R60 versus R75 help

[China2wheels]

Hi

I need some help distinguishing between an R60 and an R75 engine.

I bought a sidecar bike with a refurbished BMW engine in it, supposedly with a 750cc engine (well, that is what I paid for). The builder claimed it is an R75 (750 cc) but he put an R60 badge on it because he had "run out" of R75 badges. The builder puts various sizes of BMW engines in CJ750 sidecars.

Is it possible that this is an R75 but badged with an R60 plate?

Is there a difference in the outward appearance of these two different engines? Is it possible to mount an R60 badge on an R75 engine (e.g., are there any holes that are supposed to line up, etc?)

Here are a few pics of the left side (sorry, I don't have any right side pics of the engine)







Thanks for any help you can provide.

[Big Bamboo]

What is the serial number on the case by the dip stick? Number plates are attached to the starter cover with glue. Lots of modifications to that engine, who knows ?

[subagon]

The serial number on the engine is no guarantee. Just from the picture this engine been modified (valve covers, carbs, etc). It could also have jugs and pistons different from what the serial number would imply. The serial number will tell you what the engine was when it left the factory. Pulling the head and measuring the bore will solve the mystery. Maybe a guru will have a simpler way to ID the engine size. I think there should be some mark or number at the base of the cylinder that would ID it.

Edit: I took a look at my R60/5 and R75/5 and the jugs are slightly visually different. However, I'd pass this off as differences between year models and not engine size.

[Mark Manley]

On the later nikasil barrels the size, 80 or 100 is cast into them with raised letters at the base giving the capacity, I am not sure if the /7 have this but take a look, if it says 60 it's a 600, 75 it's a 750. Apart from that and the badge they are identical to look at.

[China2wheels]

Thanks guys - appreciate the help!

[Bill Harris]

Holy moley. It's the Ultimate Frankenbeemer engine. And I'm not even sure it's a BMW engine. Ural engine? Chinese Ural clone? 600cc or 750 cc is the least of your problems...

Run. Run away!


--Bill

[captainjohn]

My thoughts exactly, That is not a BMW engine

[disston]

The transmission is definitely not BMW and the engine may not be. The timing plug looks right but there is what appears to be an extra hole in the block in the last photo below the inline fuel filter. Also the engine front cover and the timing chest cover don't look right. Need more pictures.

Plastic name tags can be put on anything.

[chasbmw]

It's not a /2, it not a Ural engine or any of the east black clones. Camshaft position is a bit of a giveaway.
It's what the poster says it is a BMW engine fitted with a CJ750 gearbox so that the more powerfully and considerably more reliable BMw engine will work with the CJ750 sidecar.

What he wants to know is whether or not it is a 750 or a 600?

[crazydrummerdude]

Originally Posted by captainjohn

My thoughts exactly, That is not a BMW engine

Tell me how. It looks pretty damn close to a BMW engine to me, definitely the most BMW thing in the picture. The transmission, carbs, etc not so much.. but I have seen similar conversions of Urals (BMW engine mated to Ural transmission). I'm not saying it IS without a doubt a BMW, but if not, it's gotta be the best knock-off I've seen. Oh, and it looks NOTHING like a /2, that's for sure.

The best way to tell what size it is.. is to measure the bore (and remember to put the valve covers on properly when you're done).

My initial suspicion is that the intake spigots look significantly smaller than my 750, more like my 600. So, based on that alone, if I had to bet, I'd bet that it's a 600cc engine. I've thought of putting the 600cc badges (oh, and they're not plastic name tags, haha) on my 900 just to throw people off.

I don't know if it's the low resolution of the pictures, but that exhaust sure looks like it makes a weird angle as it exits the head.

But, anyways, looks pretty clean. So hopefully it's a solid bike.

Originally Posted by disston

there is what appears to be an extra hole in the block in the last photo below the inline fuel filter.

Your proper BMWs have the same hole.

[Bill Harris]

It's not a Chang Jaing or the "usual" Chinese Ural Clone-- those are either flathead/sidevalve or use the /2 camshaft location. I did a Google and didn't see anything like this engine. I dunno-- it's NOT a BMW engine, and the Chinese are the only other ones with the industrial capability to copy a clone. We'll see what the OP says. My take is that if yiou have BMW "Rxx/x" badges on anything besides a BMW product it's fraudulent and can't be good.

:(

--Bill

[crazydrummerdude]

Yeah, it's definitely not a CJ or Ural, but what makes you so sure it's not a BMW engine? I think all the collateral bits are throwing everyone off.

[Mark Manley]

Originally Posted by Bill Harris

Run. Run away!


--Bill

No not that way or you'll meet the knights that say ni to horizontally opposed twins!

[captainjohn]

I'm sorry if I came in too strongly with assertion that it is not a BMW engine. The peripherals were not what made me say that, it was the position and and angle of the exhaust port more than anything else that sparked my response. Perhaps the Chinese have produced some replacement heads that will fit on a BMW barrel.

[Bill Harris]

Originally Posted by Mark Manley

No not that way or you'll meet the knights that say ni to horizontally opposed twins!

In which case we'll don our HexHelmets and route them to the Squids who say Ekki-Ekki-Ekki-Ekki-PTANG. Zoom-Boing. Z'nourrwringmm.

I've Googled and it's not like any BMW/Clone I've seen. May be a Chinese clone of a Zundapp design????

The quest continues...

--Bill