Docile Iron rockers, couple of quick questions

[Malicious]

So I've got through a couple issues and I'm ready to test fit the rockers for the push rod length but I have a couple of quick questions.

The curved washers, I assume they are needed under the rocker shafts for the docile iron rockers as well?

When doing assembly, should I lube them with assembly lube? Or just oil? Nothing?

I noticed the oil tubes on the adjuster side of the rockers, is there a depth that I need to set them to ensure I still get oil flow? I think I remember reading that somewhere...

Thanks for the help.

 

[miller]

Without having some in my hand, just gonna 2+2 on it.

Curved washers probably for a pivot surface, needed for smooth movement. Yes, lube 'em!

Any adjustable rockers I've used...cars, airplanes...the oiling ports for them must be located inside the oil relief cut into the rocker. Usually a limited range, so, there is normally a # of threads that need to be exposed on top. That range of # of threads keeps the oil port inside the cut relief. Of course, that # of threads is at final adjustment...so, the pushrod length is important, to get that # of threads up top.

 

[66Satellite47]

Over the years, I used Isky Crane & Mopar iron rockers. The shims under the shafts can really improve the sweep of the rocker tip across the valve tip. Of course the horizontal alignment is critical. I always used assembly lube & of course pre-lube the motor prior to fire up. The number of threads above the nut did seem to vary depending on which brand of rocker & which brand of adjusting screw. I was most happy with the Isky brand stuff. Although all of them would wear. But I was running very high RPM, 7000 or higher in my 440's & 452 low decks. My Crane aluminum roller rockers held up pretty well. All of my ductile showed wear after about 300 to 400 runs.

 

[lewtot184]

the shims used under the rocker shafts are only used for geometry corrections. they are not a general purpose add on.

 

[khryslerkid]

When useing the shims under my rocker shafts, it was too much. The rocker sweep over the valve stem went too far.

I used Crane with 2 to 3 threads showing under the rocker when checking for pushrod lenth.

Doing a mock up, on intake and exhaust and running them through a cycle is key.

 

[PurpleBeeper]

Well, I'm running old Isky ductile iron rockers. Definitely lube everything (cam break in or at least oil). I'm having a hard time picturing the "oil tubes" you describe. The Iskys just have a hole & you need to make sure you line up the rocker shaft with the holes down to get oil to the rockers. I'm running a hydraulic cam, so I follow the Mopar valve adjustment chart & turn the adjusters in until it just grabs the pushrod (can tell by spinning pushrod with my other hand), then I turn them in 3/4 turn further. One issue I did have with the Iskys was not lining up over the valves. I had to grind away at the rocker pedestals and the "curved washers" that go on the hold down bolts to line the rockers up over the valves. If your rocker pedestals are a little bit narrower at the top where the rocker arm shafts bolt up you might not have this problem. Oh yeah, mine is a big block.

 

[66Satellite47]

Well, I'm running old Isky ductile iron rockers. Definitely lube everything (cam break in or at least oil). I'm having a hard time picturing the "oil tubes" you describe. The Iskys just have a hole & you need to make sure you line up the rocker shaft with the holes down to get oil to the rockers. I'm running a hydraulic cam, so I follow the Mopar valve adjustment chart & turn the adjusters in until it just grabs the pushrod (can tell by spinning pushrod with my other hand), then I turn them in 3/4 turn further. One issue I did have with the Iskys was not lining up over the valves. I had to grind away at the rocker pedestals and the "curved washers" that go on the hold down bolts to line the rockers up over the valves. If your rocker pedestals are a little bit narrower at the top where the rocker arm shafts bolt up you might not have this problem. Oh yeah, mine is a big block.

It is critical to get the horizontal spacers set correctly. Also either using the Mopar "eyebrow" shafts or modifying plain shafts with "eyebrow" grooves to spread the oil across the rocker bore. Even so, things wear, especially with big cams, high load springs & high RPM. All mine have been big blocks & solid or roller cams.

 

[lewtot184]

i strongly recommend no threads showing on the newer adjusters, and no more than one or two showing on the earlier adjusters. no threads showing will give better push rod geometry and parts will last longer

 

[66Satellite47]

i strongly recommend no threads showing on the newer adjusters, and no more than one or two showing on the earlier adjusters. no threads showing will give better push rod geometry and parts will last longer

Interesting, do you mean no threads under the rocker? I may have mis-interpreted the question. I shot for no more than 2 or 3 threads under the rocker tip.

 

[Homstead]

Not to derail the thread but how much oiling happens at the valve train with iron rockers? Mine just have a trickle but everything seems happy.

