Looking at Monk 36s and need info on Cummins diesels available. Most on the market offer 220HP but one claims a 270HP Cummins. Eng model not specified.
Appreciate any info on 270HP Cummins.
DTBrad
A little bit more specific questions would help us help you. I have 330hp Cummins in my boat. I do think they are generally the same engine. The difference in power is that the aftercoolers on the 270hp version are cooled by engine coolant. Whereas as mine are cooled by seawater. I am not going to assume you know everything about internal combustion engines.... So, the cooler the charge air, the more power it produces. Seawater cooling provides a significantly cooler air charge. Obviously, a leaking aftercooler is less disastrous when it is coolant that is going into the intake instead of seawater. Also, there is an immediate symptom when coolant is being burned....billowing white smoke and the sweet smell of burning anti-freeze. Saltwater intrusion from a leaking seawater aftercooler can go unchecked and usually causes a slow an insidious death of the engine.
Blah blah blah. The 210/220hp versions of this engine have no aftercooler.
They are good motors. The higher horsepower versions need to be more closely "monitored" because you are asking a lot of a 5.9 liter engine. Parts are (relatively)cheap and can be found anywhere.
The Sherwood raw water pumps on these motors are not very well thought of and replacements can be found on the aftermarket for half the price for a better pump.
Tony Athens on boatdiesel.com is the accepted guru on these motors. He is extremely knowledgeable. He is also seller of those aftermarket parts. He believes that most of the ancillary accessories on these motors are not very well engineered and he has hence, re-engineered those accessories. I guess I am just warning you if you decide to join over there. It is all doom and gloom...people with problems.
If I were buying a boat that was not going to plane, I would go with the 210/220hp engine as they have no aftercooler. Aftercoolers and their maintenance can be expensive and a pain in the butt. A somewhat knowledgeable owner will service their aftercoolers every 2-4 years to the tune of about a 1 boat buck if you have someone else do it. "Cheap" insurance for the health of your engine but not necessarily cheap. Most owners aren't that knowledgeable. My boat is 12 years old. POs had never serviced aftercoolers. Luckily they were okay.
I do not know if the 210/220hp versions have fuel coolers....but I doubt it. That is another cheap part that can cause significant damage if they fail....which mine did. Fouled 2 injectors and filled my starboard fuel tank up with seawater which founds it way into the engine(a racor can only do so much with that much seawater). Again, cooler fuel contributes to a cooler fuel/air charge....equals more power. That is why I am assuming the 210/220hp engines do not have fuel coolers. Check for yourself.....but that is another vote for the lower powered ones if you do not need the power.
Baker
"The Sherwood raw water pumps on these motors are not very well thought of and replacements can be found on the aftermarket for half the price for a better pump."
Do you know of one that allows you to change the impeller without removing the hoses? That's the only thing I don't like about the Sherwood.
Most on the market offer 220HP but one claims a 270HP Cummins. DTBrad
Right on. Boats hardly ever coast downhill at idle...I think comparing these engines and their reliability to a Dodge truck can be misleading. The truck versions are hardly ever asked to do the work that marine versions are asked to do. Dodge trucks just aren't subject to the loads that boats are subject to....
Baker
"The Sherwood raw water pumps on these motors are not very well thought of and replacements can be found on the aftermarket for half the price for a better pump."
Do you know of one that allows you to change the impeller without removing the hoses? That's the only thing I don't like about the Sherwood.
Re: post #5 above: fuel coolers are very easily removed by an owner. They are not generally needed in trawler-style vessels with relatively large fuel tanks which readily dissipate heat. They are a failure point you do not need to live with
As other posters have noted, the 270 has an after cooler whereas the 220 does not. As a survivor of a failed after cooler, anything you can do to avoid them is worth extra money IMHO.
You would never use the 50 HP the 270 has anyway in a Monk 36. But at the end of the day, go for the boat in the best condition and if the 270, perform after cooler service (not necessarily easy) per boatdiesel.com.
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This aftercooler is also nice in that you can run at low rpms and not worry about lowering the cylinder temps like a sea water unit will.
The aftercooler on the 270 Diamond is anti freeze cooled and requires no maintenance.
Jay
I believe you meant low, not no maintenance. Everything on the coolant side requires maintenance especially HXs whether air or liquid. Even coolant pumps give out.
Are not the O ring seals on the after cooler subject to the same deterioration whether salt water or coolant is use? I agree the metal parts should last longer, how much is a question because you still have charge air on one side that is not always pristine. Most engine manufacturers remain silent (stupid) on book related after cooler maintenance. At a minimum, a coolant cooled after cooler will require the same servicing interval as the HXs.
Right. About as much as a car radiator which isn't much. They last 20 years in busses according to a couple of bus mechanics I know.Jay
I believe you meant low, not no maintenance. Everything on the coolant side requires maintenance especially HXs whether air or liquid. Even coolant pumps give out.
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Right. About as much as a car radiator which isn't much. They last 20 years in busses according to a couple of bus mechanics I know.
Not sure whether or not Cummins offers a 270HP?? Our 6BTA5.9 is a 280HP.