I just can't get the idea out of my head. Life changes and my car is getting so close to getting back on the road. When it does it will get used as a daily driver never the original intentsion of mine. But driving a big block 1ton dually 40 miles a day eats up the old pocket book. I have really been looking over the batch fire MAF setup from the 3.8gm cars like the one from the tech archives. I am a fabricator I love building things so I have no worries about getting the setup installed, its just the tuning I am not a fan of. Mega squirt is a great product but I don't have the time to play with maps and tables. So I am wanting to know if I would get reasonable results for heavy footed spirited daily driver in the 20+ mpg range.

I allready have a recurved EI dizzy thanks to DusterIdiot, and started collecting parts for the HEI conversion just haven't gotten the 4 pin module, so I can go with a 7pin instead. I would not be using a computer to controll the timing just use the HEI keeping it simple.

I also have a offy 4bbl and holly 390. I would need to build a fuel rail and install the bungs no big deal. I was also thinking about making a 90* elbow to top the intake manifold and mount the gm3.8L TBody the same way they did like a side draft it may aid it keeping hood clearance low.

The engine is a stock bottom end rebuild block and head milled for7.8static compression. Has minor porting and valve job. The cam is slightly more than the erson 270-280. For exhaust I have dutra dual on the front and stock manifold on the back for the heat. Y pipe down to single 2.25 with an AEM wideband O2 sensor.

My thoughts are by using an adjustable fuel pressure regulator I would be able to aid in tuning the gm ECU. Again trying to keep things very simple and the more common off the shelf parts the better.

I was thinking this could be accomplished in the $750 to $1000 range. What is your thoughts and insight. Am I just day dreaming again.

The tricky part is cam & crank sensors. Everything else is a simple bolt-on. The maps in the GM ECU should be quite compatible with your slant, so long as you use the O2 sensor.

Mike

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Recognized by US Federal Courts as a Fuel Economy Expert!

One of the problems with such a project is locating a decent donor in a junkyard. Those batch fired 3.8L's are 30 years old now & much of the early electronics/wiring didn't age well. Any part can be replaced if it turns up bad but it'll cost more time &/or $$.

You may want to get a full wiring diagram for your likely donor & study it before spending $$. It's really neccessary to understand what every circuit does in the EFI system so you know what's needed (or not).

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63 Valiant Wagon
225 - 4 bbl

I think you would be surprised at how good your fuel mileage could be with that holley 390. Jet the primaries for economy and the secondaries rich enough to compensate when your foot is in it. The offey manifolds had pretty good fuel distribution. I only ended up going with fuel injection because I decided to turbocharge the engine.

I may get poked w sticks over this but...I done a ton of research in this area for my chevy 235. Close to the slant 225.
http://67-72chevytrucks.com/vboard/show ... p?t=337554
That is a link for a guy who done a junkyard tbi install on a 50's 235 and what all he done. It even starts the post of it running. If I do pursue this it would be TBI just to save time w individual injectors, less pcs, etc. and my 235 has siamesed intake ports read through it, lots of info and if you have friendly junk yards it can be done cheap. Good luck and make a tech write up to be added if you go this route.
Pohlman

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225, Offenhauser, Holley 350, A833OD, 3:55, GM HEI,99 Durango starter
BOOSTED! WH1C, BIG FMIC, 10#
Operation Noble Eagle 03-05
Operation Iraqi Freedom 05-07
Operation Enduring Freedom 12- 13

At one time, Holley made a 1bbl pro-jection. I know you can still buy one barrell tbi style throttle bodies.

When I was going to do this, I was going to use a GM 4.3 throttle body, adapted to a super six manifold, and operated by Megasquirt. Since I'm using a manual trans, there was throttle cable mount, manifold to TBI adapter, fuel return to the tank, and fuel pump to worry about. The MAP sensor is attached to the TB, the TPS is also there, the fuel pressure regulator is integrated into the TB.

At that time, there was guy in Idaho that made the adapters for cheap, but he had stopped and had only one left, which I didn't buy because I went propane, not EFI.

Now I'm looking at trying propane EFI.

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'81 W150 on Propane... Oversize valves, Oregon Camshaft cam, 10:5 static CR, Distributorless ignition, megajolt timing controller, PowerTrax lockers.

Find a machine shop with a big bandsaw and cut apart the chev. Manifold so you just have a mount, then you could either braze/weld to a pc. of flat steel or bolt and gasket to an aluminum adapter.

I went through a solid week at work tried to find a no run on a 94 4.3 pickup that put a different tranny in (didn't recognize the speed sensor) and am confident that is the system to try.

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Advise should be taken as ongoing, that way, when you get to realizing what you are doing you can include yourself.

I think Pierre ran a Howell EFI 4.3L adaptor plate on his ride...

Wouldn't be to hard to find one of these plates from Transadapt or Painless and just drilling the needed holes to bolt to a super six intake...

It really is too bad Holley discontinued kit # 501-1 for 300 Ford/292 Chevy and #501-2 for 258 Jeep, the performance replacement numbers were Model 3739...they had an airflow rating of 300 cfm at 1.5 hg (just 90 cfm under a Holley 390 cfm 4 barrel). Both kits are direct bolt on replacements for the Carter BBD/Holley 2280....

Looks like the easiest TBI 1 barrels to get would be the Chevy 2.8 and 3.1L 1 barrel TBI's in American Junkyards...I'd be dubious about a 30 year old TBI working correctly though...


-D.Idiot

Sure did - dont remind me how much a hassle that thing was. I shudder at the thought. Seems plenty of people have dandy luck with it though...

Check this link out - they have various adapter plates from GM TBI to whatever pattern. I used the holley 4bbl one on my clifford manifold and redrilled it for the clifford pattern. Counter sunk the screws voila... was convenient because then I used the 4bbl pattern for the lokar bracket. I recall one edge being close (the one facing the cylinders where the side isn't straight and has a U shape in the center) but it sealed. I may put the TBI back on now that its megasquirt powered (but rip off the injectors/regulator of course) just for convenience of linkage and such though.

I would like to use two 2.5 liter "Iron Duke" TBI units on the Offenhauser 2 x 1 manifold. The bolt pattern is different but the base plate is the same diameter.