273 rocker arms

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look like hydro rockers....may not pertain to discussion....

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interesting article on Hughes website...
"...Once the stamping technology developed to such a point that stamped rockers could be made, about the mid-60s, the more costly iron rockers virtually disappeared. They had somewhat of a resurgence when offered by the O.E.M. manufacturers from the mid-60s to the early 70s. They were a quick solution for the solid lifter or high performance hydraulic cammed engines needing adjustability. The valve spring diameters, pressures, valve lift, rates-of-lift, and RPMs today are much more aggressive than they were 40 or 50 years ago, and, therefore, we consider the forged iron rockers unsuitable in todays engines. At one time we sold them but there were so many problems with galling that we dropped them. They have the same galling problems as the unbushed stainless steel rockers..."
 
Bodyperson said:
Cam a guy do that to the 273 pushrods? Pull them apart and shorten them.
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I believe the 273 had spot welded tips, probably not enough material to cut and press. These are the harvested slant tips. I took them to a grinder and ground down until the color started changing and did that all the way around and they pulled right out with almost no support left.

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I would only bother to use factory iron rockers, in there stock form, on very mild applications.

For builds where they might be one of the few affordable options(think T/A heads), where the spring loads were going to be noticeably higher than OE........ doing something like getting them bushed to avoid the galling problem might be something to consider....... if you already have the rockers.
 
ir3333 said:
Are the any oiling mods necessary when using 273 adjustable rockers with hydraulic lifters?
A friend suggested by pre-loading the lifters the oiling hole is compromised?
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A haiku:
What is that noise That clearly I hear
By gosh it's coming From my rocker gear!
I removed a valve cover It just can't be true
The rocker arms and push rods Have turned a weird color of blue...
Now I guess I'll be searching for new rocker gear
And the only guy I blame this on Is the one in the mirror...
 
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Yes, you have to be careful to install the shafts correctly and use the right hardware.
 
PRH said:
I would only bother to use factory iron rockers, in there stock form, on very mild applications.

For builds where they might be one of the few affordable options(think T/A heads), where the spring loads were going to be noticeably higher than OE........ doing something like getting them bushed to avoid the galling problem might be something to consider....... if you already have the rockers.
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I did check with Hughes and they said no modifications are necessary unless high spring pressures are used.I wonder if adding the missing oil holes ( adding additional leaks) would create a problem with stock shafts that have a much larger single oiling hole than the 273 pieces.
Now 1966...have you burnt valve gear because you used stock hydraulic shafts with 273 adjustable lifters?
 
ir3333 said:
All good info guys..tx.My engine is built and i made no modifications to the new stock shafts or rocker arms.A friend told me that i will be sorry and the modifications are necessary so thought i would ask on the forum.
As you know... i try to use logic and question most everything.
Now....who have used stock 273 adjustable rockers with standard shafts and how did they perform for you?
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I have dragged the same 273 kit from one stock-cammed 318 engine to the next probably three or four times over the years, since about 1975. BUT
I always slammed the solids onto the old camshafts too. Everything fit, and never had a problem.
They came off a 1965 2bbl engine.
They are currently on my spare engine.
 
I clearly positioned my opinion early in this post. Life is made of choices 3333 and we get to live with them...
 
I am sure you meant well and base your opinion on thought and logic...thanks and I agree logic says improvements might be a good idea.But my post was asking if they are necessary.. and then asked for responses based on experience.
Again thanks to all.
 
can anyone with a 273 shaft measure the distance between rocker oiler and spine oiler hole? Centerline to centerline please.

shaft2.jpg
 
Pista no problem, I have a shaft in front of me & my caliper. If you need pictures, PM me your email address & I'll send them to you.
 
stockers have 2 oilers: one on top for spine and one at about -70 degrees for pushrod cup. Do 273 shafts address these holes with a timed (inline?) shaft oil port(s)? Cant see how they get oil on a smooth shaft with no grooves internally. I understand some later iron rockets dont have spine oilers.

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I would have to check some of my spare rockers. some of them have a groove in the center of the inside of the rocker.
 
cool, these are bone stock '64's IIRC. Im modding a set of hydro shafts for these with banana grooves and these oil ports. Rockers fit well just lacking a few oil ports. I may chuck these up on a head with hardware and see where the oilers line up on shaft, scribe and drill. Maybe a timed port that will oil on a lift cycle.
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Just remember the shafts are hardened & it may take a bit to drill the holes without breaking bits.
 
Demonracer said:
Just remember the shafts are hardened & it may take a bit to drill the holes without breaking bits.
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your right, My cut off wheel made quick work of the banana groove but the holes are proving tough to drill. Ill have to spot and hit 'em with the drill press with a good bit. Only drilling the adjuster oiler for now, will see how the bit holds up. If it cuts, Ill cut the stem oilers in the shaft and arm.
 
Why anyone would argue against banana grooving shafts is beyond me. Less than 30 minutes work and you're done. That includes the time to get the tools out and put them away.
 
just grind a flat through the hardening
I use a dremmel
same thing for trans shafts
like xtra oilers for the od thrust washers
 
Try a tool supply to get a titanium bit, I use them for drilling hardened steel. I have Rex Supply here but I don't know where else they are located.
 
Wyrmrider said:
just grind a flat through the hardening
I use a dremmel
same thing for trans shafts
like xtra oilers for the od thrust washers
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^^^^^^^This^^^^^^

And I use a carbide center drill to drill the hole after grinding through the hardening. It leaves a nice chamfer and the center drill is far less likely to fracture and break.
 
All good suggestions. I got Titanium bits but my drill press is OOS at the moment, needs a K27 belt and I bought a K26! :BangHead:
I need a new drill press anyway...... Hey, I just got a 20% HF coupon.....:rolleyes:
 
Shafts drilled A-OK with a new HSS bit, mine were toast. Could tell when it punched through the hardening. Found an interesting diagram of intake and exhaust lifters in a 65 FSM. Some proposed oil galleys in rocker arms based on intake or exhaust? I say proposed because I have never seen any gun drilled down the nose like these...are these 318 poly? Look a little long for 273...
rocker3.jpg
 
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