I can see where setting them up with more than .050 clearace AFTER lash could be real important, especially if a motor doesn't have really thick pushrods or it has marginal springs allowing valve loft to happen. As each coil goes solid the spring rate for the remainder of lift must go throught the roof.

By adding the beefier pushrod you have also reduced any cushion that came from the more flexible push rod. I know some drag week guys learned when they upped to a monster pushrod it moved the problem to broken rockers.

You are just hurting rockers and not lifters?


I'm a big fan of bushings. Needle bearings hate shock loading and they hate reciprocating loads.

The biggest issue with bushings on the shaft is getting enough oil at the shafts with enough pressure to lube the bushing. You aren't going to run 20-30 pounds of hot idle oil pressure and keep the rockers off the shafts.

I don’t remember where I read it, but there was a nice discussion on setting the springs up near coil bind.
Someone who was part of that discussion had a pretty elaborate computer supported spring tester.
He referred to the springs having a “soft bind” and “hard bind” height.
Hard bind is the “solid” height.
Soft bind is when the coils start touching and the rate starts to spike up.

I started looking at that situation more closely when I was setting up springs where all or most of the available range/travel was needed.
What I found was, fairly often there will be couple of springs in the set that for one reason or another the coils start touching at a taller point than the others, and those springs can have the pressure spike up a bit when compared to the others.
Not to mention that they may actually have a slightly taller solid height, compared to the others, and to the coil bind spec.

So, now I try and shoot for the “soft bind” height(when possible) as the point the spring will be at when the valve is at net full lift.

The Jesel’s use a small solid shaft for each pair of rockers, and have no internal oiling provisions.
Without creating an internal oil circuit to connect the oil supply from the pushrod to the inside of the rocker bore, it wouldn’t matter how much oil pressure there is....... the only oil getting to the bushing is what manages to leak in between the shaft and bushing via splash.

I did replace the comp lifters with Isky EZ roll bushed lifters. The comps spread a thou or so at the axle and were close to being way too tight to remove.

IMO, this is an indicator that the overall stability of your valvetrain isn’t as happy as the motors I’ve done with the Jesel’s, since my customers aren’t having any issues with the Comp 829’s or 87019’s.

Now, that difference could be something as simple as they turn a little less rpm, which keeps them from becoming unstable.

Been so busy didn't get a chance to check back in here but as far as coil bind is concerned make sure you check the inner spring for bind also with the retainer. I ran into bind problems in the past on the inner with certain retainers. I assume you have checked for that but figured it was worth mentioning.

I wont run anything closer than .070 after lash either. I only turn mine 7000 RPM max though.

If one wanted to explore the bushing thing...... especially since these are paired rockers on 8 seperate shafts......... just have one intake rocker bushed and see how it holds up.

That was my idea, to try one, warm the motor up and check, then keep a very close eye on it so i don't have a catestrphic failure.

Thanks. I did check both inner and outers.

Do you have any shims you could remove to add just a touch more installed height?

You could try the same thing with that.
Try it on one or two intakes...... see what happens.

If it were me, I’d go with adding .030 more height.

If you try that, you should install new bearings in those rockers to be sure you’re not starting out the test with a compromised set of bearings.

they hate reciprocating loads
YES!
The needles don't rotate, they only oscillate (pendulum swing), with the same 10 or 12 needles (looks like 33 or 34 may be the maximum # of needles in a full-complement bearing without separators) around 12 o'clock taking all the compression load without developing the hydrodynamic wedge (as between the mains and MB) that saves the journal from making hard contact.
Using 2 bearings isn't to increase load capacity, it's to prevent that tiny needle from cracking in half by bending. Harley learned that the hard way 60 years ago.
Any sign of local fretting inside the rocker body near the edge of the roller?

My bad. I was thinking Greg was talking about the T&D single shaft rockers.

So yes, you'd be correct.

You mean like what happened to my rear u-joint? The rollers sit in the same spot and just eventually wear it out. In this case the needle rollers are harder than the shaft material, so they win.

I have checked all the rocker arms and inspected the shafts for any sign of trouble exhausts are all fine, the other six intakes are good also, all the shafts are in perfect shape. I belive i had .070 installed height on all and don't recall using any shims, as gross lift is .867, net lift is .847 if all is perfect. I was wrong when i said what springs i have. My springs are 1228 1200 series PACs, installed at 2.050. Coil bind is 1.100.
I have very little room to increase installed height, i am maxed out with all + retainers and keepers, and thin spring cups. I will check and see what, if any room i have.

I found bushings that may be a decent option. They can be ordered with a shallow grove at angle to help feed oil to the bushing. That combined with a hole drilled through the top of the rocker in the lightened area of the bridge which will get oil from spray bars and splash from pushrod oiling should help keep oil coming. I just need to call and see if i can get them in an alloy that has both high strength and good wear resistance to marginal, unpressurized luberication.

You have plenty of room to coil bind, over .100". I'd be asking my why only 2 rockers? Is there a way to modify the rocker oil the bearings like T&D?
Doug

Did you verify each springs coil bind height, or are you going by the catalog spec?

Sounds like you’re running different springs on the exhaust?
How are those set up?

I didn't verify the true coilbind for each, as i recall i went to about .070 by the book.
There is no easy way to pressure oil this deal. Jesels are paired on a single solid 5/8 od shaft for each cylinder.