a bit OT - car engines in boats.
in [Aussie Drivers]
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From: D Walford on 24 Feb 2007 21:02 jackbadger56 wrote: > On Feb 23, 3:52 pm, D Walford <walf...(a)iprimus.com.au> wrote: >> jackbadger56 wrote: >>> At some stage in the next few years we're going to have to re-power >>> our boat as the twin SD33's are pretty tired. I was thinking (just >>> thinking!) that fitting modern twin 4cyl turbo-diesels would be worth >>> exploring. We've yet to get quotes on the Nissans but I'm sure it will >>> cost a fortune simply because it's for a marine application (diesel >>> fuel at all the marinas in Pittwater charge about $1.70 per litre, to >>> give you an idea of what they can get away with). If we were to use a >>> heat-exchanger set-up rather than pumping seawater through them, would >>> you really need to do a great deal of modification for marine use? The >>> 'engine room' (wow, that sounds grand!) is pretty well sealed and >>> there is heaps of room, so maybe any computers etc can be located well >>> out of harms way. Two of the marine mechanics I've put this to seem to >>> think it should be OK in theory, but had never put any thought into >>> it, as they had never been asked. They weren't keen on the idea >>> basically, but couldn't really give me a reason why. Has anyone here >>> had experience in fitting stock car engines into boats? If so, do you >>> think this is feasible? >>> BTW I've looked for an 'Aus.Boats' to ask this, but am also interested >>> in what 'car-heads' think of this idea. Traditional boaties are just >>> too blinded by......well........tradition, and would be horrified at the >>> thought of doing this to a 60yo Halvorsen (despite the fact that it >>> currently has Nissan truck motors, which in turn replaced a pair of >>> Holden sixes!) >> I can't think of any technical reason why you couldn't do that but I >> wonder about it being cost effective. >> The cost of purchasing and marinising two late model 4cyl TD's may not >> be a hell of a lot cheaper than buying engines made for the job. >> Have you shopped around for engine prices? >> It may be possible to reuse your existing heat exchangers etc and if you >> can do that then it may be cheaper to use car/truck engines. >> >> Daryl > > My goal is not to do it cheaper, but to utilise better engines than > what is readily available from marine-engine manufacturers. Things > like common rail injection etc have yet to filter down to 'common' > marine diesels, I.E. the more affordable ones. I'd be very keen to do > some of it myself, but finding a marine mechanic who will look at the > end result and assess it on its merits rather than trying to find a > way of earning more for themselves is the hard part. > Depends on what you mean by "better"? Hi tech isn't always better and I wonder how well they will do in a harsh marine environment, there is probably good reason soem of the newer technology hasn't been used. An engine in a car or a truck is subjected to constantly changing loads and rpm whereas a boat engine is mostly under constant load at constant rpm so most likely all the hi tech is wasted. Daryl
From: John McKenzie on 25 Feb 2007 03:22 jackbadger56 wrote: > > On Feb 23, 5:56 pm, John McKenzie <j...(a)alphalink.com.au> wrote: > > jackbadger56 wrote: > > > > > At some stage in the next few years we're going to have to re-power > > > our boat as the twin SD33's are pretty tired. I was thinking (just > > > thinking!) that fitting modern twin 4cyl turbo-diesels would be worth > > > exploring. We've yet to get quotes on the Nissans but I'm sure it will > > > cost a fortune simply because it's for a marine application (diesel > > > fuel at all the marinas in Pittwater charge about $1.70 per litre, to > > > give you an idea of what they can get away with). If we were to use a > > > heat-exchanger set-up rather than pumping seawater through them, would > > > you really need to do a great deal of modification for marine use? The > > > 'engine room' (wow, that sounds grand!) is pretty well sealed and > > > there is heaps of room, so maybe any computers etc can be located well > > > out of harms way. Two of the marine mechanics I've put this to seem to > > > think it should be OK in theory, but had never put any thought into > > > it, as they had never been asked. They weren't keen on the idea > > > basically, but couldn't really give me a reason why. Has anyone here > > > had experience in fitting stock car engines into boats? If so, do you > > > think this is feasible? > > > > > BTW I've looked for an 'Aus.Boats' to ask this, but am also interested > > > in what 'car-heads' think of this idea. Traditional boaties are just > > > too blinded by......well........tradition, and would be horrified at the > > > thought of doing this to a 60yo Halvorsen (despite the fact that it > > > currently has Nissan truck motors, which in turn replaced a pair of > > > Holden sixes!) > > > > If fuelling is the main issue, what sort of power are you in need of > > (and what sort of rpm, or do you have propellor options? I've got to be > > inclined to think that a pair of 'somethings' on lpg would have to run > > cheaper. it's not too hard to rig up a trailer with the right fittings > > so you can fill 2-4 tanks on it, then run it back and put them