Marine Conversion of Isuzu Diesel

[Paul F]

Hello All,

Thankyou for your help and very useful answers to my last thread " Underloading a Diesel "

This is a link to my photo album of the work I did last winter, converting a ISUZU 2.8 turbo diesel ( 4JB1-TC ) to replace the V8 petrol engine in my Bayliner boat : http://s1181.photobucket.com/albums/x425/Swordfish20/

[whitepointer23]

great job paul. i love how well detailed the engine is. looks like a factory job. i have an isuzu 6bb1 diesel out of a truck which i am marinising to adapt to a volvo 270 leg. its quite a big engine but puts out 145 hp at 3200 rpm naturally aspirated.

[FAST FRED]

"converting a ISUZU 2.8 turbo diesel ( 4JB1-TC ) to replace the V8 petrol engine "

Please share the performance RPM/speed fuel flow,

Both before and after if you can.

[Paul F]

Originally Posted by FAST FRED

"converting a ISUZU 2.8 turbo diesel ( 4JB1-TC ) to replace the V8 petrol engine "

Please share the performance RPM/speed fuel flow,

Both before and after if you can.

Hi FAST FRED,

I did show some information in this thread re prop sizing : Prop Question from new member


I only used the boat for a few days in one month last year, the V8 was the origional engine, 25 years old with very low compression. It drank one tank full ( 58 gallons ) during this month at 6 MPH, so I decided that I would rather sacrifice speed and go for economy with a smaller diesel.

This year 165 hours has used 350 litres of diesel fuel, approx 2.1 lit. / hour at an average of 1500 RPM.

I have tried two props, with a 15 X 13 I get: 1000rpm / 3.9 mph, 1400rpm / 5.5mph, 1800rpm / 6.8mph max rpm 2900
with a 15.25 X 15 I get: 1000rpm / 4.5mph, 1400rpm / 6.2mph, 1800rpm / 7.4mph max rpm 2600

Regards Paul

[Paul F]

Originally Posted by whitepointer23

great job paul. i love how well detailed the engine is. looks like a factory job. i have an isuzu 6bb1 diesel out of a truck which i am marinising to adapt to a volvo 270 leg. its quite a big engine but puts out 145 hp at 3200 rpm naturally aspirated.

Hi whitepointer,

I am using the same Volvo drive, I think in the US they call it the 275, ? 270 leg with 280 transom shield. Have you considered the gear ratio of your drive ? Mine is the 1.61 : 1, as the V8's use. I cannot get full RPM from the engine with a 15 X 13 prop, If I go to the 1.89 : 1 ratio I will have a better choice of available props from 15 pitch upwards, and I could also try a four blade.

How are you going to sort the flywheel cover/bell housing to connect to the drive, did you see in my photos how I did mine using the old unit plus some welding. I bought a TIG welder, then found it easy to make all the parts I needed.

Regards, Paul

[whitepointer23]

i have the 1.89 ratio. mine is easy to adapt as the truck engine has a flywheel housing which protrudes past the flywheel. so i just have to make a borgwarner pattern plate to bolt on the back and space the drive plate accordingly. i have a volvo to borgwarner pattern adaptor on the transom assembly. the biggest job for me will be making the manifold.

[comfortdiesel]

hello, every body, I am grant from comfort diesel power limited. currently we are develop our Isuzu 2.8 TDI engine for marine, I have got a heat exchanger from Bowman, now I need comments for the impeller pump. could anyone give me some comments? For which model of the sea water pump I should use, or some specification for the water pump?
I have just finished our conversion for cummins 4 and 6 cylinder engines, 130-350HP engine. they are successful, because you always request the low height engines. If you interested, can veiw our link www.comfortdiesel.com

[Paul F]

Originally Posted by comfortdiesel

hello, every body, I am grant from comfort diesel power limited. currently we are develop our Isuzu 2.8 TDI engine for marine, I have got a heat exchanger from Bowman, now I need comments for the impeller pump. could anyone give me some comments? For which model of the sea water pump I should use, or some specification for the water pump?
I have just finished our conversion for cummins 4 and 6 cylinder engines, 130-350HP engine. they are successful, because you always request the low height engines. If you interested, can veiw our link www.comfortdiesel.com

Hello Grant,

Did you look at my photos ? They show all the marine conversion I did on the 4JB1-TC engine. I machined an alloy adapter plate to bolt to the front lower pulley ( end of crankshaft ) and bolted the Jabsco pump to the alloy plate. I used the 1" Jabsco pump from my old engine, 5.0 litre V8. I think Bowman suggest that a 3/4" pump is OK, but my 1" one works well, and gives plenty of cooling water for the intercooler.

I did keep the standard Isuzu oil cooler on the engine, this is cooled by the internal engine water, and does not cool the oil enough. I am going to fit a marine type oil cooler in the circuit from the Jabsco pump, as this colder water will cool the oil better.

I am happy to help with any other questions you have. Do you possibly have a power output curve diagram for this engine, as I am trying to work out the best gear ratio and propeller size ?

Regards, Paul

[comfortdiesel]

hello pual, thanks for your comments, I have the curve diagram for the engine, but I do not know how to attached it here, if you have a email address, or MSN please forward to me, I will send the data for you.

Regards grant