273 Rockers on a 1971 340

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CFD244

"I LOST MY ID IN A FLOOD"
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Hi Everyone

I have a set of un-molested adjustable rocker arms from a 273. They have the original adjuster screws and the shafts and rocker internals are beautiful. My question is.....Can these be used on a set of 1971 2.02 J heads in their current state? I've read about sealing the top hole and drilling another in the armpit, as well as replacing the screws with lock nuts and spot facing the contact area. I would rather not modify them unless it is absolutely necessary to work on my heads. The car will only see street use, and won't be a screamer (.477/262).


Will they work as is without burning up?

Thanks.
 
Hi Everyone

I have a set of un-molested adjustable rocker arms from a 273. They have the original adjuster screws and the shafts and rocker internals are beautiful. My question is.....Can these be used on a set of 1971 2.02 J heads in their current state? I've read about sealing the top hole and drilling another in the armpit, as well as replacing the screws with lock nuts and spot facing the contact area. I would rather not modify them unless it is absolutely necessary to work on my heads. The car will only see street use, and won't be a screamer (.477/262).


Will they work as is without burning up?

Thanks.
They will work. I wouldn’t do anything with the adjusters unless they’re loose then I would replace them.


Jake
 
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If you intend to put them on an engine with hydraulic lifters, you will need a custom length pushrod. With solid lifters, you can use the stock 273 solid lifter pushrods. But yes, as Jake said, if they are in good shape, really no need to do anything to them at all. Also, later on, if you upgrade the engine, they can be upgraded also cheaper than a a set of chinkesium set or roller rockers and be far superior. They can be made to handle .600 lift if prepared correctly.
 
Received the custom length pushrods in the deal as well. Fellow had them on a 340, but I just wanted to confirm that I didn't have to do anything with them. They weren't on his engine long enough to damage them IF it was an issue. They will be on my engine forever.
 
lucky good find
pushrods? stock base circle?
many end up with the adjuster balls too far out
best to measure
whats the difference in pushrod seat height between solid and hyd
do you think all solid are the same
 
Without the pushrod in place. With the rockers all mounted on the shafts and on the heads, rock the rocker arm up and down and make sure they do not rub the valve retainer or springs.
Remember notch at the end of the shaft is to the left and down. This is unless you have later shafts and they are left and notch half way down. Or half way up. Is the glass half full or half empty.
 
Once I install them, I will confirm that the adjusters are not at either limit. From what I understand, a couple of exposed threads below the rocker max, is optimal. Am I correct?
 
What size push rod do you use when using 273 adjustable rockers & hydraulic lifters ?

It can vary because of all of the variables involved. You need to get an adjustable checking pushrod and measure to find out the correct length.
 
You need to check that when adjusted the pushrod cup does not hit the rocker arm as you cycle the rotating assembly.
 
check the pads which contact valve stems on the end of the arms for excessive wear. Also slide the rockers off the shafts and examine shafts for galling, as well as the rocker bores. If you find galling, it might be from inadequate lubrication and/or shafts installed upside down.
 
Make sure you have the correct shafts with the oil grooves cut into them [banana shafts] they will fit on normal hydraulic rocker shafts but sometimes don't oil properly and smoke the pushrod cups.
 
Thanks folks. All great advice. The last think I want to do is cause myself more headaches by trying to improve something. I appreciate everyone's input.
 
Not all 273's had grooved shafts, I believe those were only 4bl. Obviously ones with grooves are preferred, but not 100% necessary.
 
If you are running hydraulic lifters you need the grooved shafts. If your shafts don't have grooves you can do it yourself with a hand grinder.

If you're running solids it's not nearly as big a deal. The only time the rocker gets oil to the space between it and the shaft is when the valve is on the seat. With a hydraulic lifter, there is never any space there so the grooves are critical.
 
I'm running hydraulic lifters. Took a close look at my purchase.....Shafts and lifters nice with no wear or galling. Tips show a nice shine with no unusual wear indicators. No indication of spring or cup contact anywhere. The shafts do not have banana grooves, and are the type where the end grooves are pointing 1/2 way down (45 degree angle?). The adjusters are threaded down with 0 to 3 threads showing above the pushrods. (I assume this was the other guys adjustment before he removed them)

Pushrods are 7.520 inches total length with .170 cup relief for the pushrod adjuster. As measured with a dial vernier.

In addition, I received a bag of thin shims to center the rocker over the valve, all mounting bolts and washers, and a bag of (15) 7 degree titanium valve spring retainers (for OEM springs and valves). On a side note, does anyone have a single that they wish to sell?
 
ask Yellow Rose about the oil squirter for the adjuster ball
often overlooked
yr does not prefer but you can also oil your balls through the pushrod
there is a copy of one of yr's writeups on squirters ib the 318 cam stickie

if you increase the lift from stock the position of the rocker on the tip is about the same when on the seat but the position when open is further along the rocker shoe
"about the same" in the preceeding covers valve jobs, tip shortening etc
if the "stripe' has moved a lot you can shim the shafts and or try lash caps
now if you have installed long valves...
well if you went from .450 lift to .650 lift a .100 LONG Valve puts the closed tip/ closed tip angles back about where they should be and gives you room for springs to control your valvetrain
you may have gone to smaller stems too
 
Now I'm totally confused? I didn't want to grind, shim or drill anything. I just wanted to bolt them on a relatively stock engine and go, without wrecking anything. I may have to rethink, and maybe stick with the stamped steel stuff. They seem to go forever.
 
Now I'm totally confused? I didn't want to grind, shim or drill anything. I just wanted to bolt them on a relatively stock engine and go, without wrecking anything. I may have to rethink, and maybe stick with the stamped steel stuff. They seem to go forever.
To simplify it, Adjustable rockers with a mild hydraulic cam are really unnecessary. They don't really improve performance they just give you some adjustability.
 
you do not have to shim with your build
but you do need to make sure that there are holes in the rocker and the shaft to oil your balls and they have to line when the valve is closed
(right yr?)
if you do not want to check just get pushrods with oil holes in the tips
 
How do the adjuster balls get lubed? It appears to me, that oil works it's way around the threads and drips off the ball and into the cup. It this correct?
 
How do the adjuster balls get lubed? It appears to me, that oil works it's way around the threads and drips off the ball and into the cup. It this correct?

Yes. People have just slapped them on for decades. Most of this is much ado about nothing, especially at your mild power level.
 
Well we smoked our balls after installing longer valves to get longer springs for higher lift cams and rotated the iron rocker so the rocker ball lube hole was not lined up with the hole in the shaft while on the base circle
We used to offer a Lifetime warranty
customer would bring his smoked balls back and i'd say
How long do you want to live
 
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