DIESEL ENGINE COOLING TYPES

[nabeelah]

The most common cooling types in a modern diesel engines is of two types if I am not wrong-a turbocharged engine with fresh water cooled aftercooler & one that is turbocharged engine with a sea water cooled aftercooler.

What are the advantages and disadvantages of each type?

[Questsportfishing]

the first engines I ever had got to see were keel cooled big Cat industrial engines and the slant 6 gm engines.. (I was very young and I seemed to "fit" in the engine room.. at least that was what my grandpa and uncles said..) my job was to wipe up oil... not fun but cool when your a kid..

taking that a 6-71 Detroit was at 210 hp when ran naturally aspirated without any turbo chargers to the JT 485 hp block .. cooling has been a huge issue..
I opened the engine room hatch once on a striker I ran with 6-v92 engines and the turbo was glowing orange.. sacred the life outta me.. cooling has been the biggest issue when it comes to horsepower.. 'air' believe it or not has been a huge issue also.. if you don't have it .. it will not run good..

in all any internal or external engine cooling by salt water is a $ factor... temperature gauges over rated... but for some reason some of us stare at them..

[billschwabe]

The most common cooling types in a modern diesel engines is of two types if I am not wrong-a turbocharged engine with fresh water cooled aftercooler & one that is turbocharged engine with a sea water cooled aftercooler.

What are the advantages and disadvantages of each type?

Cooling charge air (what it's called after passing through a turbo or blower) makes a big difference in performance, the cooler the air entering the combustion chamber, the more dense it is and therefore makes more power. Using seawater to cool this air can bring it's temp down lower than the constantly cycled (and heated to 180) freshwater in the engine itself so strictly from a performace standpoint, seatwter is better. Unfortunately, many of these inter or aftercoolers using seawater have had an annoying propensity of developing leaks which let that saltwater inside the combustion chambers, where it quickly destroys the engine. Several manufacturers have been plagued by this and even rebranded some series of engines known for doing that after they changed their suppliers of the coolers themselves.

[seapower]

Has demanded, lot's of horse power from small packages. That's where the seawater after cooler's come in. Bill explained it very well, the guy's a genious!!!!! Frank

[billschwabe]

Has demanded, lot's of horse power from small packages. That's where the seawater after cooler's come in. Bill explained it very well, the guy's a genious!!!!! Frank

Not hardly Frank! I've not been in close to the number of engines you have but I've torn down all too many that were wiped out by the cheap coolers the manufactureres are using nowadays. I still have nightmares about those fun ones to get to under the blowers on 12V71TA's! I know the thinner wall tubes in them now transfer heat faster but sometimes you wonder if they even think about longevity, or are just pushing the envelope trying to get just to the end of the extended warranty period to generate some revenue.

[seapower]

I make my opinion, no secret when it come's to engine manucactering today. I simply don't like it, for the most part it's a "short term" proposition! It is especially true when it comes to "high horsepower" application's in the marine world. I would personally rather have, high displacement, lower rpm torque and coolant charged aftercooler's, among other thing's. All of that said, the engine company's (all of them) are answering to customer, market and emmision standard's and request's. It's really easy to figure it out from where you sit, when's the last time you had a customer that didn't want "as much hp, in as small a package as possible"? It's all about light weight and speed these day's. It's a pretty simple equation, put 50 pound's on your back and head up the "hill", now put 100 pound's on your back and you'll make it approx 1/2 the distance. It's really that easy, from my experience (remember that I am only giving my opinion. But I stand on that opinion, untill proven wrong) and I'm still waiting to be proven wrong. It's all about how much diesel fuel is run through the engine, to determine it's life span. More hp ='s more fuel.
International and EPA Emmission Standard's are requiring less and less smoke (carbon). They are not concerned with engine life or how much said engine cost you or I. Manufacter's consider an engine that last's 5 year's to have done it's job. I don't like those number's myself, given the cost's involved. But as you know there are many "customer profile's" out there. Some want speed regardless of the cost, most of these folk's do not mind swinging in new engine's regularly. Some want true longevity (mostly the commercial type's), and figure out how to make the boat function with that range of horsepower. Then there are the one's that simply hope for the best, those are the one's that end up selling the boat pretty quickly after finding out, just how much a boat really cost's!

