ir3333
Well-Known Member
mancini has grooved shafts at reasonable prices if you need one.
Factory Rocker Shaft Oil Holes-Vary by Year?
- Thread starter dibbons
- Start date
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From post #1 : The upper shaft [shown] is for non-adjustable [stamped steel] rocker arms. These rocker arms have an oiling groove built into them. The oil holes and the square notch get pointed down and to the left of each head.
The lower shaft [shown] is for adjustable 273 rocker arms. The oil holes and the half notch get pointed toward the base of the carb.
Both types of these shafts have only one set of oiling holes. I've never seen banana grooves in any factory engine, but I never had a TA 340 either [which did come with grooves].
An old parts book might have more info.
The lower shaft [shown] is for adjustable 273 rocker arms. The oil holes and the half notch get pointed toward the base of the carb.
Both types of these shafts have only one set of oiling holes. I've never seen banana grooves in any factory engine, but I never had a TA 340 either [which did come with grooves].
An old parts book might have more info.
PRH
Well-Known Member
So, it sounds like the only shafts that came from the factory with the dual oiling holes were what came on the T/A heads.
dibbons
Well-Known Member
What are dual oiling holes? Any photos?
PRH
Well-Known Member
I’ve only seen one set like that, several years ago....... they had a second set of oiling holes up by the adjuster screws.
This was a factory TA motor that was being rebuilt, but I can’t say for sure if the second set of oil holes was “factory” or not.
This was a factory TA motor that was being rebuilt, but I can’t say for sure if the second set of oil holes was “factory” or not.
dibbons
Well-Known Member
Are we talking about the rocker shaft oiling holes or the rocker arm oiling holes?
PRH
Well-Known Member
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PRH
Well-Known Member
We seem to have conflicting info......
I have no idea, as I’ve never done anything with a 273.
273 shafts pictured below With the two oiling holes and a banana groove.
The TA has the a small oil hole in the banana groove as do these 273 shafts and both also have a second larger hole for the pushrod adjuster. The TA shaft has the pushrod oiling hole offset to one side for the intake rockers due to the offset in the intake rocker.
View attachment 1715559669 View attachment 1715559670
The TA has the a small oil hole in the banana groove as do these 273 shafts and both also have a second larger hole for the pushrod adjuster. The TA shaft has the pushrod oiling hole offset to one side for the intake rockers due to the offset in the intake rocker.
I have two extra 273 rocker sets in the basement. All original, never been touched, that have the oiling as I described. I would trust "us" more than any "info". I have been corrected on things I never noticed myself by some of these guys and they were correct. I have loved high revving 273's all my life and have put many bigger engines to shame. There are reasons why they worked as well as they did, and their Heyday was 1967. I can also guarantee you, I never had an original T/A 340.
dibbons
Well-Known Member
We can discuss any number of rocker shafts which is fine, but just remember my original post was referring to "factory". My first 273 was a 1965 Valiant back in 1975 and I have another 1965 273 now, a Signet convertible--no grooves and one oiling hole in my old stuff. It's interesting to see all that's out there. Galling looks to have been a problem after so many miles.
PRH
Well-Known Member
Well, the “info” was post #27, referring to the OP’s pic of an early shaft, where the oil hole is way up on the side, and not even close to being in line with the bolt holes.
And the OP confirms there are not another set of oil holes in that shaft.
So, I’m just going to store it in my mind as....... “some” 273 shafts have dual oil holes...... and “some don’t”.
PRH
Well-Known Member
I guess it should be added to the mental notebook that......
The ones with only one hole...... don’t have that hole pointing “down”, like what you get with the std type shafts used for hyd cam motors.
The ones with only one hole...... don’t have that hole pointing “down”, like what you get with the std type shafts used for hyd cam motors.
Your single hole shaft does not appear factory mechanical to me.
Do your shafts have 2 oiling holes per rocker arm?
Mine do.
What year?
One set is from a 70 1/2 ton pickup.
One set from a 67 1/2 ton pickup.
Both sets have 2 holes and 1 groove per rocker.
I will look through some old photos for a hint.
Nope, no photos.
mechanical rockers?
I have never seen a Factory hydraulic rocker use a 2 hole shaft especially with a Banana Groove. Other than an adjustable one.
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How did they get on a pickup truck?
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