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Howell Efi - Iso 225 Odd-fire V6 Crank Trigger Bracket, Have You Made One?

Discussion in 'Early CJ5 and CJ6 Tech' started by Shop Gumby, Jan 31, 2023.

  1. Apr 5, 2023
    zinertia2

    zinertia2 "and which part are you keeping?" 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Greencastle , IN
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    Anyone else like the “hole counting”?

    Shop Gumby
    What is the distance from sensor face and balance ring?
    Did you make assumptions on a specific bolt head depth if spaced away from ring?

    Dennis
     
  2. Apr 5, 2023
    Frogfarm

    Frogfarm 1978 CJ5 2023 Sponsor

    Cottage Grove, OR
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    I have many years of dynamic balance experience. At 4000 RPM it would not take much change to effect the balance at that radius, I would guess a few grams would be noticeable on a vibration analizer
     
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  3. Apr 5, 2023
    Shop Gumby

    Shop Gumby New Member

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    I'm working with a Jeep owner in Vermont who volunteered to help out and fine-tune the dimensions, he used basic hardware store bolts and nuts etc. Other posts on this subject show people doing various things to trigger the sensor, but most are using bolt-heads or a variation on that idea. Ideal gap between the trigger and sensor is around .040"-.060", but considering all the different ideas out there and different bolts/studs/pins, my goal is to get it close enough for the customer to fine tune their own setup however they choose. The bolt and nut idea is crude, but it works. Plus they allow for adjustment to get that gap right.
     
  4. Apr 5, 2023
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    I am a bit surprised, especially as a employee of Howell, that you say the pulse signal the ECM see's has "Nothing much to do with injector signal". The ECM reads the pulse signal to determine the type of engine (4,6 or 8 cylinder) which is used to determine the fueling to the engine. If for example, if you were to use 4 bolts, you would need to go into the ECM programing and reduce the injector pulse width otherwise you would over fuel your 6 cylinder engine.
     
    Last edited: Apr 5, 2023
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  5. Apr 5, 2023
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    I believe he was referring to the odd ignition firing offset not affected by the even fire of injector pulses.
    The bolt count also is only important in regards to software and rpm values. You could have 12 bolts signaling if the pcm is configured to match regardless of cylinder count.

    Basically the same as a v8 carb on a v6 engine
     
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  6. Apr 5, 2023
    vtxtasy

    vtxtasy oldbee 2024 Sponsor 2023 Sponsor

    Tucson, AZ
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    I believe the computer is looking for a constant speed to determine rippems. It can't lock on to the constant change of the odd fire pulses.
    I believe this could be achieved in the ECM or software if some one thought it was viable or worthwhile.
     
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  7. Apr 5, 2023
    45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    There are ECM's that are designed to operate oddfire engines. They are expensive units to purchase. A design of software was looked at here a year or so ago but if I remember correctly, components were also expensive and I believe the design may have been a little more complex than originally thought.
     
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  8. Apr 6, 2023
    Mjragan

    Mjragan Member

    socal-Simi Valley
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    On the GM TBI system the ECM looks at a square wave 5 volt signal sent to the ECM from the ignition module to determine the RPM and trigger the injectors.
    The numbers of cylinders is programed into the prom in the ECM, the ignition module sends a 5 volt pulse to the ECM every time the ignition fires and the ECM fires the injectors once per pulse. With a 4 stroke engine only half of the cylinders fire per 360 degrees, one rotation of the crankshaft, so a 6 cylinder engine needs 3 triggers.
    When triggering the ECM from the tach terminal on an HEI you have to filter then convert the signal and the signal mirrors the ignition so it is an uneven signal.
    Like Grumpy stated the ECM has a difficult time maintain a stable idle with an uneven signal, by triggering the system from a hall effect sensor with 3 evenly spaced triggers the ECM is seeing the evenly spaced 5 volt pulses it likes and can better manage fuel control.
    With an uneven signal like what you get from the HEI an odd fire will run and run well but it will run slightly rich at lower RPMs, but that can be improved with programing.
     
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  9. Apr 6, 2023
    Shop Gumby

    Shop Gumby New Member

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    Sorry, didn't mean to re-start THAT discussion. :whistle: There are other threads here that cover the issues created by the odd-fire signal, and also how people are cheesed off about how their engines run with the tbi setup. Technically I'm not on the programming end at Howell, more on the mechanical side. I guess I could have worded things a bit clearer, sorry about that. I basically meant the odd signal sent to the ecm was in a way making it try to idle at 2 rpm levels at once...sort of. The end result is a goofy control over the IAC motor, injector signal, etc. Programming the prom to try to correct that behavior just doesn't quite cut it (as we eventually found out). Wailing and gnashing of teeth rightfully ensued. A crank sensor bracket is now in the works, eliminating the need for the tach signal.
     
