Engines: Old and easy to repair vs New and reliable.

[rslifkin]

I'll agree that the electronic diesels are usually not much more efficient (if any) than the later mechanical injection engines. However, the electronic ones do tend to be quieter and with the tighter emissions requirements, they leave less soot on the hull near the exhaust after running for a while.

[Suliwar]

With an electronic diesel, ask yourself what will happen in case of a nearby lightning strike? Will it continue to work?

[Simi 60]

Originally Posted by Wotname

Well I haven't had the pleasure of owning a Gardner but a few mates have and to be honest, they have never needed parts.

...

We'll, I have an acquaintance who recently had his 8lx rebuilt in situ with by one of the firms you listed.
I am sure during that process they needed parts.
They couldn't get it done in their usual part if the world as hardly anyone knows anything about them and had to get back to Brisbane, several thousand miles to get it done.
Even then, several months after they were still trying to source HE parts. (May have it now but they were still looking 12 mths after the rebuild)

Those same parts for our 855 would be on a plane from Cummins China and here inside a week, rebuild probably could have been done anywhere.

Don't get me wrong, Gardner's are a great motor but if travelling remote I would prefer engines where parts and service can be found almost anywhere.

[mvweebles]

Looks like Tier 3 standards became required for post 2009 engines greater than about 100 hp though some manufacturers converted earlier (lugger chose to opt out and stopped making propulsion engines altogether) . This is when common rail and ECU became effectively required to meet emissions. So to avoid the extra layer of electronic vulnerability, you're looking for something earlier. Turbo is mostly reliable and will more or less match efficiency of Tier 3.

Good luck !

Peter

[Cadence]

Originally Posted by GoneDiving

I'm at the very early planning stages of looking for a sub-50ft offshore cruiser/dive vessel and am becoming more and more impressed with converted Cray/Lobster trawlers as an option to allow me to island hop and, as skills and experience improve, head to remote areas of PNG, Marshall Islands etc.

Drive power in used vessels tend to fall into two categories: newer, more efficient and reliable but more technical to maintain engines and older, thirstier but dead simple ones. Older engines also seem to be far less "sexy" and significantly depress asking prices.

As extremes, if I look at a Detroit 671 vs a Yanmar 4LV producing 100 shaft hp, the 671 will use ~30% more fuel, at near half the revs, a bunch more noise but has a life expectancy of forever, user replaceable parts and servicing at comapratively very low prices.

I'm fairly mechanically minded so am leaning towards the old and simple so that I can repair faults whenever and wherever they may occur. Most likely a middle ground of Gardiner or Ford Lees/Lehman.

What are others preferences for remote and/or passage making vessels? What have I missed?

Many thanks

671s were made in such numbers parts can probably can be found anyplace in the world weather GM/ Detroit, Gray or Singer, for that matter. Injector size can determine fuel usage. Very hard to destroy.

[Compass790]

Originally Posted by GoneDiving

Thanks

The old unconverted workhorses are largely 8V92s, while the newer ones are Euro Scania/MAN/Volvos.

Note we are talking about 500 to 1000hp designed to blast 50ft out at 20kn evey day. I'm hoping for a bit more sedate pace �� but agree it's a good indication of bullet proof reliability.

There are more arguements than thought for the Screaming Jimmy's. ��

Cheers

Ok sorry didn't realise Oz crayboats were all so big. We have lots of smaller slow ones here which probably were in your power range.
I notice they are getting bigger & faster tho as they have to run big strings & cover a much bigger area now to catch the fast disappearing crays

[Lepke]

One cost in engines is their lifespan. Naturals will out last turbo engines by 3x or more. Turbos are just one more thing to fail. When they do fail all the upper hp is lost and you come home very slowly. Any electronics eventually fail on the ocean. You either carry a lot of expensive spares or plan on an expensive tow.
Having run Detroits (and many other engines) for about 60 years, a doubt properly matched Detroits have a 30% more fuel usage. And they're designed to be rebuilt many times. 71 series engines are commercial engines, not recreational. My current boat is 83' and about 80 tons. I bought it because it had Detroits. I have twin 671s naturals made in 1947 and burn 8.5 gph @ 10 knots. I run at max continuous hp and previous owners cruised about 300 rpm higher. The engines were rebuilt one time only about 5 years ago when I did it. These engines should be good to 2080 based on past history. Try that with a rice burner.

[Simi 60]

Originally Posted by Compass790

Ok sorry didn't realise Oz crayboats were all so big. We have lots of smaller slow ones here which probably were in your power range.
I notice they are getting bigger & faster tho as they have to run big strings & cover a much bigger area now to catch the fast disappearing crays

They aren't
This was the norm.
6lxb Gardner powered


https://www.boatsalestas.com.au/comm...louise/211932/


8lxb Gardner powered

https://www.tradeaboat.com.au/detail...imber-crayboat




I am thinking the OP is looking at this style of thing

https://www.boattrader.com.au/boats-...el/BTFD5003733

[Cadence]

Originally Posted by Lepke

One cost in engines is their lifespan. Naturals will out last turbo engines by 3x or more. Turbos are just one more thing to fail. When they do fail all the upper hp is lost and you come home very slowly. Any electronics eventually fail on the ocean. You either carry a lot of expensive spares or plan on an expensive tow.
Having run Detroits (and many other engines) for about 60 years, a doubt properly matched Detroits have a 30% more fuel usage. And they're designed to be rebuilt many times. 71 series engines are commercial engines, not recreational. My current boat is 83' and about 80 tons. I bought it because it had Detroits. I have twin 671s naturals made in 1947 and burn 8.5 gph @ 10 knots. I run at max continuous hp and previous owners cruised about 300 rpm higher. The engines were rebuilt one time only about 5 years ago when I did it. These engines should be good to 2080 based on past history. Try that with a rice burner.

