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Chrysler rocker bar vs Chevy Ball stud design?

Cojohnso1

Cojohnso1

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The obvious advantage of Rocker bar is more valve/head room. Disadvantage? Energy from a damaged valve train component can travel down the bar and effect neighboring cylinders. Chevy's damage does seem to be better isolated.

Thoughts?
 
Thoughts, eh?
1. I think this isn't a Chevy enthusiast website.
2. I think our engines have rocker shafts, not "bars" - but any true Mopar enthusiast would know that
already.
 
moparedtn said:
Thoughts, eh?
1. I think this isn't a Chevy enthusiast website.
2. I think our engines have rocker shafts, not "bars" - but any true Mopar enthusiast would know that
already.
Click to expand...
Don't care about your judgment of me. And I think the trade off for more room is worth any sacrifice in some strength. So stick your "True" judgment where the sun don't shine. Besides, I've called it a rocker bar for more than 3 decades. And no one but you whined. My current Plymouth's (all with Rocker "Shafts" if it makes you feel better.)

Corys Mopars.jpg
 
Mopar developed a gen 3 hemi with ball stud rockers for '72- but the gas crisis hit and it got nuked.

"The Ball Stud Hemi"
Screenshot_20210513-141609~2.png
 
Actually, its not entirely true. The Cuda did have 2 shafts per head at one time in its life. But now DOHC build. One way to settle any debate? Get rid of both designs? Lol.

ZomboDroid 27072020230012.jpg
 
Cojohnso1 said:
Don't care about your judgment of me. And I think the trade off for more room is worth any sacrifice in some strength. So stick your "True" judgment where the sun don't shine. Besides, I've called it a rocker bar for more than 3 decades. And no one but you whined. My current Plymouth's (all with Rocker "Shafts" if it makes you feel better.)
View attachment 1109833
Click to expand...
1. Nowhere in my two-item list was there any mention of you personally.
2. You've called it the wrong thing for more than three decades.
3. Your post was up all of a few minutes when I posted, hence why "I was the only one".
You wanted "thoughts". You got some.

Your retorts in post #3 were all inaccurate as hell.
There's another "thought", free of charge.
 
Cojohnso1 said:
Yeah. I've seen that article. Some called it Chrysler made a Chevy big block. Some called the obvious evolution. I wonder how that design would have held up?
Click to expand...
The motor is still around and is running in a car. The guy that bought it from Dick Landy hacked it up into a hotrod motor (bored it, ported the heads, ported intake, stroker crank)
and destroyed a piece of history...
:mad::mob::mad:
Screenshot_20210513-142459~2.png
 
Generally rocker shafts are a better design than stud mount.
Stud mount does make it easier to adjust (or mess-up) rocker geometry.
Shaft mount is harder to correct rocker geometry if needed.
Stud mount is easier to install the rocker arms because you can rotate the engine to where the cam lobe/valve is closed.
Shaft mount (full length) can be difficult to install on engines with high valve lift and spring pressures because some of the cam lobes/valves will be in the open position.
Individual or paired shaft mount is a nice system but expensive.
Stud mount uses pushrod oiling.
Most shaft mount (full length) the rockers are oiled through the hollow shaft, but can also be pushrod oiled depending on rocker system, application, and lifters.

As most mechanics say "We love Chevys, they keep us in business" ;)
Just look at how the 350 Chevy created such a large source of aftermarket parts. It's hard to find a Chevy crate engine that has any original parts.
 
Cojohnso1 said:
The obvious advantage of Rocker bar is more valve/head room. Disadvantage? Energy from a damaged valve train component can travel down the bar and effect neighboring cylinders.
Click to expand...

No clue how to respond. "Damaged valve energy"?? Anything that takes out a cylinder is like a rotten apple in the basket.... you are done at that point. Anyway, in my mind, any rocker shaft system, no matter whos it is, has the advantage of strength in numbers..... like the valve train supports itself, and the other parts with some structure, whereas individual rocker pedestals take a lot of stress in one point. My two cents, Lefty71
 
The high dollar stud replacement systems use shaft mounted rocker arms. Much more stabile.
Mike
 
Yes there's advantages to the studs but most of them are do to making different tasks easier, shaft mount has all of the advantages when it comes to strengthen IMO. As far as travelling down the bar goes, I'm not sure what you mean? Debris most likely isn't going to go down the oil feed because it's pumping oil out under pressure.. debris would be washed into the head. I've built both, with Chevies you need to upgrade to screw in studs, then if you're really going to crank on them you use stud girdles to tie them together.. shaft mount on the other hand needs nothing for most applications.
 
moparedtn said:
1. Nowhere in my two-item list was there any mention of you personally.
2. You've called it the wrong thing for more than three decades.
3. Your post was up all of a few minutes when I posted, hence why "I was the only one".
You wanted "thoughts". You got some.

Your retorts in post #3 were all inaccurate as hell.
There's another "thought", free of charge.
Click to expand...
Huh? No idea what you are talking about. Post #3? My initial point was. If one has rocker damage. The damage banging on the shaft can effect the rocker next to that initial failure. I've seen it. It stopped me in a 1/4 final. 451 is correct that it's more prominent with higher HP builds. (As is setup.) But so is everything. Including initial failure.

P.S. You got snippy for no reason. I call it a bar because that's what it is? Shafts spin. (Like "Cam Shaft. Crank Shaft.) Bars do not.
 
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A shaft rocker system is generally accepted to be stronger and more stable than stud mounted rockers. It is more expensive to make and harder to install/repair so most manufacturers went away from it.
On a Mopar the valve tip is close to the rocker arm fulcrum point so the rocker is rather short.
This is actually a disadvantage. Fine while you have 0.420" valve lift and little short small diameter springs but if you start to beef things up you get problems.
Rocker geometry and clearance under the rocker for the valve spring retainer are the first things to check for.
 
steve340 said:
A shaft rocker system is generally accepted to be stronger and more stable than stud mounted rockers. It is more expensive to make and harder to install/repair so most manufacturers went away from it.
On a Mopar the valve tip is close to the rocker arm fulcrum point so the rocker is rather short.
This is actually a disadvantage. Fine while you have 0.420" valve lift and little short small diameter springs but if you start to beef things up you get problems.
Rocker geometry and clearance under the rocker for the valve spring retainer are the first things to check for.
Click to expand...
I agree. And check ALOT. I've learned that the hard way. And that's with just flat lifter at .600 lift. I can only suspect the bigger roller world would be even more concerning? Big Hemi builds are a different animal.

The 904 DOHC Schubeck marine engine I have in my Pro Street Cuda build intimidates alot of my mechanic friends. But in reality? It's simpler. The size simplifies. Everything is so big it's easy to see how it goes together. Personally? Little components scare me. Yeah 4 cams can look complex. But it's not. They only assemble one way. To have it missed aligned is very obvious. Its transmission options that is holding up this build.
 
Chrysler did use the shafts for ages, but they switched to the ball stud design when the 318/360 Magnum came out in 1993.
 
Photon440 said:
Chrysler did use the shafts for ages, but they switched to the ball stud design when the 318/360 Magnum came out in 1993.
Click to expand...
I didn't know that. But of course I've never owned a SB thus never ran across. What about Gen III? I would think they have to have dual shafts?
 
I understand the Edelbrock Magnum heads for small blocks do use a chev rocker arm.
This may be a good thing - for a start they are cheaper and easy to get.
Stud mount rockers work Ok but I have two things I do. Always use the largest diameter stud possible and on engines over 0.550" valve lift use a stud girdle.
 
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