Oddball application: Ecotec as generator engine?

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09-13-2017
V8 Supra Builder

Oddball application: Ecotec as generator engine?

I am looking into building a whole house generator and need an engine that can output 40-50 HP @ exactly 1800 RPM. As the electrical load increases (such as air conditioning), the load on the engine increases but the RPM must remain constant. I will direct drive the generator head using a manual transmission input shaft mated to the generator shaft. From what I've read, the manual to auto stuff (flywheel, clutch, pressure plate) will interchange from the Gen 2 2.4L to the Gen 3 2.5L engine OK.

1L two cylinder generator engines are thousands of dollars, while 2.5~4.8 four~eight cylinder JY late model engies are hundreds, like < $500. Since I have HPT, I have narrowed my search to a few that are covered, and the leading one is a 2013 Malibu LCV 2.5L Gen 3 Ecotec or a similar 2.4L Gen 2 Ecotec. I want to use minimum displacement for maximum fuel economy. I'm not worried about the wiring, as I can make my own harness, and have downloaded relevant diagrams.

I need to determine if HPT will allow me to maintain the desired 1800 RPM under all loads- to basically function as a governor. I have not used the program in years, but recall you can tweak the idle and set a redline, so it seems like I could have a desired idle of 1800 and a redline of 1850~1900? It seems like the electronic throttle body may be an asset here.

Some considerations:
1) Standalone setup
2) No transmission will be attached
3) Should be able to run all sensors except rear O2 (exhaust will be manifold to muffler, no cat)
4) Will be using a generic ignition switch- not sure about what type if any security is used in these cars

At this point, I'm looking for information as to if this would be practical or if I should go in another direction. Thanks for any advice.
09-14-2017
ScarabEpic22

How much variance can you have regarding the 1800rpms? My logs show engine RPM fluctuating ~20-40rpm at constant load/throttle, so as long as the generator can handle likely +/- 100rpm it should be ok.

It should be just a matter of disabling VATS to run standalone, using a manual transmission OS (or disabling all auto trans stuff), remove any BCM-controlled ignition switch and set up in HPT, and setting redline at your desired rpm. This all depends on which ECM you use.
09-14-2017
Speedytec

You need a cruise control to keep the speed/revs steady and have the throttle increase with more load... :cool:
09-14-2017
V8 Supra Builder

Quote:

Originally Posted by ScarabEpic22

How much variance can you have regarding the 1800rpms? My logs show engine RPM fluctuating ~20-40rpm at constant load/throttle, so as long as the generator can handle likely +/- 100rpm it should be ok.

It should be just a matter of disabling VATS to run standalone, using a manual transmission OS (or disabling all auto trans stuff), remove any BCM-controlled ignition switch and set up in HPT, and setting redline at your desired rpm. This all depends on which ECM you use.

Thanks for the info. I downloaded some Ecotec stock files and have been playing with them.

The generator manual specs out a maximum RPM for the voltage regulator of 1950 and the rotor of 2100. The unloaded RPM setting is 1860 and fully loaded is 1740, so it is an operational spread of 120 RPM. The load will vary, although at 24KW I'm over-engineering this for my home, so it should not see huge fluctuations like my current 6KW unit sees when a heavy load like a well pump kicks in.
09-14-2017
V8 Supra Builder

Quote:

Originally Posted by Speedytec

You need a cruise control to keep the speed/revs steady and have the throttle increase with more load... :cool:

I looked into using one of those with an older carbed engine. I think the electronic throttle body can outperform either a vacuum or electrical servo (not sure if these could be used with an electronic TB), but all options are on the table for now.
12-31-2021
Dutch

I know this is a dead thread but this is a cool concept.

The calibration should be the easiest part: all you need to do is set the idle RPM to 1800 or whatever, and then torque management will figure out how to maintain it with the changing load.
You can also repurpose the warmup idle RPM tables so you can stay at something like 1300 until ECT reaches an appropriate temperature, and then have it ramp up to your target RPM.
If you reuse to donor's intake and whatever portion of the exhaust that contains the O2 sensor I dont even think you'd need to tune it.

The chevy volt uses its 1.4L as a generator/power assist - you could take a look at its tune and compare it to a sonic or cruze (keeping in mind its naturally aspirated in the volt) to see what GM did differently in the calibration.

The hardest part would be getting it to run outside a vehicle.
I don't know what control modules need to be present for the engine to start. I'm sure you'll need at least the ignition, instrument cluster, and fuel pump control module.
I think if you disable all TCM codes, it can run without a TCM without going into limp mode and screwing with torque management.
You'll definitely need to disable VATS.
I'm also not sure how fuel delivery would work if you didn't want to use the fuel pump control module, fuel pump, and fuel tank out of the donor.