Help rookie with EFI conversion. Junkyard style

[seanm]

As the title says, looking for advice/input on doing an EFI conversion. This isn't an attempt at peak power. Looking to learn about EFI on the cheap and have a car that is drivable anytime, anywhere.

The car is a '71 Galaxie with a stock 400 except for a Duraspark distributor swap. Plans include a mild cam, aluminum intake, mildly ported heads and headers. Nothing major, maybe 300-350hp? Have the heads done, some injectors and wiring from stock 5.0's (too small?), Might have a throttle body or two from 5.0's also. and an old single plane intake to start with. TBI or MPI is fine with me.

This could be a long term project, I tend to make a plan, then wait on deals on parts. Heck, it took almost 7 years of waiting/ looking to get this car ;D

MS I or II seems to be the ECU of choice and have helped with an MS before. So what parts combos do you guys think would be effective and affordable for something like this?

Thanks

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

For the fuel and spark, some options:

(1) simple and cheap: Megasquirt-I on a version 3.0 circuit board, KIT from DIY autotune.com that you assemble yourself (include a stimulator for testing during the build). Use the duraspark's internal position sensor, or one of those conversion kits for points that give you an electronic signal (forget what those are called? damnit)... for a tach input to the MS. Then run a cheap Summit/MSD ignition box and coil for spark. You have mappable fuel and spark, support for high or low impedance injectors, etc.

(2) a little fancier, makes a nice "phase two" challenge: Put an EDIS trigger wheel on your crank pulley or balancer, use EDIS module and pickup sensor (and coilpack) from a junked v8 modmotor, and you have instant distributorless ignition on your oldschool v8. Get rid of the distributor but don't forget the oil pump drive.


Throttle bodies aren't my expertise, but there are a TON of them out there and you can use an old carb as a throttle body too... perhaps a pair of them on some funky intake setup? other guys here will have good suggestions for the hard parts (you know the areas I stick to)

Ask questions freely. I love answering them. My only requirement is, after a few years when this stuff is old hat to you, you help some noob out when he asks YOU the same questions.
-scott

[Matt Cramer]

Re: Help rookie with EFI conversion. Junkyard style

As the title says, looking for advice/input on doing an EFI conversion. This isn't an attempt at peak power. Looking to learn about EFI on the cheap and have a car that is drivable anytime, anywhere.

The car is a '71 Galaxie with a stock 400 except for a Duraspark distributor swap. Plans include a mild cam, aluminum intake, mildly ported heads and headers. Nothing major, maybe 300-350hp? Have the heads done, some injectors and wiring from stock 5.0's (too small?),

Stock 5.0 injectors are 19 lb/hr and top out at just a little over 250 hp. The 24 lb/hr injectors used in many smallblock Chevies would be about right, though.

Might have a throttle body or two from 5.0's also. and an old single plane intake to start with. TBI or MPI is fine with me.

Most junkyard TBI units will be a bit restrictive for your power gains. You might want to try something like an LSx throttle body on an Edlebrock adapter elbow if you don't want to fab up your own adapter.

For the ignition, while TFI is a pretty easy way to give Megasquirt spark control, the Duraspark has its own advance mechanism. The good side to this is that you could start with the ECU controlling just fuel and have the distributor control the timing, then step up to computer controlled timing when you feel like it. The bad news is that to take control of the timing, you'll have to lock out its advance mechanism. Or go crank triggered - might as well go distributorless at the same time if you want. The EDIS approach Scott mentioned is a pretty solid way to do this.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Figures, what I have three of each won't work.

Might give the EDIS a try. Might be easier in the long run.

Can the MSII drive 8 low impedance injectors? I might be able to get enough 2.3T injectors. They were 35lb/hr IIRC.

Who make a TPS for a Holley carb? Might go that way if an LSx throttle body doesn't become available.


DG, just curiosity, what were the parts used on Hart's Stude? I remember looking at it, but have no clue what was used.

Thanks again.

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

Figures, what I have three of each won't work.

Might give the EDIS a try. Might be easier in the long run.

Can the MSII drive 8 low impedance injectors? I might be able to get enough 2.3T injectors. They were 35lb/hr IIRC.

Who make a TPS for a Holley carb? Might go that way if an LSx throttle body doesn't become available.


DG, just curiosity, what were the parts used on Hart's Stude? I remember looking at it, but have no clue what was used.

Thanks again.

again, the duraspark can work just fine... it's easy to lock 'em out.

But EDIS is a no brainer. Simple, distributorless, powerful, easy to find in junkyard.

TPS for a carb is easy! get yourself a "string potentiometer" or an old TPS and rig it to the throttle linkage somewhere. It doesn't have to open or close all the way, just make movement when the throttle opens or closes, then you tell the MS where "open" and "closed" is by calibration. Easy.


