Electric conversion: Project ForkenSwiift

[MetroMPG]

Nice! Tested as in engine running, or good pressure?

[Silveredwings]

Originally Posted by MetroMPG

Nice! Tested as in engine running, or good pressure?

Good pressure, from the tank to all 3 carb bowl needle valves (new Healeys didn't always do as well ).

I have a whole checklist before I feel it's safe to attempt an engine start.

Edit: actually I'm down to priming the oil pump and rotating the engine a few turns. Then I'm about ready.

Speaking of pressurization, I'll be replacing a lot of the cooling system (hoses, pump, thermostat, belt), but the that won't hold up the start.

[MetroMPG]

So... engine start yet??

---

The guy who initially explained to me how to use a 3-wire pot on the Curtis controller tells me my hack to make the forklift potbox work ... will probably eventually wreck the controller. Sigh.

So, probably got to bite the bullet and order that $29 unit to see if it'll work I guess. No point in tempting fate. DC controllers fail "on", after all.

[GasSavers_DaX]

Originally Posted by MetroMPG

DC controllers fail "on", after all.

Haha, YIKES!

[Silveredwings]

Originally Posted by MetroMPG

So... engine start yet??

I'm concerned about how well 20W50 oil gets through the engine and bearings at 8 degrees F (-13 C). I also forgot what kind of oil I need to put in the carb dashpots. I probably should use a multiviscosity oil since that engine compartment traditionally gets very hot.

I also got my speedo, temp and oil gauges back from the rebuilder.

[Silveredwings]

Originally Posted by MetroMPG

The guy who initially explained to me how to use a 3-wire pot on the Curtis controller tells me my hack to make the forklift potbox work ... will probably eventually wreck the controller. Sigh.

So, probably got to bite the bullet and order that $29 unit to see if it'll work I guess. No point in tempting fate. DC controllers fail "on", after all.

I'm still a little fuzzy about how that pot is wired. Is it off at 0 ohms and full on at 5K ohms (70 degrees)? Why did he think that "6K pot" would cause damage?

[MetroMPG]

It's not the 5 vs 6k ohms that's the problem, it's that I shorted 2 tabs on the controller together so I could use the forklift pot in its *2-wire* configuration rather than in the *3-wire* config that the controller is expecting.

It's one of these things that would take me an hour to properly describe in writing and in a diagram vs a minute to show you in person. Frustrating!

I'm just going to order the expensive potentiometer rather than trying to mod this one to make it work.

[JanGeo]

There is a spec on the three wire connection for the amount of current flowing through the pot from high to low and there probably is a certain amount of loading and current from the wiper into the circuitry that requires a certain amount of impedance in the pot to perform properly. If the resistance is lower the throttle responce is probably more exact and if the impedance is higher the effect may be a more tapered movement. In any event the only thing that could damage a controller is too much loading on the pot leads - if you have low voltage there then it should not really matter but if you have battery voltage then it is a concern. It may also be setup for forward and reverse with the full movement - depends if 0 ohms is off or not. The eCycle controller can be setup so that center position is 0 rpm and it goes forward and reverse depending upon which way you turn the pot from center. They spec a 5k pot but a 10k pot also works ok.

Best to measure what is coming out of the controller for voltage to the pot and go from there.

You should add CAPS to the controller input of sufficent value to handle the switching noise that the PWM will cause or else you produce a lot of EMF that could be harmful to your health and can induce currents in conductive materials near any of the battery cables. Just be careful of contactor currents charging the caps upon powering up - they should be limited via a charging resistor.

[JanGeo]

Originally Posted by Silveredwings

I'm concerned about how well 20W50 oil gets through the engine and bearings at 8 degrees F (-13 C). I also forgot what kind of oil I need to put in the carb dashpots. I probably should use a multiviscosity oil since that engine compartment traditionally gets very hot.

Dashpot oil usually was light weight hydralic fluid or brake fluid - I think I used marvel mystery oil or motorcycle fork oil. The heavier the weight of oil the more accelerator "pump" action you get - a richer mixture when pressing the pedal down. Too light an oil and stomping on the gas pedal will cause a lean "bog" stumble. It also dampens intake pulses at low RPM.

With 20w50 and a tight engine keep the RPM low until the oil warms up or else you will have a lot of oil pressure and put a load on the drive train turning the oil pump - timing belt or chain if not crank driven.

[Silveredwings]

Thanks for the info JanGeo, and that does make sense.