Oil heat vs coolant heat

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Additional question regarding the oil pan heaters. Wolverine/Phillips-Temro have heaters that are either without a thermostat, or have a thermostat with two different ranges - 170-200F, and 270-300F.

If I am just using these for the oil pan, wouldn't I want one with a thermostat so it doesn't just heat away perpetually? If so, it seems like the 170-200F range would be the safest/best, as from my research, most oil temps in diesel engines would never exceed 200F....
 
170-200 would be fine as a range. That would keep the oil pretty close to fully warmed up temperature (figure that running under load, oil temp can be anywhere from 180 to 250 or so depending on the engine and cooling setup).
 
170-200 would be fine as a range. That would keep the oil pretty close to fully warmed up temperature (figure that running under load, oil temp can be anywhere from 180 to 250 or so depending on the engine and cooling setup).

Thanks! That's what my research and thought process led me to as well, but wanted a second opinion!
 
If you have a loop from your engine to heat water, just leave the water heater on and it will heat the engine.
 
If you have a loop from your engine to heat water, just leave the water heater on and it will heat the engine.

I do not have a loop for the engine to heat the water, although I would love to have that option mainly so I could have hot water without having to turn the generator on.

Also, I have two engines, so even if I had this, it would likely only warm one of the two :) Good idea though!
 
Steve, an alternative to the Wolverine-type pan heaters are the immersion type with a heating element in the engine's internal coolant, installed in a block port with pipe threads. I have these, made by Kim, called Hot Starts. I only use them before winter starts or during sub-freezing weather. They are 500 watt and I run them on timers, 2 hours on, 2 hours off, alternating between engines. The engine room stays about 25 degrees above ambient. I've done this through 15 winters with both Detroits and Cummins with no ill effects.
 
Steve, an alternative to the Wolverine-type pan heaters are the immersion type with a heating element in the engine's internal coolant, installed in a block port with pipe threads. I have these, made by Kim, called Hot Starts. I only use them before winter starts or during sub-freezing weather. They are 500 watt and I run them on timers, 2 hours on, 2 hours off, alternating between engines. The engine room stays about 25 degrees above ambient. I've done this through 15 winters with both Detroits and Cummins with no ill effects.

Yeah I would very much prefer to do something like this, but I am having a difficult time finding the correct block port that I can use. The Volvo Penta manuals don't really call them out, although I have found a number of things that look like one. Even searches on BoatDiesel.com and elsewhere have not resulted in a definitive answer.

I'd most likely have to drain the coolant and start experimenting before I could find the right solution...
 
My $0.02

If you are worried about thick oil use synthetic oil and problem is solved. But how thick can the oil be if the boat is not ice bound?

If you want better start or less smoke heat the combustion chamber in the block where the combustion happens. The combustion chamber is the part of the block surrounded by coolant and the part that will be warmed by heating the coolant. The oil pan is a long way away from the combustion chamber. Heating the oil laying in the bottom of the oil pan will take a long time to spread any heat to the combustion chamber in the top of the engine.

If the engine has freeze plugs that you can replace with coolant heaters the installation would be so clean, simple and effective it is a no brainer to go that route. Otherwise a tank heater will work but add a lot of clutter to the engine room.

If the engine starts hard or smokes at temperatures where the water is not frozen perhaps the engine needs work. Leaky diesel injectors will cause smoke as the fuel that leaked into the combustion chamber burns off. Low compression or slow cranking speed will cause hard starting.

Failed thermostats will cause the engine to warm up slower. But remember compared to gas engines diesel engines produce less waste heat, especially at idle. A diesel engine will never warm up as fast as the engine in your gasoline car. Less waste is why we love them.

As someone said above the best way to warm up a diesel engine is to get underway.
 

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