Engine rebuild rate on Engine Model: 8V92TA engines

[denalicon]

I started out looking at used 43 and 45 foot Hatteras Motor Yachts and have now moved up to 48 and 52 models with the Detroit 8V92TA(s). I have been surprised at how many of these engines I see with rebuilds in the sub 2K hour range. Much higher ratios than anything I saw with the smaller boats using the smaller Detroit engines or the Cat 3208s. Anyone have any idea why the difference.

[rustybucket]

I started out looking at used 43 and 45 foot Hatteras Motor Yachts and have now moved up to 48 and 52 models with the Detroit 8V92TA(s). I have been surprised at how many of these engines I see with rebuilds in the sub 2K hour range. Much higher ratios than anything I saw with the smaller boats using the smaller Detroit engines or the Cat 3208s. Anyone have any idea why the difference.

Well, you can keep the CAT 3208's out of the argument pretty much b/c the rebuild/overhaul time on those engines is decades longer than the detroits.

I would think the reason for the lower hour rebuilds would be due to the higher HP rating of the engines. It's real simple.... the more fuel you run through the engines the faster you will have to rebuild them. So a 735hp 8v92 would need to be rebuilt sooner than a 650hp which would need to be rebuilt sooner than a 600hp which would need to be rebuilt sooner than a 500hp.

The main difference between a 735hp 8v92 and a 600hp 8v92 is the size of the injector and the amount of fuel dumped in the cylinder (sure there are other differences with cooling systems...etc)


Really with detroits, it would be nice to have a fuel meter rather than an hour meter, would be a MUCH more accurate gauge of engine life. For example 2k hours at 2000rpms is a LOT more fuel that 2k hours at 800rpm. All hours are not created equal....

[Boatsb]

3208s at high hp get shorter rebuild intervals than you may think.

[oceanjake]

Not to cloud the waters here but I would just do the math. horsepower divided by cubic inches. That is the number that will predict the life of your engines more than anything. Running an engine at 800rpms may or may not preserve the cylinder kits but will definitely cause other problems that equate to big money.

[jim rosenthal]

The higher you turn the wick up on any engine, the less time between overhauls. I have been told by Cat dealer friends that the 355 and 375 versions last a very long time, if well maintained. Above that rating, well, not so much.

I am curious to see what engine life expectancy is with the modern CR engines. I've heard that because they have better injection control and more even burn patterns, they have less internal stress from uneven combustion. So they are projected to last longer, despite all the power they put out. Anyone know if this is true, or is it too early to tell?

[Boatsb]

Cummins common rail UHP engines seem to last as long or longer than their lower hp mechanical cousins

[bobk]

Not to cloud the waters here but I would just do the math. horsepower divided by cubic inches. That is the number that will predict the life of your engines more than anything. Running an engine at 800rpms may or may not preserve the cylinder kits but will definitely cause other problems that equate to big money.

800 rpm might be too low, but , my 6V92 425 HP are happy at 1000-1100 and have been so for >4000 hours.

Bobk

[saltshaker]

Not to cloud the waters here but I would just do the math. horsepower divided by cubic inches. That is the number that will predict the life of your engines more than anything. Running an engine at 800rpms may or may not preserve the cylinder kits but will definitely cause other problems that equate to big money.

It really depends on how you run them not the HP:CI. There are a lot of big MYs that regularly get 4K-5K hours out of 16V92TAs. Those same engines in a SF usually are done around 2000 hours. Maintanance is a huge factor. There’s 65C that had over 5000 hours on 16V92TAs before they rebuilt them. That boat was run hard all the time but the owner was always on top of the maintenance. Boat was also used regularly which makes a huge difference. There’s a lot of factors that determine the service life of any Diesel engine

[Tinman]

The higher you turn the wick up on any engine, the less time between overhauls. I have been told by Cat dealer friends that the 355 and 375 versions last a very long time, if well maintained. Above that rating, well, not so much.

I am curious to see what engine life expectancy is with the modern CR engines. I've heard that because they have better injection control and more even burn patterns, they have less internal stress from uneven combustion. So they are projected to last longer, despite all the power they put out. Anyone know if this is true, or is it too early to tell?

Had a diesel mechanic tell me he could not remember ever rebuilding an engine because it was ran slow....

[Boatsb]

We repowered a navy rib with cummins 5.9 330 hp engines with over 10k hours. I'd bet the newer electronic versions woukd last even longer.

As for running slow. Not in the cards here.