Pagoda SL Group
W113 Pagoda SL Group => Research & Development => Topic started by: Benz Dr. on June 10, 2008, 17:05:04
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Since this is R&D why not do a little. Anyone interested in developing roller rockers for our type of engines? I was working on this a while ago and my research guy passed away.
I know how he was going to do it for the most part but it all takes money. A large run would be more cost effective of course.
100 sets ( 1,200 ) would be a good starting point.
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Dan:
Let me ask as a non-techie...what are "rolling rockers"? Why are they better than non-rolling rockers? Did any cars have Rolling Rockers as original equipment? Any downside to using Rolling Rockers?
Any estimate of the time or cost to install them? Do other parts have to be modified or changed when installing Rolling Rockers?
Richard M, NYC
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Richard,
Rolling Rockers are when you install go-kart tires into your rocker panels via inserting their axles into the open jack points. This allows the car to handle better and increases the maximum gross vehicle weight so you can carry heavy loads.
Ha! OK, seriously, I amuse myself. If anyone can photoshop that quick and easy, that would be worth a laugh.
With my limited knowledge/experience I will take a shot at this. I assume the roller is on the rocker arm that is pushed down by the overhead cam. The cam lobe slides along a hardened surface of the rocker arm to actuate it. If there were a roller installed at this point, it would reduce friction and extend the life of both parts. So, experts, how close am I ??
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quote:
Originally posted by rwmastel
Rolling Rockers are when you install go-kart tires into your rocker panels via inserting their axles into the open jack points. This allows the car to handle better and increases the maximum gross vehicle weight so you can carry heavy loads.
Hey Rodd, are those like training wheels for those of us who have trouble staying up with just four wheels?? ;) :mrgreen: :D
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(http://images.radcity.net/4195/1879940.jpg)
My guess is that I am barking up the wrong tree. Oh well, nevermind :D
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Tosh...
it's rockers not knockers... and certainly not beer.
Peter
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Who mentioned beer? :D
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What beer? All I see are the knockers...[:0]
Bob
quote:
Originally posted by vanesp
Tosh...
it's rockers not knockers... and certainly not beer.
Peter
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Hi Dan,
I'm interested in roller rockers. I have a new euro cam to install and would like to make it part of a valve train upgrade to reduce wear and also noise. I'm assuming the roller rockers would quiet down the valve train noise a lot.
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For those of us interested in both rockers and knockers I offer some information about rockers.
http://www.mustang50magazine.com/techarticles/18679_roller_rocker_arms/index.html
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Jeff,
Thanks for getting us back on track! The article you posted was regarding a 5.0 liter Ford Mustang engine using pushrod technology. If I understand correctly, these rocker arms have a center fulcrum and the pushrod shoves one end up so the other end shoves the valve down. The roller is at the folcrum.
Our overhead cam engines have rockers with a folcurm at one end. Would this be where the roller is in our application?
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Rodd,
The mustang article is just an example for information purposes. It discusses friction reduction and horsepower increases from using roller rockers. There are many others to pick from. Our rocker arms use a ball stud as the fulcrum. One end of our rocker arm rides on the cam lobe and the other end the valve stem. The mustang rockers in the article are shaft mounted and I don't think we are contemplating something like this. The mustang also has a roller in the end that rides on the valve stem. I suppose in our app we could have rollers riding on the valve stem and the cam lobe.
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Rocker arms vs. pivot arms. Rocker arms pivot at a intermediate point. Each end goes up and down with the pivot point anchored. The MB pivot arms(we're calling them rocker arms) pivot on the ball stud-the major anchor and pressure the pressure piece atop the valve stem which partially anchors the arm. They are driven in the middle by the cam which gives a totally different loading situation. Rollers may work, but it is a different geometry. Viewing the ball studs with the valve cover off, shows the ball studs being the major wear point. Also, knockers belong somewhere other than under the valve cover.
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These things don't exsist, yet. I'd either have to use tool steel or some sort of high end aluminium. The cost for the first one would be high and who knows how much? I'd test one in my own engine for a while to see how it works.
There may be noise reduction or none at all. That's all part of the testing.
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My what a short memory some have...
http://index.php?topic=8028
You'll see exactly what a roller versus a wiper is. Third photo down I believe.
