Common rail marine diesel engine v standard

[Compass790]

Originally Posted by billknny

Like he ^^^ said.

I just read everything in this thread so far. There has not been any actual comments about first hand problems with CR marine diesels, it is all rumor and assumption, and comments about older automotive designs.

Certainly, some of the first generation computerized marine diesels had really terrible diagnostic tools. (Volvo, I am looking at you...) That seems to have improved dramatically.

Realistically, NOBODY is ever going to repair a broken mechanical injection pump without a full specialized shop and the highly specialized tools to do so. Don't tell me you have a mechanical injection pump because you can fix it--you can't. On the other hand, they don't break often. Kind of like a well designed and built CR system.

Forty years ago we could have been having this discussion on an automotive forum about the relative merits of carburetors vs. fuel injection. A modern fuel injection system is SO much more reliable than a carburetor that such a discussion would seem almost quaint. Where are we on the technology curve for CR systems? Have they passed mechanical systems in reliability yet? I don't know for sure. And I have seen no information in this thread to help me decide.

My take on it at this point is I would happily install a CR engine for coastal cruising and be very happy with the improved performance. For longterm, world-wide cruising... maybe not yet. Part availability would be the key there.

Ultimately, I have a sailboat. From anywhere in the world I can get my boat to a place to get the diesel fixed.

I beg to differ. I repaired the Bosch injection pump in our Yanmar & I dont have a diesel shop or a pump tester. Look up Bosch PFR injection pump on Youtube ( not my video). I cant comment on the common rail argument as have no experience repairing them just to say it is possible for the amateur with mechanical skills to reco a mechanical pump.
Took a couple of attempts to get it right but it cost $200 including parts instead of the $630 the " specialists " wanted. It was a single cylinder pump but I would have a go now at a multi-cylinder pump if I had to.Everybody told me you cant do them yourself. Not true for our injection pump anyway.

[lamadriver]

I just went through with this and in the end I purchased a Beta.

It has to do with parts .....

I travel in really remote places and was able to fully quip with extensive spares from aftermarket manufacturers.

These little tractor engines are bomb proof, easy to work on and used in everything from min x's to fork lifts. Parts are cheap and easy to source.

The Beta marinization is also really well thought out .

LD

[Sulaire]

Hi lamadriver,

Thanks for the info, it is the way i am thinking too, can i ask what engine you had before? Did the beta fit without any real pain?, a little pain is to be expected!

[belizesailor]

Originally Posted by Compass790

I beg to differ. I repaired the Bosch injection pump in our Yanmar & I dont have a diesel shop or a pump tester. Look up Bosch PFR injection pump on Youtube ( not my video). I cant comment on the common rail argument as have no experience repairing them just to say it is possible for the amateur with mechanical skills to reco a mechanical pump.
Took a couple of attempts to get it right but it cost $200 including parts instead of the $630 the " specialists " wanted. It was a single cylinder pump but I would have a go now at a multi-cylinder pump if I had to.Everybody told me you cant do them yourself. Not true for our injection pump anyway.

Small engine injector pumps really are not complicated. If I had access to parts, but no access to a proper diesel lab I would give it a shot. The end result may not be calibrated perfectly, but would likely work well enough until in range of a proper lab.

[jimbunyard]

This one is really idiosyncratic. If you have the skill for mechanical repairs more involved than changing the oil or adjusting the valves, the most cost-effective answer would probably be mechanical injection. If cost is not a factor, or you have no skill as a mechanic, then the common rail might be a better choice, but if you think having advanced electronics in a highly variable marine environment is a shoe-in for reliability, you may have another think coming.

Contrary to public opinion, most mechanical injection pumps are not rocket science, I've had too many apart, from partial to complete disassembly, from single cylinder Chinese generators to 3406 cats, to remember how many, but cleaning and replacing parts is well within the realm of possibility for most pumps and most reasonably skilled mechanics. Same goes for injectors, whether they be nozzles or unit injectors. Don't think that's the case for common rail injectors.

Not sure if it's been brought up, but the ease of troubleshooting mechanicals versus electronics is another pro for mechanical, which in case you haven't noticed is where my vote lies for small marine applications...

[Cadence]

Originally Posted by billknny

LOL!! That's rich.

Have you priced a replacement injection pump for your engine??? I do not personally know of ANYBODY who carries a spare injection pump. Not a lift pump... an injection pump...

Fuel pump not injection pump. There is a difference.

