Diesel engines compared

The mechanics at our boat yard tell me that my trusty 5300 hr 1982 Perkins 4/108,which is installed in our 38 ft 13 ton Aux Sloop, has major issues. It was taken out of the boat initially for warranty work on oil seals. They have found oil getting past the piston rings.two bent journals and metal wear etc etc. They advise a complete rebuild or new? I am looking for opinion and or a site where I can get some comparisons in both relaibilty and prices. In fact any input to get my selection process started. The yard are tellingmeYamaha.

Derek

 

I think that may be "Yanmar" ? Also have a look at Nannidiesel or whoever produces marinised versions of "Kubota" To extend your options google locally for "xx hp marine diesel engines" where xx is current rating of Perkins.

If your engine is "buried " deep in the bowels of the hull ensure there is remote oil & fuel filters (for easy replacement) and sump pump out capacity for a start.

 

Thanks for the good info. Yes of course it's Yanmar ! Actually the engine is very easy to reach all the way around. Good search tip. Cheers Unionjack

 

Woah, Derek. Your 1982 Perkins was hauled in 2007... for warranty work? Must be the warranty on a sale or recent repair....
As reliable as an old engine may be, they do eventually wear down. Whether yours is at the state where the extra life from a rebuild isn't proportional to the cost of said rebuild, is hard to say.
Your boat is on the heavy and slow side as engines are concerned (no offence), and so you may be better off with a larger, slow-turning, and stocky engine as compared to the small-displacement, high-RPM, lightweight units that are becoming increasingly popular. There is a tradeoff to be made between fuel consumption rates and mean time between overhauls, in many cases.
What brand? There are many.... Yanmar is becoming quite popular; I have heard a lot of good things about Deere as well. Westerbeke and Cummins make smaller engines still, as does Volvo. A quick Google search will turn up at least a dozen. Consider what's popular and easily serviced in your normal cruising grounds... although this doesn't seem to be nearly as critical a factor with diesels as it is with outboards.

 

Derek, do you use "Google.co.uk"? as this will help filter local suppliers, else ensure you are using your local googling source as an aid.

Marshmat's advice, "Consider what's popular and easily serviced in your normal cruising grounds..." should be high on your selection criteria.

Pardon my ignorance & laziness, I am not familiar with the location of Whidbey Island.

 

MY choice would be to go to the Kubota tractor shop , and find out which model diesel engine is most common on all the NEW tractors and lawn equipment.

Your Perkins was at best 25 hp and I would assume your usual fuel burn was under 1 gallon per hou rmaybe 3/4 gph.

Thats about 15 or 16 hp (1 gph), so a modest rated engine will run just fine. As it will probably be rated smaller it will carry a higher gear reduction , but spin the same shaft at the same speed.

The Perk probably was 2-1 red so at 1800 cruise would have spun the shaft 900 rpm.

The new Kubota will probably have a 2.5 red and cruise at 2300 , no problem.

The difference is the tractor boys can never mark up their prices the way engine converters like "Yanmar" Marine can.

FF

 

Masalai,

http://en.wikipedia.org/wiki/Whidbey_Island

Pericles

 

You don't need to – just type "site:uk" (without the quotation marks) at the end of your search, and only hits from that domain will pop up. Works with any domain, even "gov.au".

 

Danish, How does that work if I wanted all EU countries?

 

Well, it's about domain names. So even though there is a ".eu" domain, you wouldn't find much relevant about, say, nanni diesels there.

In other words, you're asking the equivalent to "How can I use that to simultaneously search for .com, .au, .se, .de sites?" You can't.

However, you can exclude by typing (for instance): "-.uk -.com -.ru -.ch" (without the quotes) at the end, and thereby excluding anything else but from the ones you want.

You can have several exclusions simultaneously, so knock yourself out. It's a pretty efficient way of narrowing things down.

 

Here's how it will look, if you want to exclude international/american sites, russian, chinese, and british sites – just as an example:

http://www.google.com/search?hl=en&...anni diesel -.com -.ru -.cn -.uk&btnG=Search

The other search, where one wants something from a particular domain, would look like this, where, for instance I want to look for "orca", but I want it to be a danish website (not necessarily in danish, though):

http://www.google.com/search?hl=en&safe=off&client=safari&rls=da-dk&q=Orca site:dk&btnG=Search

 

Our yard replaced a 4-108 with a 56 hp Yanmar a year ago and it has proved to be a quite workable solution not requiring major surgery on the engine bed and providing quite satisfactory performance. Be sure to check your clearances around the engine though - we built new walls around it but that might be an issue in some installations, and access points for onboard hardware might be different locations from the 4-108.

The original engine in this boat was 4-107 so that advice probably applies to a 4-107 as well.

 

i had what i thought was a 4.108 which is actualy a 4.154, we pulled it to freshen it up and re-install further aft, its the original engine from 1985 and ive no idea how many hours are on it. it turns out that a rebuild kit for the 4.154 costs double the price of the 4.108 - and now im thinking about a replacement and wanting to compare different models. in particular the cummins 3.3 naturaly aspirated making 65 hp versus the volvo 2.2 turbo making 75 hp. any ideas where i can look for comparison information?

 

If you have the actual fuel consumption of the old engine , it will help you figgure what you need as a replacement .

1 gallon an hour was probably 16 hp frim the old Perkins, use your actual cruise fuel log to decide how large an engine to install.

If you burned 2 gph that is 30 or so hp, so a 40hp would last longer and be more efficent than a 75 hp.

In most sail boats , turbos are to be avoided as its seldome loaded hard enough to keep the turbo from choking .

What was the fuel burn?

FF

 

fred, the engine turns a hydraulic pump which in turn drives a hydraulic motor, shaft and prop. all i know is that over about 2000 rpm they didnt see much of an increase in speed but fuel consumption went up, i dont know any more than this. im leaning away from the turbo idea as it seems like something else to go wrong/maintain. i suppose another repower option would be the perkins m65, it looks to be physicaly smaller than the cummins unit.

it seems next to impossible to find any comparitive info on marine diesels, apart from forums such as this.