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greggbrat

EA81 SPFI conversion and more horsepower/torque??

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Note - I am updating this list to make it more complete as the information comes in from you nice folks.

 

I am trying to convert my 1982 EA81 Brat from carb to SPFI. I have read every post I could find on the subject but couldnt find answers to all my questions.

 

Basically.....what is it that I need to pull from an EA82 SPFI donor car at the junkyard???

 

Please add to the list anything that I am missing or correct me if I have included something I dont need.

 

1. SPFI Manifold (to include everything attached to it.....ie. wiring harness, sensors, throttle body, etc))

2. ECU (located under the steering column)

3. Airbox, MAF and air tubing to the throttle body

4. EA82 Distributor (because it has the crank angle sensor. Plus I will need to swap in the drive gear from my EA81 distributor and grind off one of the mounting tabs on the EA82 disty)

5. Fuel pump (which I will feed from the EA81 fuel pump and mount the EA82 fuel pump in the engine compartment)

6. Wring harness from under hood to the ECU

7. O2 Sensor

 

 

 

I am hoping this conversion to SPFI will give me a bit more horsepower and also better gas mileage. I know an MPFI conversion would probably be better but I dont want to muck with the motor or heads.....I am trying to keep it simple and yet do a little better climbing the steep graded roads of the rocky mountains with my 27" tires. I have already put on an Accel 8140 coil, gapped the plugs to .050 and changed the timing to about 15 degrees BTDC. I also put on a larger exhaust (I think its 2 1/4 inches) from the catalytic converter back to include a new "turbo" (less restrictive) muffler. I am not looking to make this a race car but I still need a few more horsepower to climb these big hills. Any other ideas that dont involve changing the motor/heads/cams etc?????

 

If anyone has a complete writeup on this SPFI conversion that would be wonderful. Otherwise I will be doing a complete writeup when I am done.

 

Any and all advice is welcomed.

 

Thanks,

Gregg

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If your Brat has an 02, you should be able to wire that up fine. You do need the fuel pump because the SPFI runs at a MUCH higher pressure than a carb. I sugest mounting it in the engine bay, and supplying the SPFI pump using your stock pump. You do need the SPFI distributor because it has a crank angle sensor for the SPFI computor. You'll have to change the drive gear on the disty to the one off the EA81 disty, and cut one of the mounting tabs off the disty housing for it to fit on the EA81. Rguyver is the one person on the board that I know has done this - look him up and email him.

 

GD

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Thanks GD. Any other suggestions on getting a few more HP out of this motor? Do you think the SPFI will add a few more HP over the current Hitachi carb? The reason I dont want to change the internals of the motor is that if I ever need to swap the motor I just want to run to a junkyard and put in a used motor with no fuss no muss.

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No - I think you might get a little better low end torque, but you won't gain any HP from it to speak of. Opening up the exhuast, and the SPFI might get you close to 80 HP.... but a stock hydro lifter EA81 already has 80 HP. Your's is rated at 73. If you want more horses, you need to start with a hydro lifter engine, and build it up with a different cam, decked heads, and taller pistons. The 8.7:1 compression is just too low as it is.

 

And yes - you need the ECU portion of the SPFI wireing harness.

 

GD

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spfi rules! and will give you more hp due to the precice delivery of the fuel, compared to a worn out hitachi. you wont run rich anymore, which robs hp, as rich as a old carb runs anyway. ecu, motor harness, manifold, with all the sensors, and a efi fuel pump stuck in the stock location, should be all you need. get crackin!

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You could have just PM'd me, jeez.

 

To answer your question - it's difficult to tell. The best indication is a sticker on the valve cover that says "Do Not Adjust Valve Clearances". Other than that you could drop the oil pan and compare the lifter bore's. The hydo lifters are removeable, and the solid lifters are not (without splitting the case). But I'm not sure you can tell the difference just by looking.

 

There are casting differences between the small valve heads and the large intake valve heads. But as the larger intake valve was standard on 83+ engines - even solid lifter models - this is not a determining factor. The intake valve is 2mm larger in diameter in case you are wondering.

