Cam shaft choice small seal R90/6 - Page 3

tofgasp · 12-09-2012, 03:14 PM

If this can help :

The "softer" cam is 336, the other is a special one made for a race bike, 5th place general, 1st of his class at the Bol d'Or Classic this year.
Measurements at the valve, no play.

chasbmw · 12-10-2012, 08:33 AM

In the early 70s (pre90s) the only pukka BMW race bikes were the 500 and 750 sidecar racers for which the 336 cam was developed

supershaft · 12-10-2012, 12:54 PM

Whatever the 336 was developed for, it has always been called the 'Sport' cam ASFAIK. They also had a 'race' cam. Probably the one RG mentioned earlier. It all makes good sense since the 336 is not very racy but perfect for streetable sport. It was then and still is a mild cam. Old fashioned? Mild cams are not old fashioned, they are mild. Very often the smart way to go!

But back to the subject of comparing cams: As soon as Bob times some more cams and posts the results, some of us need to time our cams and see if we can duplicate the results. After all, we not only need some specs but we need repeatable specs which is just about the whole point to start with. Since the manufacturers won't tell us how they are suppose to time, it will take a couple of samples in order to insure that how Bob cam's time are in fact how they are suppose to time.

RGregor · 12-10-2012, 11:09 PM

Quote:

Originally Posted by supershaft

Whatever the 336 was developed for, it has always been called the 'Sport' cam ASFAIK. They also had a 'race' cam. Probably the one RG mentioned earlier

Never heard of a BMW race cam other than the 336.
Helmut Daehne raced the 336 and then (early 70ies) he was working in the test department.
He probably had access to all parts available at BMW.
I can ask him if that's of interest.

BTW: I asked him about the 336 and he still is very fond of it. Used it even in his enduro "without disadvantages".

RGregor · 12-10-2012, 11:20 PM

Quote:

Originally Posted by supershaft

But back to the subject of comparing cams: As soon as Bob times some more cams and posts the results, some of us need to time our cams and see if we can duplicate the results. After all, we not only need some specs but we need repeatable specs which is just about the whole point to start with. Since the manufacturers won't tell us how they are suppose to time, it will take a couple of samples in order to insure that how Bob cam's time are in fact how they are suppose to time.

Man, you really seem to be interested in the matter. I thought this would be the start of another "praise the one and only cam" debate.
Sorry.

bmwrench · 12-11-2012, 05:22 AM

Quote:

Originally Posted by RGregor

Never heard of a BMW race cam other than the 336.
Helmut Daehne raced the 336 and then (early 70ies) he was working in the test department.
He probably had access to all parts available at BMW.
I can ask him if that's of interest.

BTW: I asked him about the 336 and he still is very fond of it. Used it even in his enduro "without disadvantages".

I'd be interested in any memories he has from that time.

chasbmw · 12-11-2012, 07:38 AM

I saw him at the Goodwood revival races a couple of years ago, when BMW brought over some 1930s? Racers, the red leathers had stretched a bit!

It would be interesting to know what the spec of the IOM TT R90/s that he rode in 1973 and 74. I was their in 73, riding my Norton Commando, BMWs were way out of my price range in those days. Even then it was amassing how fast those guys went on a 37 mile road circuit.

supershaft · 12-11-2012, 11:04 AM

Quote:

Originally Posted by RGregor

Man, you really seem to be interested in the matter. I thought this would be the start of another "praise the one and only cam" debate.
Sorry.

That has been YOU the whole time. You really should try to refrain yourself and let me get on with discussing cams.

supershaft · 12-11-2012, 11:21 AM

Quote:

Originally Posted by RGregor

Never heard of a BMW race cam other than the 336.
Helmut Daehne raced the 336 and then (early 70ies) he was working in the test department.
He probably had access to all parts available at BMW.
I can ask him if that's of interest.

BTW: I asked him about the 336 and he still is very fond of it. Used it even in his enduro "without disadvantages".

Wasn't that you that said that BMW transferred the 344 profile from car to bike. Someone did. I suspect that is the cam I knew about as a kid. I know someone who would remember but he has enough idiots bothering him so I am not going to ask.

Renner · 12-11-2012, 11:34 AM

Quote:

Originally Posted by supershaft

I know someone who would remember but he has enough idiots bothering him so I am not going to ask.

I suspect he's grateful.

RGregor · 12-11-2012, 02:55 PM

Quote:

Originally Posted by supershaft

Wasn't that you that said that BMW transferred the 344 profile from car to bike. Someone did.

