Mechanical rev counter for an R26

[bwprice100]

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Hi All

A quick question with regard to fitting a mechanical rev counter to an R26; can they be fitted and where is the drive taken from?

Thanks in advance.

Brian

[bwprice100]

[thoro]

Brian,
go for the search function and take a look to "Drehzahlmesser" or "Drehzahlmesser mechanisch". There are quite a lot of entries. Good luck.
Best regards,
Thomas

[bwprice100]

Brian,
go for the search function and take a look to "Drehzahlmesser" or "Drehzahlmesser mechanisch". There are quite a lot of entries. Good luck.
Best regards,
Thomas

Thanks Thomas but I need to know if a 'Drehzahlmesser mechanisch' can be fitted to an R26 and where would the drive be taken from?

Thanks Brian

[rolf]

Hallo Brian,
that is all "do it yourself"....the best way I know is taken from the"Nockenwelle" in front of the engine....but it is a lot of work.

[bwprice100]

Hallo Brian,
that is all "do it yourself"....the best way I know is taken from the"Nockenwelle" in front of the engine....but it is a lot of work.

I think it might be too much work.

Thanks all.

[thoro]

I guess also that its too much work. You would have been supposed to find a way to connect the mechanical rev counter to the engine. I could only find hints in the search function about electronic devices.
Best regards
Thomas

[Rütz]

Hi Brian,

Hannes did it from the crank:
http://bmw-einzylinder.de/forum/index.php?topic=10926.msg149746#msg149746 (last picture).

I have also seen solutions using the oil pump shaft, like in this pic from Dan May:
https://lh4.googleusercontent.com/-UG5G4lFdxVg/TZ98pOfFbSI/AAAAAAAAA2U/Srz-DPCShoI/w802-h639-no/BMW%252BR26%252BRacer%252B1956.jpg

See also his thread:
http://bmw-einzylinder.de/forum/index.php?topic=8231.0

[bwprice100]

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Thanks Rütz

Very helpful.

Brian

[Jollyjester]

Hello Brian

Well, yes, and easy.

You know my R25 'The Little Horror'. Back in the late 1960's, not knowing any better, I turned the 'Horror' into what I now call an R25S. That is, 1/2 an R50S, engine wise.

R50s piston, reground camshaft to match R50S profiles, 1 1/8th Amal Carburetor, ( ex BSA close down, cost £6/10/0 £6.50 new )They are now only £185.00. Re flywheel was lightened to 8. 1/2 lbs. 3.85 k. There was a spate of Aluminium flywheels for the twins then.

Everything inside was polished and lightened, valve gear, valve caps on springs etc. Using the book, Tuning for Speed by Phil Irving.

Finally fitted a rev counter, picking up the drive from the camshaft, the Druckfeder fur Nockenwellenrad, by simply cutting slot to pick up the 'spade' the turns the inner cable . The Timing chest drilled and tapped to take a BSA / Triumph fitting ( see photo ). It is blanked off at the moment.

It worked very well. Speeds of once 7200 without going 'bang'.

The ratio is 2 . 1, and the rev counter needs to be anti-clockwise.

At the time I had an ex Triumph TR2 Car Unit. As big as a kitchen clock. Why, because it worked ad was free, from my Brother

The bike was quick of the mark. always pulled away in 2nd gear. but would not stop. so fitted a Norton Dominator from wheel. 3.5 x 19. Stood on it head then

It was quite happy at 60 mph.

Other date.

Valves.

In open.        25 B.T.D.C            Closes 65  A.B.D.C.

Ex open         65 B.B.D.C            Closes 25 A.T.D.C.

Standard valve clearance 6 & 8 thou.

Ignition 9d.  B.T.D.C.

Robert

[bwprice100]

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Thanks Robert, it sounds like quite a machine.

Brian

[rolf]

This is what I mean with:"...the best way I know is taken from the"Nockenwelle" in front of the engine"

[thoro]

Hi Brian,

Hannes did it from the crank:
http://bmw-einzylinder.de/forum/index.php?topic=10926.msg149746#msg149746 (last picture).

I have also seen solutions using the oil pump shaft, like in this pic from Dan May:
https://lh4.googleusercontent.com/-UG5G4lFdxVg/TZ98pOfFbSI/AAAAAAAAA2U/Srz-DPCShoI/w802-h639-no/BMW%252BR26%252BRacer%252B1956.jpg

See also his thread:
http://bmw-einzylinder.de/forum/index.php?topic=8231.0

Rütz,

to your knowledge regarding the search function of the forum. I couldn't figure it out. I had only three hits regarding electronic rev counters, so far as I remember.
Thomas