GM DETROIT DIESEL 12V71 TI

At 1000 rpms they burn 6 gph each. At 1900 RPMS, around 40 GPH each. Providing vessel achieves 2300 RPM's WOT.

We own a 58' Bertram with the TI's. 650HP tune.
Are you sure you do not have the TA model @ 900 HP?
Wet / dry turbo is the first thing easy to see what you have.

At 1450rpm we average 10kts and 2 US Gallons per nautical mile. 1800rpm were doing almost 16kts at 3+ US gallons per mile. WOT; just under 2300rpm, 22+kts, just under or at 4 gallons per nautical mile
Ad another 1 US gallon per hour average for the gen-set.

They do use a lil bit more than the newer engines but not much more. Lots of us here at YF are DDC 71 fans.

Bertram made manuals for all their boats with test run data (Light boat). Check the Bertram web site, the Bert 65 manual may still be available.
The new owners did continue the Bertram web library.

Here are some GPH charts for the 12V71TI.

at 1200 RPM you are burning 8gph and at 1900 you are at 30 gph. I have flow scans on my boat and that pretty darn close where I am at.

The boat in my signature picture originally had 900 hp 12V71TI's and at our normal 1950 rpm cruise was 32gph per side. They were some of the last factory 71's in the Penske era (1998), not aftermarket JT's or Covingtons. If I recall correctly they did end up with 12 hole 145 injectors but could have been 135's.

My boat came with BK Power 900Hp 12v71TI's that had 12v71TA 1080hp injectors . I have since detuned it back to Original Detroit Factory Spec. Less Fuel, Less Smoke.. but Less top speed.

900hp TIs or TAs?

TI's

As many times as I changed kits in her (5!) I should have remembered the cooler was under the blower so TA's Ralph, sorry!

I ran a set of Covington TI's which were 765hp. The chart posted is for only 70 Liter per hour injectors. The Covingtons I ran had 110 Liter per hour injectors but also ran a generator injector height, 1.46". It did the figures I posted, but it also ran crystal clean at ALL rpm points.

I was scratching my head and about to dive into some research tonight. After living aboard for 13 years now, our ole Bert has gained some weight.
I'm still looking for another 100hp out of our N90 / 650hp / TIs. I'd hate to mess with my new perfect factory wheels. Just need to pick up that missing umpa and <50 rpm on top.
Have a lil problem crawling uphill on the swells also lately.
Santa brought a new anchor windlass. New chain coming to replace the nylon.
Yep, may need some of that fat injector stuff.

Was that with the cams advanced? You remember the injector model number?

My 12V71 TI engines were overhauled recently. If they need to be done, pull them out and overhaul in the shop. Approx $45k each.

The dyno horsepower is 860 hp @ 2300
The Injectors are 9215 part R5229715
The Turbos are R5101513

Yep, 9215s, fuel pushers.
thx, rc

I'm guessing the cams were advanced because 2 different Detroit Diesel dealers INSISTED on setting the injectors at the marine height 1.96" and the motors black smoked so bad, you could not see 50' past the transom. I do not remember the injector number......but look in the DD book under Covington and 765hp and you can probably find it. I haven't dealt with that boat since 2012.

Hello scandé
When technical threads come up like this, Sometimes we get carried away and chat on some things not really related to your original post (op).
I apologize for my side track of your thread.

Hope your original question was answered.

Keep asking 71 questions, those responding here live with and make a living on Detroit 71 boats. Many more 71 fans in YF.

Serial numbers from 1977?