Harley Evo Lifter options, what is your opinion ?

[afterburn 549]

It was all semi dimensional anyways.

[Jeff Higgins]

I'm running Jim's "Big Axle" lifters in my '76 Sportster. They push on a set of Crane chrome moly pushrods, which in turn operate Baisley roller tipped rocker arms that actuate Kibblewhite valves, keepers, and springs.

I can't say enough about this stuff. I run this motor up to 7,500 rpm without a second thought. I've got about 12,000 miles on this build, without a hint of trouble. Quality stuff.

[asphaltgambler]

S&S or Jims will be fine......

[Jeff Higgins]

Mine have roller bearings. I don't think they even make early Sportster lifters with bushings.

[Jeff Higgins]

Generally speaking, plain bearings (bushings) require higher oil pressure, where roller bearings require higher oil flow. I'm not all that sure that putting bushings in where rollers once lived is all that good of an idea.

I think in Harley applications, the bushing type lifter is meant to be used in motors that will be frequently rebuilt, like drag motors or really big inch street motors. They better support the loads induced by high lift cams and the then necessary stiffer valve springs than rollers would. Rollers tend to bind and not roll anymore under heavy loads, resulting in one or two rollers taking the whole load and failing.

[asphaltgambler]

My experience. As long as you use either 1 of the above suggestions, you'll be fine. I believe the Jims big axle roller lifter is more marketing than anything.

The only failures I've seen is OE lifters with high mileage, reusing OE on a new performance cam and incorrect valve train set-up or geometry..

[asphaltgambler]

Originally Posted by Jeff Higgins

Generally speaking, plain bearings (bushings) require higher oil pressure, where roller bearings require higher oil flow. I'm not all that sure that putting bushings in where rollers once lived is all that good of an idea.

I think in Harley applications, the bushing type lifter is meant to be used in motors that will be frequently rebuilt, like drag motors or really big inch street motors. They better support the loads induced by high lift cams and the then necessary stiffer valve springs than rollers would. Rollers tend to bind and not roll anymore under heavy loads, resulting in one or two rollers taking the whole load and failing.

Absolutely true^^^^^

The first gen flat head Sportster used all bushings in the cam chest. When performance cams were used the bushings would not hold up. It wasn't because it was the bushings failure - it was largely the poor machining / alignment of the case halves and cam chest. They later went to roller bearings as appearantly they tolerated slight misalignment better than bushings

[Jeff Higgins]

Originally Posted by asphaltgambler

Absolutely true^^^^^

The first gen flat head Sportster used all bushings in the cam chest. When performance cams were used the bushings would not hold up. It wasn't because it was the bushings failure - it was largely the poor machining / alignment of the case halves and cam chest. They later went to roller bearings as appearantly they tolerated slight misalignment better than bushings

I'm not sure about earlier Ironheads, but my '76 uses rollers on one side and bushings on the other. I think the idea is to firmly support and locate the loaded end, and let the other go where it may in the looser roller end. I can't remember off the top of my head whether the cover or the case has the bushings or rollers - I think the case has the bushings (hey, I have a 50/50 chance of being right...).

As an interesting side note, the first time I took that timing chest cover off, in the mid '80's (I was installing a set of Andrew's R5 cams, which I still run today), it only had one of the dowel pins in it. From the factory. Ah, the AMF days...

Edit: Upon further thought, the case side must have the bushings, so they can be fed under pressure. The cover (roller) side would be oiled by the mist in the timing chest.

Originally Posted by afterburn 549

I Used to work in an HD shop years ago.
I have never experienced a lifter coming apart but I know of situations that did .
Not pretty for sure.
I was reading an article by perhaps "Hammer"? The point being is that only three of the needle bearings are carrying the load at any one time.
Now, with the exaggerated lobe lift and much higher spring pressure, the bushing seems like a great idea.
If it did fail I would not have a grenade inside the engine going off.
But -that is the point of this thread to get a consensus of thought as to what others think.

