• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Roller rocker centered on the valve stem

Paul_G

Paul_G

Well-Known Member
Local time
3:39 AM
Joined
Dec 24, 2013
Messages
2,098
Reaction score
3,364
Location
Surprise, Arizona
Take a look at these please. I think the roller tip is not centered on the valve stem correctly. How can I get the tip to ride in the center? Trick Flow PP240 heads with Harland Sharp rockers made for Eddy and TF heads.

I have the push rod checker tool at 8.785" which leaves about 1 thread exposed below the rocker arm. Right at HS spec.

20200212-150614.jpg


20200212-150947.jpg
 
It's been a few months since I did mine. I believe it was shimming under the shaft that got mine centered. But once centered, you will have to check pushrod length again.
 
Centered doesn't matter. You're looking for the smallest sweep. You can use a kit from B-3 to get it as close as possible. To be honest it doesn't look that bad. Way to many get all worried about it. Personally, I'd run it.
Doug
 
Looks pretty good to me. Maybe a small shim under the shaft. The sweep looks about as good as can be expected. But I'm not a professional builder.
 
I am going to take a side shot of the roller on the valve tip today. I want to see where the roller is at max lift.
 
let's see the closed and max lift and mid lift
sweep is not as bad as most and you are centered close enough
your stars align
what dvw said
The TF heads evidently have the shafts moved up and away from iron head locations already
I would ask B3 what his experiences with those heads and rockers are
but I'd run them
(never heard me say that before)
 
Pics of the roller from the side. My push rod tool is at 8.875" which is an off the shelf length. I have it set at 1 turn preload. The roller lifters were soaked over night before install, but that was a couple of months ago.

This is on the cam base circle
20200213-102212.jpg


This is at max lift
20200213-102304.jpg
 
That rocker shaft needs to go down not up with shims. The only way to do that is machine the pedestals down.
Given the marked valve tip shown in your first pics - the sweep is pretty narrow and no where near the edge of the valve.
I would run it as is.
I assume you have a solid cam?
 
Last edited:
Then the mark you made is wrong unless you somehow allowed for the collapse of the roller lifter.
For a hydraulic cam you should use a light checking spring.
I would say the mark will be a lot further out than you think.
 
Would bottoming out the lifter with the push rod check tool work? Then recheck. Or bad idea?
 
Paul G, I mistook your "mark" for an actual wear pattern & presumed a solid cam. Forget my comments.
 
I called Harand Sharp and explained my issue, sent him a bunch of pictures. He said that these rockers were made specially for my combo, others have used them with the TF heads and said they are spot on. Waiting to hear back from him.

I am probably doing something wrong.
 
I have used Harland Sharp and Comp Cams(who are Harland Sharp I believe)and their geometry is not good. The best by far is the Hughes setup.
No you cannot bottom out the lifter because that is not were it will run when the oil pressure pumps it up.
It is pretty simple. Substitute a pair of light check springs on one cylinder. Set the valve lash at zero and look for mid valve tip or close at mid lift on the cam. Ensure the lifter is not compressed by the checking spring.
You cannot mark it the way you have previously done it you will need to eyeball the valve tip.
 
put a machinest rule through the center of the roller and the fulcrum- just but the bottom of the rule against the center of the shaft and the bottom through the center of the rocker
what do you see with your eyeballs at closed, open, half
pics please
I want that rule parallel with the top of the retainer at half lift
what do you see
 
Like many things during this engine build, doing the research, I have learned more about valve train geometry than I wanted to know. I need to get a valve spring compressor and some checker springs to do it right.
 
I have been doing engines since I was an apprentice and had never heard of rocker geometry until I purchased an engine blueprinting book about 25 or so years ago.
At least you knew to check it.
That video from Straub is pretty good but the old way of centre of valve at half cam lift still works fine. I have done quite a few engines over the years and your eye is pretty good.
The sweep of the rocker over the valve tip is fairly important. If your sweep on a Mopar is around or less than 1 mm or 0.040 thou you are doing pretty good. A little bit off centre will cause no issues. With the shaft mounted rockers you cannot alter the rocker geometry with push rod length as described in the video.
To alter the geometry on a Mopar you need to move the rocker shaft up or down. It would be nice to move it in or away from the valve also but as we know that cannot happen with the cast in pedestals. A Mopar rocker is pretty short and that is some of the trouble.
To optimise the push rod length put a DTI on the spring retainer and play with the push rod length until you get the most valve lift.
Have the adjuster screw far enough out of the rocker to ensure it is low enough for oil to spray in to the push rod cup. If your push rod is too long I believe you can starve the rocker end of the push rod a bit.
I modify the Harland Sharp, the push rod oiling hole is huge and no oil goes to the rocker tip. I only buy the Hughes ones now.

I will
 
You must log in or register to reply here.

Similar threads

ignition1
426 Hemi Rocker Tip Geometry Adjustment
2
Replies
26
Views
4K
RemCharger
RemCharger
mopardemon
cam selection 505 stroker build
Replies
10
Views
865
mopardemon
mopardemon
R
Perf 440 build - Pushrod Question(s)
2
Replies
28
Views
3K
not so famous bob
not so famous bob
R
Harland sharp roller rocker clearance question.
Replies
13
Views
2K
PRHeads
PRHeads
m79ded
Comp Cams Rocker Adjustments
2
Replies
21
Views
3K
Geoff 2
G
Auto Transport Service
Back
Top