Hi Chris: We've been dancing with this whole business of re-powering with diesels and the cost analysis for a very long time. We've looked at it from every angle I can think of and, as you have discovered, there's no way that it can be justified financially. That's financially, not emotionally or perhaps from a requirement. As in very extended range with extended reliability, but then you're really back to comparing apples and oranges. Heavy duty, lower HP rated, single diesels are not comparable to twin engine planing hull requirements. But you sound like you're talking about re-powering a twin screw planing vessel. right? The $76,000 replacement ballpark figure you received is about right. Each time we investigate, we get between $60,000 and $80,000. That's for twin diesels in the equivalent diesel horsepower range as our existing gasoline engines (usually 50 to 75HP less than the gasoline engine). We have had repeated estimates of $5,000.00 to replace both of our gasoline engines with rebuilt long blocks, including all the labor to remove and replace... that's for both. In a diesel replacement there is far more to the whole thing than just the diesels of course. New transmissions, shafts, couplings, bearings, props. Complete new fuel system. New instrumentation and controls. Usually some extensive modifications to the support structure for the new diesels. It's a BEEEG job <G>. So that $76,000.00 (more likely 100k) should and probably does include all of that too. The actual diesels themselves, sitting on their pallets.... I don't know. $20,000 each?? Paul Kruse would know as he buys these things all the time. If you are very conservative and assume 1,500 hours on gasoline engines and 10,000 hours on high speed diesels. If you assume gasoline fuel price differential at about 1.5 times diesel, and if you assume 50% better fuel efficiency.... none of these figures are accurate in my opinion. If you do the math based upon these figures, you can see that you could replace the gasoline engines 4 or 5 times and buy gasoline for your entire lifetime and still never get a payback against the cost of diesels. Reality is worse I think. The figure that is ballparked at $76,000 can easily (and often does) reach $100,000.00. Gasoline V/S diesel fuel cost differences are about 1.3. Gasoline v/s diesel fuel efficiency is about 1.3. Reliability between high speed diesels and gasoline engines set up for marine use (electronic ignition, etc) I would argue about 1.3 (very subjective) and we've just had a discussion where we talked about the high speed, high performance diesels with 5000 or less hours of life. Diesels are heavier, vibrate much more and can smell up a boat. If you factor in repair/replacement parts costs, especially of those item external to the basic block such as water pumps, injector pumps, injectors, starters, then the delta goes up even further. There is a company in Seattle... I don't know the name, that re-builds and marinizes pickup truck style diesels for boats. They were at the Seattle boat show. It's an intriguing idea but I have no idea what these cost, how well they work, etc. Opinions from the cheap seats <G> Joe Engel -----Original Message----- From: Chris Mangin [mailto:cmangin@email.msn.com] Sent: Saturday, July 15, 2000 3:32 PM To: trawler-world-list@samurai.com Subject: TWL: Marine diesel engine initial cost I've been easily convinced that I prefer diesels for my intended heavier-duty marine applications... but I've just noticed that I don't actually understand one basic underlying fact about 'em: why the heck do they cost so much? Even more basic: how much DO they cost? <SNIP>