in the > > boat, similar but on a larger scale than forklift tanks. I have nfi as > > to the legality, but I'd be looking into it keenly. It's likely the > > cheapest by double to run per km, of course the setup cost might not be > > choice. Then again, you might get away with a pair of holdens again, or > > something. Maybe a pair of older ford 6s, reasonable torque if not so > > rev happy. > The current engines run happiest at about 1800rpm (7 knots), but I > suspect it's still fitted with propellers more suited to a 2500-3000 > rpm cruise (again, an assumption that this is where Holden sixes would > be happy). IS 7knots sufficient for your needs or would you have been running the current motors higher (not knowing what gearing there is between crank and prop, I guess I'm speculating a little here) to get to a reasonable enough pace? If it is the case that it's fine like that for 90% of duties, then it's not a huge concern I suppose. But if not, then perhaps another set of holdens (you'd get em for free!) The reason I mentioned lpg is (aside from any buildup concerns which shouldn't happen in an even remotely adequately vented engine space) is that engine wear on lpg (with the exception of exhaust valve recession, which is easily addressed with the use of hardened seats, which would have been done as a matter of course for practically so long now with engine reconditioners that you'd have to look reasonable hard to find a head that doesn't feature them) so drastically low compared to petrol, especially in marine apps, that it extends the life probably to double or triple. Not sure how the average turbo diesel would last - as they tend to be built for longer lifespans too, but it's worth a thought. The reason is fairly simple. Gas is introduced (duh) as a gas, never as a liquid fuel like petrol. this liquid fuel can, especially when the engine is cold (as in startup, or particularly if cold seawater is used as the coolant instead of a self contained setup) condense and it dilutes the oil film protecting the bore walls/rings/pistons from wear. Aside from it being immediately washed away and thereby setting it up for accelerated wear, the petrol and the debris then end up in the oil, and this causes the oil to deteriorate below whatever levels it needs to be to do it's job far more quickly.). on a motor that likely does most of it's starts after some time of disuse, and sees low temperatures *(relatively, any morning on or near water can be) has some real potential to exploit or improve with the option of lpg. About the only thing you might consider is still running a carb of some sort, and a reserve fuel tank for any situations, as it'll generally be easier to do a makeshift at sea refuel or recovery with liquid fuel. I haven't really put much thought into gearbox's and would > like, if practical, to keep the current ones and change the propellers > so the new engines would also be able to cruise at <2000rpm. I haven't had a hell of a lot to do with boats since my old man was around, to be honest, but there was a fair few options back then that weren't all that mega expensive (including some that would be considered almost total diy, with components bought for cheap, vs paying a shitload for someone else to put the same general setup together for you, so definitely check around, perhaps even at the marina, look for some old bloke that mutters a lot, and always has grease or grime on his hands :) -- John McKenzie tosspam(a)aol.com abuse(a)yahoo.com abuse(a)hotmail.com abuse(a)earthlink.com abuse(a)aol.com vice.president(a)whitehouse.gov president(a)whitehouse.gov sweep.day(a)accc.gov.au uce(a)ftc.gov admin(a)loopback abuse(a)iprimus.com.au If you didn't know it was wrong,why did you cover it up? abuse(a)msn.com $USER@$HOST $LOGNAME(a)localhost -h1024(a)localhost root(a)mailloop.com abuse(a)federalpolice.gov.au fraudinfo(a)psinet.com abuse(a)cia.gov $USER(a)localhost abuse(a)sprint.com abuse(a)fbi.gov abuse(a)asio.gov.au $LOGIN(a)localhost
From: eeviil inc. on 26 Feb 2007 17:30 D Walford wrote: > JD wrote: > >> had one of those myself forty years ago, except it was a three cylinder >> Perkins. Box was a standard marine one, as you say, forward, neutral, >> reverse by a small lever that actuated the hydraulic application of >> epicyclic gears, giving a 2:1 reduction both forward and reverse. >> Probably >> not very accurate to call it a slushbox as there was no torque converter. >> Can't remember the brand of gearbox. Most marine applications need a >> reduction gear for the propeller. > > > I did my apprenticeship with a Perkins diesel dealership so I > occasionally got to do a bit of work on marine engines (I mostly worked > on tractors and machinery). > I can't remember ever putting a spanner on one of those transmissions > because nothing ever went wrong with them. > IMO replacing a diesel with a petrol engine in a yacht is crazy and > asking for trouble from dangerous petrol fumes. > > > Daryl I remember this box was pretty knackered, but he fixed it, or got it fixed. It seemed to be slipping badly, to the point that if you grabbed the uni joint it would stop spinning while in either gear. Mind you when he bought the yacht it was sitting on the bottom of Rose Bay (in Sydney), yes, on the bottom. So water would have well and truly impregnated everything. I can't remember why he had bolted it to a Holden 6, but the Perking copped a complete rebuild and went back in the yacht along with the fixed box. Adam
