Harland Sharp Roller Rocker Arms

[spmdr]

Thanks Tom, I hope I don't have to take you up

on the shafts. I hope to find something locally.

...And I have really not hit my piles of parts yet.

But here is more info on the HS Rockers I have.



The oil holes are interesting.







It looks like the valve side is dimensionally the same as stock.



On the pushrod side is all the magic.

....and/or some of the challenges... (pushrod length??)



Based on my measurements,

A stock Rocker has a Ratio of 1.417

HOWEVER, my real world had the actual

Valve lift yielding a 1.36 ratio!

Using the same measuring, the HS Rockers

have a ratio of 1.542

Real world valve movement is yet to be seen.

So there it is so far.

DW

 

[alpine_64]

Thanks Tom, I hope I don't have to take you up

on the shafts. I hope to find something locally.

...And I have really not hit my piles of parts yet.

But here is more info on the HS Rockers I have.



The oil holes are interesting.







It looks like the valve side is dimensionally the same as stock.



On the pushrod side is all the magic.

....and/or some of the challenges... (pushrod length??)



Based on my measurements,

A stock Rocker has a Ratio of 1.417

HOWEVER, my real world had the actual

Valve lift yielding a 1.36 ratio!

Using the same measuring, the HS Rockers

have a ratio of 1.542

Real world valve movement is yet to be seen.

So there it is so far.

DW

Dan iirc,

Stock was 1.36.. so that measurement makes sense..
HS offered 2 ratios ..1.36 and 1.6 ... So your 1.542 is likely the later.

Jarrod Gross went into detail on this back in the day...

@RootesRacer are you still on the forum??

 

[Scotty]

Following!

 

[puff4]

I'm curious. When designing roller rockers, why are the shaft bearings simple bronze bushes, when needle bearings would offer less friction?

 

[Asm109]

One word, expense. High hardness on shaft. Maybe an increase in rocker size to fit the radial space of the needles.

 

[alpine_64]

I'm curious. When designing roller rockers, why are the shaft bearings simple bronze bushes, when needle bearings would offer less friction?

I'm looking at making some..and pedestals.... So that's an option we can look into

 

[spmdr]

I did a quick and dirty mock up

to test real world valve movement.

With a stock SV cam and its .294"

lobe lift, the HS rocker lifted the

valve .449" (with 0 lash).

So that looks like a ratio of 1.53


I looked at the pushrods I could find.

One thing I didn't notice before,

there are 3 different pushrods.

The small / short end ones are rare in my

collection.


I checked the weight of the pushrods.

- Small end, 3 piece 80 Grm.

- Big end, 3 piece 83 Grm

- solid one piece 87 Grm




The shorter one piece pushrods

are the only ones that will work

with the HS rockers without mods.

It looks like the STD Alpine 3 piece

pushrods would need a spacer under

the rocker pedestal to keep the push

rods from hitting the rocker arms.

Of course, this was, as I said, a quick

and dirty test and does NOT take into

account all the variables.

- actual Head thickness

-actual cam, with a smaller base circle.

- actual valve lengths, etc...

AND, I want to play around with pushrod

lengths and pedestal height.

Also, I want better location of the stock

pedestal.

DW

 

[SoCal'beaming]

Also, I want better location of the stock pedestal.

???????

.... David

 

[husky drvr]

???????

.... David

David,

Just a wild guess on my part, but could one of two issues.

First is the machining of the head mounting holes for the pedestals leaves the rocker arm shaft centerline a bit inconsistent and/or variable to the valve guide centerlines - on each head and/or on different heads.

Second issue would be to find a way of fixing the pedestal position to prevent movement between pedestal and head at loaded high RPM's.

Or both.

Remember these heads were produced long before the advent of CNC multi-axis milling machines.

Just a thought,

 

[spmdr]

The STD pedestal appears to be die cast

with oversized mounting holes.

I have measured .015" movement/play

in the pedestal mounting positions.

I have not seen any movement

with tightened pedestals.

BUT, I have not checked for that.

BTW, I wouldn't discount PRE CNC

machining, there STILL is a fair

amount of possible screw ups with the

human element in CNC.

It really still comes down to QC/QA.

DW

 

[SoCal'beaming]

Thanks Guys .. The ?? was I thought you meant literal "location" and not a more positive/secure locating of the pedestals. clears it up ? for now .. waiting for the the results of your valve train workup.

... David

 

[alpine_64]

Iirc @Five Reviver has made custom billet pedestals on his racer.

 

[spmdr]

I found a rocker set that I

I could not feel any wear in

the movement of the rocker on

the shaft.

Disassembly found less than .002"

Max wear on the shafts.

And, as you can imagine, there

is more wear father away from

the oil source.

AND, I found the HS rockers

would Not go on a Test rocker shaft.

I had to polish the shaft Down

in size just to get the HS rocker

to move freely.

I'm guessing the HS rockers MAY

not Fit on an NOS rocker shaft!??

I'm on the fence about polishing

the inside of the HS rockers...

At this point, I'm hesitant to

install the HS rockers until I

get a higher oil flow.

If it isn't one thing, It's 15 others...

DW

 

[spmdr]

Here is a graphic example of the pushrod

length issue, and the valve is held open.



And the shorter pushrod, with 0 lash.



Also with 0 lash, may have the pushrod

hitting the rocker with lash and a higher lift cam.



DW

 

[spmdr]

I dug out a big reground cam to see

how the geometry looks with a smaller

base circle and more lift.

The new cam has a .100" smaller base

circle radius and .047" more lift.

The long push rod still hits the rocker

but with some grinding, it works,

after a fashion.



I played around with spacing the pedestal

up and That was going in the wrong direction.

After moving the adjuster down, the geometry

at the pushrod to adjuster goes bad.

The goal is to have the adjuster in

line with the pushrod at mid lift.

Here is the stock rocker with better

geometry:

valve closed, note angle at adjuster.



And then at mid lift.



And then full lift.



Unfortunately, the HS rocker has the

adjuster lower than stock and that is

not a good thing.

The angle at the pushrod to the adjuster

is extreme at full lift, with the long pushrod.

Next step is to mod a pushrod Shorter.

AND, most likely shorten a pair of pedestals.

THEN, It all changes IF/when I go to longer valve

stems, a desirable thing with high valve lifts.

DW

 

[Jay Laifman]

Same problems I reported on. I ended up buying the shortest rods that Sunbeam Specialties sold at the time.

 

[Limey]

Hi Jay,
You can buy adjustable pushrods from Racing supply co's. I plan that for my HS set. Did you get me email about those Microcells in Classic and Sportscar mag?, Cheers, Oliver

 

[Jay Laifman]

Well Limey it's you Oliver! Ha. I did get your email and I responded. I was of course super appreciative in the email! I'll have to re-send.

Good idea about the adjustable pushrods. However, I'd note that with the HS rockers, since they moved the relative location of the adjuster, it changes the angle of the pushrods and therefore moves the pushrod closer to the head. I had to trim one spot on the head where it was close to contact. I don't know how wide adjustable pushrods are.