43' Double Cabin 6-71 Prop sizes

[Will]

Our 1980 43' Double Cabin is powered by 485 HP, 6-71 TIBs with 1.51:1 gear boxes. Hatteras put 24D x 23P, 4 blade props on the boat.

What reduction gears ratios and prop sizes did they put on other 6-71 (6-71 N's, 6-71 TIs, etc.) powered 43' DCs?

Just curious -
Will

 

[Bill Allen]

My 6-71's 310 hp are now running 24x26 a very nice combo for slow cruising. I can turn them (if my memeory serves me around 22 to 23 hundred). Bill

 

[Trojan]

I have 24X26 wheels on My 43DCFB with J&T 6-71Ns that will run up to 20MPH at 2450rpm with 1.51:1 gears. My motors have very low hours. I go on plane at 13MPH with full down tabs. I purchased a set of 26X24s last winter. Had them on for one hour and never got the chance to run them up before I ran over a log in the river. It was at night just after a hard spring rain and I knew better. I removed them had them fixed, but I did not get them back on. Now I won't be able to try them again until next spring. What a bummer. The superlatives I said are still echoing in the harbor.
BILL

 

[Bill Allen]

I couldn't get that speed if the boat fell off the travel lift (lol). Bill

 

[sgharford]

485 HP a pop, that is so sweet! How fast will she go WOT? I got my 43 DCFB with up 21.8 knots beginning of season with fresh bottom and 400 HP Cummins 903s at 2750 RPM swinging what I believe are 24x27 4 blade props on on 2:1 transmission. She starts smiling big and wide at 18 knots.

 

[Will]

Sorry sgharford,

I'm one of those guys who likes to poke along and enjoy the sights. I usually run about 1600 RPM at 11.5 knots. WOT is rated at 2500.

Bet you get quite a ride at highers speeds.

Will

 

[sgharford]

How can you resist throttling up all those ponies? I have often day dreamed of what she would be like running her with 450+HP engines. You can live the dream! Anyway, sure if I had what you have I would be dreaming about 550HP+ engines. Maybe I need a convertible, or maybe I need to stop daydreaming and get back to work - tough decisions -TGIF.

 

[Bill Allen]

I have no problem at all cruising s l o w l y along. Sight see, relax, sit in my big ol helm chair, cup of coffee on the helm. Everytime I power them up, right after I get over the sound of those old DD rumbling I think about how I'm burnning three times as much fuel to go twice as fast and I have no problem pulling the throttles back. Relaxing once again and enjoying the old girl do her thing. Bill

 

[sgharford]

Seriously Will, you've never opened her up and clocked the speed? Not in even under the disguise of blowing carbon? I am not judging anyone here, I’ve been a sailor first my whole life. Just really curious how fast she’ll go with 970 ponies running free and wild.

 

[Trojan]

I have no problem at all cruising s l o w l y along. Sight see, relax, sit in my big ol helm chair, cup of coffee on the helm. Every time I power them up, right after I get over the sound of those old DD rumbling I think about how I'm burning three times as much fuel to go twice as fast and I have no problem pulling the throttles back. Relaxing once again and enjoying the old girl do her thing. Bill

I can go along with that Bill. I too just ease the throttle until any increase in RPM shows no gain in speed and then back off an RPM or so. Usually its around 10/11 knots. Its nice to know that there is still a lot more speed if I need it. I'm hoping in the spring the new old props show some improvements. This is why they call our boats cruisers. I'll drink to that.

BILL

 

[Finalee]

Was out yesterday and was getting 16 knots at 1800 RPM against the tide off Ft. Monroe. Tabs down. If memory serves me she has 24x24 props. 6v92 435 hp DD's. When the stabalizers are turned off she drops .5 a knot when on plane? Fuel tanks half full, water full, holding tank half.

 

[Bill Allen]

I think I can run at around 15kts cruise, don't even remember what it tops out at. With the hatt, to me it's about an nice relaxing time on the boat. I also have a 37 topaz we run as a dive boat (6 pack) cruises 24 kts. loaded with 8 people and all the stuff divers and crew bring with them. Puts the waterline down by 8". Gotta tell ya I really don't enjoy running it. Way to fast can never relax and it actually burns more fuel if you slow down. Bill

 

[eze2bme]

1979 43DC 6-71N's with 24x24 props

 

[troy454]

Im not sure what My 73 DC has but she has 903s no turbos and every person that gets on board is shocked at how fast she runs out at. Its crazy that a 35000 lbs boat can move like she does. WOT is about 2450. so I must have low pitch props.