Let's start a junkyard fuel injection discussion

[HotRodmicky]

Well, a big cc flathead with low octane fuel will knock.... bad chamber design.
Happend to me when we traveld to Wales for the Pendine Sands racing.
Best cure is 102 octance German fuel. Second is octane booster.
I run 24 degrees at 2000 rpm. Nothing radical.and not needed.
But i also think that a knock sensor is not needed.

[Kilohertz]

Okay, well that's great news, I'll forget the knock sensor and carry on.

I continued cleaning up the harness yesterday and brought a 4.3L throttle body unit home to play with until I find the 2.8L one. I have all the sensors and such and am ready to start assembling the system, I just need to find that elusive Merc manifold. I know of 2 but am waiting for a road trip to get one.

Ken, your suggestion of having each injector spray into only one side of the manifold is definitely my plan and I may go even one further. I found that the GM ECM has 2 different injector drive signals but they always fire at the same time in original configuration. As I work my way thru understanding the EPROM code I am going to try to find a way to fire each injector separately, I'm not sure how important this is, but if I can batch fire 4 cylinders at a time instead of 8....just thinking out loud. I know the wet manifold isn't the best design.

Cheers

[Ken Henry]

I bet it will work just fine batch firing both of your injectors four time per engine cycle given that they are shooting into different planes, but I totally understand your desire to make it 'theoretically' better! I'm doing a bunch of minor modifications to my system right now that I doubt will change much, but should look a little 'cleaner'. If you decide to pick up a Megasquirt ECU it can definitely alternate injector firing between the two circuits. I had mine set up that way at first but it didn't work well due to my single plane manifold I think, with one injector closer to the rear cylinders and one closer to the front. Can you use a WB O2 input into the GM ECM?

[Kilohertz]

Originally Posted by Ken Henry

If you decide to pick up a Megasquirt ECU it can definitely alternate injector firing between the two circuits. I had mine set up that way at first but it didn't work well due to my single plane manifold I think, with one injector closer to the rear cylinders and one closer to the front. Can you use a WB O2 input into the GM ECM?

If I can find a Megasquirt at a reasonable price I would certainly try it, I have wanted to for a few years. I was going to fuel inject one of my dune buggies, was going to build an old D or L Jetronic system but just never got around to it. I have all the parts and good FI engine cores.

I'm not sure about wide band O2 on the GM ECM? I am still searching for how to program the darn thing. I can find lots of BIN files with mods that have been done by others, but just not the logic or program that translates the binary into something like, "add more fuel at this RPM and vacuum" etc. I'll figure it out eventually.

I am currently building a WIN95 or 98 machine, boy that's fun, so I can run my old DOS based EPROM programmer. Sure glad I kept all my old Windows software...once a nerd, always a nerd. The hardest part is finding a 486 machine...ha ha.

Cheers

[HotRodmicky]

You can get a 8x8 Ecu for around $300 from Australia if you want to go full sequentiell
Just weld some injectors bungs in a manifold , crank and cam sensor , and use COP or coil packs and try it.
Lots of fun , but will it be worth it ?
Good question....

[Ken Henry]

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I decided to clean up my EFI installation a bit and converted to these ignition coils from a Cadillac northstar engine. The coil pack has a built in ignition module which I bypassed, so they're controlled by the Ford EDIS system. The spark plugs are run through plastic tubes and wrapped in 'ClassicBraid' split wire looms. A nice benefit of the coils is that they use standard HEI style terminals rather than the oddball two-piece EDIS ones...


F42DB928-8DFA-4DFA-8AD3-B8264D05CF0A by kenhenry_06268, on Flickr

[markdtn]

That setup is very nice! I have thought about this and I would have done it like Bubba suggested-TBI with 4.3 GM ECM and small-cap Chevy distributor converted to flathead. But going Ford EDIS is next level. I am just finishing a 5.0 Explorer swap into a '66 Mustang using the coil packs and all (not converting to Mustang computer and distributor). Not many people go this way as it is hard to find someone who can program the computer.

[cmbrucew]

https://www.motec.com.au/m800/m800overview/
You guys might consider this.
Bruce

[mrtexas]

I installed a FITech unit on my 41 flathead. Didn't try very hard but couldn't get it to work. It ran WOT all the time. Must have been a vacuum leak...

[big job]

My thought bottom line: Think I'll take a ride for some milk in my 23 touring. Well come out of driveway and WHOOHO a 23 touring car across the street gas station getting a inspection sticker I turn around got behind him. Very nice 'nice as mine'. Middle age guy proud of his ""modern"" electronic distributor? foolishness: Now his turn for the sticker. No start nothing? I say I got a screwdriver in my toolbox. Huh? I say I have four coils no nonsense even If one goes bad got 3 more coils get ya home.
So he didn't a sticker but got a flat bed! Thats what one is up against Injection and computers can not be fixed results you are done, so no thank you. My V8 starts on a dime with out a choke in the coldest temps, and its 6volts too.

