Author Topic: BMW 600 Wanted  (Read 1532 times)

LeeBuckman

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BMW 600 Wanted
« on: March 28, 2014, 09:07:31 PM »
Hi,

I am looking for a BMW 600 project to restore or something that's quite good and part done. Anything considered.

Regards

Lee

Big Al

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Re: BMW 600 Wanted
« Reply #1 on: March 29, 2014, 06:45:41 AM »
Lost track of who has them now. There is one stolen one still unaccounted for, John Dobb. I have several loose sidescreens for one.
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LeeBuckman

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Re: BMW 600 Wanted
« Reply #2 on: April 04, 2014, 08:44:51 PM »
Thanks Big Al ?????

Question for you all :

Does the BMW 600 have an R67 engine or an R67/2 or R67/3 engine. What is the difference or isn't there any ?

I also noticed different sized pistions available for the BMW 600 engine. Can someone just explain what the difference is and why some are oversized. Sorry if it seems a dumb question.............

Lee

DaveMiller

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Re: BMW 600 Wanted
« Reply #3 on: April 04, 2014, 11:05:13 PM »
I don't know anything about BMW 600 engines, but pistons are available in different sizes for nearly all engines.

When new, the engine will have "standard"-sized pistons.  When the engine gets old, it may get rebuilt, and as part of that process will have a "rebore":  in other words the cylinder is bored out again, to give a fresh surface.  The cylinder will now be very slightly greater in diameter, and will need pistons that are also very slightly wider.  The difference is a matter of a few thousands of an inch, so pistons might be available in, say "standard", "+20" (for 20 thousandths bigger) "+30", "+40" and so on.

When an engine is rebored, it's usually bored to the minimum extra amount necessary, subject to the new dimension being a recognised size, to fit available pistons.  (If you can get away with a "+20" rebore, you do so, so that you might do a second rebore, to say "+40", at some future time.  There's a limit to how far each kind of engine can be rebored, but some might allow several rebores - and need several new sizes of piston.)

British engines quote the size difference in thousandths of an inch, whereas continental engines may quote it in metric.

Does that help?

Big Al

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Re: BMW 600 Wanted
« Reply #4 on: April 05, 2014, 08:52:14 AM »
There is a stationary engine version of the 600 unit, commonly seen in generator packs. These have low compression pistons and a governor, being designed to run at a constant rev per minute. While these units can be fitted to cars without the governor they are normally stripped and the car piston and outwards spec parts fitted. Effectively the generator is used for its unstressed crank as a short engine.
The 700 has the same situation. In addition there is a more tuned version of the engine which can be found in some coupes and in DHC. I have no idea if there was an uprated 600.
This may account for the differing numbering.
Messerschmitt set, Goggo Darts, Heinkel 175, Fiat Jolly, Autobianchi, Fairthorpe Electron Minor, Borgward, Isuzu Trooper
Citroen BX 17TZD & GTI 16v
Held - MG Magnette ZB & 4/44
For sale - Vellam Isetta, Bamby, AC Type 70, Velorex, Church Pod, Reliant Mk5, KR200,  Saab 96, Bellemy Trials, Citroen BXs