Forum bmwbike.com

My project restoration bike is a recently acquired R-27 having different numbers for the frame and the engine.

The Frame number is 375319, and the engine number is 236832. Did BMW have dissimilar numbers for the frame and engine on any given year?

Can anyone help me pinpoint what I have? It would be nice to know if the engine belongs with this bike or at least, what year it was made and if it is for an R-25, R-26 or R-27.

Any assistance is greatly appreciated.

Norman Castaneda

Hi Norman,

If you send the above information to BMW's historian, Fred Jacobs, at he can identify the motorcycle(s) and provide the date of manufacture of the chassis and engine., as well as which distributor the bike was originally delivered to. BMWs have sequential matching frame and engine numbers. My late 1960 R26 has is number 367993, so your chassis was manufactured at a later date. You definitely have a non-matching engine and chassis, with a much earlier engine. Are you sure the chassis is an R27? Look at the engine mounts - R27s have tabs on the frame that hold automotive-type rubber mounts and a mount at the top of the head. R26s have mounts that bolt horizontally through the front and bottom of the engine and no mount at the top.

On checking another source, it appears that R26s (1955-1960) used numbers 340005 through 370242, and R27s (1960-1967) started with number 372001, so your chassis appears to be an early R27. Your engine number appears to be for an R25, which was manufactured 1950-1952. You won't be able to bolt the engine to the frame without quite a bit of modification. IMHO, you would be much better off finding an R27 engine.

Best wishes,

Dave

I forgot - this site won't post a third party's URL in a message. E-mail me directly and I'll give you Fred Jacobs' address.