55 Hatteras Re-Power

[triniswordfish]

Our 8sy's are smokeless and I mean smokeless
The yanmars are great engines and we are really enjoying ours
I personally think the 55 would want the heavier engines down low after all they are taking out 12 71's I think with the reduced weight downlow the boat might roll more might want to think about that??

[Fortunate One]

Nick,

I can't recall, CRS sysdrome has kicked in.

What engines you replaced with the Yanmars?

Mike

[triniswordfish]

8v92's ddec 735 hp and before that the old girl had the 550hp 8v92's she has come a lonnggg way hahah

[PacificBlue]

The MTU Detroit Diesel Series 60 (825 bhp @ 2300 rpm) are THE perfect replacement for 12V71's.

Long life, wide range of parts and service, great torque and good fuel economy out of 14 liters of displacement.

[True Grit]

What kind of cruise would I get with the MTUs as I currently cruise at about 19 knots at 1950 with my 12v71S that are rated at 900 HP.

[PacificBlue]

I am sure you can get a repower analysis from your MTU Detroit Diesel Distributor.

I know they have repowered some 54 Bertrams from 12V-71's to Series 60's with great results, higher cruise and less fuel burn.

I'll try to dig up some figures...

[BubbaBert]

I'd love to see some figures between the 60's and 12v72's. are the 60's smaller?

[Rob Rondini]

i would have a naval architect look over the aplication before i spent that kind of money. there are many factors such as hull and balance that would dictate the necessity for one engine or another.you may spend alot more on the bigger motor and not get any better performance.just something to think about.

[PacificBlue]

Dug up some numbers on older 53 Hatteras repowers, going from 12V-71TI's to Series 60 engines at 825 hp:

1. 1979 53 Hatt (about 61,000 lbs.) - 12V-71TI's, 650 hp, had a 1900 rpm cruise of 16 knots (42 gph), 2100 rpm cruise of 18 knots (55 gph) and WOT speed of 20 knots (72 gph).

With Series 60, 1900 rpm cruise of 22.8 knots (45 gph), 2100 rpm cruise at 26 knots (61 gph) and a WOT speed of 29 knots (86 gph)

2. 1979 Hatt (about 63,000 lbs.) - 12V-71TA's, 900 hp, had a 1900 rpm cruise of 22 knots (52 gph), a 2100 rpm cruise of 24.5 knots (72 gph) and a WOT speed of 28.5 knots (94 gph).

With Series 60, 1900 rpm Cruise of 22.6 knots (45 gph), a 2100 rpm cruise of 25.8 knots (61 gph) and a WOT speed of 29knots (86 gph)

Series 60 Dry weight with gear is about 4,055 lbs. while the 12V-71's come in at about 5,200 lbs. The Series 60's are also 39" wide versus 46", giving you more elbow room in the engine room.