volvo

[Thad Van Gilder]

OK, do any of you know if MD2B parts fit a MD11C?

Thad

[StevenBauer]

Maybe you could ask here: www.volpen.org.uk (http://www.volpen.org.uk)

Steven

[seo]

Here's an involved answer to a simple question:
The early Volvo little diesels were the MD 1, 2, and 3, the number corresponding to the number of cylinders. They shared many parts, because the combustion chambers, heads, pistons, fuel injectors and etc were all the same. The base, injection pump, and water pump were different.
As Volvo's product line got longer, the model designation worked like this:
M=Marine
D=diesel
B=gasoline (benzene)
T=turbocharge
A=aftercooled
The number refers to the cubic displacement of the engine in liters.
SO: A TAMD 70f is a turbocharged, aftercooled, marine diesel engine, seven liter displacement (427 cubic inch) series f (which means that they made enough changes to want to differentiate it from a series e)
An MD 11c is the third version of their 1.1 liter (two cylinder) engine. The next bigger engine was the 17, which had a longer base casting and three cylinders instead of two.
Very few of the a series of the old MD!,2,3 engines were imported. They almost all arrived in the US in an imported boat. They had a Bosch Dynastart (combination of starter and generator) and an old fashioned mechanical gear.
By the time you get to the MD 11c, they all had a ring gear on the flywheel, a conventional starter, an alternator. Some had heat exchangers. Most had the "MS" monoshift reverse gear, which was a lot like a Hurth. They can be shifted with a Morse 33 cable, instead of needing big levers.
So the short answer is: They're basically the same engine, using the same base, combustion chamber, heat, etc, with lots of little tweaks and modifications, with a completely changed electrrical system and reverse gear. So it depends on the part you were thinking of swapping.
seo

[Thad Van Gilder]

I have a MS gear off a MD7A, but it won't fit the MD11C. I think there is some bell housing issues there.

-Thad

[seo]

"MS" stands for "Monoshift," which somehow describes the workings of one of these gears. They do not use bands or clutches like other transmissions. It's too late at night to attempt to describe how they work.
Volvo got into a lot of trouble by putting these gears on engines with too much horsepower, that were run above their continuous rating (in charter boats) and had a terrible reputation. The Hurth gear is just like this, and it, the Volvo MS, and the various oriental gears that I think are built under license, all work fine for engines of this horsepower class.
It may be that the gear for the MD7a is too small for the 11, which has a lot more torque and horsepower. The bell housing would certainly be different, maybe an adapter plate would allow you to make it work, if the input shaft was long enough.
I like Volvo engines a lot, and have enjoyed working on them. On the other hand, they can be hard to get parts for, expensive, and heavy.
A few years ago I had a passenger boat with a pair of TAMD 70f propulsion engines, and a Westerbeke generator set that was driven by (I'm quite sure) a Mitsubishi engine. It was a really nice little 3-cylinder, maybe 20 hp. Nice little engine. If the Perkins 4-107 in my current boat ever dies, or I get tired or tinkering it, I'd look for one of them for a propulsion engine.
By the way, a useful rule of thumb for an auxiliary sailboat iis that you need one DIN continuous horsepower per thousand pounds of actual boat weight (not registered tonnage). This will give you hull speed, and reserve for pushing against a headwind.
seo