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1967 R502
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Back in the day, before AMOL Racing switched to a RS54 platform (which they built themselves), they used various R50 pushrod motors, with shorten strokes, widened bores, etc. They also used roller rockers. This seems like a pretty elementary performance (and reliability) improvement to the valve train.

Likewise I know that San Jose BMW use to offer Roller rocker conversions to later airheads...but has anyone offered, or do they still offer roller rocker conversions for /2?

olebmw
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Interesting post, I was

Interesting post, I was hoping for some replies,especially on the AMOL built RS54.

1967 R502
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I kinda get the feeling that

I kinda get the feeling that most on the board are interested in stock restorations, and not so much in racing or performance modifications. I'm quite sure that AMOL made their own roller rockers. Their machine shop was something to see. To be clear AMOL produced many racers, push-rod as well as DOHC.

Look in the attached article on page 77 you can see and read about the Roller Rockers

AMOL Article

  • capture.jpg
Twocams
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For me, I figure my 70 MPH is

For me, I figure my 70 MPH is just as fast as the next persons 70 MPH. So it take me 5 sec. longer to get there.
And not sure it would be worth the price one has to pay for such an up grade.

twocams

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olebmw
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Thanks for posting the Amol

Thanks for posting the Amol article,very interesting. I wonder how many of the OL Specials are accounted for?

1967 R502
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I know of at least one

I know of at least one push-rod R50 that was shipped to Australia in the late 90's and another pushrod R69s that resides locally. This one is quite unique. No gaskets. All the parts fit together with interference fit for better heat transfer.

The rest are anyone's guess. I am sure the RS54s have found their way into someone's collection. Even the magnesium engine blocks alone would be worth a lot to a vintage racer.

I should add that once I was in the attic of their machine shop and there was a pre-war compressor engine just sitting gathering dust. Purchased from race salvage in Europe, although I don't know if it was ever campaigned on this side of the Atlantic.

Daves79x
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Back To Your

Back to your original question about roller rockers for the street, I think it's a classic case of a solution in search of a problem. The stock valve train is very reliable. Just my HO.

Dave

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1967 R502
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Maybe I should have been

Maybe I should have been clearer in the first post. I am really talking about racing performance, not improving reliability. There have been a number of successful BMW racers over the years, many transplanting R50S mills into /5 frames for a high revving, light handling combination. However, unlike with /5/6/7 engines, there seems to be only limited performance improvements available in the day (Bowman flywheels, and 750 conversions)...and of course no roller rockers which seems to be an obvious one.

stagewex
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I think you hit it on the

I think you hit it on the head with your 2/15 post. Probably not a lot of "racing performance" interest here. Not that it's not interesting, I love reading about AMOL and their racing program... but keeping the bikes running and as original as possible seems to be the flavor on this site.

I have a friend who worked at AMOL for many years and think/thought he was a member here. I'll give him a call tomorrow and tell him to check in at this thread. He may be able to answer some of your questions as he just recently got back into Vintage BMW's (r69S).

I bought my first and only brand-new BMW at AMOL in 1984, an r80. They sold Honda too. Big loss to the BMW community when they closed.

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stwilliams
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AMOL Roller Rockers

First a little context. The original long stroke RS54 did not use a roller rocker, but rather had a rubbing block that ran against the cam lobe. It was of of a different hardened material than the body of the rocker itself and was slide in place by means of a dove tail, and then peened.

Later on with further motor development and coinciding with the emergence of short stroke 253.2 version of the RS54, there was utilization of a roller on the cam end of the "kipphebel".

Oscar Liebmann of AMOL, as is pretty well known and discussed in the above article, built a short run of AMOL Specials in the 1960's, with continued development of the bike until his death in early 80's. Two bikes were completed. They differed from the original factory RS54 by having the cylinders and heads canted up 2 degrees from the horizontal. This necessitated innumerable changes to the motor, to accommodate. The discussion of which is beyond the scope of this post.

Attached is a drawing by Liebmann for the rockers on the AMOL Special.

  • kipphebel_amol.jpg
1967 R502
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STwilliams- Your drawing is

STwilliams-

Your drawing is dated 1962. Pretty cool. How did you come by it?

stwilliams
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Luck....is how I came by the

Luck....is how I came by the drawing.

Roller rockers are not practical for a worthy of the expense for a pedestrian R50 or R60. I have a few friends in Germany racing short stroke R50's, although I doubt any of them are running rollers either. Requires a completely new forging to construct. Nobody would go through the time and expense.

1967 R502
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Yes. I agree it would be a

Yes. I agree it would be a lot of effort ot make a forging, but in this day of C&C, doing a small run or even one offs is relatively easy. This may be my next line of research,

As pointed out earlier in the post, San Jose use to offere roller rockers for /5+ airheads....so at least someone has thought along these lines and a /5's rocker arms are not dramatically different from a /2.

stwilliams
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More power to you

Its a deep and dark rabbit hole to go down.....

First off you need a forging, unless you plan to make from a steel billet. Then you need the right material. Then you have to have machine to the correct size and dimensions, which by the way, there will be no drawing for. You have to harden it. Then you also need to fabricate the roller itself and find needle bearings, etc, etc.

Not worth the time and energy I can assure you. Would cost thousands of dollars in time, energy, expense, etc.

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