Marinising automotive engines

[chrisharris]

Following on from the earlier thread about computers on boats, and marine engines, I have been thinking about the marinisation options for the current batch of automotive engines.

The horror scenario of having the re-engine a mid size, say 80's 90's boat, would/could prove uneconomic relative to the value of the boat, basically because the cost of the new engines - say £20k a piece?

I am slightly surprised that the economics have not led to a more extensive marinisation of existing automotive base engines - I know Lancing Marine did/do some bits for Ford engines, but what about all the Jap stuff and larger truck engines? I would have thought that it would be possible to develop a set of generic water/water heat exchangers to suit varying power outputs (would not actually matter if the heat exchanger was over capacity as the engine thermostat on the closed circuit side would maintain the correct engine temp), maybe use an electric raw water pump (with lots of failure detection stuff, actually potentially 2 pumps for redundancy!). Gearboxes could be an issue, but must be possible to adapt bellhousings to suit a different engine - most marine gearboxes (of the age I am talking about) are just simple (albeit heavy duty) hydraulic units anyway.

Engine electrics could be taken straight from the donor vehicle, the clever bits probably mounted outside the engine bay for a kinder operating environment, looms would need modifying, decent waterproof connectors etc....but all do-able.

Probably not affordable on a one-off basis if paying for engineers time to do it all, but as a partly DIY exercise I would have thought its got to compare favourably with the book cost of a re-engine? Another big plus is cost of spares, and the knowledge that if the engine ever did go pop a replacement lump would be a fraction of the cost of an equivalnet marine version.

Sure there would be negatives in terms of (potential) reliability, service life, resale value etc, but I have to say I would seriously be looking at the options if the time ever comes...

 

[tico]

Looked at this several years ago and one problem is the exhaust manifold. Either run as a 'dry' exhaust, in which case youve got a very hot exhaust manifold... 'red' hot in a small engine room!, or spend a lot of money in making a 'wet' manifold.

other thing is the turbo on a diesel.... ever seen one running hard!

Lancing do very reasonably priced adaptations of Ford lumps (or at least they did). Speaking as a very satisfied customer, and a whole lot cheaper, if you have the ability to solve installation issues, than a VP engine.

 

[PCUK]

Marinizing is a long established business and all the problems raised were ironed out years ago! It's done all the time by DIY'ers as a matter of course. Oh, and ignore all the subequent posts about "marine" engines being different to truck engines and therefore a truck engine won't do the job!

 

[chrisharris]

Re Tico - The turbo temp thing is interesting - I guess some automotive/truck diesels (most?) don't have water cooled turbos? I know my car engine (albeit a petrol) has a water cooled turbo... I do see the point about having a glowing red turbo in an semi enclosed space as not being too clever though! I would have thought making up a mixer elbow for a wet exhaust would not be too difficult? If I ever went down this route I would probably try to use and modify the VP elbows I have on the present engine...the manifold would be a problem...

Re PCUK - I am sure that some DIYers go down this route, and have heard of several cases with smaller engines, just not many with large truck engines and/or modern engines, most I have heard of have been small 4 pots..

 

[Firefly625]

I had an interesting chat to a friend of mine who has spent a while with his boat in spain. Apparently a lot of Spanish fisherman use the same basic style boats which are powered buy old diesel car engines. They are fitted along with gearbox and clutch and radiator. He witnessed first hand a engine being replaced in a boat which lead him to have a conversation with the guys doing the work. They have in their workshops around 5 engines on pallets at any one time all stripped out of old Peugeot's or Citroen, they take off the turbo, they increase the size of the radiator and adjust throttle setting and fuel pump and thermostat. Plus they are fitted with an electric fan to help feed the radiator with enough air and then produce around 70bhp. The best bit is they sell these engines at 400 euros fitted! Apparently they can do an engine change in an hour and that includes removing the engine cover that takes around 20 minutes..

I though this sounded fantastic!

 

[PCUK]

I had a 7 litre Bedford in the boat for ten years that I marinized myself. Fairly big I would say!

 

[tico]

Yup, wet elbow not a problem..... it's the manifold. Contemplated taking the existing one and just boxing it in with sheet steel and fitting inlet and outlet connections but a fair bit of fitting/welding required and even then not sure it would last

 

[ulyden]

I have used old car engines to power my boats. I used a 2.5liter engine with direct injection and cast-iron block and head! I bought the coolers from bowman (Heat exchanger and exhaust manifoild) and lined up the engine to the drive (Mercruiser) my selves! The damping plate I drilled new hols in to fit the old clutch treads!

