425 injected

Discussion in ''Da Nailhead' started by rb25, Oct 7, 2008.

  1. The Devil

    The Devil Well-Known Member

    Dave Ray helped me quite a bit when I went to the TPI on one of my 425's. I used a complete Holley Commander 950 injection setup, with single 4 bbl dry throttle body, and Dave made me a set of spacer plates with the port nozzles in them for between the head flanges and intake manifold. The nozzles are aimed at each other under the intake manifold.

    Dave also made me one of his EFI-HEI distributors for it as well, uses the GM 8 pin EFI-HEI module, and all went together like it was stock, no problems at all. Dave has built me a few of his EFI-HEI setups for a lot of different engines other than Chevrolet I have converted to EFI with the Holley systems, and the Affordable and FAST systems as well.

    The most fun one was for my Olds 442 with the 455 engine in it, we Holley 950''d it, and my side line hobby is McCulloch superchargers, so, we did one for that too, blow through system with port nozzle EFI. All we did was have Holey add a couple of enrichment circuits for boost, and a pressure sensor for them, and we were ready to go with it.

    The Holley system dials in really easily, may not have as many confusing items for adjustment as FAST and Mega-Splat, but, overall, it works very, very well.

    Regards,

    Milton
     
  2. Hawken

    Hawken Hawken

    Just an FYI comment, but would info and technical data about the 2001 Buick Blackhawk concept be relevant to this discussion. I know Mike T. at TA Performance was involved in building the 455 that had sequential fuel injection and that car may have some info that could be helpful in how the FI system was designed - good or bad.

    There is one particular picture on page 2 of the the link below showing some FI plumbing, etc. Link

    I am sure there are many more resources available for this and propably more than a few people on this board in the "know" about the Blackhawk and the development of the FI system it meeded to run properly. The Blackhawk did end up running a mid-13 ET at more than one Buick event - so it is not just for show.

    Ken
     
  3. 56familykar

    56familykar knuckle banger


    Swapping cylinders wasn't too much of a problem with our Pontiac. Then again we used a FAST system. I dont see why changing the arrangement would confuse the ECU as long as the whole system is in the right order. We actually used a late model HEMI wiring harness for the Poncho.
    Mike
     
  4. CTX-SLPR

    CTX-SLPR Modern Technology User

    Aftermarket systems are designed for user defined firing orders, OEM systems, atleast GM systems, are not. The Gen III/IV system uses the Ford HO/351 firing order and the Gen I uses a different firing order. Even after translation the Nailhead order is different than any production EFI V8 I've found. I wouldn't be surprised if you reprogram a Ford EEC IV for this order but I've never looked into it.
    Megasquirt would be the easiest and cheapest way to do it as it uses a distributor with a 7-pin module if you want electronic timing control as well as the EFI. The injectors would just have to be wired in properly for the firing order and the WBO2 would be easily moved from bank to bank to ensure proper mixture on both sides but would only have to stay in 1.

    TBI is pretty easy to setup and since a lot of the earlier Chevy 454 TBI systems were actually bolted to Q-jet intakes they can be made to work relatively easily with a proper driver controller. Its a better idea to use something like a Megasquirt for this since you can control it rather than letting some shop continually burn you chips or having to burn your own.

    I have a design on file in my engineering sketches for a tuned runner tunnel ram for a Nailhead to utilize an LT1/TPI twin blade throttle and it would have been run by a Megasquirt setup since I couldn't find a way around the firing order with any of the GM systems though I might try a Ford EEC IV system if I can find a tuner that would explicitly state I could change the firing order and such.
     
  5. nekkidhillbilly

    nekkidhillbilly jeffreyrigged youtube channel owner

    jack at the moment but heres the list

    junkyard injectors
    megasquirt 300 bucks
    http://www.auto-nomics.com/cgi-bin/showresults?a=detail&part=10850-002-D

    tb from there only about 200 bucks
    tank sump and injector bungs little over a 100 bucks
    and a 200 dollar fuel pump
    then just your wiring fuel line and hoses rails that would be a few hundred bucks
     
  6. nekkidhillbilly

    nekkidhillbilly jeffreyrigged youtube channel owner

    dodge also had a tbi setup that you could use on there trucks
     

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