Propane Conversion Tech Write-Up

[Spduffee]

Very nice writeup!
Is the system something that could be salvaged from a scrapped transporter/bus? I used to drive an Econoline V8 school van that was propane powered. Or is the headache and risk too great to bother?

 

[MDPJeep]

Very informative and something I'd never thought of. I put the Howell TBI on my CJ and was very happy with it. Like your propane conversion, I'm sure it would solve the off camber fuel starvation problems from the stock carb.

Question - Could you carry a 5 gallon lp tank and use it as a spare for really long days off road ??

 

[TeamRush]

Excellent write up by the OP!

I did this myself a few times, mostly with seasonal equipment since liquid fuels do have storage issues.
I also did dual fuel capability to a Full Size Jeep (FSJ/Grand Wagoneer) Expedition rigged vehicle.
Seasonal equipment will have fuel preservation issues and LPG or CNG never goes bad.

I do recommend a 'Hotter' ignition, and a high torque starter, high output battery (batteries) if it's not started regularly. When it sits for 8 or 10 months, it will take a little cranking to get started...

For someone doing off camber/high angle driving and has experienced fuel delivery issues, this is a fix you will love!
If it had a dry sump/scavenged oil system, it would run up-side-down!

 

[Belizean]

One of the things that really impressed me was how clean the engine remained after high mileage tear down TR

 

[TeamRush]

One of the things that really impressed me was how clean the engine remained after high mileage tear down TR

Don't mistake lack of carbon soot (black) in the oil for 'Good' oil.
The oil still collects moisture, acids, and the molecules still sheer and become ineffective for proper lubrication, so it still needs to be changed.

Lack of wear... That's not always a good thing...
We ran about 6 races using synthetic oil, and the race car smoked which worried us.
On tear down inspection, the rings hadn't seated!
We had to run a break in oil for about an hour to break the rings in, then switched back to synthetic and the trace smoke went away.
All in all, stopping wear on hard parts is a very good thing...

It depends on the engine, we normally used stainless steel valve seats & valves, and rings when we knew it was going to run propane since CNG/Propane doesn't have the lubrication & is more corrosive than gasoline.
Seats were for the engines before hardened valve seats for unleaded fuel most times.

Higher milage engines usually won't need anything extra, there is extra lubrication getting past valve guides and rings, lubrication issues solved, but if you build specifically for CNG/Propane, you might want to consider stainless.