Auto Diesel for Jet

mate, why don't you find a wrecked navara with one of the 2.5 common rail motors, light weight and about 130 kilowatt, should be one around the territory somewhere thats cleaned up a cow or roo.

 

In that sort of power range you'd be looking at perhaps a Kodiak, Scott jet, older Hamilton 773, Flow-pro, or similar.

Jets are fine on open water. Once again some people have a pre-determined view of jets based on things transpired in the '80's when sea boats were merely fitted with jets rather than designed for them, or river boats were scaled up with cabins fitted and sent to sea with poor handling characteristics.

EVERYTHING NEEDS MAINTENANCE. Whether it's your lower gear case in an out-drive, gearbox, gland and bearings in a vee-drive or a jet.

5m isn't overly small. I frequently fit jets into boats less than 5m. For your application a variable deadrise or warped hull will be of advantage, and as was mentioned a delta section along the keel line to both aid lift at the transom and allow good clean flow into the jet.

 

How many 5 metre diesel powered jet boats have you encountered, speedboats ? Sounds like a tough essay to me. You don't see them that size with diesel sterndrives, and given the higher losses thru a jet than a prop, hardly seems a likely bet.

 

Here's one I made earlier

 

I built one with a centre console powerd with and LD28 coupled to a Hamilton Jet Colorado in about '97 (before I thought to take pics). Scott jet has built one with the motor from a Toyota Prado in it direct coupled to one of their pumps. Went for a ride, it was no V8, but did everything we wanted.

At the risk of over-simplifying, a motor is a motor, has crank, pistons, valves, inlet and exhaust. If you are a diesel mechanic (pronounce; dis-ease-al)then it makes sense to marinise a diesel. Custom marinising is not really a big deal, even easier with closed circuit cooling. The crank doesn't care if it is turning wheels or impellors.

Could always try these guys for small diesel motors. There are a few manufacturers in the US toying with these in small boat appications.
http://www.fnmalaska.net/HPE225_250Series.html

 

Thanks for those replies, I knew there'd be one or two out there somewhere.

 

One thing you need to consider is the operating range of the jet pump. You'll find that the pumps start working at higher RPM's which will limit your choices for a diesel engine.

That's not to say you can not use one, I have a 28' with twin Volvo penta 150 hp diesels and Hamilton 214's in it. But the engines turn up to 4000 RPM. I don't believe you'll be happy with an engine which tops out at 2400 RPM.

Otherwise, go ahead and have fun with that.

 

Wrong!!

Due to the power characteristics of the jet pump (Power=const*rpm^3), a specific part power is produced at a slightly higher rpm than that same power with a propeller, (Power~const*rpm^~2.65). But since we here talk about a percentage of the max power rpm, your conclusion is wrong.

In fact, as long as we are discussing "normal" diesel rpms (and 2400-2500 rpm belongs there), the low rpm range makes cavitationfree low-speed, full power operation possible.

So for "errant", the question is which engine to go for; you will need minimum100-110 hp from a light engine, including the weight of a heat exchanger, possibly an intercooler, oil cooler and water-cooled exhaust manifold. It is very easy to enter an "outward running design spiral" when you find you need more hp's; bigger engine=heavier=more fuel=more wheight aso........ . Start with a revision of weights, and search for light-weight equipment, including engine.

I'm a bit surprised you feel uncomfortable with more than 80 hp from the 2.4 l engine. If you check the Iveco "Daily" engine (the 8141 type), the older versions come at 120 hp/3600 rpm; the VW engine is even lighter. Both of these use timing belts though, which requires that you keep an eye on running hours, but otherwise, they are excellent work-horses.

Since most commercial jet units in this power range come with a cooling-water tap, there is no need for a separate sea-water pump in this installation, which makes conversions easier.

 

BBandura don't think your Hamiltons are 214's maybe 213 or 241 both very different to each other. Unless they were renumbered for Canada.

 

Sorry, they are HJ213's... http://www.hamiltonjet.com/pages/hj213.html
The Salt water version of an HJ212. And if you look at the spec's on the Hamilton site it does say 4000/4500 RPM.

I will admit I have more experience with the Berkely jet's and they as well need RPM to get up on step, once there you can throttle back but I doubt my boats would get onto plane at much less than 2400 RPM. Just saying.

The boat with the two Hamilton's is a shipyard built boat which was used for the Canadian government off Vancouver so I can only imagine they had a clue when building it. I've not had it in the water and likely will not, I bought it for the engines and pumps to replace the 453 detroit's with props in a 56' Catamaran I also own. Mostly so I can get into shallow areas since the props need an extra 2' below the hull.

I am a heavy duty mechanic by trade and would not want to run a diesel at top RPM for extended periods, that would be my real issue. There are diesels which will run faster than 2400 and a careful look at what the jet requires as well as the weight and speed desired are would be in order.

My other boats are:
15' river boat, 350 chev, berkely jet
19' Cougar bubble deck w/ 454 chev, berkely jet
19' Tahiti with plans on a 454, berkely jet

 

Hi I guessed from your figures they were 213's ,this was the diesel version of the 212. The 241 had a larger diameter mixed flow impeller and could be a high flow low velocity pump, which would have transformed the performance of that boat .Good luck with your project.

 

The toyota 1HD loves high RPM, 3800 is cruising.

But this is what you get when putting a deisel on a jet.

Did I say talk to the jet manufacturers --yes Im sure I did.

 

the 4000-4500 rpm is for the HJ212. As was pointed out the 212 is the 'gas' version and the 213 for salt water diesel. They look almost the same, but the 213 comes with anodes, hydraulic bucket actator with pump and cooler mounted to the suction piece (actuator arm comes through the bulkhead on the stbd side, the easiest visable external give-away), larger diameter and heavier mainshaft hence the 'gas' impellers of the 212 won't fit.

What about something like the D-4D by Toyota (1KD-FTV). 410Nm of torque and 127kW of power in a tidy 3.0l straight 4 turbo package. Well in excess of the 100hp that has been mooted here, and again coupled to a scott jet or Kodiak or Flopro with coarser impellers would see the performance you look to be after.

 

Yes a lightweight auto diesel can work very well in a jetboat. I built an 18' welded aluminum jetboat in 1992 and put a Mitsubishi 2.3l turbodiesel out of a small pickup in it(with a fresh rebuild when installed). It ran very well for me for 14 years and about 2500 hours and made about 105hp with the pump turned up a little. Was still going strong when I filled it with gas by mistake which blew the head gasket and broke a piston. I replaced it with a VW1.9l tdi which has been even better. With a little software tweaking and a bigger turbo it makes about 250hp and performs very well, well getting me a consistent 10 to 12 mpg. I have 4 seasons on the vw now and 750 hours with no problems whatsoever. I am using an American Turbine SD309 pump. The 2.3 mitsubishi turned an A impeller to 3150rpm, the 1.9 vw turns a 9.5" impeller to 3800rpm. I would recommend the vw, it's been the best jetboat engine I have had to date and I have been playing with jetboats since the mid 70's. I also have a 2.4l toyota turbodiesel in a 86 toyota pickup and can't say I would recommend it for a boat. It has been about the worst diesel engine I have ever owned. Reliable enough but it doesn't make much power and burns a lot of fuel doing it. Just my opinion, others may have different views on the toyota and it may be an entirely different engine than the one your looking at.

 

shakescreek ,when did you last have your dyno serviced ?