Question

[poopdeckpappy]

Whats the real difference in a marine diesel and a commercial diesel eng?

I'm asking because, what started as minor maintenance & repair on a single boat has turned into minor maintenance & repair on several boats, so, before I get to carried away I want to enroll in a diesel eng tech course, but Orlando Florida is 2100+ miles away.

I know nuts and bolts are nuts and bolts, but is a diesel a diesel is a diesel? I'm thinking so and I'm thinking I could get the necessary background at a local college.

what am I not taking into account here ??

[kd3pc]

there is no difference between them, perhaps some more sophisticated engine management systems, injectors and pumps...but the basics are the same.

Where the vendors get you, is what is connected to the engine, I thought it would be easy to work for a commercial generator firm, as I have decent engine skills, licensed electrician, and computer guy...but they don't.

Not sure you would get a lot out of the basic florida class and at what price.
dave

[chucklesR]

'Marinizing' a diesel engine involves swapping out several parts for ones that are intended to handle the corrosive environment of the salt etc.
As such it is mainly in the coolant system, but also spark arresters and all the other exposed metal. Adding zinc's is a good example.

A diesel that is originally intended to be a small tractor engine is shoved into a tractor with a closed loop coolant system, and very little concern for air flow, it also generally has access to the parts needing routine maintenance.

The wiring harness may or may not be changed out - depends on the original and of the course the quality of the product.

It does not affect how to trouble shoot, but does affect what can go wrong (broken off bits of zinc in the heat exchanger blocking flow for example).

Any diesel school will do you in good stead, it doesn't need to be marine related. Many community colleges have them available.

[klem]

The basics of the engine are certainly the same but many of the parts are different. The important thing is that the diagnostics are essentially the same. As chucklesR points out, marine diesels have to deal with the more corrosive environment so they use different alloys in certain parts. In addition, many have a heat exchanger which is not necessary on an OTR engine. The plumbing for intake and exhaust is usually different because the space requirements and access are different but if you know engines, it takes about 2 minutes to figure out the difference.

The internal differences come from the fact different emissions regulations, almost unlimited cooling potential, and different load characteristics. A lot of marine engines will run different pistons, head gaskets, injectors, and injection pumps because of this. If you want a good comparison, look up a cummins 6bt which can be had in the dodge pickup trucks and in a lot of power boats and there is a ton of information out there on that engine.

Basically, there are some different parts but they work the same. Not going to a marine school, you will not learn about marine exhaust systems, marine throttles, and marine transmissions. As long as you are pretty handy and not looking to do this for work where you might need a certification, you will be fine going to a non-marine school.

[JimsCAL]

Many of the marine engines are converted industrial engines from companies like Kubota or Mitsubishi. As noted the cooling and exhaust systems are different on the marine installation and the marine transmission is unique. Other than that, a diesel is a diesel.

[poopdeckpappy]

Thanks for your insight guys, I think we're on the same line. I have a good mechanical background (I think) rebuilding race motors for offroad bikes and few HD's. although, back then I had a 4 car garage


Thanks again

[jackdale]

Our local technical institute offers a diesel course for sailors. They use the same engines found on reefer semi's.

Jack

[tdw]

I was (indeed still am) under the impression that all marine diesels are based on auto engines with the exception of Yanmar and Bukh.

You'd figure therefore that working on a marine diesel is no different to an auto diesel except that you get to do it upside down in a space fit only for a midget.


(Bukh.....I think they are known as Westerbeke in America.)

[bubb2]

Originally Posted by tdw

except that you get to do it upside down

Only if you live in Australia.