Possible to replace points assembly with timing wheel?

[TheFieryMan]

Most of the efi or ecu conversions I have seen have added a crank / cam sensor in to front of the engine on one of the cam shafts or crank shaft. I am planning to also use the ECU for ignition. I'm wondering if it's possible to remove the points assembly and replace I with the sensor the new ECU requires for ignition timing. I'm planning to use "missing tooth" type timing.

The only reasons I can come up with that it wouldn't work is because of the size requirements of the wheel itself and space required for the sensor itself. I would have to fabricate a much smaller wheel than what I've seen others use.

Any other thoughts on this?

[CYBORG]

check out C5 ignition. It uses a timing wheel and L.E.D at the point location

[TheFieryMan]

check out C5 ignition. It uses a timing wheel and L.E.D at the point location

Interesting concept. Unfortunately it looks like they are no longer making it.

[CYBORG]

True, but might be some good used ones around. They were made from other manufactures parts. Mostly for drag racing aplications.

[Rednaxs60]

Most older GW FI conversions have used the Megasquirt family of aftermarket ECUs regardless of whether the project has come to fruition, lots of threads on this and other forums. Other, older systems are used as well.

You could start with an ignition system upgrade, then transition to ignition and fuel. An ignition system upgrade allows you to deviate from the OEM type design (and fitment) for coils, coil drivers, coil wire - plug cap -spark plug install, lots of good options out there.

I have removed the 5K OHM resistor in the plug cap, kept resistor plugs, use copper wire core coil wire instead of steel core. There are threads on this and other forums regarding the removal of the 5K OHM plug cap resistor. Use a #10 solid core wire in place of the resistor. Modern and older automotive FI system do not overkill the coil to plug resistance. Mr Honda incorporated his company's automotive ideology into the GW.

The most used triggering system regardless of fuel or ignition, or both for the GW is to have a crank trigger wheel 36-1, 36 teeth with one removed sandwiched between the crank timing belt pulleys - keep thickness of trigger wheel to approximately 4 mm. Use a VR sensor from the '85/'86 FI models or the PG sensors from the '85 to '87 GWs.

I am upgrading the OEM ECU on my '85 Limited Edition FI model with a Speeduino Project ECU and tried to use the existing OEM cam and crank trigger system - sometimes easier to upgrade components as well. The sensors are VR, not Hall effect. The crank sensor is fine with the 8 tooth crank trigger wheel because of the rotational speed and number of teeth, but the cam VR sensor caused sync losses - low speed resolution. Honda has 2 cam sensors with a single tooth cam trigger wheel that enabled waste spark operation, older technology, quicker starts and such. The new aftermarket ECUs only use/require one additional rotational input, cannot use two. A Hall effect sensor is better for the 1/2 crank speed cam rotation and single tooth trigger wheel, but space to install a hall sensor for the cam trigger wheel is limited, especially if you want to keep some of the original look.

You only need a second rotational input if you are going to do sequential fuel injection - not a lot of gain with this, or a COP/CNP (coil on plug - coil near plug) install. A 75 mm crank trigger wheel should do the trick.

Socrace, Casper and irishcarbomb have threads on this forum regarding FI conversions, good information.

Check out the Megasquirt forum and its manual, the Speeduino forum is good info as well.

Good luck.

[TheFieryMan]

A 75 mm crank trigger wheel should do the trick.

I'm leaning towards a missing tooth crank trigger wheel primarily for the higher level of resolution but I was thinking it might be helpful to have something on the cam as well which ledme to the thought of putting it back in the points housing.

[Rednaxs60]

Socrace did this on his 1100. Check out his threads

[TheFieryMan]

Socrace did this on his 1100. Check out his threads

I nearly have that thread memorized.