Lotus 907 project

[gregam]

New to the forum, I am in the process injecting a 1974 Jensen Healey with a Lotus 907 engine. I originally started the project about 20 years ago. The original injection was taken from a 1974 Porsche 914 2.0l. I machined two, two barrell throttle bodies using Weber 48DCOE throttle shafts and throttle plates to mount on the factory manifold, mounted the the Bosch fuel injectors in bosses already available on the manifold and used the Bosch fuel pump, pressure regulator, distributor, throttle positioner, and sensors. I ran into a problem because the ECU was not abled to be configured to support the modifications to the engine so the project came to a stop. The engine is a dry sumped, twin cam, 4 valve engine running 11.25:1 compression, long durration high lift cams, Formula 2 head, crankshaft and pistons. it has a 10,000 rpm redline and idles about 1800 rpm. I plan on using a MS-II and a Wide Band O2 sensor. I will use the MS-II for injection only in the beginning and then after I get it running well I plan on adding the ignition. Any sugestions will be apreciated.

[gregam]

I see that the MS-III is on the horizon. Should I get a MS-II or wait for the MS-III? Will there be an upgrade path from the MS-II to the MS-III? Sequential Injection offered by the MS-III may be something I would eventually want to play with. Anybody have any pro's and con's on the subject?

[Matt Cramer]

Yes, there will be an upgrade path from MS2 to MS3; you'd need to add a couple expansion boards and get a new case. However, the MS2 will be quite adequate for batch fire fueling and distributor based ignition control.

[StevenD57]

I too am working on adding EFI to a Jensen-Healey. I am in Phoenix. I have my altered manifold almost done and I have gathered things like twin throttle bodies. EDIS bits, throttle position sensors, coolant temp sensors, and etc. I plan on either having the 36-1 teeth cut into the rear edge of the crank pulley or if that does not work out then a separate toothed wheel. I really want to get rid of the OEM distributor as well as add EFI. I am using the North-American twin Zenith-Stromberg intake manifold rather than the European Dellorto manifold as a starting point.

I would be interested in discussing things like if you are planning on running any sort of swirl tank to pull gas from or what you plan to do for idle control.

Pictures of my progress can be found at:

http://s685.photobucket.com/albums/vv21 ... FI%20work/

[gregam]

I haven't yet decided on the fueling design, I curently have a high volume pump at the fuel tank and a high pressure pump and pressure regulator in the engine compartment and added a return fuel line back to the tank. I will use an idle adjustment on the throttle bodies. I am still changing the design of the system. My basic goal is to get it running and tweek it later. Most of the EFI components are Bosch, I am updating the Bosch Throttle Position Sensor to a newer model, but for now will keep the Bosch Distrubitor and Injectors and temp sensors. I plan on fitting a 36-1 wheel into an old distributor at some date.

[StevenD57]

What do you mean by Bosch distributor? Are you planning on fitting a different ignition distributor than the OEM Lucas?
I don't see the point of that. I figure that by fitting the coil pack crank fired ignition I not only get better ignition but
I also get rid of the distributor which on every Jensen-Healey I have ever owned has been a source of a chronic oil leak.
When I asked about idle control I am talking about idle speed control for cold start & running verses a completely
warmed up engine at different outside air temps. Are you planning on constantly playing with the idle adjustment screws
on the throttle bodies?

[gregam]

The Bosch distributor was modified to fit the 907 engine. The reason I chose it was that it was designed for EFI and already provides the pulses I needed for the MegaSquirt. I replaced the ignition points with a Hall sensor for the ignition which will also feed the MS II. The oil leak issue with the Lucas Distributor is easily fixed, in fact I will use a Lucas distributor body when I go to a 36-1 wheel. They make a 2" wheel that should fit. As for idle adjustment, there is no efective way to change air flow at this time, all I can do is change the air/fuel ratio. If that doesn't work I will have to modify the throttle bodies to provide some sort of air bypass that can be controled by the MS II.

[StevenD57]

I thought if I had to I could drill a port into the balance tube that runs between the two
sections of the manifold on the North American ZS intake. I don't know the various
benefits or issues around using PWM verses stepper motor IAC. That is something
I have to research. As you say get it running first and then look into the other issues.

What sorts of high volume and high pressure fuel pumps are you planning on using?

[gregam]

I am running a Carter back at the fuel tank and a Bosch pump and pressure regulator. I started this project 30 years ago arround a Porsche 914 2.0L setup, but stopped when I couldn't make the necessary modifications to the Bosch ECU. Along comes MegaSquirt and solves the ECU problem but there are still some to overcome. I am still running the Bosch injectors as they are the correct size for the engine and match the fuel pump and pressure regulator.

[StevenD57]

Are these high impedance or low impedance injectors? Depending on the type and condition
of these injectors and the circuits necessary to drive them you may want to look at using
something a little newer.

[gregam]

They are new. Low impedance. The MegaSquirt II will handle them without any problems.

[StevenD57]

I got the basic EDIS crank fired ignition system parts installed on the car (VR sensor, toothed wheel, coil pack, and EDIS4 controller). I am able to start the car using the EDIS system default timing of a fixed 10°BTDC. Next is installing the wiring for the Megasquirt ECU into the car and properly connecting it to the EDIS stuff so it can control the timing advance. I need to double check the VR sensor to toothed wheel alignment using a timing light to make sure I am indeed getting 10°BTDC. I have to connect some ground wires from the Megasquirt to my common ground point on the engine and check continuity to all of the required control bits. At that point I think I am ready to go on the Megasquirt for the first time.

If you are interested I have photos of the installed VR sensor and toothed wheel available at:

http://s685.photobucket.com/albums/vv21 ... _29931.jpg

http://s685.photobucket.com/albums/vv21 ... _29941.jpg

http://s685.photobucket.com/albums/vv21 ... _29951.jpg

[StevenD57]

I have the car running quite nicely on the crank-fired distributor-less ignition. I also have the coolant temperature sensor and wide band O2 sensor installed in preparation for the EFI bits. I have been trying to figure out the fuel supply and return line issues. I am waiting on a friend who is doing a final little bit of machine work on the intake manifold where the bottoms of the injector bungs are needlessly sticking down into the intake and partially blocking the flow.

The pictures of the coolant temperature sensor installation can be seen here:

http://i685.photobucket.com/albums/vv21 ... G_3017.jpg

http://i685.photobucket.com/albums/vv21 ... G_3014.jpg

[trakkies]

Getting the trigger wheel/ trigger relationship exactly right for the 10 BTDC limp home isn't really required IMHO. For that facility ever to be needed, you'd have to have both MS and EDIS working normally - with just the SAW signal lost. Rather unlikely. Any slight offset can be catered for by MS. So just lining up the sensor to the correct tooth by eye initially will be fine.
Although EDIS will work standalone, MS won't provide any fuelling if it doesn't get the PIP signal from it.

[jcarruthers]

Indeed - I don't see the limp home being useful unless you happen to have a set of carbs in the boot