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  10. Apr 6, 2023
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    Block really does not matter when it comes to the OF - EF... I've had OF parts in an EF block and visa versa. What makes it OF at the real core is the crank. Having built one for the Pikes Peak Hill Climb, I know that you can use various balancers on the front depending on your skills and how you want to balance the motor as we built a custom one for that motor (its running in the '51 only not as 'wild' as it was at one point) and even has a 231 timing cover and water pump on it.
     
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  11. Apr 6, 2023
    zinertia2

    zinertia2 "and which part are you keeping?" 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Warloch

    A lot more variables and permutations than I thought there could be!:)

    Dennis
     
  12. Apr 8, 2023
    zinertia2

    zinertia2 "and which part are you keeping?" 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Shop Gumby

    Can you provide the sensor hole size? Already have a sensor - threaded body so it provides depth adjustability, high temp and reliability ratings. Would be a great thing if the hole was small enough to thread. This sensor is good for setting the gap between 0.040 and .080.

    probably too hard to make one bracket for the shown sensor and one with either a smaller hole that could be sized and threaded for the standard threaded size 12X1mm or other?thanks
    Dennis
     
  13. Apr 10, 2023
    Shop Gumby

    Shop Gumby New Member

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    The sensor we will use is GM#12591720. The diameter is roughly .780", the mounting hole is a few thou larger. It comes with an o-ring already installed, though it serves no purpose for this application. It'll be secured with a 1/4-20 bolt, the bracket will be drilled and tapped for it. The threaded sensor idea is a good one, but either way it'll need to be fine-tuned for position, depending on how the customer decides to trigger it. The bolt-through-the-balancer-hole idea is probably the simplest, even as crude as it may seem, but that way allows for gap adjustment with the sensor we'll have available.
     
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  14. Apr 10, 2023
    zinertia2

    zinertia2 "and which part are you keeping?" 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Thank you!
     
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  15. Apr 27, 2023
    68CJ-5

    68CJ-5 Had to get away

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    @Shop Gumby , will you be offering this bracket as a stand-alone for those of us who have another brand of EFI? I'm getting ready to build a bracket for my FiTech unit, but I plan to use one of the adjustable threaded 12v pickups, or perhaps this one which is similar to the Vette:

    https://www.diyautotune.com/product/crank-position-sensor-hall-effect-tab-mount/

    FiTech uses a 12v signal. My unit is installed and running but will not perform correctly without the crank trigger; same problem everyone else is having.

    If you have one to send me for test purposes I'd be glad to try it out. Just the bracket, not the sensor, unless that sensor will also output a 12v signal as others do.

    Thanks
     
  16. Apr 28, 2023
    Shop Gumby

    Shop Gumby New Member

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    Thanks for the offer, where were you a few months ago?? :D
    I'm working with a guy right now who volunteered his Jeep as a guinea pig, and the bracket proto is almost ready to go. Just a few more minor tweaks and should be available whenever the fab shop bangs them out. I'll post here when that happens.
    The word from On High is that these are for customers who have bought the Howell kit, or do so in the future. As for availability otherwise, I'm told it may be a possibility at some point, but not at the moment. I honestly didn't consider that part when all this started, just wanted to remedy an understandably frustrating issue.
    Waiting on our tech guy to get back with me on the voltage output question. I'll reply when I find out. - Dan
     
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  17. May 2, 2023
    Shop Gumby

    Shop Gumby New Member

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    I'm told the crank sensor is not 12v output. It's a GM part, #12591720.
     
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  18. May 31, 2023
    Shop Gumby

    Shop Gumby New Member

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    Updatification: It took a bit longer than expected, but the final ok was given, and the brackets should be in the process of being banged out as I type this. I'm hoping to see the first small batch within a week or so. I'll ring the dinner bell here when they're finally available.
     
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  19. Jul 12, 2023
    Shop Gumby

    Shop Gumby New Member

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    They are here, FINALLY. Available individually for customers who already have a Howell 225 TBI kit that needs a bracket (unsure of price at the moment), or anyone who orders the kit in the future. Will include the sensor and mounting screw, gasket, and connector/pigtail to splice into an existing harness. For now, they won't be sold on their own, though I'm working on getting that changed. A HUGE thank you to Walter Breck (he's here somewhere) for the time, effort, and patience, and for volunteering his chariot for guinea-pig procedures. And also big thanks to all of you for the suggestions and input. - Dan

    And of course the photos I have are too big to upload. As soon as I figure that one out, I'll post a few.
     
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  20. Jul 12, 2023
    colojeepguy

    colojeepguy Colorado Springs

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    Gotta reduce photo size under 1MB. Or put them on a 3rd party photo hosting site & link them here.
     
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