[a64pilot]

See, I think electronics can live happily in a Marine environment.
I have one of those electronically fuel injected Suzuki outboards and have had it so far for four years.
I even out of stupidity dropped it running into about 5’ of salt water where it sat for ten minutes or so, and it was at least another hour before I could begin to flush it out with fresh water.
Well a couple of years later, all that electronic computer controlled fuel injection and ignition stuff is still working fine.
If you can make that work, then surely an inboard Diesel is child’s play compared to an outboards operating environment, even if some idiot doesn’t send it swimming?
All of the large outboards are very, very sophisticated electronic beasts, yet they seem to get by.

We don’t need to run our Grandfathers engines anymore, it is the 21st Century

[Stu Jackson]

Originally Posted by billknny

I guess it matters if you consider your boat a sailboat that has an engine, or a motorboat that happens to have sails.

Interesting observation.

I thought long and hard about this issue (and your post) about my boat some five years ago, having had this boat for 15 years at that time. I was then sailing SF Bay, The California Delta and the surrounding ocean. I did a LOT of sailing.

I was getting a little long in the tooth [still doin' that, too!). when I had the "it's time for this old dude to get a trawler" thought in my feeble little head. Then I had an epiphany.

I was reading Maine Sail's excellent article on programming external regulators. He used this phrase: "...unless you have a trawler with a stick..."

I realized that that is exactly what I do have. My boat is more stable than a trawler at anchor, doesn't roll with cross seas, and, most importantly, I know ALL of the systems on the boat because I either installed them myself, replaced them myself, or worked on every single one of them at one time or another.

Instead of changing boats, I decided to keep this one.

And then we unexpectedly had to move to Canada to support my aging father-in-law in 2016.

I decided to sail the boat up, rather than either leave her in California and "visit" regularly, or sell and change boats.

We designed that trip up the coast, based on extensive research, to be a motoring trip. We were successful in that we chose days with NO WIND and scampered north as quickly as we could, harbor hopping day-by-day. Six weeks, 165 engine hours later. Once in a lifetime great trip.

Now that I have had 1 1/2 seasons here in BC, I must report that there are days here where one simply CANNOT sail. Because there is NO WIND. Compared to any day from April to September in SF where wind was almost guaranteed, that simply is not the case here.

I DO have a trawler with a stick.

Thanks to Maine Sail.

And I also LOVE to sail. It's just the reality of the climate and location, NOT how I would like for things to be.

Of course, I don't have an enclosed steering station and a flybridge like a trawler. And I have this dreaded "cave" down below with dark wood teak that I just adore. And I have to carefully negotiate those dreaded companionway stairs, up & down, up & down many times daily. Oh, the horror! Importantly, I have always liked trawlers and their looks.

Your boat, your choice.

Point is that "I guess it matters if you consider your boat a sailboat that has an engine, or a motorboat that happens to have sails..." can be taken in a positive way, too.

Reality is a bitch, but I've learned to live with it.
Oh, and I have a tractor engine, just got some good parts from our local Kubota tractor dealer at 1/3 of the price of the marine versions from Universal. 3,422 engine hours.

[jmschmidt]

The modern common rail/electronically controlled marine diesel engines are proving to be a nightmare for the average sailor/cruiser. We were in the hot-tub at the hotel in Papeete one time (after chartering for a week on Raiatea) waiting for our the flight back to HNL onetime? We met up with this American guy on a delivery gig from Australia to Florida with a new cat. He had been waiting in the hotel (and the hot tub, I guess) for a solid month for Volvo to fly in some technicians to fix his brand new Volvo engines which had packed up on him 400 miles east of Tahiti? He may still be there.

We had a similar experience in Grand Cayman on a delivery trip with the EEC's (Electronic Engine Controls) on a 70' Sun Reef cat. However, help is at hand. In an effort to impress those of us that are less interested in some new whizz-bang technology and more interested in actually getting there in one piece, Yanmar now runs full page ads in the trade publication for a series of its engines. The ad reads "NO COMPUTERS - ALL MECHANICAL ." I love it.

Jack

[john61ct]

Does anyone have suggestions for a very reliable diesel that is relatively light and **very compact** relative to its HP output?

ideally commonly available second-hand

I'd even go for a gasser to get the above.

The idea is to have power generation,

for charging a large LFP bank, electric galley and high-gph watermaking, as well as some hot water output

all from the motor also used sometimes for propulsion

There is no room for a separate standalone genny, even a little Honda inverter suitcase unit.

If necessary, I'm willing for the two use cases to be either / or, i.e.

when the horses are needed for propulsion, disable the genset power head, or

when living on the hook long term, put all the power to the genset, none to the prop.

Note the "genset power head" may be DC only output, as in a robust alternator, rather than generating mains AC to then drive a charger.

I realize that such a physically small engine will limit its horsepower,

apparently the 500A 24V units I've been drooling over, require 30HP just by themselves to spin up!

So maybe 10-15 HP peak output?

