Why such a short life span?
#1
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Why such a short life span?
Can someone explain to me the reasons that marine engines (gasoline) have such a short life span in running hours as compared to vehicle engines, or other equipment with similiar engines?
300 hours, time for top end rebuild, another 300 hours, total rebuild.
Other engines in vehicles, generators, pumps, etc last for thousands of hours without rebuild. What makes these engines so short lived? Is it the fact that the cooling is an open system without radiator?
I was told that the engines are worked very hard while in a boat, at high RPM, not much different than some equipment mentioned above.
Is it the fact that the engine has many high performance mods in it that in itself makes it prone to self destruction at a stock level?
IF that is so, how would a stock vehicle engine last if modded to use the marine cooling system and installed in a boat?
If the same engine was in a vehicle, how would it hold up? Any different?
I have a 454 on a 12" water pump with 3000 hours on it, still running.
300 hours, time for top end rebuild, another 300 hours, total rebuild.
Other engines in vehicles, generators, pumps, etc last for thousands of hours without rebuild. What makes these engines so short lived? Is it the fact that the cooling is an open system without radiator?
I was told that the engines are worked very hard while in a boat, at high RPM, not much different than some equipment mentioned above.
Is it the fact that the engine has many high performance mods in it that in itself makes it prone to self destruction at a stock level?
IF that is so, how would a stock vehicle engine last if modded to use the marine cooling system and installed in a boat?
If the same engine was in a vehicle, how would it hold up? Any different?
I have a 454 on a 12" water pump with 3000 hours on it, still running.
#2
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On diesel engines, "they say" that the time to rebuild is really based on gallons of fuel burned more than on engine hours. That is probably true on gasoline engines too, because fuel burn equals work which probably equals wear.
Say your truck gets 10 miles per gallon. After 150000 miles you have burned 15000 gallons. On a boat that burns 40 gallons per hour per engine, that is 375 hours. Not far off from observation for factory engines run in a fast boat. Boost it up and burn 100 gallons per hour, and 100 to 150 hours and the engine needs a rebuild.
That's probably the key issue.
On my boat, I can only run as fast as the ocean allows, so at 750 hours per engine I've still got good compression numbers, no rod knock, everything seems fine, but I burn about 10-15 gallons per hour per engine, so I should see 1000 to 1500 hours. Seems about right.
Say your truck gets 10 miles per gallon. After 150000 miles you have burned 15000 gallons. On a boat that burns 40 gallons per hour per engine, that is 375 hours. Not far off from observation for factory engines run in a fast boat. Boost it up and burn 100 gallons per hour, and 100 to 150 hours and the engine needs a rebuild.
That's probably the key issue.
On my boat, I can only run as fast as the ocean allows, so at 750 hours per engine I've still got good compression numbers, no rod knock, everything seems fine, but I burn about 10-15 gallons per hour per engine, so I should see 1000 to 1500 hours. Seems about right.
#4
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Road-going vehicles see no where near the load a boat motor sees. Imagine your tow vehicle pulling your boat around full time, mostly at highway speed, without overdrive. Every so often you mash the pedal to the floor and occassionally you get to coast downhill. How many miles/hours ya' think it would put up with that?
#6
21 and 42 footers
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My old stock 454's had over 1,000 hours and still ran OK....500's are a little different. As far as your cars.....put your car in second gear and drive around ALL the time in second gear. Let me know how long your willing to drive on the interstate like that. (but you do it all the time in your boat)
#9
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HIgh rpm and high load is the reason. Multi gear transmission would not stop the load cruising or at high speed just get you to speed faster. How often does a car run at 4000-5000rpm at nearly full throttle going up a steep hill? Same thing as a boat on the water.