 

There is a slight casting difference in the hydro lifter block. Where the heads mate up on the bottom there is a spot in the solid lifter block for a bolt that would go through the small intake valve heads..... on solid lifter engines with large valve heads there is simply no bolt (they did away with it on the head), and on hydro lifter blocks they also eliminated the hole on the block. There is still a protrusion there, but it's not as wide. Without pictures this is difficult for me to explain, so I'm not sure it will help you....

 

GD

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anyone? Anyone at all. Bump

there is a guy by the neame RGUYVER who had put spfi on an ea81 hatch and a TURBO!

 

as far as your list goes, dont forget the coil bracket and the ignitor.

 

in my opinion, you should just find the whole ea82 spfi motor as one piece, as an ea82 will fit with no mods.

 

i have "mocked up" spfi to ea81, and this is what i encountered.

1 the disty is going to fight with the thermostat housing for space. i took the ea81 dist mounting tab and flipped it over. i installed the spfi dist(with ea81 gear) backwards. the wires will bve 180 off with the cap, but true with the rotor. the egr valve is going to be in the way of the engine bellhousing, i had to remove it and make a block off.

 

i have a project in mind for an spfi 84 sedan, but i am using the whole ea82 motor for 3 reasons

1. proper compression

2. no modifications to any of the components

3.i can replace components with unmodified parts

 

if yo uinsist on the ea81 motor, and you dont mind gettin in deep with it, get some hatch 1600 pistons from a leter ea71, and that will bring your compression to 9:1 like it should be.

 

spfi is a DOG on a carb block, at least mine was with the 3spd AT.

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you could use that one for a fuel enrichment injector, instead of just not running it

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if thats the case, might as well start with an ea81T body(with, with/o motor)

 

but if that's the case, might as well go with an ea82T

 

my vote is the whole ea82 motor, might as well, less work, and you can have a whole motor for as much as all the stuff separate.

 

this would be reasonable if you havent started yet already. timing belts are not that bad(to replace)

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there is a guy by the neame RGUYVER who had put spfi on an ea81 hatch and a TURBO!

Found this on a search for spfi. I happen to have access to a spfi set up, ecu, intake, whole nine yards. And also a EA82 Turbo, up-pipe, down pipe. Where is this guy? and I understand the spfi scenario, but what about the addition of turbo? how much more work is needed? is it all mainly bolt up? I deal with the issues that greggbrat had, hill climbin everyday on I-80 UPHILL BOTH WAYS!

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you could always megasquirt it and then run any dam injection you wanted to bolt on it or build for it :)

you could do a blow thru spfi setup that way ...

 

or build your own intake

 

or run dual spfi throttle bodys one for each head ... kinda like a weber ir setup but injected...

with dual table code each throttle body would be independandtly controlled based on o2 feedback <one for each head> at least untill you stomp on it then well .. cya!

something like that wil ... or shoudl get good mileage as well as have a pretty decent tourque curve to it most ir <independant runner> setups are pretty tourquey

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whoa whoa whoa, back up a bit here. I'm not asking what kind of for any multi turbo, quad injection, powerband tire smokin set up here. I have a spfi set up and a EA82t set up, ecu, harness turbo intake, spfi intake, harness ect.ect.. Can I with these units, not anything else, put together a spfi swap with turbo on a EA81 carbed motor with a limited amount of fab work. I know about the disty mod and egr block off and so on. But will the turbo and spfi coincide together??

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you could probably very easliy, get a rising rate fuel pressure regulator, like the turbo honda guys. just turns up the pressure in your fuel rail, or in this case fuel casting =], richens it up when it sees boost.

 

just runing the spfi with the turbo at stock boost lvls will not work too well, as far as i can remember from what Rgyver told me. i think it blew up? or at least he didnt use it that way for long, but he aloso had nitrous on it!

 

either just run the spfi intake with the harness and computer, and bolt the turbo stuff onto it. also you have to grind out a spot for the turbo up pipe to go on your crossmemeber, or get a turbo crossmember, from an ea81t.

 

or go find a mpfi ea82, change the timing belts when you should, and floor it!

 

 

intercooler for the win =]

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what if I use the ecu from EA82T will that help the fuel pressure issue that your talkin about? And as long as I have everything what about using the turbo intake and all the other goodies from that and leaving the spfi for another project?

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the spfi has one injector, and the mpfi has 4 injectors, the wiring is totally different, and the computors arent interchangable. its all or nothing =]

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