I wrote that AFAIK the 344 was developed for the BMW 700.
But not that BMW transfered it to the bike.
Schleicher is not BMW.

supershaft · 12-11-2012, 03:41 PM

Quote:

Originally Posted by RGregor

I wrote that AFAIK the 344 was developed for the BMW 700.
But not that BMW transfered it to the bike.
Schleicher is not BMW.

But didn't Schleicher do most all of BMW's cam development back then? At any rate, it really doesn't matter other than I remember a 'sport' cam AND a 'race' cam being available but I never looked into getting the 'race' cam kinda like I never looked into getting a 2.60 something rear end. I never needed one! At least we got past the need for specs with a check point!!!

RGregor · 12-11-2012, 11:56 PM

Quote:

Originally Posted by supershaft

But didn't Schleicher do most all of BMW's cam development back then? At any rate, it really doesn't matter other than I remember a 'sport' cam AND a 'race' cam being available but I never looked into getting the 'race' cam kinda like I never looked into getting a 2.60 something rear end. I never needed one! At least we got past the need for specs with a check point!!!

The man in charge for tuning the BMW 700 engines was Ludwig Apfelbeck.
And AFAIK he made his own cams. I would have to check it but AFAIR he also did a conversion to roller cams at the very beginning. And the last evolution of the race engines had bevel driven overhead cams.

chasbmw · 12-12-2012, 12:20 AM

you can see on the racer No 4 in my photos above that it has the overhead cam engine.

RGregor · 12-12-2012, 01:27 AM

Quote:

Originally Posted by chasbmw

you can see on the racer No 4 in my photos above that it has the overhead cam engine.

That was the RS54 race-bike. It was developed with that design.
The BMW 700 car engines were OHV engines like our beemers.
Apfelbeck converted them into bevel driven OHC engines.
If I remember right the final tuning stage had 850ccm and 95PS.
That was this engine here:

In large:
http://www.bmbikes.co.uk/photos/phot...beck%20(1).JPG

12-10-2012, 08:33 AM	#32
chasbmw ^OP Beastly Adventurer Joined: Feb 2006 Location: Bath Uk Oddometer: 1,026	In the early 70s (pre90s) the only pukka BMW race bikes were the 500 and 750 sidecar racers for which the 336 cam was developed __________________ Charles http://i46.photobucket.com/albums/f1...ps6e61ae2e.jpg R90s 1070 replica, R90/6 1971 Commando Fastback

12-11-2012, 07:38 AM	#37
chasbmw ^OP Beastly Adventurer Joined: Feb 2006 Location: Bath Uk Oddometer: 1,026	I saw him at the Goodwood revival races a couple of years ago, when BMW brought over some 1930s? Racers, the red leathers had stretched a bit! It would be interesting to know what the spec of the IOM TT R90/s that he rode in 1973 and 74. I was their in 73, riding my Norton Commando, BMWs were way out of my price range in those days. Even then it was amassing how fast those guys went on a 37 mile road circuit. __________________ Charles http://i46.photobucket.com/albums/f1...ps6e61ae2e.jpg R90s 1070 replica, R90/6 1971 Commando Fastback chasbmw screwed with this post 12-11-2012 at 07:52 AM

12-12-2012, 12:20 AM	#44
chasbmw ^OP Beastly Adventurer Joined: Feb 2006 Location: Bath Uk Oddometer: 1,026	you can see on the racer No 4 in my photos above that it has the overhead cam engine. __________________ Charles http://i46.photobucket.com/albums/f1...ps6e61ae2e.jpg R90s 1070 replica, R90/6 1971 Commando Fastback

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12-09-2012, 03:14 PM	#31
tofgasp Adventurer Joined: Mar 2008 Oddometer: 58	If this can help : The "softer" cam is 336, the other is a special one made for a race bike, 5th place general, 1st of his class at the Bol d'Or Classic this year. Measurements at the valve, no play.

12-10-2012, 12:54 PM	#33
supershaft because I can Joined: Sep 2010 Location: San Francisco Bay area Oddometer: 6,206	Whatever the 336 was developed for, it has always been called the 'Sport' cam ASFAIK. They also had a 'race' cam. Probably the one RG mentioned earlier. It all makes good sense since the 336 is not very racy but perfect for streetable sport. It was then and still is a mild cam. Old fashioned? Mild cams are not old fashioned, they are mild. Very often the smart way to go! But back to the subject of comparing cams: As soon as Bob times some more cams and posts the results, some of us need to time our cams and see if we can duplicate the results. After all, we not only need some specs but we need repeatable specs which is just about the whole point to start with. Since the manufacturers won't tell us how they are suppose to time, it will take a couple of samples in order to insure that how Bob cam's time are in fact how they are suppose to time.