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Before I buy the ProFlo 4...

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  • Before I buy the ProFlo 4...

    I'm about at the point of switching from the current set up (Powerjection III) on my SBF 331 to the ProFlo 4. A few questions on compatability and if this new system will finally gain some real world driveability.
    Looking at #35940
    Engine is an 11.0:1 SBF331 with a Comp solid-roller cam with .609/.611-inch lift and 242/248 degrees duration at .050 and 2.05/1.60 valves in ported Canfield heads with Scorpion 1.72 roller rockers.
    I have the necessary fuel system components and currently using a Crane (HI-6) ignition box with MSD Blaster 2 coil.
    Assuming I will need to port match the intake but will the injector bung be an isssue? Or just gasket match as best as possible?
    I'm guessing I'll need a different throttle cable bracket since the current one mounts about where the new fuel rails would be.
    Will I be disapointed if this new system doesn't like the size of the camshaft? My current system works OK but long drives, traffic, hot restarts are always a concern.


  • #2
    The #35940 kit uses the #29285 intake manifold - install instructions here: https://edelbrock-instructions-v1.s3...rock/29285.pdf From the instructions, recommended gaskets are either Fel-Pro 1262 or 1262-R which have 2.10" x 1.28" or 2.25" x 1.40" ports respectively so that should give you a reference for size if you know your port size now. The injector holes in the intake ports shouldn't be a problem for port matching. Can't really say what fitment will be with your existing throttle cable bracket but our #8041 bracket works very well.

    Didn't find a specific Comp Cam based on your specs - do you have a part number or know the lobe separation angle? How much idle vacuum do you have now and at what rpm?

    I'm interested in knowing more details about how long drives are a concern for your Powerjection system. Also, what issues do you have with traffic and hot restarts?


    • #3
      Thanks fro the reply Nate,

      Last night I typed up a big ole reply then upon hitting the submit button I was asked to log in again...then it booted me out for too many password attempts...weird. Anyway the cam part # is 35-000-9 but I think that was the number they used for the billet steel cores however the LSA is 110. I think it was their Extreme Energy line back iin the late 2000's when I built the engine. I believe the vacuum was between 9-11'' though I could not find any docummentaion to confirm. I do run power brakes with no issues so guessing it's at an acceptable range.

      The driveability issues are similiar to what one would experience when using a single plane intake with a carburetor on the street, puddling, loading up and the need to "clear it out". There are times while cruising at freeway speeds that it feels like the TPS is unresponsive. It takes a bit of throttle movement to kind of wake it up, then a bit of unlinear acceleration before it feels crisp. After a 10-20 mile run if I encounter traffic, stop and go, etc. the idle becomes inconsistent.Then the occasional popping/backfiring in the exhaust. The idel doesn't hunt, it just decides to pick a different rpm. In fairness to the Powerjection III I never spent a lot of time working on driveability as I was mainly open tracking the car. But the plan now is to make it more liveable on the street and I realize the shortcomings of TBI vs SFI. I would like a system that wouldn't require a clear flood mode after a heat soak everytime it's driven, a system the behaves civil though I can deal with a bit of cam surge and one that I feel confident in taking a race car turned street car out for a nice long drive in the oh so crowded Pacific Northwest.


      • #4
        That LSA is a little on the tight side but if your power brakes work adequately with the cam then you should be okay but you could just take a quick glance at the Powerjection software to see what idle vacuum you have now. I'd say you're probably on the fringe as far as what an "acceptable" cam to use with EFI is but it seems you've managed to get by to this point.

        Sounds like you have many of the typical TBI problems because your fuel introduction point is still basically the same as a carburetor which leads to problems with wall wetting and fuel distribution. And you're right - simply going from TBI to sequential port injection is going to greatly improve on all the little nagging problems you've experienced. I obviously can't really guarantee everything but I think you're in a position to see some great improvements with a Pro-Flo 4 over your current setup.


        • #5
          ProFlo 4 has been ordered!! Thanks again for the information...

          Just need paint the intake black!


          • #6
            Quite the difference between the PJIII and the ProFlo 4...Combined with the Super Victor intake I'm getting excited to get tuning on this new set up...just have to wait to get the intake back from Cerakoters. 20190618_172138.jpg


            • #7
              Finally got everything installed, pretty straight forward, fired up on first attempt, yet to drive. Time to work on it has been the biggest challenge. Took two weeks to get the intake back from Brand X Customs who did the Cerakote ceramic coating but it turned out bitchin!

              Only issue I've noticed is my auto meter tach reads twice as many rpm's as it I need a tach adapter to work with the magnetic trigger distributor? Was using an MSD Pro billet before.

              Hoping to get on dyno soon.
              Attached Files


              • #8
                Blue fuel hose for mock up, using ptfe braided line
                Attached Files


                • #9
                  Good looking setup. Regarding the tach, you don't have it connected to the distributor do you? The distributor only sends an engine position signal back to the ECU, not an ignition trigger signal to a coil or tach so you definitely don't want to be connected to that signal. I'd first try to use the tach output wire that's in the Pro-Flo 4 harness. Give that a try and report back.


                  • #10
                    Thanks Nate

                    The green tach wire from the Crane Hi-6 is hooked directly to the tach wire from the ProFlo harness and splices to the auto meter tach. Which is how it was wired with the Powejection system that I removed.


                    • #11
                      Apologies but I'm a little confused. Are you using a Crane Hi-6 CDI box? If yes, it sounds like you have your tach connected to two different tach signal sources: the CDI box and the Pro-Flo 4. That might explain why you're seeing double the rpm. If I'm understanding your setup correctly, then you need to eliminate one tach signal or the other - don't need both connected.


                      • #12
                        my cheeper auto gauge works just fine out of the tach wire form my pro flo 4 unit . try this and see what you get .
                        73-87 gm trucks is my thing . i have a few of them .


                        • #13
                          No apologies needed, yes using a cdi box and yes having it hooked to Proflo tach wire was the cause of the issue. I disconnected wire to ecu and tach reads correctly.

                          Gotta say cold start is so much better now!! Just need to tidy up some wiring and go for a test drive.

                          Thanks again



                          • #14
                            Holy sh$t I'm happy I bought the ProFlo 4 kit. Instructions were thorough, kit was complete, installation was easy, only had a few modifications to perform to make things fit the way I wanted. Fired up on first attempt though I had the distributor a tooth off but easy to fix.

                            Maiden voyage last weekend and couldn't believe how well behaved the engine was. The previous injection system was classic case of Jekyll and I just have the good doctor. Stop and go traffic on an 80 degree day was a breeze, no drama, hot restarts were no problem. Exactly what I was hoping the result would be. I'm scheduled for dyno tune August 10th at

                            Thanks Edelbrock team for a great product and tech support!
                            Attached Files


                            • #15
                     was my much anticipated dyno appointment (at a very busy shop that's booked months out) and instead of paying for dyno time II ended up paying for tow truck time. So I guess I need to carry a jack and a box of 02 90 miles on the supplied sensor. All my confidence just flew out the fucking window.
                              Attached Files