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Thread: P400 Input

  1. #1
    Join Date
    Jul 2008
    Location
    Australia
    Posts
    20

    Default P400 Input

    Hi all,

    I currently own a 96 Hummer with the DS4 pump all electronically controlled.

    In an effort to become more reliable I have begun undertaking a rather complex project to convert the truck back to a mechanically controlled 6.5 Turbo.

    I have been fortunate enough to have owned every engine in the 6.2/6.5 family, most notably a 6.2 Humvee which was by far the most reliable mechanically.

    Since this truck is a keeper, I've spared no expense (within reason) in obtaining all of what I consider the best parts, starting with the purchase of a P400, this project has no time frame, although I am being fairly reasonable in not letting it drag on for years and years.

    I have a DB2 pump from a turbo humvee (I'll post the pump # here for reference later).

    In a previous truck my 6.5 N/A, I rebuilt the engine and being someone who likes to modify things (again within reason).

    I machined and ported the heads with some additional cooling modifications which included bleeds off the side of the water pump routing the cooling to the welsh plugs with deflectors to push the water to the rear of the exhuast ports, I had a machine shop then re-drill the water passages in the heads to increase the flow.

    This resulted in a dramatic increase in cooling efficientcy, at the time I used a particular engine development company, and I plan on using them this time around also.

    http://www.bennettclayton.com.au/?page_id=6

    Some mechanical machining aspects are beyond me so when faced with this I usually outsource the work although I'm fairly competent mechanically with the 6.5 generally in diagnosing issues and working on it as being in Australia that engine family is not common here, so i've had to do most things myself.

    With the P400, I am also going to have the heads machined and add some cooling modifications, however I am looking for some imput from you guys on what injectors are best for use with the DB2 pump as I'm not well versed in that area, and generally some ideas of what you'd do if it were your motor?

    Thanks in advance,

    Travis
    Travis
    96 Hummer - Project P400

  2. #2
    Join Date
    Aug 2010
    Posts
    419

    Default

    Use the stock injectors with bosch nozzles set to 2200-2300 PSI pop pressure.

    Also the Bobbie Martin Guide is a big help for most who want to do the mechanical conversion:
    http://www.mediafire.com/?4wj51rn22o6z6
    2005 Chev K3500 CCLB

  3. #3
    Join Date
    Jul 2008
    Location
    Australia
    Posts
    20

    Default

    Quote Originally Posted by racer55 View Post
    Use the stock injectors with bosch nozzles set to 2200-2300 PSI pop pressure.

    Also the Bobbie Martin Guide is a big help for most who want to do the mechanical conversion:
    http://www.mediafire.com/?4wj51rn22o6z6
    That's the best info, I never knew/expected to ever find anything like this

    So basically I'm not alone in wanting to get rid of the DS4 pump..
    Last edited by axemann; 09-18-2013 at 18:42.
    Travis
    96 Hummer - Project P400

  4. #4
    Join Date
    Apr 2010
    Posts
    359

    Default

    Just an FYI: the optimizer heads were redesigned in both coolant flow paths and material thickness.

    For the better that is.....
    1998 k2500

  5. #5
    Join Date
    Jul 2008
    Location
    Australia
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    20

    Default

    Quote Originally Posted by greatwhite View Post
    Just an FYI: the optimizer heads were redesigned in both coolant flow paths and material thickness.

    For the better that is.....
    Thats true, I'm away with work at the moment so will post some pictures when I get home.

    I'm looking forward to the build.
    Travis
    96 Hummer - Project P400

  6. #6
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,553

    Arrow

    Quote Originally Posted by axemann View Post
    With the P400, I am also going to have the heads machined and add some cooling modifications,
    I recommend not straying far from the latest cooling system components used on the P400 by AM General. Cooling system performance was a critical design element in the new engine because of the experience gained in the 130F heat found in the deserts of Iraq and the rest of the Middle-East.

    Back in 2003, there were some HMMWV overheating issues in Iraq. Through email, I communicated over several months with an AM General engineer who was on-site in Iraq trying to help our soldiers and Marines keep their HMMWVs up and running properly. AMG took the lessons learned to make the P400 better. I recommend not straying far from the latest cooling system components used on the P400 by AM General.

    Jim

  7. #7
    Join Date
    Jul 2008
    Location
    Australia
    Posts
    20

    Default

    Quote Originally Posted by More Power View Post
    I recommend not straying far from the latest cooling system components used on the P400 by AM General. Cooling system performance was a critical design element in the new engine because of the experience gained in the 130F heat found in the deserts of Iraq and the rest of the Middle-East.

    Back in 2003, there were some HMMWV overheating issues in Iraq. Through email, I communicated over several months with an AM General engineer who was on-site in Iraq trying to help our soldiers and Marines keep their HMMWVs up and running properly. AMG took the lessons learned to make the P400 better. I recommend not straying far from the latest cooling system components used on the P400 by AM General.

    Jim
    I accept that, and point taken.. I've decided not to proceed with what I was originally intending to do, but I am going to go with a cooling modification I used on a previous truck.

    When I was in the US in 2009, I met with Bill Thompson and John Ward from AM General and spent a few days four wheeling in Moab which was a good opportunity to pick their brains over a few ideas that I was doing at the time with another engine.

    One of the cooling modifications I was working on at the time that John said was an "interesting concept" was to machine bleeds off the sides of the water pump and run hoses down both sides of the block to the welsh plugs, I machined deflectors on the back of the welsh plugs which pushed water up behind the exhaust ports, the heads were re-drilled to accommodate this.

    I had good results from that modification and overall it increased my fuel economy as the motor wasn't working as hard, I've since travelled an additional 80 000kms across the desert here without overheating once.

    But I'd be interested if anyone actually knows what AM General actually did in changing the cooling of these engines, rather than just telling me it's the latest cooling system?

    Thanks in advance.
    Travis
    96 Hummer - Project P400

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