Don't have the boat yet, but it will be under 30', older, heavy classic-plastic, and likely full-keel if that makes a difference.

Willing to give up some "camping space" for the right engine if necessary, obviously lower the CoG the better.

I realize this idea is unconventional, but is it actually whacko, too unrealistic?

[john61ct]

Originally Posted by billknny

They are easy to find, they have the tinfoil hats.

Easy to say, but plenty people feel we're closer than ever to the possibility.

For some it's even a big factor behind why they're getting into sailing.

[Dockhead]

Originally Posted by john61ct

Does anyone have suggestions for a very reliable diesel that is relatively light and **very compact** relative to its HP output?

ideally commonly available second-hand

I'd even go for a gasser to get the above.

The idea is to have power generation,

for charging a large LFP bank, electric galley and high-gph watermaking, as well as some hot water output

all from the motor also used sometimes for propulsion

There is no room for a separate standalone genny, even a little Honda inverter suitcase unit.

If necessary, I'm willing for the two use cases to be either / or, i.e.

when the horses are needed for propulsion, disable the genset power head, or

when living on the hook long term, put all the power to the genset, none to the prop.

Note the "genset power head" may be DC only output, as in a robust alternator, rather than generating mains AC to then drive a charger.

I realize that such a physically small engine will limit its horsepower,

apparently the 500A 24V units I've been drooling over, require 30HP just by themselves to spin up!

So maybe 10-15 HP peak output?

Don't have the boat yet, but it will be under 30', older, heavy classic-plastic, and likely full-keel if that makes a difference.

Willing to give up some "camping space" for the right engine if necessary, obviously lower the CoG the better.

I realize this idea is unconventional, but is it actually whacko, too unrealistic?

Well, if you want very high power to weight and power to volume, and you don't care about anything else, then you'd like a snowmobile engine or ultralight aircraft engine.

My snowmobile has a direct injected 600cc water cooled Rotax two cylinder two stroke which makes 110 horsepower but I can pick it up with one hand. It's smooth as silk and reliable as a ball peen hammer. Specific fuel consumption (because of the direct injection) is similar to a good four stroke gas engine, but of course is worse than a diesel, but you didn't mention that as a value.

Otherwise, what you want is a small turbo diesel. If the smallest turbo diesel you can find is too big, then you will have to choose a small high speed diesel over a larger low speed one -- ick. I'd rather have the snowmobile engine, probably. My generator is driven by a 1000cc three cylinder which makes only 12 horsepower or so. That achieves quiet and long life, but violates your announced design values.

I guess you could marinize a motorcyle engine. Now there's a thought.

[Cadence]

Is anyone taking some of this serious?

[a64pilot]

Originally Posted by Dockhead

I guess you could marinize a motorcyle engine. Now there's a thought.

I was actually thinking of one as I was reading his wish list.
Honda at one time bored out their popular baby Interstate, which was a CX500 90 degree V twin and was smooth as silk.
A ninety degree V twin is actually nearly perfectly balanced, it’s not at all like a Harley, which is a horrible design.
Anyway, Honda punched it out to 650 cc and put a turbo on it, which at the time everyone said wasn’t possible the exhaust pulses were too erratic to turbo a two cylinder, you needed at least three.
Odd motorcycle, but the engine was brilliant and lasted forever, sort of like it’s bigger Interstate brother.
I’ll try to find a link.
OK it was an 80 degree engine. But I have raced against one in WERA and the motor made a whole lot of power, it worked great for racing cause you were given advantages for not being overhead cam, four valve etc.

https://www.motorcycleclassics.com/c...3-honda-cx650t

Probably ridiculous to try, but interesting to brain storm on it.

[Cadence]

Originally Posted by a64pilot

I was actually thinking of one as I was reading his wish list.
Honda at one time bored out their popular baby Interstate, which was a CX500 90 degree V twin and was smooth as silk.
A ninety degree V twin is actually nearly perfectly balanced, it’s not at all like a Harley, which is a horrible design.
Anyway, Honda punched it out to 650 cc and put a turbo on it, which at the time everyone said wasn’t possible the exhaust pulses were too erratic to turbo a two cylinder, you needed at least three.
Odd motorcycle, but the engine was brilliant and lasted forever, sort of like it’s bigger Interstate brother.
I’ll try to find a link.
OK it was an 80 degree engine. But I have raced against one in WERA and the motor made a whole lot of power, it worked great for racing cause you were given advantages for not being overhead cam, four valve etc.

https://www.motorcycleclassics.com/c...3-honda-cx650t

Probably ridiculous to try, but interesting to brain storm on it.

I had a Honda CX650. No turbo but it was one ballsy scooter. 6th and 100MPH wasn't even halfway the red line. I also had an Interstate, one comfortable ride.