PDA

View Full Version : 8v92 - fuel consumption



Charley Foster
08-30-2011, 03:28 PM
I need fuel consupmtion chart and spec sheet for 8v92 turbo engines in 1978, 58' cockpit motor yacht

searmstrong72
12-18-2011, 09:51 PM
Charley,

Did you ever get an answer to your 8v92 fuel consumption question? Trying to work that and tank size for our 1977 58 MY. Lots of conflicting info from the Local Hatteras guy.

Thanks
Scott

JLR
12-19-2011, 10:11 AM
On my 56 MY with 892TI's, at 2130 rpm, I burn 3.53 gallons per nautical mile and average between 47-50 gallons total per hour. That is based on 13 years worth of data. Hope it helps. I cruise between 15.5-16 knots at that rpm.

GJH
12-21-2011, 09:52 AM
At the other end of the spectrum with the same boat as JLR's I can squeeze about statute mile per gallon at 1100 RPM and 7 to 8 knots. Converting to statute miles only because it makes me feel better. Our boats are relatively wide at 18'2", so that should reduce our results vs a 15'10" boat of similar lengthand displacement.

Bill Root
12-21-2011, 03:46 PM
At the other end of the spectrum with the same boat as JLR's I can squeeze about statute mile per gallon at 1100 RPM and 7 to 8 knots. Converting to statute miles only because it makes me feel better. Our boats are relatively wide at 18'2", so that should reduce our results vs a 15'10" boat of similar lengthand displacement.

Fuel consumption for my 54 MY w/8V92TA's is similar to JLR and George. I topped off my tanks in Fernandina Beach and ran 190 miles to Sanford, Fl at the end of the St. Johns River. Average speed was about 9 knots at 1150RPM. I topped off the tanks again when I got to Sanford - took182 gal.

Glory
12-21-2011, 06:09 PM
My 58YF, 8-71Ts, 9 Knots about 10 GPH with the gen.

JM

clarkegillespie
04-02-2013, 04:22 PM
At the other end of the spectrum with the same boat as JLR's I can squeeze about statute mile per gallon at 1100 RPM and 7 to 8 knots. Converting to statute miles only because it makes me feel better. Our boats are relatively wide at 18'2", so that should reduce our results vs a 15'10" boat of similar lengthand displacement.

I am considering a 1981 Hatteras 56 MY and am really nervous about the fuel burn. It has DD 892's. can I really expect a 1 mpg at 1100? It that with generator?

Since you have had yours a while does it seem to accept the low RPM running ok? Do you blow it out at the end of the day or periodically during the day?

We are stretching to do this but I don't want to be on y death bed looking back and wishing. At the same time I want to be able to do the Loop and Bahamas and still be able to eat.

Any feedback is more than appreciated.

Clarke

GJH
04-02-2013, 04:57 PM
If it is that tight an issue for you then you might well not be able to afford one of these boats. Even when cruising full time (500+ hours a year) as we did for a few years, fuel is not the biggest expense of these boats, certainly if you want to keep it in good condition. "Buy the smallest boat you can be comfortable in, not the biggest boat you can afford"... some of the best advice in cruising.

But to answer your question, yes 1mpg at 1100 say 7-8 knots from both engines is realistic, that is without the generator. Keep the bottom smooth and the running gear clean. I don't know what generator the boat you are considering may have, but the 20kw Onan on my boat was put in in 1991 and consumes an average of 1 gallon per hour. Yes, blow out the main engines at the end of the day for 15-20 minutes at 1800-2000. What boat are you looking at? Make sure you get a good engine survey by someone who specializes in these engines and has good references from boaters, not brokers. Ask on this forum for someone in the area where the boat is.

We love our boat, it has been perfect for us, but you have to pay to play.

Bill Root
04-02-2013, 07:18 PM
"Buying the smallest boat you can be comfortable with" is great advice, particularly if you want to do the "loop". We did the loop three years ago, but would not want to do it in the boat we have now.

Boat length, height and draft are critical to do the loop. There is a 19' fixed bridge in Chicago that you have to be able to clear or you can't do the loop. There are ways to get around
the other fixed bridges, but not that one. 56' length would keep you out of some of the best parts of the trip like the Dismal Swamp and the small boat channel in Georgian Bay. The number of marinas able to handle a boat that size, particularly in Canada, is limited. At the same time, the combination of 56' of length and 4.5 feet of draft would eliminate at least half of the anchorages. Do you really want to be running in a narrow river at sundown with your heart in your mouth because you can't find a marina or anchorage where you will fit?

To be sure, people have done the loop in boats the size of what you are considering, but it cuts out some of the most interesting parts of the trip and creates an additional stress factor, particularly if you don't have a lot of experience handling larger boats. My wife and I did it in a 43' DCMY and found it to be about perfect. It had plenty of room for the two of us and a couple of occasional guests. With only 3.5' of draft we could go just about anywhere and most marinas could accomodate us. Fuel burn was about .75 gal/mile at 8knots, but we could do 18 knots when we needed to. We waited for the bigger boat until we finished the loop.

Whatever you decide to do, I wish you the best. You have made a good decision to look for a Hatteras.

captainwjm
04-03-2013, 10:27 AM
My fuel consumption is about what has been described - around a gallon per statue mile at 9 kts. at 1000 rpm [8v92s 735 hp; 55' w/' 17' beam]; genny [20kw Onan] use averages 1 gal per hour at 1/2 to 3/4 load. FWIW, no problem w/ finding marinas/anchorages [4.5 draft] on inland portion of the Great Loop, although had to lower the arch for the BN RR bridge south of Chicago.

clubdowd1983
04-04-2013, 12:47 PM
What boat are tou looking at?

clarkegillespie
05-04-2013, 11:04 AM
Wow. i havent been on here in a while. i wasnt really sure i would get any responses. thank you.

We have been looking at a 1981 Hatteras 56 MY. My wife loves the volume and the style. I have to admit it is a handsome boat. My concern is my Scotchness. Be able to afford and being willing to afford are two different animals. She tends to like bigger more complicated boats. I tend to like very simple mid sized trawlers.

It seems like we creep up in length every time we think we have it narrowed down. Or the draft gets too deep. It the fuel burn is absurd. Plus I know I will need to be willing to take a 10-20% loss to unload it after the Loop.

What I am realizing is that their is no perfect Loop boat and we need to decide if comfort, and the limitations it brings, are worth it.

I appreciate the fuel numbers. I am guessing .66MPG if I figure it that way. So around 36000 in fuel for the loop for that Hatteras.

Regards,

Clarke

GJH
05-04-2013, 03:25 PM
If you keep at 7 knots or so, you can improve that mileage, not counting generator time by about 50%.

I have an '81 56MY, would be happy to answer any questions. We've put 10,000 miles on it. My wife has the same tastes as yours so the boat has been perfect for us. It is a lot easier to work on than any of the trawlers we rented, including almost all flavors of Grand Banks. Which boat are you looking at?