I will say this and it would pay anyone that read's this post to heed it. Keep up to your zinc's!!!! Figure out how long it take's (usually) to disipate, then check them more often than you think is necessary! Every boat's engine's will be different than the next guy's, as a rule. It has everything to do with the wiring on your boat and just as importantly the wiring of the dock you are tied too!!! Stray A/C voltage on a dock close to your boat can (and will) take your zinc's out literally over night. If this happen's it is imperative, that the leak (source) is found like right now. Or simply leave that dock. Once salt water start's entering the cylinder intake air, catistrophic failure will be close behind. Frank

[PacificBlue]

the first engines I ever had got to see were keel cooled big Cat industrial engines and the slant 6 gm engines.. (I was very young and I seemed to "fit" in the engine room.. at least that was what my grandpa and uncles said..) my job was to wipe up oil... not fun but cool when your a kid..

taking that a 6-71 Detroit was at 210 hp when ran naturally aspirated without any turbo chargers to the JT 485 hp block .. cooling has been a huge issue..
I opened the engine room hatch once on a striker I ran with 6-v92 engines and the turbo was glowing orange.. sacred the life outta me.. cooling has been the biggest issue when it comes to horsepower.. 'air' believe it or not has been a huge issue also.. if you don't have it .. it will not run good..

in all any internal or external engine cooling by salt water is a $ factor... temperature gauges over rated... but for some reason some of us stare at them..

I know my last 6-71 naturals were 310 hp before J&T started introducing higher turbocharged engines. Those engines ran forever and sounded great, and even better you could work on them with tools and no computer! I belive the CAT 3208 was 210 hp (natural, no turbo's) before they tapped out at 435 hp.

[billschwabe]

I make my opinion, Frank

I was referring to the "genius" comment Frank, not the high output engines today! I most certainly don't qualify for that designation, I'm a boatbuilder remember? One can't be all that smart and be in this field.

I completely agree with you on preferring nothing but freshwater anywhere near the insides of an engine, heck I would gladly add an extra feed pump and heat exchanger just for the intercooler but those engine manufacturers are trying for smaller packages too and we know those engineers are sitting at a comfy desk, not in a bilge up to their necks in grease.

You are right I think about the amount of fuel that goes through an engine being the determining factor, Tommy Kenney and Cleveland both told me that decades ago and they should know. It is amazing how often those pencil zincs are forgotten, I always painted them red just to remind myself. Bad dock wiring is also deadly, everyone should have at least a galvanic isolator or isolation transformer to help protect your boat from
other boats or docks.

I may be old school but I still prefer the old two strokes to the newer electronic diesels. Something about their sound just gets the blood flowing and the fish hungry too. Repowered a 61 from 1271's to C-18's and didn't gain a knot, actually lost a couple until CAT finally turned them up to close to rated hp. Boat never caught fish the same though, flat lines were useless. Funny thing, fuel consumption stayed the exact same, makes you go hmmmm? The sound of a pair of v12's synched up running trolling is quickly becoming an old memory. There is a charter boat down here with a single 1292 straight piped out the back, if it doesn't get your heart pumping when she fires up in the morning, you might already be dead!
Our first boat was going to get derated CAT 3412's @1000 hp which would have lived forever but they sent me the wrong drawings and we switched to the 12V's, haven't had one since want less than the most they could get in the size, oh well. I'm still looking for that someone who wants to just b done with it and go turbine. Talk about power to weight ratios and I have had a design gathering dust for years now waiting. Don't worry though, it will have a pair of flanking diesels for manuvering so you have something to work on too!
Bill