Stock Rocker Arms - Limits? Inspection?

[PurpleBeeper]

I'm building a "budget, low-rpm, highway cruiser" 440 & I'm trying to use some used stock rocker arms.

1. What are the limits of a stock rocker arm? I mean, are they limited by spring pressure, cam size, or what? What are those limits?

2. When re-using stock rocker arms, what exactly should I be inspecting? I think I might have 2-3 in my used set that need replacement.

THANK YOU

 

[Moparstyle]

Cam size would definitely put a strain on stock rockers

 

[vintage chromoly]

You will be fine with the stock arms on a stockish engine.

 

[wyrmrider]

Too much load allows the pushrod to push through the cup (load is spring pressure- rocker ratio- cam grind- rpm- all together)
run AMC/ Magnum lifters and oil through the pushrod's pushrods == there is some discussion on hole through the tip size
having the geometry correct is very important you may have to shim you shafts up
and/or lash caps can help the geometry and provide a larger wearing surface (increase the valve length 1/2 the increase in lift from Magnum will get you close)
we ran "industrial" (not flash) hard chrome shafts and it's said that heavy wall shafts are available but IDK about the chrome thickness
triple chrome-- brass/copper then nickel then grind and polish then chrome- only way to go
why not iron adjustable rockers same drill on the pushrods and shafts but bulletproof
we ran them in NASCAR and when I was with AMC the Chrysler guys ran them in Trans Am (we bushed them) some ran the larger FORD adjusters/ balls and FORD cups on the pushrods

 

[wyrmrider]

all that said for a highway cruiser what I said would be way overkill
however lash caps and oil through the pushrods is easy and inexpensive

 

[66chargerpat]

I'm still getting a way with 130# closed and 330# @.504" on stock rockers for 160k miles. They were new when they started. Pat

 

[lewtot184]

limit open pressure to 300lbs. I don't like higher lifts with them due to the large scrub pattern across the valve tip. stock push rods are heavy and not particularly strong. be sure to check push rod length with those edelbrock heads.

 

[IQ52]

Just my stupid opinion but.......Stock rocker arms are for stock cams and stock valve springs. If you "think" 2 or 3 may be bad......replace them, they are cheap.

 

[PurpleBeeper]

I'm still getting a way with 130# closed and 330# @.504" on stock rockers for 160k miles. They were new when they started. Pat

I was hoping to hear something like this. My cam should be no larger than yours and the springs I'm hoping to use are slightly weaker than yours, so that's good news. I do recall many years ago using stock rockers with a 292/509 purple shaft & double green stripe springs (old Direct Connection stuff), but I spun a bearing in that motor and didn't get more than 10k-20k miles testing on the rockers.

Anybody else with GOOD or BAD experience with something similar.... Please speak up.

Also, what areas should I be closely inspecting on the rocker arms? How tight should they fit up & down on the shaft? What should my side clearance be?

Should I be using some rocker "shim rings" from Hughes like I do on my street racing motor (Isky adjustable) to center the rockers or is that ridiculous with stock rockers?

 

[moper]

I've run them on a few engines with milder cams. The smaller MP, and the XE comps up to the XE268. As soon as you go with true dual springs I would upgrade. With any real spring pressure you can actually see the shaft and rockers bend as you turn the engine by hand... They are not really designed for real beating.

 

[wyrmrider]

you asked about inspection
just a machinist rule across the tips to look for cupping
I've run them lot's of times with true dual springs
setting the shaft height (and tip height and then pushrod length) i.e. geometry really helps on the scrub
lash caps help- much bigger area
X2 on checking the length Edelbrock heads or not-- solid are different height than hyd and AMC/ Magnum are different than the RB or older RB
I do not run shafts that bend
I get mine from Rocker Arm Rebuilders

 

[POMONAMISSEL]

well i can only say this . i bought a challenger r/t with a mildy wild 440 six pack a while back . i'd just put a clutch in it . i went on a cruz . stop at my chevy buds house . he was ''oh whats this a new slopar '' . i replied '' maybe you should brake out your chevy and find out '' . well it was broke or something , so i rev'd it up and dump'd the clutch and dug a pair of ruts in front of his house and the nieghbors 3 . it burn rubbered off them tires , and yes the point . that tach was bouncing off 8k the whole time . stock stamped steel rockers . the rods are carillo's h beams . no worries there . oh ya the chevy guys never call it a slopar again .

 

[BBishere2]

Hot Rod magazine ran an article that said .545” is about the maximum lift you can have on a stock rocker arm. You can search for it - something like 537hp 440 MOPAR engine, and it will give their information. It was a good article from what I remember.

 

[Darter6]

I ran the old .509 MP cam with stock rockers,pushrods and the single with damper factory springs for many many runs down the 1/4 mile. No problem for me. As said above new ones (Mancini)are inexpensive so I would go all new.

 

[6PKRTSE]

I ran the old .509 MP cam with stock rockers,pushrods and the single with damper factory springs for many many runs down the 1/4 mile. No problem for me. As said above new ones (Mancini)are inexpensive so I would go all new.

I have a Comp Cams XR292HR-10 in my red 70 Charger with over 25,000+ street miles & over 100+ 1/4 mile passes on it now still with the stock rockers with no issue thus far. I know I am right there at there limit probably though. 549/544 adv, 242/248 @ .050".