Boat Engines - Short Life Spans?

[fyrfightr]

Re: Boat Engines - Short Life Spans?

I have a 93 Crestliner with a 4.3 Mercruiser with over 2200 hrs. Still running strong.

 

[SnappingTurtle]

Re: Boat Engines - Short Life Spans?

from Snapping Turtle:
Where did you get that number, Turtle?

From the many boat ads I see posted that say boat has a new, or rebuilt motor. Boat has about two to three hundred hours of use.

Very few of the people I know have LESS than 500-600 hours on their engines. Found this article looking around (good article by the way), the NMMA (National Marine Manufacturers Association) says the AVERAGE hours on an engine before rebuilding is 1500. Means there's a lot of them out there with MORE than that on them.

Even at 500 or 600 hours I would laugh. Several thousand should be possible, if not something is really wrong. I have been saying this the whole time, that a properly maintained engine should last many, many, many years. Even ones run extremely hard. 1500 is more like it, but I am sure you can get more.

 

[SnappingTurtle]

Re: Boat Engines - Short Life Spans?

I have a 93 Crestliner with a 4.3 Mercruiser with over 2200 hrs. Still running strong.

We also have friends in the states with Chris Craft Cruisers from the 50's & 60's with perfect running original motors, some never rebuilt. They are used often and regularly maintained.

 

[45Auto]

Re: Boat Engines - Short Life Spans?

several hundred hours of use is about right before an engine change or rebuild. This seems like a very costly planned regular maintenance feature.

From the many boat ads I see posted that say boat has a new, or rebuilt motor. Boat has about two to three hundred hours of use.

You're assuming from the boat ads you see that several hundred hours is the planned interval before an engine change or rebuild?

For every one of those ads you see there's another one out there with the same boat with about 2800 hours on it (to get the NMMA 1500 hour average). I can understand why the owners probably wouldn't be real interested in putting that in their ad trying to sell the boat .....

 

[SnappingTurtle]

Re: Boat Engines - Short Life Spans?

You're assuming from the boat ads you see that several hundred hours is the planned interval before an engine change or rebuild?

For every one of those ads you see there's another one out there with the same boat with about 2800 hours on it (to get the NMMA 1500 hour average). I can understand why the owners probably wouldn't be real interested in putting that in their ad trying to sell the boat .....

No I am not assuming that is normal. I think it is ridicules. I was being sarcastic.

"Big White Boat"
"Little White Boat"

Good night 45Auto.

 

[45Auto]

Re: Boat Engines - Short Life Spans?

LMAO!!! Must be getting late over there in Germany, it's 6 PM here!

 

[SnappingTurtle]

Re: Boat Engines - Short Life Spans?

LMAO!!! Must be getting late over there in Germany, it's 6 PM here!

It's not that late, I'm just getting old.

 

[Doc_Vegas]

Re: Boat Engines - Short Life Spans?

Thanks guys, I learned a lot here. The outboard concept is interesting, and the National Park Service Rangers swear that multiple-outboards is the way to go. However, I am looking at express cruisers, and I have not seen one yet that uses outboards... any ideas?

Thanks again.

 

[marine4003]

Re: Boat Engines - Short Life Spans?

I too am interested in why the older marine engines are capable of 2-3K while no matter how well maintained my motors are,i need rebuilds at 1-2K, theory, different materials used in manufacturing,old engines cast iron...new motors aluminum/steel,tolerances not as good?or what. I am anal about all my boats,all are certified marine mechanic maintained,all get the best oil-gas-parts ect..and no matter what...come 1500,but no higher than 1800 hrs...compression drops, one even spit out a spark plug.....Celebrity has a Merc 350..Scarab has twin 502's.....Outboards....HHHMMMM.......

 

[mthieme]

Re: Boat Engines - Short Life Spans?

Aside from regular maintenance, anyone care to explain why the powerplants in workboats seem to last forever? Certainly waaaaay beyond any of the numbers mentioned so far.
I'm on the Chesapeake which teems with workboats. Most have old car engines in them. Some look absolutely hideous but run strong (as they have to).

Marine4003:
The materials certainly have something to do with it. Aluminum is not a good choice. Tolerances...the small block chevy design which is most common, has been around for over 50 years. It's proven itself. Oils have improved drastically over that time period. But the basic design, despite technological improvements has not.
Here's something to contemplate though. I play with vintage farm tractors that seem to last forever. They were overbuilt (have seen many working with cracked block!). They turned much slower rpm (<2000 typical). They are simple. They are economical. They have low compression.
Examples: 1945 Farmall 5.33:1 compression 1600 rpm max, same pulling power as Dodge Diesel p/u (on paper) and can run off kerosene. Farmall Cub, burns 1 quart of fuel an hour. I can mow circles around my buddies 23HP V-twin Home Depot monster special (and don't have to replace the blades twice year.)
I have actually seen a Cub motor in a sailboat before...great application.
I'm just wondering out load (so to speak). How can we use motors like these and maintain performance?
Sorry, the ol' mind wanders too much before a full complement of coffee in the morning!

 

[180shabah]

Re: Boat Engines - Short Life Spans?

Thanks guys, I learned a lot here. The outboard concept is interesting, and the National Park Service Rangers swear that multiple-outboards is the way to go. However, I am looking at express cruisers, and I have not seen one yet that uses outboards... any ideas?

Thanks again.

Multi-outboard setups are starting to show up - check out intrepid and pursuit boats.

 

[45Auto]

Re: Boat Engines - Short Life Spans?

Aside from regular maintenance, anyone care to explain why the powerplants in workboats seem to last forever? Certainly waaaaay beyond any of the numbers mentioned so far.
I'm on the Chesapeake which teems with workboats. Most have old car engines in them. Some look absolutely hideous but run strong (as they have to).

Be interesting to see how many actual hours some of those workboats have on the engines. I have a cousin who does commercial oystering/fishing in the Apalachee bay. They run the motor till it gets tired or dies then go to the local U-PULL-IT used auto parts yard and grab another small block chevy for $169. Takes them about 2 hours and the boat is back in the water. Seems like he swaps motors every year or 2.