SB rocker and lifter questions

[CudaRunner]

I have a SuperCommando 360 crate motor that I run street/strip in a '65 Barracuda. I replaced the original heavy-duty rockers with Harland Sharp roller rockers a while back and all seemed fine. Now a lifter has died and I have some questions. Harland Sharp tells me the rockers are for "all out competition" only and are designed for "taller valves, larger springs, and solid or roller cam". Does anyone here have experience/opinion on running these rockers in street/strip on stock valves? Also, I am looking for experiences/recommendations for lifter replacement. I can obviously go stock hydraulic. I have had other cars with solid lifters and am not opposed to regular valve adjustments, but is there any real advantage these days? I could put the heavy-duty rockers back in (kept all the parts), any opinions on that?

[skankweirdall]

Do these rockers have needle bearings at the fulcrum?

[dwc43]

I have run Harland Sharp rockers for years on our dirt track engines and I have never failed a lifter. Just install a new set of aint pump up lifters and readjust them and let it go.

[Billydelrio]

CudaRunner
I have never used Harland Sharp rockers on a Mopar. Look to see if the rocker's roller tip has a centered pattern on the valve. If the pattern is Okay, then I can't see where the designed for "taller valves" is a problem.

Billy

[CudaRunner]

Yes, I recall that they have needle bearings in the fulcrum. In a visual inspection of the rocker-roller to valve contact it does appear that the contact patch is not centered, but is somewhat to the outside of the valve. Only slightly when the valve is closed, more so when open.

[CudaRunner]

I don't really think that the Harland Sharp rockers being there are related to the lifter failure, although I asked my question this way in case someone here might think differently. Assuming I do buy a new set of hydraulic lifters, can someone recommend any brand(s) over others? Does anyone disagree that anti-pumpup lifters are a good choice for street/strip?

[dwc43]

I'd put a set of Rhoads lifters in it. And my Harlands dont use long valve stems either. The are stock lenght stainles steel. Forgot to mention that earlier.

[pishta]

Hey neighbor! I think I have seen your car (if you ever get it out) only because I always remember 64-66 around here. Not alot! Anyway, I used Crane Hi-Intensity lifters when I had a 340 with a 284/484 Purple shaft. It pulled great idle vacuum and hauled ass up top too. Let me know if you ever get out to Fudruckers on car night. Id like to see another '65! pishta68@hotmail.com

[CudaRunner]

Alright, I guess the answer depends on the cam: it's a .484" lift, 284-284-68 duration Mopar (is that the Purple shaft?). I also have Mopar's high perf valve springs. Are the anti-pump lifters more for when the engine is spending long periods at hi-rpm (minutes) and the hi-intensity more for short (less than 15 seconds)? From what I can tell aren't the Crane Hi-Intensity and Rhoads lifters the same design?

I haven't been to Fudruckers in several years, used to be a regular. I do drive the car regularly, but haven't for a month or so working out trans then exhaust and now valvetrain problems.

[pishta]

hi intensity and rhoads are similar, they bleed off a bit at low RPM's to help with idle quality but are normal at higher RPM's. They work well with the 484 stick. If you have a loose convertor, I would go with regular hydros. I had a little over stock convertor in mine and it needed the help down there.

[CudaRunner]

I am a little confused by your last: are you saying that if I have a high-stall (loose) converter that I should NOT put in anti-pump, but should put in stock lifters? I guess you are saying that these anti-pump lifters increase the lower rpm torque, which isn't of much help with a high-stall converter. Is that right?

I have a converter that has a higher than stock stall speed (I think around 3000 rpm), but not what most call high-stall (more like 4000-5000 I think). You describe yours as a "little over stock", which is probably a good way to describe mine.