I removed the electronic fuel pump and replaced it with a ordinary bosch VE pump.
To increase the power I mounted larger nozzles (from 0.19mm to 0.26mm holes) a 140hp charge air cooler and a KKK 26 turbo without waste gate un cooled. This was the hard point. I used a relative low A/R ratio to get enough boost at low speed! Later I open up this by 10% to decrease the boost! This winter I changed the piston rings but there was no sign of anything wrong! Bearings and all looked very good! The last engine I have used for 5 seasons! I made a stainless steel exhaust outlet and this is connected to the mercruiser drive! This looks fine after 5 years!

 

[Latestarter1]

Marine conversions

I do not know much about little puddle jumper motors. And not really fair that I comment too much as I am currently involved in development of 180 to 270 Hp conversion kit and I disaprove of using forums for back door advertising.

However marinisation has to be done with a reasonable understanding of engineering.

For example you CANNOT take short cuts with items like exhaust elbows. Most mainstream are poor and two in particular which have cast elbows are utter junk. Fabricated ones are 316l stainless, hot seawater and sulphur from exhaust forms potent mix with high sulphuric acid content which eats away from the inside. I have always specified Inconel 625, guys at local yogurt factory know all about the metallurgy, so guess where I get my elbows manufactured!

 

[Davy_S]

I had an interesting chat to a friend of mine who has spent a while with his boat in spain. Apparently a lot of Spanish fisherman use the same basic style boats which are powered buy old diesel car engines. They are fitted along with gearbox and clutch and radiator. He witnessed first hand a engine being replaced in a boat which lead him to have a conversation with the guys doing the work. They have in their workshops around 5 engines on pallets at any one time all stripped out of old Peugeot's or Citroen, they take off the turbo, they increase the size of the radiator and adjust throttle setting and fuel pump and thermostat. Plus they are fitted with an electric fan to help feed the radiator with enough air and then produce around 70bhp. The best bit is they sell these engines at 400 euros fitted! Apparently they can do an engine change in an hour and that includes removing the engine cover that takes around 20 minutes..

I though this sounded fantastic!

Many years ago I got wind of a load of Ford Transit diesel engine 2.5 litre I think, that were erm, nicked to order, they were shoehorned into series Landrovers, plus used in displacement fishing type boats in exactly the way you describe, so they must have worked!

 

[ulyden]

Many years ago I got wind of a load of Ford Transit diesel engine 2.5 litre I think, that were erm, nicked to order, they were shoehorned into series Landrovers, plus used in displacement fishing type boats in exactly the way you describe, so they must have worked!

Of course it works! The engine doesn’t see any difference running at the high way at 4000revs than in a boat with the same revs! I use the same engine.
If it brakes down I swop engine in a few hours. Just move the manifolds and coolers over to the next. It’s a low demand so the prices on these engines are low. You get an engine fore 5-800euros here in Norway! If this engine had a 6 cylinder version I would have a bigger boat!

Spare parts are cheap and maintenance is easy!

 

[volvopaul]

Following on from the earlier thread about computers on boats, and marine engines, I have been thinking about the marinisation options for the current batch of automotive engines.

The horror scenario of having the re-engine a mid size, say 80's 90's boat, would/could prove uneconomic relative to the value of the boat, basically because the cost of the new engines - say £20k a piece?

I am slightly surprised that the economics have not led to a more extensive marinisation of existing automotive base engines - I know Lancing Marine did/do some bits for Ford engines, but what about all the Jap stuff and larger truck engines? I would have thought that it would be possible to develop a set of generic water/water heat exchangers to suit varying power outputs (would not actually matter if the heat exchanger was over capacity as the engine thermostat on the closed circuit side would maintain the correct engine temp), maybe use an electric raw water pump (with lots of failure detection stuff, actually potentially 2 pumps for redundancy!). Gearboxes could be an issue, but must be possible to adapt bellhousings to suit a different engine - most marine gearboxes (of the age I am talking about) are just simple (albeit heavy duty) hydraulic units anyway.

