Click for Detroit Diesel manuals!
Results 1 to 3 of 3
  1. #1

    Default 12v71TI conversion question

    This may be a really dumb question but I am looking at a boat with twin 12v71TI 's in it rated at 650HP each. We really don't need all that HP since the boat will only cruise at 5-10 knots. Is it possible to remove the turbo's and Intercoolers and replace the injectors with a set from a non TI motor and basically convert a TI to a non TI motor? This is a 1973 boat and we are worried about the condition of the turbos and IC's. If we don't need them could we just remove them to save on maintenance costs.

  2. #2
    Join Date
    Nov 2009
    temecula, ca., usa

    Default Re: 12v71TI conversion question


    Not try trying to hose down your parade but....

    My short answer is I don't know....never tried it....never heard of it being done.

    But I do think that, if you do a bit of research, you'll find that it's not a simple delete operation with injector swap. I know the turbo engine is equipped with lower compression pistons for one thing. Check part numbers to verify.

    There will also be a valve timing variance that hurts me to even think about.

    If you do what you're thinking, I'm sure they will start and run...well...idle anyway. But you might be very disappointed with absolutely no power at all and gobs of black exhaust even with smaller injectors. I would liken it to a very inefficient cloud making machine that won't go anywhere slowly. .

    If your base engines are solid I think your most cost effective route would actually be to refresh the turbos and intercoolers.

    The only real maintenance with turbos is to always provide them with fresh, clean oil. If you don't keep up with that then, yes, you can expect trouble.

    Remember, just because you have all that power doesn't mean you have to use it.
    EXCEPT, of course, only when you're HAVING FUN ;>)

    Just my opinion.

    Good luck.

  3. #3
    Join Date
    May 2015

    Default Re: 12v71TI conversion question

    The best way to save fuel and increase life of a Detroit is go slower.
    Turbo Detroits have lower compression pistons than naturals. You'll have less power than you plan on.
    Turbos fail because of bearings, and that is partially caused by not changing oil. I change the bearings and seals on Detroit turbos I have owned . It's not that tough. Change the bearings and seals early, before they fail and damage the shaft or turbine. You can find them at a good bearing supply or online. Someone probably has a video on Youtube about rebuilding the turbos.
    You can bypass the intercooler. You loose top end hp. Sounds like you're not using it anyway.
    Changing injectors doesn't always lead to fuel savings. The governor is going to open the injectors as much as necessary to meet the rpm needs. Putting in smaller injectors usually means the governor opens the smaller ones more.

Similar Threads

  1. 12V71TI Rpms not stable above 1850.
    By Captoz in forum Detroit Diesel
    Replies: 14
    Last Post: 11-25-2017, 12:26 PM
  2. 12V71TI Fuel Injector Timing
    By Captoz in forum Detroit Diesel
    Replies: 0
    Last Post: 05-18-2017, 02:04 PM
  3. Manual of GM 12v71ti Diesel
    By Roa Yacht in forum Detroit Diesel
    Replies: 0
    Last Post: 06-23-2010, 04:22 PM
  4. DD 12V71TI Fuel Consumption
    By alandubuisson in forum Detroit Diesel
    Replies: 0
    Last Post: 07-29-2008, 04:09 PM
  5. 12v71ti capacities
    By Trigve Papenfuse in forum Detroit Diesel
    Replies: 1
    Last Post: 02-27-2008, 11:23 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts