340 with old Harland S rockers geometry?

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Marcohotrod

Marcohotrod

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so I am running the old Harland Sharp roller rockers with the .625" shafts, shorter than the newer units. these rockers are from around 1975. they are better in a way than the newer ones because they have more needle bearings-no spacers in between the needles. running a .550" lift flat solid cam for 35 years. hey B3, what U think? I have not measured anything. stock heads, 11/32" valves, about stock length, (small chevy +.100") . runs good to 7000
 
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I guess if I was in your shoes I would install checker springs on a pair of valves... mark the tips of the valves with some type of marker and see where the "scrub width" is located on the valve. Then take note on the width of the sweep pattern on the valve tips.
This will let you know what's going on and will help Mike at B3 with a starting point.


I'm not a fan of needle bearings. I bought the PRW 1.6 stainless steel rockers in which they are bushed to fit the shafts. No needle bearings. When I received the PRW rockers I read the instructions before taking them out of the box. It spoke of needle bearings. I immediately took a rocker out to make sure they did not have needle bearings.:)

Needle bearings might me better than bushed ... I don't know...but my personal preference is not to run them. Small little part that is subject for failure. If you have been running them since 1975 without problems .... just disregard every word I have said.:D
 
mullinax95 said:
I guess if I was in your shoes I would install checker springs on a pair of valves... mark the tips of the valves with some type of marker and see where the "scrub width" is located on the valve. Then take note on the width of the sweep pattern on the valve tips.
This will let you know what's going on and will help Mike at B3 with a starting point.


I'm not a fan of needle bearings. I bought the PRW 1.6 stainless steel rockers in which they are bushed to fit the shafts. No needle bearings. When I received the PRW rockers I read the instructions before taking them out of the box. It spoke of needle bearings. I immediately took a rocker out to make sure they did not have needle bearings.:)

Needle bearings might me better than bushed ... I don't know...but my personal preference is not to run them. Small little part that is subject for failure. If you have been running them since 1975 without problems .... just disregard every word I have said.:D
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Problem is the needle bearings wear the races out, the race ride on the shafts after that and get a little noisier and then it forks the road right there depending on the shafts used "induction hardened" "hard chromed" etc...2 things now, the guys setting them up don't space them tight... .010...and so "A" races go away and needle bearings get loose through huge side clearances or "B", the shafts go bye bye and all that debris takes out the bearings and oil pump. Thing with MOST but not all, needle bearings rocker arms, is that they have a limited life span and people misrepresent that as destined for failure. It's the same as tires, milk, meat...you
Something to remember also is most parts failures are user related, not design...or not beyond lifespan or cycle usage . Just like a tooth brush....you gotta replace it ever so often. If given a choice I'd take the bushed or steel bore over a needle bearings on the street because then it's something I'd worry about less...but if I were competing I wouldn't shy from using the needle bearing rockers because they lighter n theoretically run cooler, less surface area contact and moslty I would be on top of that motor like flys on **** to check them.
 
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Marcohotrod said:
so I am running the old Harland Sharp roller rockers with the .625" shafts, shorter than the newer units. these rockers are from around 1975. they are better in a way than the newer ones because they have more needle bearings-no spacers in between the needles. running a .550" lift flat solid cam for 35 years. hey B3, what U think? I have not measured anything. stock heads, 11/32" valves, about stock length, (small chevy +.100") . runs good to 7000
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Guessing your valvetrain geometry without any measurements is like guessing your bearing clearances without any measurements. It could be anything. But, based on what I know, and past experience, it's probably pretty bad. I'm thinking at least off by 300% or more.
 
[QUOTE="MOPAROFFICIAL, post: 1] Just like a tooth brush....you gotta replace it ever so often.[/QUOTE]
Says who? I've grown rather fond of my baby toothbrush. I just send it back to be re-bristled when they wear out.:D
 
MOPAROFFICIAL said:
Sounds like a faster lift...lol
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Actually, it's the opposite. It comes off the seat so slow, it practically stops to have lunch. Of course then at full lift it's nearing a sonic boom. Isn't hyperbole fun?
 
Is this why it's called a toothbrush?
old+asian+man+with+only+one+tooth.jpg
 
the old steel bracket that bolts to the bellhousing with the pivot for the Z bar broke in half today.drove her home about 5 miles with no clutch, got lucky and timed it thru 3 traffic lights
 
yellow rose said:
Dang that's harsh right there.
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It's all good. I look much better now that I got a gold crown on my tooth. Lol.

Marland couldn't beat my wife in the harsh category if he tried. You ought to hear the bellyaching if she catches me with a Mountain Dew. Man, are we off topic!!!
 
B3RE said:
It's all good. I look much better now that I got a gold crown on my tooth. Lol.

Marland couldn't beat my wife in the harsh category if he tried. You ought to hear the bellyaching if she catches me with a Mountain Dew. Man, are we off topic!!!
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I'd just like to say, that I blame it entirely on MO. He brought up the toothbrush analogy. Way to go MO.:poke:
 
Marcohotrod said:
the old steel bracket that bolts to the bellhousing with the pivot for the Z bar broke in half today.drove her home about 5 miles with no clutch, got lucky and timed it thru 3 traffic lights
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Good job! I lost clutch cylinder in War WV on my honeymoon and made it all the way back to Salem VA....128 miles.
 
nm9stheham said:
Recent customers can get away with more LOL
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Yeah, someone goofed on the rocker set I sent him, and there was a 1.5 rocker in the 1.6 set. There's another 1.6 on the way, but I guess he owes me some payback for his lost time.
 
B3RE said:
Yeah, someone goofed on the rocker set I sent him, and there was a 1.5 rocker in the 1.6 set. There's another 1.6 on the way, but I guess he owes me some payback for his lost time.
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I'm not sweating it. Car will be there tomorrow and the day after.:p

Comparing the 1.5 to one of the 1.6s .... I can't see a bit of difference. I think the 1.5 rocker is stamped wrong. I've set them aside one another.... compared...installed them side by side on a shaft.... compared.... and just can't find a difference. I know you said the difference is in the adjuster side.... but I just can't find the difference. :BangHead:

If there is a difference.... it must be so small that it is microscopic. :D
If I hadn't already removed the checker springs I would have used my dial indicator and compared each rocker on the intake valve. See if the lift is any difference than the other.... between each rocker.
 
The difference will indeed be small. On the stock stamped rockers, you only have to move the pushrod dimple by something like .054" to change it to a 1.6 ratio.....
 
B3RE said:
Yeah, someone goofed on the rocker set I sent him, and there was a 1.5 rocker in the 1.6 set. There's another 1.6 on the way, but I guess he owes me some payback for his lost time.
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I got the new rocker in the mail. I will get the other one back to you but it will be a little while. We are required to work 12 hrs each day this week. Usually work 10 hrs a day but going to 12 I don't leave work until 6:30. Post office closes at 5 I think. Tell you what... I'll ship it UPS... they are open when I get off work.

nm9stheham said:
The difference will indeed be small. On the stock stamped rockers, you only have to move the pushrod dimple by something like .054" to change it to a 1.6 ratio.....
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Well..... the whole time I been looking in the wrong place. I didn't realize it's just the dimple that has been moved. I've never had compare rockers so didn't know the differences. Learn something everyday.
 
mullinax95 said:
Well..... the whole time I been looking in the wrong place. I didn't realize it's just the dimple that has been moved. I've never had compare rockers so didn't know the differences. Learn something everyday.
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The stock rocker dimple was just an example of how small the changes can be to change from 1.5 to 1.6 rocker ratios. The change can be in the pushrod location or the valve tip location. Or even the location of the bore in the same rocker casting can be moved to change the ratio.
 
I got to compare the 1.5 to the 1.6 rockers today after work. Took some pictures.
Just can't seem to find any difference. The rocker on the left or top in all the pictures is the 1.5
The dimples look to be in the same location on both rockers.
The part number on the rockers are the same... SPE16.... however one of the rockers is stamped 1.5....?????
Seems to me the 1.5 should have a part number of SPE15... wouldn't you think?

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