Rocker Decision

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Orange67

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So I'm building my 360 and have two sets of rockers laying around to choose from for my build. Car is a 67 Barracuda I'm building mostly as a street car. Building a stroker engine. Should I go with the Chinese made roller rockers or the crane ductile iron rockers? I'm having a hard time deciding. I don't know if I trust the foreign made rockers.

20180805_212237.jpg
 
If the chicoms have needle bearings I'd pass. If not, I'd check both sets for ratio and the one that was closest to 1.5 or 1.6 or whatever they should be that's what I'd use.
 
What lift are you running? if it's under .550 I would check the Isky's or cranes what ever they are and run them if I could, make sure they don't hit the edge of the valve and they will work fine.
 
brian6pac said:
What lift are you running? if it's under .550 I would check the Isky's or cranes what ever they are and run them if I could, make sure they don't hit the edge of the valve and they will work fine.
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Hard to read the pic. .507 lift
 
Orange67 said:
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you'll need really thick hardend shaft to run the needle bearing kind and you have to run really tight side clearance like .008 .Also but some harland sharp adjusters.
Check retainer to rocker clearance as well.

Both will work if set up properly, with the needle bearing races wear tendencies...they will cycle out 1st before the iron rockers.
 
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I've never run chicom rockers but have run many bushed and unbushed ductile- Crane- Isky, Erson (including 1.75)- white box
Bulletproff best with banana groves and hard chrome shafts like Rocker Arm Specialists up near Anderson/ Redding CA do
NO FLASH CHROME- it peels and flakes
also with roller rockers you need to relocate the shafts up and usually back to get the geometry and the best way to do that- B3 - adds another layer of cost
for the iron rockers-and especially with the rollers get your geometry right B4 ordering pushrods
you want the adjuster up to near the max- fewest or no threads showing depending on the adjuster
If you have to get lifters get AMC/MAgnum oil through the lifters lifters and hollow pushrods to oil the rocker balls- a weak point
you do need Case Hardened shafts if the needle bearings are going to run on the shafts- lots of hidden costs with roller rockers plus they fail disastrously
remember that some chicom rockers are chevy bodies which have longer arm than true mopar rockers - which are too damn short- but the chevy rockers tend to run off the exhaust side of the valve stem- and long valves (or sunk valves) make it worse
I hear that there may be more pushrod clearance problems with the cheap rockers- so plan on a test fit
saw your post- good choice- if used rockers check your balls and tips- if they need a tune up or bushings get hold of rocker arm specialists or whatever their name is now, they can also give you the shaft
run 3/8 pushrods if possible
 
I'd run the ductile arms and forget about it. Been running the same set of stock 273 rockers on a solid lifter 340 with dual springs since the early 80s. Tons of hard street miles and plenty of strip time. 4speed and 4.88 gear, its been north of 7500 after a few missed shifts! None of the headache or costs of roller rockers. They're alot stronger then people give them credit for, and SIMPLE.
 
I can't tell what cam it is from thepic
but I'd usually run the higher lift shorter duration version of whatever it is
if you looked at the A new article with photos on the T/A & AAR rocker arms with a W2 / W5 rocker arm comparison
you can see where the oils want to be for the pads and balls- look at the w2s The TA's are like yours
drilling and plugging is not hard - and I'd still oil through the pushrods
there is a reason MA MOPAR made these changes
do you have the cam/ lifters already?
I can't even tell if it's solid or hyd
would new glasses help?
 
I obtained a set of those 273 arms in about 73/74 . They are still with me and have been on quite a few builds since. That's 45 years, NOT non-stop; but they've still got a lotta lotta miles on them.
 
We tried some of the rockers with needles exactly like those shown. The shafts were probably wrong and not hardened properly, so that may have been the real issue, but regardless, the needles wore some deep grooves in the shafts in 1 k miles. I was pretty careful with the oiling, and valve spring pressures are under 300 lbs full open so nothing out of line there. Needles bearings put a lot of pressure on a few needles at a time, on a much, much smaller area than a bushed rocker.

We changed to Hughes AL rockers.

IMHO, the stock 273 rockers are probably near their useful lift limit at .507". Also, I have read reports of them not being really 1.5 ratio, so you may lose lift IF that is true.
 
simple question....off shore roller rockers or crane ductile?
simple answer .....crane ductile.
 
nm9stheham said:
We tried some of the rockers with needles exactly like those shown. The shafts were probably wrong and not hardened properly, so that may have been the real issue, but regardless, the needles wore some deep grooves in the shafts in 1 k miles. I was pretty careful with the oiling, and valve spring pressures are under 300 lbs full open so nothing out of line there. Needles bearings put a lot of pressure on a few needles at a time, on a much, much smaller area than a bushed rocker.

We changed to Hughes AL rockers.
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That there is what steered me away from them in 1999.Fear of the unknown,suspicion of the needles............ and a limited budget.
I went with the blue-anodized,aluminum,roller tips only, 1.6ers, Mopar kit P4529692. At the time, they were about $850C delivered.
Also got the color-matched hold-downs; another $150C, but the supplied bolts were too long for the Eddies; mo-money,lol.
And I increased the side clearance a bit, and installed a high-volume pump, and drilled the oiling passage a bit, and converted the oil delivery holes from the cam bearing, to slots. Hyup I was paranoid of losing those $1000 smackers;they were incredibly hard to come by in the first place. The arms currently have over 100,000 miles on 'em.
Sorry for your loss
 
nm9stheham said:
We tried some of the rockers with needles exactly like those shown. The shafts were probably wrong and not hardened properly, so that may have been the real issue, but regardless, the needles wore some deep grooves in the shafts in 1 k miles. I was pretty careful with the oiling, and valve spring pressures are under 300 lbs full open so nothing out of line there. Needles bearings put a lot of pressure on a few needles at a time, on a much, much smaller area than a bushed rocker.

We changed to Hughes AL rockers.

IMHO, the stock 273 rockers are probably near their useful lift limit at .507". Also, I have read reports of them not being really 1.5 ratio, so you may lose lift IF that is true.
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In the early 80s when this motor was built, there weren't many choices, especially on a tight budget. Cam is a mechanical 528" 286 racer brown. Car has went into the 11s many many times, and is VERY reliable for a stock appearing engine and car. They serve their purpose well
 
Wyrmrider said:
aj, nm
another dcr article i do not know if you've seen
Dynamic CR
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Yes, I have, wyrm..... Scroll to the bottom and there is the link to the Pat Kelley Calculator that I use, for 90% of the work.

I use the outputs of that Pat Kelley calculator and use them as inputs to the Wallace DCR calculator; the Wallace DCR calculator accounts for altitude effects in its output for both cranking pressures and 'effective DCR'. You can also input turbo/super-charger pressures to see where you get for DCR.

Part of the trick to getting close is to try to account for the effective closing point of the intake valve (discussed in the middle of the page that you linked). For example, I'll subtract 8-10 degrees from advertised duration for a solid cam to account for lash, and put that into the Pat Kelley calculator.

It is not a perfect science. But you have to do something to get in the ballpark with DCR if you want to know what you are going to have. And as an aside, all of this has been worked on and used for at least 90 years; a lot of serious engineering research went into the compression ratio matters in the 1920's and then was expanded when superchargers started being applied in cars and airplane engines by the 1930's.
 
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