The key is to keep that circle of rollers rolling, so that although only three carry the load at any given time, they keep passing the buck. Once spring pressure and lift get too high, they can no longer do that.

I remember back in the late '70's to early '80's, someone introduced roller rocker arms for the Sportster. Not the tip like Baisley does, but the actual pivot shaft. What a horrible idea. Nothing spins, it just rocks, continuously on the same three poor old rollers. Very bad, misguided application.

[Jeff Higgins]

Originally Posted by afterburn 549

Iron head Sportsters have bushings in the outside cover for the outboard cam ends.
I will keep my finger in the air and feel / listen see if Jim's bushings was a good idea or not.
Of course, they told me is a great idea..

O.k., thanks. I stand corrected. I just couldn't remember, so I tried to reason my way to an answer. Should have remembered there was no room for that in any discussion of Harley "engineering".

What cam are you running? What springs? Do they warrant the precaution of going to bushings? You say you have never seen, but have only heard of roller failure. In well over 200,000 miles on the old Sportster, I never experienced one. At disassembly for the last rebuild several years ago, the bushings and roller bearings were well worn, but still serviceable. I replaced both anyway. Interestingly, it turned out cheaper to buy a whole new timing chest cover than to remove and replace everything pressed into it.

[Jeff Higgins]

Originally Posted by afterburn 549

Not sure what you mean by that black highlighted remark.

Oh, just a poke at Harley. They suffer a lot of derision over their engineering. I kind of have a love/hate relationship with it myself.

Funny, though, in engineering circles, these guys get massive respect. They have accomplished a great deal with an inherently "flawed" and severely "outdated" design through sheer engineering prowess.

Now your armchair quarterbacks, with no engineering background whatsoever, only see the "flawed" and "outdated" part, assuming competent engineers would recognize those aspects and "correct" them. Harley engineers, on the other hand, see those parameters in which they have chosen to work and have accepted the challenge to continue to refine their chosen platform. Big, big props from the rest of us, who understand what all that entails. Pretty impressive, really.

So, yeah, I was just being a bit cheeky.

Originally Posted by afterburn 549

I ran a hopped up Iron head Sportser for years, From Coast to coast and so much more.
Never a problem with cams.
Working in an HD shop and knowing of "others" the Big Twin seems to have a problem in that area.
The Sportster, of course, has a correct cam geometry, the BT not so much.
Right now I am running a DM 530 lift, With hipo springs to match, and will probably up it to a 590 lift.
But i want to try the new port job out and roller rockers ETC with my old baseline to tell the difference.
After learning all about the Evo nontapered pinion shaft the hard way, I don't trust much else.
Losing a lifter no matter the distance from the house is a disaster.
I am just trying to make this bulletproof.

Understood. My basic bike has been bulletproof for almost 40 years and over 200,000 miles. Things have worn out, but never broken. I have done several top end jobs to get it that far, but only split the cases for the first time several years ago, long after it surpassed that mark.

The only problems I have ever had have been on the ancillaries, and they have all pretty much failed due to its severe vibration, poor quality of that particular component, less than attentive factory assembly of it, or some combination thereof. Each and every such item only failed once, with its replacement being of the same or better quality, and much more carefully assembled and installed.

Yeah, and I think we agree on the whole cam geometry issue. The Twinkie was a huge step in the right direction on the Big Twin. The Milwaukee Eight is revisiting past sins. I don't get it. The geometry is better than the Knuckle/Pan/Shovel/Evo but, back to a single cam? Jeezus...

[Jeff Higgins]

While we are at it, why on earth would any motor running at the specific output of a Big Twin, making power so low in the rev range, ever need four valve heads? An added complication with no real world advantage. Pure marketing b.s. My old Ducati 900 SS hits that 100 hp per liter milestone, far, far higher specific output than any big lazy HD, and it does it on two valve heads. And it's a wonderfully simple motor.

I think I'm sticking with my Twinkie. Unless I get hit again, this one should last me until I have no business riding anymore. No "dual cooling" or any other such complication.