Yes it's on a Packard Merlin engine, but nonetheless you can see what it is all about. Yes they are good, and it would be a good thing to develop. Thankfully you will not need a stack of papers 3 feet high and a million dollars for FAA certification, you can just make it.
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Mike, Looks like the roller rides on the cam. The wear on our MB engines is on the ball stud. The Packard 'stud' end is rotating on a bushing/shaft, yes? Looks workable. Has any auto engine manufacturer tried such a design?
Also, down here in North Carolina - Mooresville/Denver - there is a auto fabrication shop on every street. 'Dale Earnhart St.' is everywhere. Have yet to see 'Pagoda Passageway'.
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Not sure which look better - the girl or the plane.
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P-51s were the long range escort fighters for the bombers over Europe in WWII. Some of those were 12 hour trips. Guess they expected a one way trip or in flight engine overhauls.
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quote:
Originally posted by glennard
Mike, Looks like the roller rides on the cam. The wear on our MB engines is on the ball stud. The Packard 'stud' end is rotating on a bushing/shaft, yes? Looks workable. Has any auto engine manufacturer tried such a design?
Also, down here in North Carolina - Mooresville/Denver - there is a auto fabrication shop on every street. 'Dale Earnhart St.' is everywhere. Have yet to see 'Pagoda Passageway'.
Couldn't tell you much about the internals of the V12...however, the roller vs. wiper design from Roush intriqued one of our members, Bob Sirna (he of Gullwing at Twilight fame http://www.szwedo.com/gullwing.htm) who owns the Gullwing used at Bonneville. He's blown up a few engines in his Bonneville quest, and I believe he had roller cams fabricated and put on his 300SL engine to replace the wiper style to make the engine better...at least that's what I've heard.
It's a piece of cake for our engines. All it takes is money. ;)
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quote:
Originally posted by glennard
P-51s were the long range escort fighters for the bombers over Europe in WWII. Some of those were 12 hour trips. Guess they expected a one way trip or in flight engine overhauls.
I stand corrected, I think...the specifications with and without drop tanks don't seem to jive with history. When watching a PBS special last night they discussed the long-range aspects of the P51's as bomber escorts on full bombing runs. While these runs were long indeed--and included the Mustangs until the bombers were out of harm's way--they didn't indicate time or mileage. But they did indeed do the full escorts...and I think these had to have been more than 950 miles!
No P51 could fly for 12 hours. The bombers did; not the escorts. The range of a P51 was only about 450 miles; the later and more common P51D was about 950 miles (unless equipped with drop tanks; in-flight fueling wasn't done back then).
From what we were told about these planes/engines at the Roush rebuild facility, a typical mission didn't last more than a few hours. Average engine life was just over 7 hours, if you can believe that.
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I think the crank is hollow on these big V 12 engines. The weight savings would be a lot.
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Wow!These gorgeous aircraft engines !!
On the pictures, it looks like 4 valves heads.What were the others technical data? OHC? DOHC? Carbs or injection?
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quote:
Originally posted by philmas
Wow!These gorgeous aircraft engines !!
On the pictures, it looks like 4 valves heads.What were the others technical data? OHC? DOHC? Carbs or injection?
Phil,
Let's not stray too far off line here. This thread is about roller rockers. Feel free to ask detailed airplane engine questions in that thread.
http://index.php?topic=8028
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Sorry if I got carried away...these are beautiful pieces of engineering 8)
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I was just in the Air & Space Museum in San Diego today and saw a Spitfire engine with a cutaway cylinder. It was a predecessor to the Merlin engine in the Mustang. It was a V-12, 4 valve, OHC with roller tappets.
Dan, would the roller arms you're considering anchor on the same ball stud?
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That's actually the hardest part of this idea. I can make ther roller part work but the ball stud is a real challenge.
Although there's a lot of friction on the ball stud it doesn't wear all that quickly if everything is kept adjusted and maintained. It is however, very prone to barrier lubrication failures due to dirty oil.
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You can use a metal with self lubricating properties for the problem area. I forget the metal we used for bearings on our injection molding machines...it would end up being a maintenance item...
Or use an aerospace plastic. Research research research.
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Drilube! Drilube is the answer. It's a molybdenum-disulfide coating, grey in color. Boeing uses it on all fasteners and other places that may be subject to galling. Talk to your local plating shop.