Newby looking for info on the 6.5 P400 engine to go in a 94 Suburban

Discussion in 'GM 6.5 Diesel Engines' started by spdgofast, Mar 9, 2011.

  1. spdgofast

    spdgofast Member

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    I have a 94 K2500 Suburban that I am thinking about installing a P400 6.5. I have allready done away with the DS4 pump and have compushift computer for 4L80E. Has anyone done this install on this model truck?
     
  2. WarWagon

    WarWagon Well it hits on 7 of 8...

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    LMC truck will have the rare throttle cables you will need from a ~1992/1993. Bobbie Martin, also on here, wrote and sells a book on DB2 conversions.
     
  3. ak diesel driver

    ak diesel driver Active Member

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    you'll need to make a custom oilpan
     
  4. spdgofast

    spdgofast Member

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    Yea, the oil pan info is what I am looking for I am told that the p400 comes with a cast aluminum pan that may or may not clear my front diff even with the 4" suspension lift. I already had the DS4 to DB2 conversion done and had cruise control set and hit a couple (ok maybe more than a couple) of mountain passes and the boost shot over 20 PSI before I tapped the brake to shut down the throttle so I think I stretched the head bolts, cause she's asteamin. I'm running a penninsular 340 HP DB2 pump with a GM 8 turbo and spearco intercooler all match ported and HPC coated intake and exhaust system thats how I can make so much boost. I have a 12 valve cummins that I wanted to install but I want to find out about the p400 beacause it would be a much easier install especially with all the $ that I have spent on the present 6.5 hang on parts. I appreciate any info any one has, Thanks
     
  5. ak diesel driver

    ak diesel driver Active Member

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  6. spdgofast

    spdgofast Member

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    No, I wished I had! Before I put the DB2 340 HP pump I put a (supposedly good and tested used) DB4 marine pump on it that I got from penninsular and had to turn it up as far as I could and I felt that it was not enough fuel (low EGT's) so penninsular had me send that pump to their local Diesel Injection Service in Grand Rapids MI. While they were testing the pump on their stand the pump blew apart. Which I thought that there would be problems because I had the DB4 put on my local test stand before sending it back and the tech told me it was putting out alot of fuel but he had to back off the RPM's while he was testing it because the driver started to wobble. Well all I have left of that pump are in a clear plastic bag.
     
  7. btfarm

    btfarm Quarter Million Worth Staff Member

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    At least you found out about it's design limit...:hihi:
     
  8. spdgofast

    spdgofast Member

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    Yea, I just got lucky and didn't throw a rod or break the crank, so how much boost can you put to 18:1 or 20:1 pistons? I'm hearing 20 lbs is still too much even for a P400. I am at a big disadvantage I have a size 13 foot and I think having HP is like having a gun "It's better to have and not need it than to need it and not have it".
     
  9. buddy

    buddy New Member

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    Its really easy to get 20psi of boost on a GM8, so its not necessarily because of all that other work. I can push a GM4 to 30psi pretty easily with a stock engine and electronically tuning my DS4. Although the GM4/8 is inefficient and chokes the engine, so if you want to make horspower, try a larger turbo and keep the 20psi. There is a cheap HX40WII that shouldnt be a hard install, wastegated to 20psi. Or the A-Team Turbo, but I doubt your DB2 will push it as hard as a DS4 can. The ATT designer is running modified programming that can drive his ATT over 20psi of boost, and the turbo is like twice the size of the GM8.

    I would have no issue running 20psi of boost on a P400, but actually, I would just purchase a used, but tested Navistar Optimizer engine for less than $2k to your door. Put head studs and +.01" gaskets and youre good to go.
     
  10. WarWagon

    WarWagon Well it hits on 7 of 8...

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    Headstuds and forget about head gasket and head bolt issues. I have ran a DB2 at 14psi with head studs WOT nearly continuous for hours pulling a trailer. You will break or bend other things before the gaskets let go with studs...
     
  11. Missy Good Wench

    Missy Good Wench Wild Blonde from Cloud Mt

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    Non charge cooled 6.5 should not be run past 14 PSI and EGT should not be taken past 1000F pre turbo.

    The P400 is one Helluva engine, but as mentioned the oil pan clearance can be an issue.

    With the 4 inch lift (should have the front diff dropped some, the P400 may fit in there without mods

    I have seen two custom oil pans done for the P400 so that they will fit the stock GMT400 4x4 chassis.

