A friend said

[Grace and Favour]

Buy him a good bottle of his favourite tipple and apologize for being a bellend.

[mark99]

 

 

The perfect xmas gift for someone I know!

[Naughty Cal]

Surely that depends on the boat engine. I mean, a Bolinder is very different to a modern common rail diesel engine.

Indeed.

 

Our Volvo engine (2.4 litre diesel) probably kicks out the same HP as a similar engine in a vehicle at 170hp

 

Probably doesnt rev as high though at 3800rpm.

[Keeping Up]

I don't understand the idea of a multi speed gearbox for a displacement boat. Am I missing something?

 

I once saw a small Springer that had 12 forward gears. It had been stripped out inside and fitted with an American lorry engine (a Mack?) specifically to enter and win a tug of war competition. It looked like a normal old Springer although it did sit a bit low in the water, but it towed every other boat backwards with ease. He said that he did have to change up to 4th in the final though.

[Tony Brooks]

Whilst its true that modern vehicle engines and OUR marine engines are all compression ignition engines I would contend they tend to be rather different beasts (possible exception of NC).

 

The size of our engines means they would normally be used in cars and light vans where (for some reason) the makers put some sort of premium on performance.This means that they will strive to reduce the mass (weight) of the moving parts to reduce the inertia and thus improve acceleration. Our engines tend to be based on plant and industrial engines that often tend to work at one speed and all have a degree of longevity as a design requirement. This means they will probably use heavier parts.

 

The use of turbocharges and/or superchargers plus intercooling as already been mentioned. I note the Bukh DV48 is really a turbocharged DV36 but it doe not use an intercooler.

 

The biggest difference is in the fuel systems. IF the friend thinks he is going to plug his fault code reader into Dar Kumar's boat he will be in for a shock. We use mechanical fuel injection equipment that has not altered in principle since the 1930s or when the DPA/Rotary pumps were designed (1960s?). Modern vehicles use very sophisticated electronically controlled injection systems usually providing more than one "shot" of fuel per cycle and operating at much higher injection pressures. From memory our systems usually pulses at about 2500 PSI while a modern car will inject at around 30,000 PSI.

 

Then there is the technology used on modern engines to reduce the exhaust emissions which can involve mechanisms on the actual engine.

 

I would say they are now distance cousins rather than the same thing, but its certainly not worth falling out over..

[WJM]

I understand that my Isuzu engine is a standard Isuzu car/van engine. The adaptations to 'marine-ise' it centre around the fact that in a boat an engine runs for long periods at the same speed, while a car/van will accelerate repeatedly. A standard road engine will be susceptible to coking in a boat environment so the marine-isation changes involve (I am told, please correct if you know better) the firing sequence of the cylinders? through the use a different crankshaft? Thats what I have been told!

[Tony Brooks]

I understand that my Isuzu engine is a standard Isuzu car/van engine. The adaptations to 'marine-ise' it centre around the fact that in a boat an engine runs for long periods at the same speed, while a car/van will accelerate repeatedly. A standard road engine will be susceptible to coking in a boat environment so the marine-isation changes involve (I am told, please correct if you know better) the firing sequence of the cylinders? through the use a different crankshaft? Thats what I have been told!

 

It may be derated, that is the injection system set to inject less fuel so it produces less power. The only "cooking" that marine use may involve is overheating the oil, although I doubt that would happen in canal use - more likely running the oil too cool, and that can be solved with an oil cooler.

 

Changing the firing order will make no difference to the heat produced unless you start cutting out individual cylinders but on a four cylinder that would make it very rough and jump about. Altering the crankshaft could only reduce or increase the compression ratio and that is critical to cold starting, anyway changing the pistons would be a cheaper way of doing it.

 

Now tell us who told you!

[Peter Reed]

I once saw a small Springer that had 12 forward gears. It had been stripped out inside and fitted with an American lorry engine (a Mack?) specifically to enter and win a tug of war competition. It looked like a normal old Springer although it did sit a bit low in the water, but it towed every other boat backwards with ease. He said that he did have to change up to 4th in the final though.

Wow, I would like to see that.

[Laurie Booth]

Picture of my new diesel engine being delivered awaiting fitting to my 35ft. Springer.

 

 

[Roadsteam]

Picture of my new diesel engine being delivered awaiting fitting to my 35ft. Springer.

 

 

Photoshop image of a Ford Festa engine sitting on a corgi 1/50 scale model truck and trailer.