Chang Jiang and related engines
From Jim Bryant of Jimbo's Classic Sidecars: "We stumbled upon this motor which is damn near identical to a BMW R75/5 motor but, it's made in China. Looks like it was built in the late 1980s. Apparently China reversed engineered one and put in all the tooling. It was made for a racing version of the Chang Jiang 750."
"As far as I know there are only two motors left in existence and one is right here in our shop. Almost every piece from an R75/5 motor can interchange with this motor. The reason it's in our shop though is one of the rod bolts broke taking half the motor's internals with it. A one-RMB piece of bad quality hardware took out this rare motor."
"I can only imagine what would have happened to the Chang Jiang had they put this motor into production back then. You might see Chang Jiang dealers in the States nowadays instead of Ural dealers." [Scroll down the page and see the CJ750-X engine. This appears to be one.]
 
Below: This M72 engine is virtually identical to the Type I CJ engine.
 
A Soviet flathead. The jug castings are crisp and clean, unlike those found on most CJs. Also, the cylinder heads look like they would do a superb job of dissipating heat. One other significant difference is the shape of the front cover. I'll bet this is a very decent motor.
 
Ever hear of a Kahena? This particular model used an OHV CJ engine. Think it runs hot inside that taco shell?
 
Here's an XA engine and gearbox from eBay. All the variations from the R71 motor are interesting.
 
"Hello. I just bought this is 12V engine. The distributor is inside the front cover. It has a three-speed gearbox. Anyone know more about it? Please send an e-mail to info@motosidecar.com Thanks!"
 
One look at this XA engine and gearbox reveals the significant differences between the R71 and XA. It also illustrates why building an XA replica from a CJ is waste of time.
 
An M72 engine for comparison with a vintage Type I CJ750 flattie.
 
Another Russian SV engine.
 
One more Russian flathead.
 
This OHV CJ750 F2P78FMFla engine turned up on eBay recently.
It's quite a bit different from the familiar SV engines, that's for sure.
The front cover has a distinctly different shape.
The engine ID tag says South Engine Machinery Factory in Zhuzhou, Hunan Province and Ministry of Aviation and Space Technology Industry.
 
These Russian mills are closely related to the CJ engine, especially the flathead. These pictures were sent by Russian & Chinese bike enthusiast Holger Behncke, the man behind schlingels.com.
The first three images show a Dnepr K-750 SV engine. Those heads look like they'd do a good job keeping things cool. The last picture shows a 650cc OHV Ural engine, a bit removed from CJ but still of interest nonetheless.
 
An M1 engine? Almost. It's a Russian M72 engine.
 
A 1966 type I engine and gearbox.
 
This could very well be the oldest CJ engine in existence. It's a 1959.
 
This M1 engine is from the CJ parts catalog.
A catalog from the Main Changzhou Lanxiang Machine Factory with an M1M engine on the cover. The 12V SV engine was introduced in 1986.
This is the M1S OHV engine, introduced in 1980.
M1S engine on the cover of a manual from Peter Gray. The enlarged image shows the whole thing.
 
This is a CJ rarity. It's a 6V OHV engine which had a very short production run due to the introduction of the 12V system.
Illustration of the rare 6V OHV engine. The enlarged image shows more.
This is the real thing—a 6V OHV.
1981, serial number 005. It's 22 years old and still new!
The distributor is located in the same position as on the M1 engine.
 
This tag is from a 6V M1 crankcase which was made for a CJ650 engine. Has anyone ever seen a 650cc CJ engine? They were made by the South Engine Machinery Factory in Zhuzhou, Hunan Province.
 
Here is a completely finished 6V OHV racing engine. It features a dual exit ignition coil. The cylinder head covers are old production made with much thicker aluminum.
You can see how much better they are when you take them in hand. They have some interesting markings on them. There is also a picture of the engine tag.
CJ650. This engine is 34HP. The standard 12V OHV engine is 30HP.
This engine has been fitted with PZ26 26mm carburetors that are the best in size for this type of engine. They are not produced anymore.
 
Here is a the 6V OHV CJ650 engine with aluminum jugs, all rebuilt. The 650 does not mean that the engine is 650cc. It's a 750cc and the 650 does not stand for cc.
The original CJ 650 engine was a 12V.
 
Here is a crank from a CJ650 OHV engine. The crank is the one at the bottom of the picture. The crank at the top is a standard one.
The body of the crank at the bottom is shorter than the standard one. The rods are the same length but the stroke is shorter due to a shorter body.
 
Aluminum racing jugs for the OHV engine.
Such an engine generates 36 HP. These jugs were made in the eighties and nineties and are surely rare.
 
Take a look at this monster.
Looks a little like an R75 engine doesn't it? This is a rare motor. It's a 900cc OHV CJ engine!
These engines were built by the State Owned Chang Jiang Machinery Factory as indicated by this certificate that accompanied the engines.
According to the documentation, there was indeed a very small production run. They were made in response to the BMWs used by the Chinese Armed Police and are largely copies of BMW engines. They never went beyond prototype stage.
It dates to December 28, 1980.
 
This is a CJ750-X engine. According to Shao Yi Qi it's actually a BMW engine in disguise. When China founded the first national motorcycle team they bought the bike from which this engine came. During that time there were only two of these BMWs.
Both were sidecar racing models. For some reason they put the CJ logo on the engine. In the race there were ten CJs and two BMWs. They only raced twice and result was for sure—the BMW won every time.
This is most certainly a rarity and if you're keen on repowering your CJ with a Beemer engine. This one would be perfect!
Let's take a look inside the CJ750-X engine. What's this? Some of the castings have BMW logos! (The enlarged image shows much more.)
 
Engine number tag from a CJ750D. t's from the South Engine Machinery Factory in Zhuzhou, Hunan Province. It also says Ministry of Aviation and Space Technology Industry.
This tag is brand new—never been mounted on an engine! It's also from the South Engine Machinery Factory in Zhuzhou, Hunan Province. It also says Ministry of Aviation and Space Technology Industry.
Here are four CJ750Fla tags. They state the power output rating in kilowatts. And again, they read South Engine Machinery Factory in Zhuzhou, Hunan Province and Ministry of Aviation and Space Technology Industry.
This tag is marked CJ750D, Ministry of Aviation Industry, South Engine Machinery Factory.
Final drive tag from State Owned Machinery Factory No. 51. Below it is a tag from a 6V M1 engine from State Owned Machinery Factory No. 52. Both are from the same bike, a 1985 model.
Look at this Lanxiang engine tag. They were the main producer of PLA engines in the 1990s. The tag reads Ministry of Aviation and Space Technology, Main Changzhou Lanxiang Machine Factory.
A tag on a 12V M1M engine from the State Owned CJ Engine Machinery Factory, the second name this factory used. It was located in Hunan Province.
This engine tag is dated June, 1996. It's from CNAMC, the China Nanchang Aircraft Manufacturing Company. (CJS)
 
These are older timing covers with markings cast in them. The one on the right has a neat CJ750 logo.
A highly polished Lanxiang cover.