Is there any way I can reconfigure a D series engine to run reliably at low RPM with low fuel consumption? I am thinking of building a generator (fixed; not portable) using the D series engine. I am not impressed with the diesel generators I've been looking at, and they're very expensive.

I was thinking with some cam modification I could eliminate valve overlap and run the engine at about 800 RPM and connect several large truck alternators to produce electricity. Of course the engine would probably never reach operating temperature. Any ideas of what I could do?

The objective is low speed and great fuel economy (because it will be running nonstop until it blows up).

 

How much power do you need?

 

6kw... 24 hours a day 7 days per week

 

That's not very much power. Why not use a smaller engine?

You'd be looking at running the d-series engine way out of its efficient range.

 

So you're looking at making a D16 engine into a home generator? Make sure it's mAd JDM y0!

This I have to see....

 

I would try to go with a smaller engine, but if you do go with the d series get the crx hf motor.

why would you need to modify the cam?

 

To eliminate valve overlap, which is optimized for midrange and high RPM operation. Low speed engines like steam engines have no valve overlap.

 

Two reasons: I want it to be reliable. With the size of the D-series engine, it should run for much longer (on a nonstop basis) than a smaller engine would with less maintenance. The second reason is fuel consumption. If I run the engine at 800 RPM, it should get better fuel economy than a smaller diesel engine. Most small diesel generators run at 1800 or 3000+ RPM. I plan on rigging a 50gal drum as a fuel tank, so I'd imagine it would run for about 6 days (hopefully more) without refueling.

 

The thing is, if you're running a d-series engine at 800 rpm, it would not be efficient, and BSFC would suffer. Keep in mind that a smaller engine operating at a higher speed could be more efficient, and fuel flow might be less.

From a maintenance perspective, then yes, it would be a good choice.

 

where did you get the target RPM? that's just off idle for a d-series which i suspect would result in high fuel usage and maybe low oil pressure for the given output.

if you're serious about this setup, i would suggest finding the ideal engine RPM and needed generator RPM, then working out a gearing or pulley system that allows each to work in the optimum range.

i'm thinking something like 3000 rpm for the engine and (shot in the dark...) 1000 rpm for the generators. rig up a pulley system with a 3:1 reduction and you're set.

i'm very interested in what you come up with and how well it works.

 

I am wanting 800 RPM for better fuel economy. I need it to run for as long as possible using as little fuel as possible. I may even aim for a lower RPM.

I have some 4 to 1 pulleys that I could rig to the crank and alternators, and I have various truck alternators I could use. At 800 engine RPM, the alternators would spin at 3200 RPM. I don't think the engine would have any problem spinning four or more alternators under high reduction if that was the only load.

As for oil pressure, I am hoping synthetic oil and some added barrier lubrication would fit the bill at low oil pressure.

If I could find a smaller displacement engine that was reliable and cheap I would use it. The D series is the cheapest thing I can think of offhand that is reliable.

 

My suggestion, D15Z1 engine(VX), 1500-2k RPM, get everything right with the stock ECU and it will run in lean burn mode(16-16.5:1). The Z1 is designed to run at 2k RPM at 60mph, should be right in the butter zone for mpg.
But you'd need to get the VSS setup right.

 

I like that suggestion.

I'd also recommend chipping the ECU so you can datalog and look at pulsewidth (and with some math, fuel flow).

 

A standard automobile engine is designed to be as efficient as possible across a large RPM range. A generator only needs to be efficient at 1 specific RPM.

Convert a turbocharger into a turbine to power the generator. I had some friends do this and ran it off of natural gas, cut their monthly power bill from $100 to $25 in gas, and received a check for around $12 a month from the power company for feeding the grid. Only noise complaints from the neighbors ended the experiment, but mufflers could always be fitted if needed.

 

I thought about the turbine idea, but I don't see how I could easily fabricate a shaft off of the turbine to spin a generator. I've seen some homebrew turbines in action and they looked red hot. That also seems kinda dangerous to me, especially near a fuel source; but cost/watt & dependability are my biggest considerations. If I could make 20kw constantly and pay less than $600 per month on fuel I would be in heaven.

 

Making a generator for your plantation?