Nothing wrong with a Roots (sp?) blower. I think 220 HP with 90 injectors 55s will take one down to about 160 HP.

[Bundyon]

No common rail for me, am running a little 4-236 Perkins 80h.p. pushing 24 ton at around 6knots @ 1500rpm for about 3.5 li/hr.
I run a Racor for a primary filter & a C.A.V. 796 for a secondary filter. After getting down lower than normal on fuel and in 5 metre seas and having heavily dosed my fuel tank with fuel doctor, I came into a safe anchorage after crossing a Bar with black smoke chuffing out the exhaust.
A much needed filter change, the Racor bowl was full of sludge, both filters full of "black death". The Perkins never missed a beat, I could only imagine a common rail engine would have left me stranded in big seas.

[Tillsbury]

I agree to avoid common rail and electronically controlled engines, but I don't think turbos are a worry. They're a very simple part, they can easily be replaced or rebuilt if you need to, and the engine will still work even if the turbo is hopelessly shot and rusted solid.

[mvweebles]

Originally Posted by Bundyon

No common rail for me, am running a little 4-236 Perkins 80h.p. pushing 24 ton at around 6knots @ 1500rpm for about 3.5 li/hr.
I run a Racor for a primary filter & a C.A.V. 796 for a secondary filter. After getting down lower than normal on fuel and in 5 metre seas and having heavily dosed my fuel tank with fuel doctor, I came into a safe anchorage after crossing a Bar with black smoke chuffing out the exhaust.
A much needed filter change, the Racor bowl was full of sludge, both filters full of "black death". The Perkins never missed a beat, I could only imagine a common rail engine would have left me stranded in big seas.

I too have a 4.236. I ran it 500nms straight through on 15-year old diesel that smelled like linseed oil (I wanted to dispose of it, but California required hazmat suits and hazardous waste fees which were outrageously expensive). When I got to Mexico, had a hard time getting rid of what was left - it looked like a Black Russian cocktail and I couldn't even give it away to the Mexican fishing fleet.

But that Perkins ran 76-hours on that old fuel (and one change of racor filter). A lot to be said for old technology.

BTW - don't try the above at home. Not for the feint of heart.

[Simi 60]

Originally Posted by Lepke

One cost in engines is their lifespan. Naturals will out last turbo engines by 3x or more.

Even on engines where they don't get worked hard?

On ours, I don't hear the turbo spinning up until we get up around 1500rpm of her 1800 max, but that does little more than burn excessive fuel and only gets done occasionally to blow out the cobwebs.

Turbos are just one more thing to fail. When they do fail all the upper hp is lost and you come home very slowly.

99.9% of the time we do miles in the 1150 to 1250 rpm range for 8 knots.
Would the turbo be doing anything?

[GoneDiving]

Originally Posted by Compass790

Ok sorry didn't realise Oz crayboats were all so big. We have lots of smaller slow ones here which probably were in your power range.
I notice they are getting bigger & faster tho as they have to run big strings & cover a much bigger area now to catch the fast disappearing crays

No problems. Quotas fundamentally changed the industry and turned it into a high powered dash for cash.

As Simi says I'm looking at an older, 1970's, model as many have now been converted to private use. Only a few are still being used as originally intended. That's why I referenced the newer models that live and survive a brutal life.

Thanks

[GoneDiving]

Originally Posted by Lepke

One cost in engines is their lifespan. Naturals will out last turbo engines by 3x or more. Turbos are just one more thing to fail. When they do fail all the upper hp is lost and you come home very slowly. Any electronics eventually fail on the ocean. You either carry a lot of expensive spares or plan on an expensive tow.
Having run Detroits (and many other engines) for about 60 years, a doubt properly matched Detroits have a 30% more fuel usage. And they're designed to be rebuilt many times. 71 series engines are commercial engines, not recreational. My current boat is 83' and about 80 tons. I bought it because it had Detroits. I have twin 671s naturals made in 1947 and burn 8.5 gph @ 10 knots. I run at max continuous hp and previous owners cruised about 300 rpm higher. The engines were rebuilt one time only about 5 years ago when I did it. These engines should be good to 2080 based on past history. Try that with a rice burner.

I think a lot of their lifespan is because of their displacement per horse power. 426 cu in is a lot of iron and bearings supporting just 170 hp.

Plus, as you said, short of a cracked block, everything can be replaced easily and cheaply.