MudHippy

Long story short...this guy I was talkin' Toyotas with awhile back says he's got "a 3VZ-E that runs on propane" in his. I said "how'd you do that?", "I've only seen the kits for the 22R(E)". He says "I had my brother do it", "I've got about $60k into the thing so far". And that's about as much as I got out of him on it.

Soooo...

It's had me wondering for the last few weeks if that could be done very easily/cheaply.

And...

It turns out it CAN be done very easily. But NOT very cheaply. For around $995 or so.



http://www.dudadiesel.com/choose_item.php?id=6cyl

What you get is actually a dual fuel setup. Meaning the ECU will allow the engine to run on propane or gasoline. Even with some degree of manual correction/tunability.

http://www.dudadiesel.com/files/prop...panemanual.pdf

It's just another one of those cool things I want for my truck that I'll never be able to afford.

Anyway...now ya know!

aa1911

iTrader: (1)

very cool; I really want to do a diesel swap into my runner but I don't have $15k laying around. This is a much more realistic idea.... I think propane is still under $3/gal last time I filled up the home tank.

irab88

iTrader: (4)

hang on, i got all the links you'll need...

and it ain't nowhere near $1k for the kit...

irab88

iTrader: (4)

start here. even with the exchange rate and shipping, you could put the entire system together for much less than if you bought everything stateside

http://autogas-lpg.co.uk/10-conversion-kit

Dirt Driver

I'm wondering how the kit does sequential injection on engines like the 22RE/3VZE that never employed sequential injection.

MegaSquirt-II and III are still options for a complete, sequentially-injected propane conversion. Some OEMs used conventional gasoline injectors to meter gasous propane. I think it involved something like 160lb/hr injectors on propane to be about equivalent to ~14-19lb/hr on gasoline.

Something I have only heard from others about using gaseous fuels is that valves and seats don't last as long, but the engine oil stays cleaner a lot longer.

irab88

iTrader: (4)

yes, because the liquid fuel helps, to a small degree, to cool the valves. gasseous fuel is already a gas, so there's no cooling there. that, and it burns cleaner and leaner, creating slightly higher temps. and because there's a lot less carbon input, there's a lot less carbon output (like in the oil)

it basically pulses the 'pane injectors to the beat of the 'oline injectors, so the fuel delivery is timed roughly the same.

Dirt Driver

That's why I brought it up; these Toyota truck engines only use batch- and bank-to-bank injector firing. Propane injection is not something I have played with, so I don't know what affect shooting fuel into a closed port has vs. doing it with gasoline.

I do like the idea of a switchable dual fuel setup. I would be tempted to build a high compression engine to take advantage of the octane and get some power back and just put up with running premium gas through when necessary. Unfortunately it would never get through smog here, even if tailpipe emissions were a lot lower. CA lawmakers are so sensible in that regard.

MudHippy

I don't think it does. Unfortunately...

The only thing missing from that equation is the regulator. Fuelling an engine with any kind of fuel via any kind of electronic fuel injector(s) also requires regulating the fuel pressure supplied to said injector(s).

Good question. I don't know either. But I assume it isn't a major cause for concern. Intake valves by their nature run cool anyway(they're air-cooled too you know), so I don't think it would significantly affect how long they would last. And I'll take their word for it when they say that it will work on half-sequential and non-sequential engines. Sounds reasonable to me...

The only thing I can find mentioned in the manual that pertains to it is in the LPG injector nozzle size recommendations.

Which makes sense...if you understand how simultaneous injection works(and/or why it might need to use relatively lower flow rate fuel injectors than if a sequentially fired fuel injection system is used). Which I'm not going to explain in thorough detail. But you can take what I'm about to say and extrapolate your own conclusions from.

So...for those not in the know...

The 22R-E, 22R-TE, and 3VZ-E all use the same type of non-sequential fuel injection system. What's known as simultaneous injection. Where the ECU fires all of the fuel injectors simultaneously once for every two or three intake strokes. Resulting in one half or one third of the engine's cylinders recieving a fuel charge from the injector into their intake port while the intake valve is open(just before the intake valve closes). While the other half or two thirds recieve fuel injected into their intake ports while they're still closed(just after the intake valve closes or just before the intake valve opens). Then as the engine cycles what happens? And how is that relevant?

Hint: 4 or 6 fuel injectors fired simultaneously, even once for every two or three intake strokes, will tend to yield more fuel to any of the cylinders than is really necessary(due to how often they are fired). Even vs. half-sequential(group or bank fired) injection, and especially vs. sequential injection. Think about it long enough and you'll realize why(if not...every cylinder gets 2 injections of fuel to the intake port for each of it's intake strokes). And that's why you'd want smaller nozzles on simultaneous propane injectors.

Fuller definitions of Toyota's sequential and other EFI types found on page 15 here: http://autoshop101.com/forms/h22.pdf

Dirt Driver

I think that's the same case with this conversion kit, although I assume the gasoline injectors would need gaseous propane to be regulated down to acceptable EFI line pressure.

On a side note, I just stumbled onto an injector site that has 225lb/hr injectors rated for 123psi. That's almost tank pressure.

My mind immediately went to mixture distribution since the propane displaces a much larger volume of intake air than gasoline.

Are we getting into the lower nonlinear operating range, or am I reading too far into this?

MudHippy

That's what this contraption is...

2big4arunner

I want this..... I want this bad. has anyone seen the RC injectors for propane to replace the original ones that are in the system already?

Dirt Driver

Those are low-z injectors and would require either a peak-and-hold driver or a resistor box. They are also $225 each....$900 for a set of four and $1350 for six.

Based on their numbering system, I would guess that they're actually 3200cc/min gasoline injectors. The highest rate I can find in mainstream injector suppliers is 2250cc, although 3200s are mentioned a lot in the Chinese manufacturing suppliers that pop up in Google's results.