reasons not to use high-performance diesels

Water cooled exhaust manifold will be a challenge.

Cool air to feed the turbo will be a challenge.

The VW turbo diesel is marinized by some company that I cant remember.

Also look at the marinized Korean diesels. Hyundi I think. They produce an inboard outboard range.

 

Michael,
i like challenges
A watercooled manifold will take some work but do a lot of tig-welding on exhausts and motorcycle frames so if i find any collector that is near to what need, i think modifications can fix this.
For the intercooler i think the best solution is a extra pump to feed a water-air cooler and then a oversized turbo anti-heatsink.

Hyundai makes the seasall-engines. They used the same cases as VW-engines i believe.

Joris

 

Hi Joris,
Normally I would suggest against 'common rail and electronically controlled engines with turbo chargers', as the engine room heat may prove a little overwhelming, but from the tone of the thread and your posts I gather that you are after short bursts (for water-skiing or paragliding), on good days and retrieving the boat after the day's use. Good ventilation and a wet exhaust with a good (stainless steel) heat exchanger should be a start to enjoyable boating and help reduce the engine bay heat...

Best wishes and have fun...

 

I put a 1.9l Volkswagen tdi in my welded alumunum jetboat six years ago. Have put just over 1100 hours on it since then and been very happy with it. I average about 10mpg at a 30mph cruise compared to 1.5 to 2mpg on my previous bigblock V8 jetboat. I just got a low mileage engine from an autowrecker in the UK and installed it with a dry exhaust. No internal changes just eliminated the egr and used a air to water intercooler and changed to a larger turbo and of course an ecu remap.The engine I used was 160hp stock and makes about 230hp with my current tune at a weight of 350lbs, although I never run it at more than 150hp output for any extended length of time. No issues with it so far.

 

Well done and an excellent post, Thanks - masalai

 

If Bowman in the UK doesn't have the manifold for your intended engine, they certainly have something similar in size and shape. You can weld adapter flanges from stainless or ordinary steel if the mounting hole patterns are different.

A heater core from a large passenger car unit makes a good intercooler.

 

Masalai,
The boat will be for small trips, cruising mostly. And yes i will not leave the boat in the water overnight. I'm glad you mentioned the engine bay temperature as this is something i am very concerned about. Good to know i need to pay extra attention to that.

CDK, if i use a heatercore from a passenger car i guess i need to run it with cooling fluid, not outside water?

Thanks for all the advice, now i know it is possible to use such an engine i need to decide on which boat it will be. I've bought The runabout Book online. Not cheap at 150euro but i've read so much about this book i'm sure it will be a good source of information and help me make up my mind on the design.

 

I would make some calculations before marinizing a diesel car engine. The final cost can be surprising as you buy all the accessories one by one at the worst price.
I've done that, and kept simple to get it cheap; dry escape and blowers to feed air in the engine. That works and it's pretty noisy because of the blowers, but i could have done a better silencing work.

Most of the European diesel car (and gas) engines are able to go WOT long hours without problems as German have free speed highways, and I can say that WOT is a common situation for 2 or 3 hours on the small gas and diesel engines.
If you leave the original ECU, you can simply "derate" it by installing a spring on the throttle making giving a hard point you can feel at the desired RPM. The map of the car ECU is made to accommodate 99.90% of the situations and will take care of that, and has all the sensors for that purpose. it's not an old Detroit, modern diesels are made for working at partial or full load whatever, at the difference of the "museum" pieces.

An acquaintance of mine has installed a diesel car engine on a little plane, an Isuzu 1500cc from an Opel Corsa entirely genuine, and the engine has been able to take 4 hours WOT at 3500 RPM without any problem. The TBO is estimated 2300-2600 hours, but kept to 1000 hours. The Isuzu engines make easily 350000 to 500000 km, and the big Mercedes and BMW diesels 500000 to 800000 km in Europe.
The old 1990 Citroen 1135 cc 65HP gas engine air cooled flat four has been tried 1000 hours WOT at 6000 RPM full charge with just a stop of 5 mn every 120 hours to change oil and plugs. The engine worked 42 days WOT at full charge and was in pretty good shape at the end. The lone modification was a bigger oil cooler. The Guzzi V75 motorcycle engine had a similar test and succeed, it has been used as engine drone.

For recreational use of 100-150 hours year I'd stick to a gas engine, marine of preference. The price and complication of marinizing a diesel is not worth in this case.
Several Ford DURATEC engines are very good candidates as the side clutch is SAE 6 if I remember well and will accept marine transmissions without pain.
For example the 2.3L 4 cylinders 150 HP, designed by Cosworth, weights only 130 kg...and it's very strong, it can take 7200 RPM for long times without problems, at 6000 RPM it is purring. In England they are tuned to 220-240 HP just changing the cams and nothing other except a custom ECU and a exhaust. These engines make a complete rally races season (and it's very hard use) with just servicing.
You can find many at good prices. The V6 used on the Focus are good candidates also.
The will cost 50 % at least less than a diesel, are easier to marinize and the savings will pay the gas for at least 5 years.
Or simply a good Crusader or even Mercruiser 6 liters if weight is not a problem.

In boat use a SMALL turbo diesel will have a specific consumption of around 180-190 gr. of diesel per horse per hour, and a gas engine of same power around 230 gr. of gas per horse per hour. For 120 HP that gives for the diesel 26 liters hour and the gas 37 liters hour. Now you can make a excel sheet...

 

Or 155 g/hp/hr and 187/g/hp/hr for these common diesel and gas engines respectively if you operate near their most efficient loads/rpms.

http://ecomodder.com/wiki/index.php/Brake_Specific_Fuel_Consumption_(BSFC)_Maps#Saturn_1.9L_DOHC

http://ecomodder.com/wiki/index.php/File:ALH_BSFC_map_with_power_hyperbolae.png

 

These consumptions are made in laboratory and not representative in real life on a boat. So if they are very interesting I doubt you can achieve them with engines buried inside boats under the nice summer sun...

There were only rough estimations for a calculation of cost. They do not mean to be representative of a particular engine.
In real life the best small engines specific consumption I've seen on boats were around 210 gr/hp/h in 4S (EFI), and 170-175 gr/hp/h in diesel (with mechanical injection).
Consumptions on small boats are very variable with the wind, currents and sea state and just indicative.

If you're able to get 157gr/HP/h from a small diesel on a small boat, make a thread on the subject because it's not far from the real life specific consumption of a 1500 HP Man.

 

With all the air to water intercoolers available these days online for cheap in just about every conceivable configuration, some for under $100 it doesn't make sense in my opinion to bother messing with a heater core to make one.Heat exchangers for the engine coolant on the other hand are harder to find cheap so it may make some sense there to build your own there or go to something like a keel cooler in a metal hulled boat.

 

Very interesting shakescreek!
I looked at frozenboost.com where they offer coolers starting at $150, a real bargain. Unfortunately the material is unspecified aluminum and wall thickness is not mentioned, so the life expectancy with seawater as a medium maybe very short.

At that price it would not be a problem to replace a unit after one or two seasons, once a month would quickly become a nuisance. Does anybody have experience?

I suggested a heater core because some of these older ones are copper or brass and are impervious to seawater. A core from a gas boiler or central heating unit is also a likely candidate.

 

Much more important for the choice between gasoline and diesel is the difference in price. The gasoline engine for Joris offers no option but the ridiculously expensive Belgian gasoline, where the diesel allows the use of all kinds of CH based fluids with the approximate viscosity of diesel fuel, ranging from low taxed heating oil to bio-diesel or even frying oil with 5-10% gasoline added.
My VW 1.9TD engines have never tasted a drop of diesel fuel since they began their marine life.

 

I don't want to hijack the thread, but it seems to have collected the right people to answer my vaguely related question. I have often heard concerns regarding intercooling that condensation can develop in the charge air if separate loop cooling is employed. And that same circuit cooling which puts charge air in the range of 190F is preferable on small machines. Is this just theoretical? Does anyone have any experience with intercooling troubles. As Shakescreek mentioned, there is a pretty strong temptation to increase turbo size when converting to marine since throttle response is usually a much lower priority than in a car and I suppose because the average load is higher as well.

 

There are various online calculators that will tell you at what pressure and temperature you will get condensation (the dew point). For example:
http://www.srh.noaa.gov/epz/?n=wxcalc_vaporpressure