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Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 9:07 am
by prowlersfish
just a fun poll on Diesels and some good info to come

You can pick more then one answer BTW

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 9:17 am
by prowlersfish
How hard can you run them ? this is from Cummins and IMO is the max and assume your propped to get rated rpm plus

Rated Speed (rpm)-------------------Cruise Speed (reduction from rated speed, rpm)----------Mine opinion reduction from rated speed, rpm to be safe
Less than 2800 rpm ----------------------200 rpm ------------------------------------------------------------400 rpm
2801 to 3500 rpm-------------------------300 rpm-------------------------------------------------------------400 rpm
3501 to 4500 rpm-------------------------400 rpm-------------------------------------------------------------500-600 rpm
4501 to 5000 rpm-------------------------500 rpm===========================================That's a chain saw diesel run

This rating is for applications operating less than 500 hours per year.

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 2:02 pm
by ramblin
bought a 1989 12 meter motor yacht this year with twin 6 71 Detroit's and love it. First time with diesels. There is very little if any fumes in engine compartment and I get as good mileage as I did in my 10 meter mid cabin with gassers. And the 12 meter is about twice as heavy. In addition to all the comments made I did find out this year that it takes 6 gal per engine for an oil change. (yes gal not quarts)

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 3:05 pm
by prowlersfish
Mine only takes takes 4 gal per engine for an oil change LOL . My fuel burn on My F36 is less then what my F30 was and it also is almost twice the weight .

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 7:43 pm
by Cmount
So this is my first diesel boat. I went from a 77 f32 to the jersey, more than 2x the weight approx 30,000lbs, and at cruise, I burn 20-22 gph...21knot cruise. My f32 struggled to get there. Where I was comfortable with revs on the 318's, I cruised about18 knots...burned 24+gph. push them to 3400 and OMG mid to high 30's gph... And I was always nervous . Love my diesels now, will never go back to gas. Mine hold 4 gallons with two oil filters... :D

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 8:26 pm
by larryeddington
Everything I own has Diesel except my mid cabin. :cry:

That is excluding the F28 and Bay boat.

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 11:00 pm
by Cmount
One other thought...Handling? The diesel in my opinion is soooo much more responsive around the docks...almost never have to touch the throttle. I felt my gas power was a "lazy" feel around the docks vs. the bite of the diesel...much easier to handle in diesel once you learn how it reacts. interesting to know where that would rank on the survey.

Re: Diesels The perfect engines or not ?

Posted: Thu Oct 27, 2016 11:39 pm
by prowlersfish
Cmount wrote:One other thought...Handling? The diesel in my opinion is soooo much more responsive around the docks...almost never have to touch the throttle. I felt my gas power was a "lazy" feel around the docks vs. the bite of the diesel...much easier to handle in diesel once you learn how it reacts. interesting to know where that would rank on the survey.
I would think low . Unless you own or have run a diesel good chance you would not know that . But you could call it part of the feeling :mrgreen:

Re: Diesels The perfect engines or not ?

Posted: Fri Oct 28, 2016 8:32 am
by RWS
When our vintage Trojans were designed, there were few choices for diesel engines.

Today's technology for both gas and diesel has come a long, long way.

Additionally, outboards today are pretty darned amazing in both efficiency, power and horsepower to weight ratio.

I have owned outboard boats and my 10 meter which I have experienced both as a gas boat and as a diesel.

IMHO there are two choices available for a boat.

Either outboards or inboard diesel.

avoiding the high tech common rail diesels provides one with a simple, reliable, economical and safe boat.

our 17 gallon generator fuel tank recently developed a seepage leak, with the fuel ending up in the bilge.

Imagine if that was gasoline.

RWS

Re: Diesels The perfect engines or not ?

Posted: Fri Oct 28, 2016 11:28 am
by Svend
Another big factor for diesels is safety... gas has fumes and can explode... diesel fuel does not explode just like heating oil in many homes ;-)

Re: Diesels The perfect engines or not ?

Posted: Sat Oct 29, 2016 7:52 am
by Allen Sr
Svend wrote:Another big factor for diesels is safety... gas has fumes and can explode... diesel fuel does not explode just like heating oil in many homes ;-)
+1

Re: Diesels The perfect engines or not ?

Posted: Sat Oct 29, 2016 8:35 am
by prowlersfish
RWS wrote:When our vintage Trojans were designed, there were few choices for diesel engines.

Today's technology for both gas and diesel has come a long, long way

RWS
I have agree to a point but .....

There were a few options in the F32 you could get a 225 cat ( pre 3208 but same basic engine ) in the F36 Cummins of 210 and 240 HP( 555 Cummins) were available all 3 were very very heavy a shoe horn fit. . I the larger F boats Cummins of 555ci and 904ci and the 671 were Offered .
There were other Diesels offered through the years like Renault and Mitsubishi but these were on the low power side IMO .


The Trojan F Boats were built with price in mine and the few diesels available added greatly to the cost . Ad the fact the were primitive and had a poor power to weight ( and size ) not many were sold in F36 and smaller . F40 up they were more common

Diesel have come a long way since then . Lighter and more powerful The Cummins B and Cat 3208 in the 90s putting out much more HP and Yanmar with its very compact engines you could put almost any where you had gassers

Re: Diesels The perfect engines or not ?

Posted: Mon Oct 31, 2016 11:09 am
by WayWeGo
RWS wrote:avoiding the high tech common rail diesels provides one with a simple, reliable, economical and safe boat.
For a boat that you maintain yourself, I agree with this.

I have a Ford F350 with a Navistar (International Harvester) 7.3L diesel. It is certainly more expensive to maintain than a similar power gas engine, and when something breaks, it can be more difficult to deal with. A seal in my high pressure oil pump failed, and the oil at 3,000 psi leaked out rather quickly. I was losing about a quart every ten miles, and of course, the failure happened 40 miles from home. A $1 oil seal ended up costing me about $1,000 to replace because I had the HPOP professionally rebuilt and changed some other parts in the area while working on it.

All that said, there are certainly good things about the newer diesels like better fuel efficiency and lower emissions.

Re: Diesels The perfect engines or not ?

Posted: Mon Oct 31, 2016 5:33 pm
by RWS
I probably should not say this but will do so nevertheless.

My Yanmar 6 cylinder, intercooled turbodiesels have completed 11 seasons.

Aside from regular maintenance, including zincs and coolant changes, the only failure I can report is one starter solenoid.

I immediately replaced the Yanmar solenoids on BOTH engines with Ford simple 3 pole units..

It's a beautiful thing !

RWS