8v92?

[Tmccar1]

Hello,
I'm looking at a DE right now that has a rebuilt 8V92 dropped into it (at the build oddly enough). The engine has just under 400hrs on it since it was rebuilt. Seems like it hasn't been run that often when she's in the water.

My question is...
What do folks think about these rebuilt 2 strokes and what kind of life do they usually get if well maintained?

I've always had 4 stroke diesels (CAT and MAN) so i'm looking for the real story on them. Thanks in advance!

 

[captcod]

i would avoid it if at all possible. they are ok if run easy, under 1400 rpm but are still thirsty and dirty

 

[Tmccar1]

i would avoid it if at all possible. they are ok if run easy, under 1400 rpm but are still thirsty and dirty

That's what i've heard. I think the advertised "20 Gal/Hr of fuel at 20 knot cruise" seems questionable.

The hull is a beast so if I could get the seller to price it as the kit boat it basically is it might be worth using it for a season and doing a repower over the winter to a CAT 3406E or something.

 

[jerseysportfisher]

Burn rate depends on HP, as with any diesel. 600hp detroit burns just as much as a 600hp name your brand. being that alot of boats STILL run them, after 30 + years give you an idea on longevity.

Just remember, that repower pays for alot of fuel

 

[MASTERENEGADE]

Imho. They are very sensitive to improper loading. Make sure the motor is making proper rpm's, dont try to run the snot out of them either.

I run a boat with twin 6v92(550hp). So far so good but they do not have alot of hours since the overhaul and the owner is still trying to get the correct pitch in the props.

Like any motor the less fuel you run through them the longer they will last.

I know alot of people use them commercially and run them forever.

Good luck with your decision.

 

[petrel]

The Elizabeth Thomas- 43 Lowell?

 

[WoundUpMarine]

Ive always had respect for the old 2-strokes, like everyone has said, and it applies to EVERY engine, make sure you pitch it correctly so it isn't overloaded. I don't know if i agree with running it easy all the time, the old engines want to be run and run hard, it keeps them clean. I've seen 2 strokes run easy their entire life and they didnt last as long as a pair run HARD most of the time. They need the air pressure and movement to keep everything clean and happy!

 

[MASTERENEGADE]

Wound up marine: I cant argue with you on that esp that i dont have all the time in the world with 2stroke diesels. I kinda have been a believer in hours and how much fuel goes through a engine are two differant life determining factors. But this may apply more to the 4strokes like a cat with the amount of fuel.

Im not an expert in this field nor will i ever try to come off as one.

 

[Tuna Pursuit]

The 6-71's and 8-71's are great engines. The 6-92's at 550 aren't too bad but the 660's are good for about 500hrs. They tried to crank too much HP out of these blocks. You have to run them up to temp and monitor the exhuast temp or they don't last long. You can't give them a steady diet of easy cruising, not with a 2 stroke.

 

[petrel]

I think you should run it harder than 1400. I've seen them run for many thousands of hours at 1600 to 1700. 892 will last a lot longer w/ smaller injectors too. Cooling system needs to be tip top also. Unless you run about every day, it is hard to justify a repower from 2 stroke to 4 stroke on a fuel price basis in most cases. Kind of like the part timer in a small boat w/ a gas engine. Takes a lot of use, especially to crack the nut of a 600 plus horsepower engine and installation.

 

[Tmccar1]

Takes a lot of use, especially to crack the nut of a 600 plus horsepower engine and installation.

Agreed. I wasn't thinking fuel so much as reliability. 100 mile haul to get home is what's in my mind. Especially when you potentially have a group of paying dive charter customers stuck on board who have work the next day.

 

[jerseysportfisher]

Agreed. I wasn't thinking fuel so much as reliability. 100 mile haul to get home is what's in my mind. Especially when you potentially have a group of paying dive charter customers stuck on board who have work the next day.

if detroits were as reliable as you are insinuating, do you think they would put them in emergency vehicles ?

 

[Tmccar1]

if detroits were as reliable as you are insinuating, do you think they would put them in emergency vehicles ?

I wasn't insinuating anything. I trully have no idea what their reliability is like, it's why I posted.

 

[petrel]

They have been pretty damn reliable in a lot of boats, less so in others. They work very well within certain parameters. I did not used to like them, but I bought a boat w/ 671 TI's and they have been good to me, but I take care of them and don't run the piss out of them either.

 

[jerseysportfisher]

they even run when broken

 

[WoundUpMarine]

We ran one with a couple burnt valves and a couple scored liners for the remainder of the season last year, maybe a little over a month. She still made rated rpms when asked, smoked like a chimney though! This is a 12-71ti. If they have fuel and enough battery to turn them over, they are one engine i would feel very comfortable having beneath the deck as far as reliability goes.

 

[Tmccar1]

Dirty, thirsty, smokey, loud and reliable. Sounds like my kinda woman!

 

[Tuna Pursuit]

Most of the hard core stories are about 71 series or even 53 series, 92 is a different story.

 

[Pedlyr]

92 series doesn't share the same reputation as the 71 series. We have a few 692's that have been good but they are 1800 or less RPM engines in barges that don't get abused.

I personally am not worried about the reliability of them since we try to take care of them. I just don't like all the smoke, noise, and leaks which seems pretty typical. Not to mention the fuel economy. Plus, Detroits to me always seem hard to work on in tight areas.

It always comes down to money. If you can deal with what you got, go for it. My $.02

 

[petrel]

92's have wet liners, so that is something to watch out for.