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

I work in the Mad Scientist Dungeon at Howell EFI, and am looking for Jeep owners who have made their own crank trigger mounting bracket for a fuel injection conversion on the Buick 225 odd-fire V6. Recently we've been receiving more calls for FI conversion kits for this engine, and while not very common, they are coming in often enough to consider making the brackets to include in the kits we make. What we don't have is an engine available to mock-up a prototype to have produced, and so far it's been left to the customer to fab their own sensor bracket because it just wasn't feasible to produce them in any quantity reliably ($$$). If anyone here has fabbed their own bracket, or has the detailed dimensions of one, we'd be interested in talking to you, or maybe even 'borrowing' one from you to get the dimensions down for an eventual production piece. If it turns out to be do-able, you'll get the first official production piece on the house as a thank you. Any help or tips you can offer will be greatly appreciated. Thanks! - Dan

 

@Norcal69 is your guy.

 

Thank you. I commented on an existing post about this a while back, and I think he was in on the convo. Thought I would make a dedicated post about the subject so it's a little easier to keep tabs on.

 

I will be following this thread. I have an odd fire with the stock carb. I would like to go EFI but it would have to be a complete install kit for me.

 

@truckee4x4 also made one which is clean and laser cut.

http://www.earlycj5.com/xf_cj5/index.php?threads/149605/

 

It's a simple fab job. I think you need to decide what trigger you would provide with the kit first. The bracket can be built around it. A factory GM piece would be nice for ease of sourcing in event of failure.

 

Hey @Shop Gumby is Troy working this week?
I emailed with no response.

 

Already have the sensor, an official GM part, and have seen a few different and creative brackets already. I realize it's not too complicated, I just want to make a 1 piece stamping that doubles as the fuel pump block-off plate without welding or making any guesses on measurements. Simple as possible to keep the cost down because it won't be a high-volume piece, but solid enough to not worry about it once installed. Also want to keep it out of the way of any mounted accessories...alternator, p/s pump, etc. We just don't have an engine available to use for mock-up.

Troy can get pretty busy, but he's not on vacation to my knowledge. I'll let him know to double-check his mail.

 

I would be very interested if you can make the bracket for the trigger sensor. I would purchase your complete kit.

 

I'm loving this, and will very likely buy a Howell kit if you can put together a good kit. Thank you for the effort to reach out to the forum, especially on a vehicle as old as ours, which we obviously adore

 

I'm another ECJ5'er with a dauntless that would buy a ready to go, off the shelf fuel injection kit without batting an eye!

 

I am curious why the uneven firing signal from the distributor can't be corrected in software. Even a very simple 2 point moving average filter on the time between pulses should produce a reasonably steady signal, and the memory/processing cost is almost zero. Has Howell tried to implement something like this? @Shop Gumby

I understand why users are resorting to a crank trigger for the even signal, since they can't access the software. But from the manufacturer's end, a software fix seems like the proper solution vs. adding additional hardware.

Anyway, I am glad to see Howell offering kits for this engine and interacting with us.

 

Jeep owners are a big part of our customer base, a creative and dedicated bunch for sure. There are quite a few things we'd like to offer that are just not possible at the moment because demand is not quite enough to cover the expense of development or manufacturing, especially for a smaller business like ours. Single-barrel 4 cylinder Jeeps are also an area we looked into, but finding one for sale locally to use as a test/tuning mule, or someone in the area to volunteer theirs was about impossible. The odd-fire V6 request showed up enough for us to put a kit together to offer, but just didn't expect an oddball part like a non-existent crank sensor bracket to hang things up like it has. If we can find one to use to nail down the prototype, we should be able to bang out as many of them as our customers want. Until then, the search continues.....

 

I'm more involved with the mechanical end of things, the tuning/software is handled by Troy and Matt. I understand what you mean though, and I'm thinking that correcting the odd signal would require more than could be done with the existing ECM. An add-on module would be a possibility, but considering the development cost/time factor, the crank sensor and bracket is probably the best solution to use. Cost to the customer is also a big consideration for us, and has to be factored into it as well. This is just my guess on the subject, as I said I'm not involved in the software/programming side of things. But I'll ask the question up front just to see how wrong I might be.

 

@Shop Gumby, Troy writes that there is no fuel pressure check valve. Is there a reason?

 

I think it should be possible to implement on the existing ECM at no cost. It is trivially simple from a processing standpoint.

To expand on what I said before:

Right now I am guessing that each time a pulse comes in, the time since the last pulse is recorded and then the RPM is calculated as follows: RPM = 60/(seconds since last pulse * number of pulses per rev). The problem with this is that it assumes each pulse represents 360/(number of pulses per rev) = 120 degrees per pulse. With the odd fire engine, pulses come at alternating intervals of 90 and 150 degrees. Therefore you get two alternating RPM readings, one which is too high and one too low.

The solution is to average each measurement of time between pulses with the previous measurement. That way you are always averaging one 150 degree time period with one 90 degree time period. (90+150)/2=120. In pseudocode:
current_time = seconds since last pulse
average_time = .5*(current_time+previous_time)
RPM = 60/(average_time * 3)
previous_time = current_time

Just two additional lines of code and one additional variable to be stored in memory.

I'd be happy to talk to Troy or Matt about it if they want.

 

I get the basics of where you're going with this, but again, I have limited experience with the programming/software end of it. The last time I did any coding (if you can call it that) was on TRS-80's in high school. * insert barf emoji here * But as I understand it, the ECM's we use (GM units from the TBI era) reliably do what they need to do under most circumstances pretty well. The only changeable aspects of it are limited to the prom. Set the basic parameters and let the rest do it's job. I just talked to Troy, and suggested an add-on module to correct the tach signal, and he brought up some good points...one of them being if we make a dedicated part to add into the system, it would be proprietary to us, it wouldn't be a readily available part at any auto parts store (as almost all of the parts in the kit are) to replace should anything go wrong with it. I suppose any bracket we manufacture would fit into that category as well, but a steel bracket is much less likely to experience issues than an electronic module. Using a bracket with a commonly available (Corvette) crank sensor tied in would just be the hardware equivalent of a software fix. Same result, much simpler (and probably less expensive) path. But....you do make a good point, and might be worth discussing it with Troy, as he would be more qualified to explain the details. He's busy, as always, but I let him know he may get a few more questions on the subject.

 

Not exactly sure what you mean...there's a fuel pressure regulator built into the throttle body, and a check valve built into the electric fuel pump. Maybe that's what you're looking for?

 

I relize we are all excited about having some company presence here but please, Let's stay on topic and help him help us. He may think this is the wrong place to be. I have had customers on this forum and taken that to private e-mail to not clutter up the topic at hand.

I can take a look at my in-laws 225 powered jeep but I'm backed up on my own projects.

 

I get the feeling this is the right place for this particular subject. Seems to be so far anyways, and glad to be whatever help I can be. I check the responses as time allows, but the online tech thing is not a full-time gig for me. I realize getting someone to volunteer their own homemade part is a pretty big ask, especially if it's already installed and in use. We're checking into some local sources, hopefully they will pan out and get this project underway soon. I know it seems like an obsolete way of thinking for some places these days, but I like happy customers.