question in Powerboat. But I don't buy it. I've ran synthetic Mobil 1 15-50 in my gen VI 454's for 230+ hours with no problems.

Has anybody actually experienced this first hand? I'd be interested in the details of the failure.

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

I run solid rollers, so my experience is a little different than the hydrauilc lifter guys, but the same basics. If there is not enough friction to allow the roller wheel to turn, then there isn't enough friction to wear a flat spot onto the wheel. This is my opinion!! If the wheel slides on the lifter periodically this is OK for the same reasoning as mentioned earlier. In a solid roller application the spring pressures keep very high loads on the lifters and the wheels may only slide between the lash ramps where there is no load. This will not hurt anything. You hydraulic roller guys may have more concern on this issue than the solid roller guys!!! That's wierd!! :D

Craig

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

Heard that "rumor" myself but have been using a fairly stressful roller cam with Amsoil HD 20/50 synthetic for the last 2 years and have experienced only lower oil and engine temps. and absolutely NO internal problems. --- JP

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

Roflmao.............. :rolleyes:

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

heard of the rumor but I have never had, heard or seen anyone I know with this synthetic oil on hyd lifters issue.

Roby

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

Thats my thinking. Vettes have been running rollers and mobil 1 since 92.

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

The thing I really don't understand is how he sees wear on the needle bearings of the lifters. If the roller isn't moving, then how could the needles be affected in any way? Also Wettevette, a radical cam such as yours is supposed to be more suceptable(sp?) according to powerboat. :rolleyes:

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

I have a theory on this and again, Just a theory. If the roller isn`t rolling and in fact ''skating'' over the lobe, I don`t see what harm that would do to either the cam or the wheel. However, if the wheel does`nt roll the little needle bearings don`t pick up any new lubricant and the existing lubricant gets pounded out. Now, without any rotation, the same needles are subject to constant hammering without lubricant and will be subjected to a condition know as ''brinnelling'' causing them to fail. This also happens in U joints where there is perfect alignment of the drive train. There needs to be one or two degrees of misalignment to cause the u joint to ''work'' so the film of lubricant can be replenished.
Again, this is just my theory, but the needle bearings need to roll so they can pick up new lubricant or they will fail. and when they do, all of the bad little parts go down in the engine where they can do some real damage.

Roger Holmberg

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

Yes I have!! Too many times. So I went to a flat tappet cam and have ruined two of them. One with synthetic after about 90hrs. The new one lasted about 10rs on dino oil.
I was told that synthetic isnt an issue on roller cam. The high spring psi's and low idle speeds are. The axle doesnt get enough oil at low speeds. All the load is on one or two needles, and they dont like it. So the wheel stops turning, it starts to wear. Remember the cam was designed to have a wheel turn while opening and closing the valve on those steep ramps. If it slides, does the oil film hold up or go away and allow it to wear. The wheels fall off, the parts end up in the pan and between the expensive rods.. etc. The lobe goes away, etc. The GM cars probably dont have the spring psi that we run. Not sure about the hydraulic, but the solids are way more. So we try to idle at 2k in the channel.. to keep the lifters alive...
I am going to look at the solid rollers without the axles, we'll see what happens.. Just keep trying till find an answer.

Hey Craig, how big a stick do you run in that motor of yours? I am thinking big inch motor this next year.. can you give any advice.. ?

Jpclear, how big a cam and what kind of spring psi??

Dick

Re: Has anybody flat spotted roller lifters w/synthetic oil?
 

Gadget, Roger1 and others are right, synthetic oil is not the real issue unless you're running really low viscosity numbers like 5-30. Hp boat motors at higher rpms run high oil temps and you need to start with at least a 15-40 weight synthetic or conventional oil. the biggest issue is that aftermarket HP cams in general because of higher lifts and durations tend to have smaller base circles and higher velocity ramps. Couple these with the high multiple spring poundages and you have a formula for a roller lifter meltdown. The boys at GM designed the roller lifter for modest velocity ramps and lifts on the cams so the loads were not a big issue and the roller lifters worked fine. How do you lessen this border line condition. Just as we have done with our new 496 heads. First, use cam profiles that have moderate ramp velocities and slower closing ramps. Two, use the new single variable rate valve springs that don't kill your valve train with big poundage numbers. Three, lighten the mass of the valve train so its stable at all rpms with moderate valve spring rates. Do these things, use good oil and keep it cool and your roller lifters will live long and hardy even over 6000rpms in a big block. Don't do these things and the GM big block will suffer from its roller lifter valve train weakness, you would too if you were having the **** beat out of you!
Raylar