[Pete]

Many have tried and a few have succeeded in making a mechanical fuel injection work on the street with no flat spots. When it works, the throttle reaponse is like nothing you have ever driven.
I have done 2 flatheads, one 296 with an original flat base Hilborn right out of the box and the other using an adapted 2.5 inch BBC unit on a 352 ci engine.
On both I had to make new barrel valve shafts with curves I arrived at by cut and try.
I am all for electronic injection but just sayin' the old stuff can be made to work also.
Costwise probably about the same with used parts.

[Kilohertz]

After a crazy busy stressful summer dealing with wildfire threats, work etc., I am getting ready to continue the FI system for the flathead.

I finally found a 2.8L throttle body which has 1 3/8" bores that match the Fenton 4bbl bores. I came up with an idea to use the 4bbl manifold, by rotating the throttle body 45* to match up the left front/right rear holes of the manifold. The bore spacing of the TB is only about 1/8" wider than the diagonal bores of the manifold so very little machining will be required, and the TB mounting holes will be out of the way of the 4 square bolts of the manifold. I would remove that Holley 4bbl adapter and build my own to match up the bores and mounting bolts required, and cover up the other two unused intake bores.

I also have made tremendous progress on the software side of things. I'm using the 1990 GM TBI system and have TunerPro software which allows real world data manipulation of all parameters, fuel, spark etc. and then programs that into a BIN file which I can then burn into the PROM, which pops back into the ECM. I found some EEPROMS which are reusable chips that can be erased in seconds and programmed the same.

I'm still busy at work but have all of this in place for when the snow flies and work slows down.

What do you think about mounting the TB rotated like I describe? I don't see why it wouldn't work. Each plane of the manifold is isolated from left to right. The gasket I used in the picture is from the larger 4.3 TB, the 2.8L has smaller bores.

Looking forward to getting this running this winter.

Cheers

[Ken Henry]

I think that would work if you go with some kind of throttle cable. Do you have wideband O2 sensor to help with tuning?

[Kilohertz]

Thanks Ken,

I bought an Innovate LC-2 to tune my BMW bikes this year but haven't opened it yet. I think it is wide band but will confirm.

Cheers

[Kilohertz]

A quick update on my progress with the GM TBI injection project.

I picked up a scrap piece of 1/2" aluminum from the local machine shop, bought a Rota-Broach set and got to work laying out the adapter plate to mate the 2.8L throttle body to the Fenton 4bbl manifold, paper tracings, center punch, straight edge and a little patience and I have it built, just need the proper countersink bit for the 4 holes to mount to the manifold and thread the holes for the TB and trim the excess material and it's ready to install. I'm going to just hang the computer on the firewall for now, connect the sensors and try it just programmed as is for a 305, fine tuning can come later.

I'll keep you updated as I make progress.

Cheers

PS Ken, yes LC-2 is a wide band O2 controller.

[Ken Henry]

Interesting, I’m not familiar with the Rota-broach. Seems handy! I think there was another guy on here who was using the GM TBI computer and posted a running setup 4-6 months ago. Will look ok to see if I can find it…

[V8COOPMAN]

Originally Posted by Ken Henry

Interesting, I’m not familiar with the Rota-broach. Seems handy! I think there was another guy on here who was using the GM TBI computer and posted a running setup 4-6 months ago. Will look ok to see if I can find it…

Quite likely this thread in the link BELOW! DD


https://www.fordbarn.com/forum/showt...fuel+injection

.

[tubman]

"Rota-Broaches" while kind of expensive, are very handy for stuff like this for those of us without milling machines. I use them a lot in making my condensers. You will need an arbor, and then you can use a variety of sizes of cutters.

[Kilohertz]

Originally Posted by tubman

"Rota-Broaches" while kind of expensive, are very handy for stuff like this for those of us without milling machines. I use them a lot in making my condensers. You will need an arbor, and then you can use a variety of sizes of cutters.

I bought the large set. 11091 I think, it was $250 cdn on Amazon...works as slick as can be...I drilled those 1.375" holes in less than 30 seconds each...very slick. And a beautiful finish as well, very smooth.

Drilled and tapped the TBI body holes today and will cut off the excess material tomorrow....EFI, here we come.

Cheers

[Kilohertz]

I finished making the adapter plate and custom gasket for it and can now proceed with mounting the 4 bbl manifold and throttle body.

It's interesting to note that I used more woodworking tools than metal tools to make this plate. The drill press for the holes and my compound sliding miter saw with carbide blade to cut the outside dimensions, and a router with the roller bearing 45* cutter to radius the edges, both worked amazingly well on the aluminum, cool.

More later....

Cheers