    This is a bit of a job and requires making a new pan rail and then tig welding the original pan to the new rail assembly.

    Quite doable.

    The P400 will tollerate more than the old stocker 6.5

    If you dont want to spend quite the $$$$ amount, you may want to look at the optimizer 6500 instead.

    This engine will drop right in and go to work.

    Missy
     
  12. spdgofast

    spdgofast Member

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    I wished I could have found someone that could reprogram my chip and get me enough fuel before I did the pump conversion. I already had a BD “RACE CHIP” installed and not enough fuel so I had a guy in Denver (where I lived at the time) burning me custom chips to get the fuel and the tranny shift points and line pressures corrected due to the increase in power from the intercooler because I burned the second gear clutches just by adding the intercooler and not raising the line pressures on the first test drive. So after hitting that wall of not enough fuel I got the DB4 Marine pump from peninsular, still not enough fuel, obviously there was something wrong with that pump by the results on the test stand. So after speaking with Dave @ Diesel Injection Service in Grand Rapids MI. who I believe does all of Peninsulars work he told me that the 2 plunger 340 HP DB2 puts out more fuel than the 4 plunger DB4 and to date is the highest performance pump that they had produced and Matt @ Peninsular told me the other day that the DB2 puts out more @ top end and the DB 4 is better for midrange. All I know is my motor ran stronger with the DB2 than the Marine DB4. Both of them ran way better than the DS4. I wished I could have found an adjustable on the fly programmer that would have made my DS4 put out the fuel that I needed but the most I could get out of the DS4 with the most aggressive programmed chip that I could find @ the time was 74MM @ WOT on a tech II . Trust me it would have saved me allot of trouble not having to do the pump conversion. Anyway I am no rocket scientist nor computer wiz I am just trying to catch up on all the latest 6.2/6.5 stuff to see if I can get a reliable 350 to 400 HP without having to do a Cummins 5.9 B 12 Valve conversion cause I can get 400 HP out of one of those real easy but the conversion isn’t so easy. This truck has been sitting for 5 years and it’s way to nice of a truck to let sit not running. Buddy thanks for the reply I guess I need to research some turbos because I sure don’t need to suck a GM 8 turbo into a new P400 motor. I still am not sure what compression ratio I should run because I want to be able to run over the Continental Divide towing without problems.
     
  13. great white

    great white Active Member

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  14. buddy

    buddy New Member

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    What is the actual fuel volume claim of the 340hp DB2?

    If you had come across the site sooner could have got you hooked up with that DS4, it really can sling a lot of fuel. And mind you when it says 74mm, a good programmer that knows how these work might have it spitting over 90mm3 by then. BD hardly does anything for the 6.5 and doesn't make a real "race" tune, in fact Westers claims to as well, and its crap.

    I think you would be fine with the Optimizer and save some money. Although, there is a lot of mods to get to 400hp. Not just fuel. I have a list of mods you can consider, ignore the PCM stuff.
    http://www.thetruckstop.us/forum/sh...o-A-Year-Later&p=336594&viewfull=1#post336594
     
  15. Missy Good Wench

    Missy Good Wench Wild Blonde from Cloud Mt

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    The one thing you want to keep right up front and personal.

    The cooling system will not handle anything past about 300HP

    This is the achiles heel of the design. The radiator and such simply will not reject the heat that you can build with all that fuel and power.

    The Boat engines that Peninsular offers have a whole pond of COLD water to handle the task.

    The frontal area of a Pickup and the limitations of the radiator size plus the fan and such all contribute to the power limits.

    Jim Over at the page did a POWER project a few years back and they were able to manage 300HP and keep the heat in check.

    A custom radiator may give you more room to play with, but the ability of the block design to reject heat is still a limiting factor.

    Missy
     
  16. buddy

    buddy New Member

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    I have found that the Dmax fan really keeps temps in check if it does get hot, and modify the fan clutch if it isnt kicking in early enough. But also running lower percentage (10-20%) of anti-freeze. There are tricks to keeping them cool.

    That said, you have to have it set up for success, and the latest 2000 year water pump with thread on fan clutch is the way to go. And the radiator has to actually be clean inside and out.
     
  17. great white

    great white Active Member

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    Good points Missy.

    I've been meaning to get a membership to get a closer look at that ol' red oil burner. The towing stats they posted are intriguing.

    Although, it sounds like an 18:1 rebuild and a few other minor "tweaks" was the essence of it all.

    I really should get a membership.....:rolleyes5:
     

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