 

[lewtot184]

Interesting, do you mean no threads under the rocker? I may have mis-interpreted the question. I shot for no more than 2 or 3 threads under the rocker tip.

quoting the engine manual, "the rocker adjusting screw is to have only one thread showing below the rocker arm with the valve lash set properly (two may be okay, three shaky, etc)". i think the newer longer adjusters are more problematic. the ball is extended from the threaded section an additional .100", equal to 2 1/2 threads. add a couple of turns and smoked push rods or broken adjusters. definitely no turns for the new stuff.

 

[lewtot184]

Not to derail the thread but how much oiling happens at the valve train with iron rockers? Mine just have a trickle but everything seems happy.

the oil supply from the block to the rocker shaft is the same. adjustable rockers cover the shaft 360 degrees and don't pond or bleed off as much oil as stock stamped steel.

 

[66Satellite47]

Lew, you know lot's more than me. I sure saw a difference between adjuster screw brands with the same pushrods.

 

[lewtot184]

Lew, you know lot's more than me. I sure saw a difference between adjuster screw brands with the same pushrods.

people tend to ignore push rod geometry but it can be as important as rocker/valve tip geometry. in my opinion i think folks expect too much out of the ductile iron rockers. i've used a few sets thru the years and do like their simplicity but they have limits.

 

[Cranky]

What number were old Iskys? 1402's? Can't remember now but I have one new set left. Ran a set on my 10.60 car back in the mid 80's. 300 passes shifting at 6800 and crossing at 7300 with a .660 lift roller cam. The whole valve train was Isky.....

 

[Garys1969RR]

It makes sense to have only a thread or 2 of the adjuster bolt extending below the rocker arm. If the pushrods are just a little too long, where no threads are showing, you can compensate some by shimming the rocker shaft at the pedastals by .020 to .040". And you also need to make sure the rocker arm is at the center of the valve stem tip at 50% of total lift. Otherwise, it may get too close to the edge of the valve stem when at full lift, or at the fully closed position. I am going to pay close attention to these things when I swap my 906s for my Performer RPM heads.

 

[Garys1969RR]

It seems that my old 413, with ductile iron rockers and a Racer Brown .690" lift mushroom lifter cam, had several threads showing below the rocker arm. I had no idea what to look for back then, but it ran fine for several years at the track. These parts are pretty durable, and you would be surprised at what some guys get away with. I was one of them!

 

[lewtot184]

It makes sense to have only a thread or 2 of the adjuster bolt extending below the rocker arm. If the pushrods are just a little too long, where no threads are showing, you can compensate some by shimming the rocker shaft at the pedastals by .020 to .040". And you also need to make sure the rocker arm is at the center of the valve stem tip at 50% of total lift. Otherwise, it may get too close to the edge of the valve stem when at full lift, or at the fully closed position. I am going to pay close attention to these things when I swap my 906s for my Performer RPM heads.

using shims to compensate for long push rods or milled heads will probably screw up the geometry. you'll find that the RPM heads will need a custom length push rod and possible rocker shaft shimming to get proper geometry. don't have any threads showing if you use the latter long adjusters.

 

[lewtot184]

in my opinion the ductile rockers are beyond obsolete for any of the higher lift cams, especially rollers. keep in mind that they are a product of 1950's technology when lobes were gentle and spring pressures were low (by today's standards). since the mid to late '90's camshaft, valve train and head technology has moved far beyond their capabilities. the fulcrums gall up (iron on iron; similar metals problems), the sweep area across the valve tip is large and harder to control, the crane rockers have tip problems with high spring loads; it just goes on. again, i think folks expect too much out of them.

 

[Cranky]

in my opinion the ductile rockers are beyond obsolete for any of the higher lift cams, especially rollers. keep in mind that they are a product of 1950's technology when lobes were gentle and spring pressures were low (by today's standards). since the mid to late '90's camshaft, valve train and head technology has moved far beyond their capabilities. the fulcrums gall up (iron on iron; similar metals problems), the sweep area across the valve tip is large and harder to control, the crane rockers have tip problems with high spring loads; it just goes on. again, i think folks expect too much out of them.

Seems even the newer modern rockers have problems with the huge cams. Not sure anymore who has what but T&D was one to look at for the more exotic grinds at one time. The non roller tip rockers do not like big cams but back in the 80's .660 lift was considered pretty big. It's been nearly 20 years since I've had a hand in anything that was quick so I'm pretty much out of the loop on it.....that is if you call low 9's quick. I still do but there's plenty of people who say 9's is pretty much ho hum these days lol.