I'm thinking about retrofitting my gen 1 sbc 350 with a ls1 efi system from a stock truck/car. I've got the skills to fabricate all of my fuel system mods and build the intake. basically I'm going to fabricate an ignition system that'll work with the gen 1 motor that uses a magneto/crank position sensor just like a gen 3 motor does so I can control spark, and im going to fabricate a custom intake/throttle body/fuel system that'll be controllable by the PCM.

Im looking for opinions on how to set this up, and what kind of harnesses/pcm's to use. Im open to any suggestions.

it's really just a winter project and I'm curious to see if I can make this motor run off a semi-scratch built EFI system. if it all works, the dune buggy will turn into a track car and get a full roll cage/turbo setup.

btw the specs on the buggy right now are:
1972 4 bolt main high nickel block
CR is about 9.5:1
stock heads (that'll be changing soon)
dual plane 1975 antique corvette intake (this will change soon too)
cam is 242/242 .512/.512 112
the motor is bored .040 over
crank is a stock truck crank which was rebalanced when the motor was built 5 months ago
cylinders aren't anything special, hypereutectic flat tops
tranny is a Th350 with a 2800 rpm torque converter
rear end is a 1968 camaro 10 bolt with limited slip diff and 3.73's
back tires are 31" boggers right now
frame was scratch built by myself and a friend
front end is IFS longtravel with 14" racerunner coilovers, spindles are off a S10 blazer with disc brakes

anyways, if there's any opinions and suggestions, im open to them. I really want to make this happen over the winter.

thanks,
jake

 

cmon im sure someone has somethin to say about this...

 

Well, I've thought about doing it to a buddy's truck but wasnt sure exactly if it would be worth the money, but it would definitely be bad@ss imo.

 

i've done a **** load of research and it's going to take some time and engineering, but the only major thing we have to do is modify my stock hei dist. to house the crank/cam position sensors and be able to get the sensors to read correctly, if we can do that, the rest is a piece of cake. I'm well on my way to starting this thing now, I've almost closed the deal for the injectors/sensors along with the stock truck rails and stock truck intake. all I need now is the damn coil pacs/pcm/harness

 

If you go coil pac you don't need a dis but you can't remove you dis. because you need it to run the oil pump. Why not just buy a aftermarket MPFI kit and save yourself time and money.

 

i know i dont need a dist, the reason why Im keeping the dist is b/c I need somehow to locate camshaft position, and that's the easiest way to do it is through the dist since it's a 1:1 with the cam. i'll post some renderings of the drawings I made last night of how we're going to modify the dist.

I dont wanna buy an aftermarket MPFI kit b/c really it isn't going to save me money, and also I already have half the parts and all the tuning software to make the motor ls-based. i'd much rather use hptuners to tune my motor vs. using edelbrocks shitty command interface that really is a POS.

when everything is said and done my estimated cost so far is around 750 including materials for our new intake/fuel rails.

 

i guess I'm just kinda keep this as a "journal" of how everything's going.

i have the whole intake/ignition planned now.

im going with a RPM air gap intake that has the bosses right on the runners so it'll be easier to mount the injectors there. as for the harness/pcm i dont have them right now, if anyone is sellin a harness/pcm for a truck or whatever lemme know.

i have the coilpacs figured out now (how to mount them) and im workin on designing a custom harness possibly once I have a donor harness.

does anyone know if the PCM can function without a BCM/TCM hooked up to it feeding it info? just curious... im pretty 99% positive it can, but ya never know.

also, the only thing left really we need to figure out is how to fabricate our own reluctor ring and make it work with a 4x resolution... sounds like fun

once this thing is done, it'll be interesting to see the power differences. im gonna dyno the buggy soon along with my truck. i'll keep everyone updated

 

I've got to ask.... "why?"

 

well there's a few reasons why.
first off, it's going to be a huge learning experience for myself in the way the GenIII motors work, Yeah I understand mechanically how it works and what parts add power, but I want to fully understand how all the sensors/ignition/fuel system work together with the PCM. Not just what causes the motor to throw codes, but understand the mechanics behind how the crank sensor actually works and how the coilpac ignition system communicates with the PCM and so on.

second reason is b/c I want to learn as much as I can about the GenIII motors before I start modding my daily driven truck intensly. I'm going to turbo the dune buggy, and if everything works out well and I can learn to tune the buggy with a turbo and some other mods, i'll feel much better about modding my truck then since I have taught myself how to do everything.

and third, I haven't really seen anyone modify a GenI 350 to work with LS-based ignition/fueling/PCM computing. There's been GenII motors converted to use GenIII ignition/fueling setup, but I haven't seen a GenI motor yet like this.

and really, It'd be fun to drive a turbo smallblock in a sandrail that weighs only 2500 lbs.

 

You should be able to use a crank trigger vortec 350. The crank trigger is in the timming cover. It should work with the Gen III pcm. If that helps