77 Scorpion Megasquirt Install

[Scorpionista]

Thought I would contribute to the topic. Just finalizing the install of Megasquirt 2 and MS Relay board on my 77 Scorpion.

Used the Lancia Beta EFI intake manifold, 24lb Bosch Injectors, 56mm Weber throttle body, Aeromotive custom fuel rail and adjustable Fuel Pressure regulator.

Currently running 9:1 compression with Elgin 29 - 59 Cam (slightly milder than 40-80 cam) and ANSA 4-2-1 exhaust

In process of installing Ford EDIS distributorless ignition and 36-1 trigger wheel on crank pulley.

Anyone out there with sucesseful fuel/ignition mappping for a similar setup?

Thanks,
Cary

[DJ]

Thought I would contribute to the topic. Just finalizing the install of Megasquirt 2 and MS Relay board on my 77 Scorpion.

Used the Lancia Beta EFI intake manifold, 24lb Bosch Injectors, 56mm Weber throttle body, Aeromotive custom fuel rail and adjustable Fuel Pressure regulator.

Currently running 9:1 compression with Elgin 29 - 59 Cam (slightly milder than 40-80 cam) and ANSA 4-2-1 exhaust

In process of installing Ford EDIS distributorless ignition and 36-1 trigger wheel on crank pulley.

Anyone out there with sucesseful fuel/ignition mappping for a similar setup?

Thanks,
Cary

My setup is very similar but I used stock Bosch injectors, a 60mm Weber "Big Throat" TB, an Alquati 40-80 on the intake, Croft 4-1 exhaust, end-cam distributor driven by the MS, and 4 mm domed pistoni that I haven't cc'd but generally provide just over 10:1 CR on a 2 liter.

Is yours a 1.8 or 2.0 liter?

I haven't had it on a dyno for tuning yet but I have it running pretty nicely overall. Still needs some tuning, though once we get some better weather.

[Scorpionista]

My car presently has a 1.8 motor with 10,000 miles on it. I also have a rebuilt blueprinted/balanced 2.0 motor with 9.8:1 pistons. I want to sort out the Megasquirt/EDIS install first, before eventually swapping in the new motor.

I found the larger Bosch 0280150151 240cc/min 23 lb injectors that were fitted to 1978 -1981 633 BMW's. Somewhat larger than the Fiat/Lancia stock 178 cc/min 16.95 lb injectors.

With the increased injector size, they will provide fueling to support up to a theoretical 185 HP ( .45 BSFC @ 55 PSI). More than sufficient for a streetable, naturally aspirated motor.

This will be fun!

[Scorpionista]

Update 3/6/10

Megasquirt 2, relay board and Jim 1.4 Stim board completed.

Intake tube designed and tig welded, along with fuel rail and water housing.

Next project is removing crank pulley and fitting a 36-1 trigger wheel for Ford EDIS distributorless ignition.

Kudo's to DJ for clean and thoughtful design of relay board bracket to hide IAC and wide band LC-1 reset button/led. I will be fabricating something similar.

I will be uploading some of the fotos to my gallery.

[John Allen]

DO NOT use the relay board! I have one of the first MS installations and used this board (the only thing you could use back then) and the ONLY problems I have ever had with my car has been with the relay board.

The traces are too small and will oxidize quickly if installed in the engine compartment. The terminal bindings, appear like a great idea, are not. It is much easier to just mount a couple weather proof relays and fuses and use GOOD weather tight connectors to allow quick disconnects at the engine. Besides, soldering up that 37pin connector (at two ends) is a REAL bitch!

My car is currently dead because the trace to the main relay on is corroded. I will no fix that again! It is time to pull the board out and fix it properly, once an for all....


Update 3/6/10

Megasquirt 2, relay board and Jim 1.4 Stim board completed.

Intake tube designed and tig welded, along with fuel rail and water housing.

Next project is removing crank pulley and fitting a 36-1 trigger wheel for Ford EDIS distributorless ignition.

Kudo's to DJ for clean and thoughtful design of relay board bracket to hide IAC and wide band LC-1 reset button/led. I will be fabricating something similar.

I will be uploading some of the fotos to my gallery.

[Scorpionista]

John,

Thanks for the advice, I may have to reconsider my wiring design.

Appreciate the voice of experience. DJ's design is very clean.

[beek]

My setup is very similar but I used stock Bosch injectors, a 60mm Weber "Big Throat" TB, an Alquati 40-80 on the intake, Croft 4-1 exhaust, end-cam distributor driven by the MS, and 4 mm domed pistoni that I haven't cc'd but generally provide just over 10:1 CR on a 2 liter.

Is yours a 1.8 or 2.0 liter?

I haven't had it on a dyno for tuning yet but I have it running pretty nicely overall. Still needs some tuning, though once we get some better weather.
im looking for a 60 cfl! cant find one anywhere:mad:

[beek]

found the 60cfl, thank you ebay. this is going to be a zagato project. 9.8-1 compression, big valve head, 40-80 cams,going to larger injectors, probably 22-25lb, a better regulator, probably aeromotive. i know this is off topic abit. but what do you people think about running the l jetronic with this setup? tuning the afm. maybe a larger afm. any ideas?