Hart's studebaker is a junkyard extraveganza - no shit. Throttle bodies are a pair of Ford Mustang GT units, using one TPS for the MS. Injectors are 95 lb/hr aftermarket units. He runs a Megasquirt 1 on a version 3.5 circuit board (I recommend v3.0 for someone like you, it is easier to modify later on). The turbos in Gary's car are straight off a powerstroke 7.3 diesel, but this year we replaced the compressor wheels with a newer design, and clipped the turbine blades for more exhaust flow and less backpressure. You are better at picking turbos than he is :-)

for ignition, he uses a regular BBC distributor, locked out (no advance), and an MSD 7-AL box and matching coil. He used to run it locked at 36 degrees of timing with an MSD boost timing retard module, this year he scrapped the BTM and we're controlling the spark with the megasquirt.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Would a single TB from a Mustang GT work for the hp goals here? Or is there something better about using an LSx TB? I have three of the stock GT TB's. My cheap side says use them. ;D Using two can be done also.

Do LS and Chevy style injectors use the same plug as Ford injectors? And most Domestic injectors fit in the same hole, 14mm? Just wanting to know what to look for and avoid at the junkyard.

Will this need a MAF, or MAP or something like that?

Damn, I'm green on EFI.

Thanks

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

Would a single TB from a Mustang GT work for the hp goals here? Or is there something better about using an LSx TB? I have three of the stock GT TB's. My cheap side says use them. ;D Using two can be done also.

Do LS and Chevy style injectors use the same plug as Ford injectors? And most Domestic injectors fit in the same hole, 14mm? Just wanting to know what to look for and avoid at the junkyard.

Will this need a MAF, or MAP or something like that?

Damn, I'm green on EFI.

Thanks

I am sure the GT TB will "work" but I am not smart enough at airflow subjects to tell you if that's the best junkyard/OEM piece you can/should use. Sorry... anyone else here have suggestions? (turboforums.com = friend)

Most "Bosch Style" injectors are the same connector and physical size (I've heard them separated by terms "top feed" & "side feed" - again, a great turboforums.com question). If not, they're available online pretty cheap to make your own harness. All the injectors share a common 12v power source (switched with ignition), then the remaining 8 wires are combined to 2 groups and run to your injector outputs on the MS. (which supports both low or high impedance injectors)

The MS will come with a built-in 2-bar MAP sensor. Just run a manifold vacuum line into the MS itself.

green is only a bad color for racecars ;)

-scott

[91xcabpro]

Re: Help rookie with EFI conversion. Junkyard style

(turboforums.com = friend)

I've seen you say this a few times, but when I try to go there I get the below site. I think there is a language barrier between me and the people there. Is there something I'm missing?

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

Sorry! try this link

http://www.theturboforums.com/smf/index.php

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Well, I've asked enough questions of members here and else where that I thought is was time to just get started.

This is where it starts. An old single plane Holley intake that I've welded holes and cracks on and seen general abuse for years.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Made a simple jig that bolts to the two center intake bolts. The jig will help align the drill bit when drilling the intake for the injector bungs, hold the bungs at the same height when tack welding the bungs in the intake and be used for aligning the hole in the fuel rails when they get drilled.. Look close at the second picture you might see the small holes that are alignment holes for the drill bit.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

The initial drill holes were 1/4" done with a hand drill through the jig and into the intake. Then a Unibit took the holes out to 1/2" without the jig. Took a 3/4" drill and finished the holes so the bungs can fit in the intake.
First picture is after the unibit. Second picture is after the 3/4" drill and the jig is bolted back on. A 1/4" bolt and washer is used to hold the injector bung up against the jig while it is tack welded.





After the bungs are tacked, the jig is pulled back off and the bungs get finish welded. The excess bung inside the intake will need ground smooth.

First picture is of the fuel injector bungs and fuel rails before starting. Second picture is of the welded bungs with injectors in them. Glad you can't see the welds. They be ugly!

Thats it for the night. Most of it can be done with hand tools if needed. Of course it isn't as precise as a mill and the proper tools, but I think it will work.

[Caveman]

Re: Help rookie with EFI conversion. Junkyard style

What kind of welder are you using?

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Miller 250 syncrowave, I seldom weld aluminum, usually improve about the time I'm finished.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Did some work on the fuel rails. started by drilling 1/4" pilot holes in the bottom of the rails



Then a 17/32" bit is used to step the holes up to the size the o-rings on the injectors will hopefully seal against.



Mounted the rails on the injectors and made some simple brackets to hold it all down. 1/4" holes were tapped in the side of the fuel rails to bolt it to the brackets





Its a simple cobbling of parts, but it might work.