Engine electrics could be taken straight from the donor vehicle, the clever bits probably mounted outside the engine bay for a kinder operating environment, looms would need modifying, decent waterproof connectors etc....but all do-able.

Probably not affordable on a one-off basis if paying for engineers time to do it all, but as a partly DIY exercise I would have thought its got to compare favourably with the book cost of a re-engine? Another big plus is cost of spares, and the knowledge that if the engine ever did go pop a replacement lump would be a fraction of the cost of an equivalnet marine version.

Sure there would be negatives in terms of (potential) reliability, service life, resale value etc, but I have to say I would seriously be looking at the options if the time ever comes...

You cannot compare a pure bred marine engine to an automotive based unit.

Look at whats on offer to todays buyers, look what people want and look whats actually fitted in todays modern boats.

Yes pure bred marine engines that start on the drawing board as a marine engine only, thats why they do the job, well most of the time.

Volvo and cat make pure bred engines that are light, quiet and take up less space, together with the correct camshaft profiles for marine use, look at the heat in such a small space, I still laugh at the ford sabres and mermaids with asbestos wrap around the turbos and dry risers that are an instant fire hazard! not including the dust particles when you have to remove one.

Very few pleasure craft builders buy these type of engines anymore, the fishing comunity will as there not bothered abou smoke, bad vibration and oil in the bilge so they still buy them.

To be honest stick with whats on offer unless you have millions of spare £££ to invest and bring to the marked the ultimate marine engine that will make me redundant!!!

 

[omega2]

I still laugh at the ford sabres and mermaids with asbestos wrap around the turbos

Don't you laugh at my 30 year old Sabres, they do what it says on the tin, and will not require a rocket scientist to repair, that is if they ever break down.

 

[ulyden]

You cannot compare a pure bred marine engine to an automotive based unit.

Look at whats on offer to todays buyers, look what people want and look whats actually fitted in todays modern boats.

Yes pure bred marine engines that start on the drawing board as a marine engine only, thats why they do the job, well most of the time.

Volvo and cat make pure bred engines that are light, quiet and take up less space, together with the correct camshaft profiles for marine use, look at the heat in such a small space, I still laugh at the ford sabres and mermaids with asbestos wrap around the turbos and dry risers that are an instant fire hazard! not including the dust particles when you have to remove one.

Very few pleasure craft builders buy these type of engines anymore, the fishing comunity will as there not bothered abou smoke, bad vibration and oil in the bilge so they still buy them.

To be honest stick with whats on offer unless you have millions of spare £££ to invest and bring to the marked the ultimate marine engine that will make me redundant!!!

You have to remember that smaller marine engines are original automotive engines. They of course have different turbos, camshafts, and coolers but the basic is a car or a truck engine!

A lot of new engines today also have uncooled turbochargers. It’s cheap to isolate. Less heat loss to the exhaust and they are much cheaper to by. Even VP D3 I think have uncooled turbo!

To compare 20yers old engines with brand new is unfair. Most of the old engines were not smoking when they were new!

I have a neighbour that owns a Volvo car with a D5 engine!( same as D3). The smell from this is not good. The gray smoke does not look ok either!

You also have to remember that some of us don’t want to relay on workshops that is fully occupied the whole summer and an engine that have 100 ways of giving trouble! I only need an engine that takes me were i want when I want. No rocket science! My engine don’t smoke even when its cold, it don’t leak any oil, its not using more fuel than a new one It don’t even care about the diesel quality! Maybe its making more noise and have a higher nox emissions. But i don’t care! I’m just using it less then 100hours pr year. The few days we have in Norway with good whether I want a working boat!

 

[PCUK]

Give me a big truck engine with modest output and sensible revs - say 300hp rather than a 3 litre turbo nutter b*st*rd like Volvo push out!

 

[ulyden]

I really do agree! Problem is if you want a Z drive. Most of the truck engines have low speed and hi torque! Only VP D6 D4 has hi speed and low torque! And bad fuel consumption at hi load/speed! If you go back 3o years you will find similar engines as VP D4 D6. Fiat 5.5 from 1978 share the same bore and stroke! When all these light trucks started with turbos the stroke was increased! (Like the VP 60 series)

I was working with MTU engines and they had curves that showed the cost/power density. More power from a specific volume higher cost pr hp hour!Mainly because of shorter service intervals and higher consumption!
MTU is powering a lot of the fast ferries here in Norway.