[Scott H]

There is little real tuning with a vane AFM. Yes, there are are tuning products out there that allow tuning but they are very limited in their range.

You are changing the entire fuel demands of the engine and the flow rate of the injectors. In my opinion you will be forever chasing your tail trying to get it tuned with the vane AFM.

>Scott

[Scorpionista]

Progress on MS conversion:

Cold weather in the Sierras, but beginning to warm up. Wait, snow today!

Per John's advice, I sold my MS relay board and built one like DJ's design.

It's a great improvement with Hella modular blocks that have splash proof covers for the fuses & relays. Nothing is exposed to corrode or cause potential problems.

Considering that it's not mounted inside the passenger compartment, it's a more robust physical design for power & wire connections than MS relay board.

All the connections are protected behind the panel with shrink tubing on the terminals.

Installed/hid the MS2 ECU in glove box for easy access to connect laptop.

Wiring from starter to relay panel is complete, now to begin splicing in sensors & testing their operation.

Next will finalize fuel line fittings to fuel rail, then connect wiring for injectors.

Any one with MS2 Megatune spark advance table for EDIS application that includes vacuum advance?

Her's a recent foto of progress in engine compartment.

Cary

[Darren]

Nice work Cary and good progress. DJ's idea for a distribution box makes a lot of sense and really looks the part so that the install doeslook as though it were meant to be rather than an afterthought. Must admit, I hadn't thought about hiding the ECU in the glovebox - good call! One question though, why to you need a vacuum advance table if you're using EDIS and programmable ignition?

I'm sure that eith DJ or Jon will be able to help you out with some base maps as you have a similar setup there.

Keep at it and keep the updates coming!!

Cheers

Darren

[Scorpionista]

More progress this week!

After many trial fittings & adjustments, I installed the intake manifold, injectors, fuel rail, throttle body and linkage for the final time.

Megasquirt grounding & sensor grounding finished.

As you can tell by the fotos, wires are everywhere...

Lots of time spent pondering wiring diagrams (thanks all the sharing in the forum's data base).

Previous owner, in a fit of inspiration, disconnected everything electrical in the engine compartment, various smog fittings and misc wiring left with no identification. Fortunately for me he decided the restoration was beyond his skills & patience.

Nevertheless not a project for the weak hearted:'(

You really have to love theses cars to follow through their resurrection.

Purchased a new battery from Costco that fits the battery well. It's small, not too heavy and has the right binding post polarity to fit like OEM.

More to follow...

[Scorpionista]

Hi Darren,

Thanks for the question. If I understand it right, it's possible to add total additional ignition advance based on part throttle/high vacuum levels that exceed the old style centrifucal distributors and their total advance (initial & mechanical adance timing of 34 - 37 degress).

I'm trying to build the ignition timing table to include a vacuum advance for driveability/economy at city/freeway RPM. A lot of the OEM Fiat and Lancia distributors were built without vacuum advance. Those distributors used an initial setting before TDC plus added centrifugal advance as the RPM increased.

Guy Croft mentioned in his book that total advance should not exceed 34-37 degrees (initial & centrifugal) at full throttle. But you can run additional vacuum advance (possibly 8 - 14 degrees) at lower RPM and part throttle vacuum levels to increase torque, MPG and engine response.

With my specific application of EDIS, I utilize the EDIS module at 10 degress BTDC (limp home mode) and build additional advance based on the parameters of vacuum and RPM.

I'm just trying to gather more info and build that into Megatune for a more sophisticated ignition table.

I'm open to what anyone has learned on the subject.

Thanks,
Cary

[beek]

im looking for a 60 cfl! cant find one anywhere:mad:

finally found the 60 cfl, but now im pondering a 6g72 maybe a twin turbo, imagine 320hp in a street scorpion.... hold on

[Darren]

Hi Cary,

Thanks for the response - presumeably you can use the MAP sensor and table to achieve what you're looking for? Sorry, I got sidetracked in thinking about other things and it wasn't instantly apparent to me! Doh!!

[Scorpionista]

Spring time in the Sierras: temperature swings weekly from 30 to 75 degrees, cold, rain, wind, snow and hail. Better than other parts of the US though.

All wiring complete, CLT, IAT and TPS sensors - tested fine, fuel system brought up to pressure - no leaks, starter turns over smoothly but no RPM or spark for EDIS.

I had used a 3 wire crank sensor but found out it is not compatible with Megasquirt 2 when used for EDIS triggering. Apparently it is a Hall sensor with a digital square wave signal. My configuration needs the 2 wire Variable Reluctance sensor for an analog sine wave signal.

Supplier contacted and aware of triggering problems in some configurations so he's sending new sensor in about 2 weeks.

Megatune looks fine and have loaded the tables for initial starting tune.

In the mean time, I have bleed the clutch & brake system and replaced with fresh DOT 3 fluid. Also flushed cooling system, added antifreeze and distilled water.

Getting closer, more pictures to follow.

Cary

[Scorpionista]

While waiting for shipment of the correct 2 wire crank sensor, I spent part of a day checking my electric system.