From: the_dawggie on 26 Feb 2007 22:33 On Feb 23, 2:00 pm, "jackbadger56" <castl...(a)gmail.com> wrote: > At some stage in the next few years we're going to have to re-power > our boat as the twin SD33's are pretty tired. I was thinking (just > thinking!) that fitting modern twin 4cyl turbo-diesels would be worth > exploring. We've yet to get quotes on the Nissans but I'm sure it will > cost a fortune simply because it's for a marine application (diesel > fuel at all the marinas in Pittwater charge about $1.70 per litre, to > give you an idea of what they can get away with). If we were to use a > heat-exchanger set-up rather than pumping seawater through them, would > you really need to do a great deal of modification for marine use? The > 'engine room' (wow, that sounds grand!) is pretty well sealed and > there is heaps of room, so maybe any computers etc can be located well > out of harms way. Two of the marine mechanics I've put this to seem to > think it should be OK in theory, but had never put any thought into > it, as they had never been asked. They weren't keen on the idea > basically, but couldn't really give me a reason why. Has anyone here > had experience in fitting stock car engines into boats? If so, do you > think this is feasible? > > BTW I've looked for an 'Aus.Boats' to ask this, but am also interested > in what 'car-heads' think of this idea. Traditional boaties are just > too blinded by......well........tradition, and would be horrified at the > thought of doing this to a 60yo Halvorsen (despite the fact that it > currently has Nissan truck motors, which in turn replaced a pair of > Holden sixes!) Ok, I've lived by the sea for all my life, and had a number of boats. That would range from outboards, to a yacht, to ... nothing ATM (got shites with). A friend had a largish boat at Pittwater IIRC with a petrol engine in early 1990s. Don't even want to go near how much petrol the thing needed - not feasible these days. I had a Chrysler 130 HP outboard I rebuilt for the boat I had too around then. It chewed fuel like I don't now what. Fairly powerfull at the times it actually worked though. Diesel engine idea is good. Depending on what you use, they are heavy engines. What you have to figure on is getting the boat up to speed on a plane, I think a diesel would be good at it. A turbo diesel certainly would be. Plough along with much water resistance, with a petrol engine and yeah, you gunna use fuel. In a diesel, I'm suspecting you are going to use less fuel than a petrol guzzler. .... and there is the biodiesel option Heck, ships use the biggest diesel engines (and most powerfull) engines ever built in the world .. it's gotta be all good. I'd be wanting to consider salt conditions. Car diesel engines should be generally good with it, however some components might not like being in a marine environment all the time, and *certainly* might not like sea water as a coolant. Set up a radiator with proper coolant arrangement would be better. Unless a proper off the shelf kit of engine and parts in mind for a boat, it would be a lot of work, and a few oooops, "tweak that and this a bit" moments I would think.
From: D Walford on 26 Feb 2007 22:38
eeviil inc. wrote: > D Walford wrote: >> JD wrote: >> >>> had one of those myself forty years ago, except it was a three cylinder >>> Perkins. Box was a standard marine one, as you say, forward, neutral, >>> reverse by a small lever that actuated the hydraulic application of >>> epicyclic gears, giving a 2:1 reduction both forward and reverse. >>> Probably >>> not very accurate to call it a slushbox as there was no torque >>> converter. >>> Can't remember the brand of gearbox. Most marine applications need a >>> reduction gear for the propeller. >> >> >> I did my apprenticeship with a Perkins diesel dealership so I >> occasionally got to do a bit of work on marine engines (I mostly >> worked on tractors and machinery). >> I can't remember ever putting a spanner on one of those transmissions >> because nothing ever went wrong with them. >> IMO replacing a diesel with a petrol engine in a yacht is crazy and >> asking for trouble from dangerous petrol fumes. >> >> >> Daryl > > I remember this box was pretty knackered, but he fixed it, or got it > fixed. It seemed to be slipping badly, to the point that if you grabbed > the uni joint it would stop spinning while in either gear. Mind you when > he bought the yacht it was sitting on the bottom of Rose Bay (in > Sydney), yes, on the bottom. So water would have well and truly > impregnated everything. I can't remember why he had bolted it to a > Holden 6, but the Perking copped a complete rebuild and went back in the > yacht along with the fixed box. > "Twin Disc" is a common brand of boat transmission, they have been around for a long time and I think that was the brand most commonly fitted behind most Perkins marine engines. I've overhauled quite a few Twin Disc torque converters that were fitted to road graders but no boat stuff. Being full of salt water doesn't usually do them a lot of good but if it hadn't been under too long it would have been ok after a strip and rebuild. Daryl |