[pishta]

Rhoads/Hi-intensity lifters are NOT anti pump lifters, they are variable duration lifters. The might not pump up at high RPMs due to a better design (?) but they were made to bleed off at low RPM's. Im trying to say that if you have a tight convertor (stock or a little above) and a lumpy stick (284 is kinda lumpy) you want the motor to have more torque at lower RPM's to get the wheels turning. That is what they help. If you have a 2800+ stall, you are already into or close to the motors powerband when the convertor starts to get into the tires. You dont really need the crutch of the VD lifters (what an awful acronym!) because the stall convertor is not loading up the motor at the low RPM's. I would go with stock or anti pumps with that convertor. I had a 2400 in mine and the Crane lifters drew more vacuum and a smoother idle than the stockers in mine.

[drag-n-cuda]

Is the crate motor a magnum or original LA? If it's a non-magnum I've been told by a very respected engine builder, Bill Richardson of RAM (advertises in MP and MA magazines) that I would have to put in .100-.150" longer valves to use the Harland Sharp rockers to get the correct geometry the rockers were designed for. Since he's been building performance mopars for 30-40 years, I'll take his word for it. I'm going with the HS rockers when I can, can't beat the full roller fulcrum in my opinion. If it's a magnum motor, I don't have an answer for you.

drag-n

[sanborn]

Maybe this explaination will help!

How to check for proper rocker arm geometry!

First check the front/rear alignment. You want the roller to be centered on the valve stem. Misalignment can be corrected by use of alignment shims. Don't care what aftermarket rocker you use(high$ or low$) they often need correcting.

Now check the cross alignment(for intake side to exhaust side).
The rocker should start (at closed position) slightly toward the intake manifold side of the valve stem tip. As the rocker depresses the valve the rocker tip moves across the valve tip center to the exhaust manifold side. As the rocker depresses the valve to its full lift the rocker tip moves back to the approximate same location as it was at "closed position". Of course the rocker tip moves again as the valve closes.

How to check very precisely for this? Take the rocker shafts off the head. Coat the tip of the valve with machinists marking fluid(Prussian Blue). Reinstall the rockers. Rotate the engine by hand two full revolutions(one full valve cycle). The rockers will press off the exact travel of the rocker tip. Then you can look, measure the exact travel of the rocker tip.

[drag-n-cuda]

To add to sanborn's explanation, the roller should be at the center of the valve tip at 1/2 of maximum lift. This can be done more easily with checking springs. Adjusting pushrod length is the best way to achieve this. Rule of thumb, one thread showing on adjustment screw below rocker body.

drag-n

[CudaRunner]

Sorry I wasn't responding, I had a little difficulty with responding to this MoparChat's request for authentication because my spam filter blocked their email. I couldn't get in all day yesterday.

Anyway, the motor is the original LA type, so, drag-n-cuda, your comments apply. This agrees with what the tech from HS said, unfortunately (for me). Are the longer valves easy to find? What are they called? Other than fitting with my rockers, are there any other benefits to the longer valves? Disadvantages? Since I would have to replace the springs, this opens a whole new set of questions... Maybe I should just put the stock rockers back in. Anyone want to buy a good set of HS rockers?

Also, I am wondering if my diagnosis of a dead lifter might be suspect. The symptom is a ticking noise, followed by finding that I can push on the rocker and compress the lifter easily. I am concluding that something in that lifter is broken. Comments?

[dwc43]

That lifter has failed. I'll take those Harland Sharps. I run the old LA engines and not a single one has longer valves using the HArland rockers. I can use another set for the next engine I build too.

[CudaRunner]

So, I guess I will conclude that what we have here is the difference between theory and the real world. Theoretically, the fact that the contact patch isn't perfectly centered will cause some sort of problem or reduced efficiency or something. But the reality is that the difference is insignifigant, at least in terms of wear or breakage. At least based on dwc43's experiences (and my own, assuming the lifter failure is unrelated).

So, after all these great comments I have concluded that I will buy a set of Rhoads lifters and leave the rest as is.

Now, for a new thread on how to adjust these rockers...

[dwc43]

When rocker makes contact with push rod turn another 1/2 turn. Make sure cam lobe is not up. Lifter needs some preload to work right.