225 W/Pro-jection

As long as we are speculatiing.....

with a 9:1 comp ratio we could realistically run about 8psi of boost safely without any internal modifications.



(used to have a thing for inport tuning glad I out grew that several years ago)

 

I don't think I follow you. The points or lack thereof doesn't determine timing control. The GM TBI system can control timing; I should say the TBI system can retard the timing. Someone who used to frequent ECJ5 built himself a hybrid 225 OF/4.3 EF distributor to give the ECM a clean ignition signal. Worked like a champ though it still had no timing control. And another thing worth mentioning is that he estimated the cost at somewhere between $3-5K to make another one for someone else. The timing control is a moot point in my opinion anyway. It just allows for the maximum amount of timing without preignition or detonation. Fuel control is much more important for what most of use our Jeeps for.

 

we need some sort of rpm feedback for the ECM to operate.

We are talking about building a crank trigger to give a GM EFI the "rpm" signal it needs when it normally would recieve this from the spark signal.

Ford seems to get this RPM signal from a crank trigger already.

If we use the petronics points modual to sent the the crank signal to the Ford ECM it will make whatever adjustment it needs to to optomice spark, send the signal to the coil, (which is a passive component) and then to the cap that has mechanical consession for the oddfire built into it.

What I don't know is if the signal from the petronics module can be interperated by the ECM. I would wager to guess it can since it is nothing but a simple magnetic pick up just like a crank trigger.

So we get rid of the points (good thing) gain spark time ability and TBI as a stand alone system.

Optimum conditions all around if the facts support the theory.

 

Oh I spent 15 minutes typeing and hit the bak key on the stupid 5 buttom mouse and lost everything.........

 

Finally found a decent source of info.

The Ford EFI uses a stator moduale inside the distribuor with a stator "wheel" for timeing. The wheel is nothing but a sheet metal drum with teeth cut in it that corilate the respective cylinders. the #1 tooth is slightly smaller telling the EEC (thier term for the ECM) when to pulse the injector and fire the spark.

I think that either with the use of an existing wheel, and the stock Distributor cap we can accomodate spark time "mechanically" to bypass any EEC glitch. (in theory)

I did ask if a "modified" wheel that would properly corilate with the oddfire pattern would work, and not throw the EEC into some sort of convulsion. I'll let you know IF I get a responce.

Spark time is adjusted by the factors the other sensors provide so the actuall rotational "time" of the spark should be inconsiquential unless the EEC actively searches for a consistant rotational "time"

Seems that this system is idealy suited for the application since the fuel pulce would ultimatly be perfectly timed with the ingition time.

Sound like progress?

 

Just a thought starter, not sure how it would work, but has potential with what you are doing --

Late 80's Buick V6 cam sensor. Run a GM distributorless CCC coil pack and module.

 

I think the simplest solution to the problem would still be the crank sensor. It wouldn't involve changing the distributor or adapting anything...

 

I think we got our lines crossed somewhere. I (and others) had discussed installing a GM TBI system on the oddfire 225 as it is fairly straightforward. There is a guy in my area who did this but took it all out (and sold it) to install an LT1 into his 5. Can't say anything about the Ford systems because I haven't done any research into it since the GM system seems to be a logical choice. On the GM system, you can't use the uneven pulse from the distributor because it uses the spacing between them to determine RPM. You could get it to run (though not well) with the uneven pulse, but the ECM gets "confused" into thinking the RPM is constantly going up and down with each ignition event since the amount of time between them is different.

With or without the even pulse, the GM ECM has no way to retard the timing on a distributor that it wasn't originally equipped with.

An even better way of saying it: the 225 distributors have no way to allow an ECM to control the timing. And again, it's kind of a moot point since the main purpose of going to EFI in the first place (in an early Jeep) is to be able to have a correctly metered supply of fuel going into the cylinders... A carbureted fuel system issue, not an ignition issue.

That was a mouthful! I think it would be pretty damn cool to see a Ford or any other type of EFI system working well on an oddfire so please don't think I am trying to pee in your cereal here. With the way I write, sometimes I think I might come across a little harsh...

 

X2

And it's cheap, too.

 

mruta,

I agreed with your whole mouthful. I also agree we aren't trying to dismiss the Ford EFI idea as it would be trick. I think the original topic of this thread has been almost solved. A GM TBI from a 4.3 and a crank trigger for the "tach" input and we would be in business. Now, someone needs to try it. I would but.....

Mike

 

I agree that in terms of what I have been exposed to (the adapted 4.3 GM system I currently run on my CJ7) and the GM origins of the engine we are discussing that the GM TBI crank triggered system seems logical.

What got me on the tangent of the Ford system is this.....

I had info that the Ford system used some sort of magnetic pick up already to determin RPM, follow up showed that it did.

subsiquently I found out that the same pick up (the drum shaped piece of sheetmetal inside the distributer) controled both the spark input that the computer alters for the coil trigger, and the injector pulse and diration.

Sounded cool, I could gut an ols 84-94 taurus and bolt it into a dauntless and shazamm we are running.

Factors for fabrication.

1 Don't need the Ford distributor just the stator and modified Wheel, adapt them into the dauntless distributor

2 the throttle body to intake adaptor. (I know a machinist that can handle that.......me)

2 possible ways it would work.

1 put the ford dist. guts in a dauntless dist. and the modified wheel works off the get go.

2 the afore mentioned situation minus the modification to the wheel (which in this situation would not be required) and the stock oddfire cap takes care if the unequal spacing.

Either way we still get the timeing ability.

The only reasons I looked into ford are

1 Already has a magnetic pick up for rpm

2 possible to bolt on all JY parts=cheap!

I have an adapted 4.3 so its not a bias thing. Just brainstorming.

No offence ment.....none taken

 

more directly to the point here is a link to the inside picture and degrees between each pole
http://home.off-road.com/~merls_garage/oddfire/cap_evnodd.jpg

 

ok but what if you've installed an OF HEI dist in your 225? could you use the tach out plug on that? since it seems to run my relatively cheapo tach now.

 

Ya know, that is what I'vve been wondering as I've watched this whole thing unfold, I know several people must be runnin tachs off of their HEI, how if the signal is such a mess??

 

so would we still be talking about a 1986-89 astro 4.3L v6 TBI? ecu, injectors, harness, etc.

direct to a 225 no manifold change etc.?

 

You could use any 4.3 TBI engine from 86-95. The differences between the years are very minor. You would have to use a TBI to 2bbl or 4bbl adapter. If 4bbl, you'd have to use an aftermarket manifold.

 

I do run a HEI distributor, I also run a "factory look" tach off my distributor. I just tapped the Tach wire for the signal input on my Pro Jection kit. Want pics?

 

Boy, MegaSquirt is sounding better all the time. Has built in support for odd fire (fuel only). Modifying the guts of the distributor to provide the odd fire spark and the even pulses for a Ford / GM ecu sounds like a mess. Crank sensor would be the way to go IMHO, but you still need a distributor if your ECU doesn't support odd fire. You'll still have to tune it somehow to get the mixture right through the RPM band. If I ever tackle this, it'll be with MegaSquirt2 and a wide band O2. There is a member or two who have done the MegaSquirt and were happy with the results.

Off topic, how much would people pay for a bolt in EFI system for their Dauntless, pre tuned for a standard engine, including all parts for installation?

 

If'n it isn't too much bother

 

Not at all.

ftp://67.41.175.185/jeep6.jpg

Factory look tachometer

ftp://67.41.175.185/jeep7.jpg

Tach feed with tap running to Pro Jection ECU (White wire)