Since the car had 'nt been registered for 11 years, I thought it best to check the brake lights, turn signals, hazard and headlights. To my surprise, nothing worked but the left rear hazard light.

Knowing that corrosion is an electron's mortal foe, I wire brushed and alcohol Q-tipped all fuse holders, fuses and relays under the left side dash.

Great, now everything works with the exception of the right rear brake light. Brushed & cleaned that bulb & socket, but to no avail. Will try a new bulb and or check power/continuity to bulb base.

While cleaning the bulbs in the rear tail lights, I noticed at least half of the 12 plastic headed screws were disintegrating from 34 years of UV damage. Did a quick price check and found out they cost around $5 to $6 each plus shipping. Besides that, they are not available from any of the well known suppliers in all the colors (red, amber or white/clear to match their respective lense).

Not wanting to spend $70 to $80 for the 12 screws, I've decided to turn some small aluminum bushings on my benchtop lathe and use a stainless steel screw that matches the same thread pitch/diameter of the OEM one. This should match the same dimensions of the plastic shouldered phillips head that retains the lense in position.

Cary

[Darren]

Hi Cary,

Missed your last couple of posts, but sounds like you're making good progress. i used this - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280306814287&ssPageName=STRK:MEWAX:IT does the job perfectly and also fits nicely without fouling the belts. Simple matter of making a mounting plate.

Good work on the electrics - if you haven't done so already, make sure you have good earths, and I ran a new battery cable from the engine block to the -ve battery terminal and I now have no earth issues with the MS.

Good idea on the light screws - seems you can easily get red & white screws, but orange appear to be a little more difficult to find and they always end up getting corroded to the lens.

Look forward to the next update.

Cheers

Darren

[Scorpionista]

Thanks for the kudos & tips Darren. If I recall you had a problem with a 3 wire sensor also. By the way, your Montecarlo and engine compartment set a high bar of excellence.

Still another week waiting for shipping of the back ordered sensor. So spent some time tidying up the wiring/engine compartment.

See latest fotos attached.

I also removed the OEM rear tail light lense screws when replacing a few bulbs. 6 of the 12 were sun damaged and the plastic screw caps disintegrated upon removal.

I turned some alloy bushings on my lathe and used some stainless steel screws that matched the OEM dimensions & screw pitch. These should last much longer without issues.

See attached fotos of this fix. If anyone else needs these, I'll post more info in the classified section.

[Darren]

Good work on the screws there - I would maybe see if there were a countersunk version available and tailor the bush to suit, but that's a definite improvement over the plastic items.

Yeah, major problems with the sensor - I got mine as part of an orderfrom Jason over at Miller's Mule - he reckons that he's used a powered sensor on 2 separate MS installs without a problem, even using EDIS. For me, I couldn't get it to work properly, or at least I could, as long as I kept the revs under 3k rpm! Thanks for the compliments and hope your stuff turns up ok.

Very clean install by the way - looks great. One question though and you'll forgive me if I'm asking a dumb question, but I'm guessing that fuel runs from right to left and the fuel pressure regulator is at the far end of the run, with the injectors coming before? The reason I ask is that every other install I've seen or at least can remember, has the regulator the other end! ;o) I do like the look of it all though!

Cheers

Darren

[Scorpionista]

Darren and all,

I tried to improve the fuel rail and regulator arrangement over the stock Beta design. Fuel flows right to left (through the DIY Edelbrock fuel rail) feeding the injectors, than pressure being regulated (via adjustable Aeromotive regulator) before returning to the tank.

The regulator is mounted to the end of the cam box tower, so both fuel lines and vacuum line are short.

The regulator is adjustable allowing easy changes in fuel rail pressure. I'm using BMW 633 injectors with a rated flow of about 23.1 lbs/hr at 43 psi. Stock Beta 2.0 liter EFI injectors flow about 16.9 lbs/hr limiting power to about 120 hp with OEM fuel pressure.

Should be an improvement over the non tuenable Bosch L Jet EFI and restrictive Air Flow Meter. Between Megasquirt, adjustable fuel pressure, and the larger injectors there should be a lot more flexability to tune the injection with various engine mods, compression, cam duration/lift/timing, ignition, exhaust, etc.

Cary

[Darren]

Hi Cary,

Thanks for the info - makes much more sense now! Any reason you're keeping the air flow meter?

Cheers

Darren

[Scorpionista]

Hi all,

I actually eliminated the air flow meter (BOSCH vane type AFM). Megasquirt 2 utilizes Speed Density measurements via MAP (Manifold absolute pressure) sensor, IAT (Inlet air temperature), TPS (throttle position sensor) and RPM to determine the fueling needs.

New 2 wire crank sensor arrived this weekend from Jason Miller of Millers Mule. Good guy, responsive and backs his products if there is a problem.

Need to connect shielded wires to sensor pig tails and extend over to EDIS module. Will then tidy up engine compartment, test ignition timing & set Megatune.

Anxious to get the Scorpion running, registered and ready to enjoy for the summer. Also want to drive it to the Monterey Historic Races in August.

Cary