Engine Dilema - Perkins 4.236

[coopec]

This really is a non issue for sailboat motors. Most people if using their motor will load it well. a cruising speed of a 9-11m yacht with an engine in the 20-40hp range will cruise between 5-6.5 knots which will require 50%+ of maximum load and usually higher, particularly with smaller engines. The issue with generators is well known, but is not transferable to yacht use. As I suggested earlier the only situation where you might get long term light load running is using the engine to "top up" sailing speed, but this is not common.

My last post on this thread! (A very busy day ahead!)

What about using the diesel auxiliary to charge the house bank? Is that OK?

 

[Spirit (of Glenans)]

" causes the pressure inside the cylinders to drop, impeding proper combustion and leaving ..." Really? I suspect a bit of poor translation.

I would have thought that bore glazing and gumming up of piston rings WOULD cause loss of compression....

 

[Tranona]

My last post on this thread! (A very busy day ahead!)

What about using the diesel auxiliary to charge the house bank? Is that OK?

No - already mentioned this in an earlier post - although in reality the few hours that people are likely to do this probably won't result in any serious damage.

You have to remember that the vast majority of yacht engines do around 100 hours a year and rarely actually wear out. They die from underuse and neglect and it usually the bits in contact with salt water that fail rather than the basic mechanics of the engine.

 

[coopec]

No - already mentioned this in an earlier post - although in reality the few hours that people are likely to do this probably won't result in any serious damage.

You have to remember that the vast majority of yacht engines do around 100 hours a year and rarely actually wear out. They die from underuse and neglect and it usually the bits in contact with salt water that fail rather than the basic mechanics of the engine.

Yes I just saw your mention of charging batteries with the auxiliary

We have to motor 50km from A to B. Should we travel at hull speed (90% load) or motor at 5knts (40% load)?

AND this time I am going.......

 

[jdc]

While I have the greatest of respect for Vyv Cox, his paper (which I am thoroughly familiar with) is not an academic one, cites no experimental evidence and is not peer reviewed. Google search shows most articles link back to his as a source, which speaks volumes for his authority rather but is not additional evidence.

 

[dankilb]

While I have the greatest of respect for Vyv Cox, his paper (which I am thoroughly familiar with) is not an academic one, cites no experimental evidence and is not peer reviewed. Google search shows most articles link back to his as a source, which speaks volumes for his authority rather but is not additional evidence.

Indeed - ‘Google and take your pick’ is not quite the advice I’d give in response your request for peer reviewed evidence!

 

[Obi]

Apologies if already mentioned: Perkins Marine Parts and Engines - Sabre Plant and Marine Ltd

They did a marinised 4236. Mine was one, and it was rebuilt albeit about 15-20 years ago with replacement parts from Sabre, including the exchanger.

 

[Beneteau381]

My last post on this thread! (A very busy day ahead!)

What about using the diesel auxiliary to charge the house bank? Is that OK?

Not really, not enough load. 1 hp is about 750 watts, 10 amps charge at 14 volts? Do the math.

 

[Beneteau381]

I would have thought that bore glazing and gumming up of piston rings WOULD cause loss of compression....

The point I am making is that the words used imply that light running causes low compression in the cylinder whilst it is running at that point in time. Therefore my comment about poor translation.

 

[Beneteau381]

While I have the greatest of respect for Vyv Cox, his paper (which I am thoroughly familiar with) is not an academic one, cites no experimental evidence and is not peer reviewed. Google search shows most articles link back to his as a source, which speaks volumes for his authority rather but is not additional evidence.

Oh dear me.