Propane Injection

[ReycleBill]

Has anyone here tried propane injection on carbed motorcycles? Any insight is appreciated.


Update: In the interest of clarity, propane injection is not the same thing as running on 100% propane. Nor is it a substitute for NOS (Nitrous Oxide.) Propane injection is also not a dual fuel approach where a vehicle can be run on gasoline OR propane.

In propane injection, a gasoline or diesel engine runs on gasoline or diesel and a small amount of propane is injected into the engine continuously at all throttle settings above idle speed.

A propane injected ICE will see some increase in horsepower but more importantly it runs cooler, gets better fuel mileage and reduces carbon build up on pistons and valves so that an engine will remain efficient over a longer period of time.

 

[scabber]

Are you looking for a faster way to remove your carbs ? nitrus would be better for horsepower.If that's what you are looking for.

 

[jchrisk1]

You mean like this?

 

[hooktool]

That's pretty cool.

John

 

[ReycleBill]

I'm looking for slight increases in HP along with an increase in MPG, cooling of the engine and removal of carbon from the valves and pistons.

PS. I'm planning on keeping my carbs.

 

[Punkskalar]

If you want to run propane only, you'll need a special mixer (carb) and you'll want to watch your valves and valve seats. We did a few rockbuggy's years ago on propane. it was the poor man's Fuel Injection back then... There was a loss in HP, as the stock internals on the engines weren't built to take advantage of the propane. If you built an engine specifically for propane, you can get some gains, but you'll want hardened valve seats for sure, and you'll want to overkill the rods and crank to handle the "octane" boost you'll be getting from the propane.


The propane itself will not remove the carbon from your valves and pistons unfortunately, as we never saw that happen in the real world when converting an old engine to propane. BUT, if you build a new engine for propane, you'll see the oil stay gold for damn near forever and the internals will stay super clean throughout their lifetime..


If you just want to add propane to your existing setup, there would only be a few gains in running cooler, but you'll not likely see much in addition to economy or power unfortunately...

But, its always worth a shot

 

[Patches]

+1 for what Hugh said.

And you can run the bike at more extreme angles for that offroad rock crawler bobber you have been wanting to build.......

I too worked at a custom offroad shop for many years building tube buggies and jeeps. The propane injection fad came and went pretty quick.

 

[ReycleBill]

If you want to run propane only, you'll need a special mixer (carb) and you'll want to watch your valves and valve seats. We did a few rockbuggy's years ago on propane. it was the poor man's Fuel Injection back then... There was a loss in HP, as the stock internals on the engines weren't built to take advantage of the propane. If you built an engine specifically for propane, you can get some gains, but you'll want hardened valve seats for sure, and you'll want to overkill the rods and crank to handle the "octane" boost you'll be getting from the propane.


The propane itself will not remove the carbon from your valves and pistons unfortunately, as we never saw that happen in the real world when converting an old engine to propane. BUT, if you build a new engine for propane, you'll see the oil stay gold for damn near forever and the internals will stay super clean throughout their lifetime..


If you just want to add propane to your existing setup, there would only be a few gains in running cooler, but you'll not likely see much in addition to economy or power unfortunately...

But, its always worth a shot

Thanks for the info. What I'm considering is adding propane to the existing system, something along the way NOS is done except the propane could/would be used at all throttle settings above idle.

 

[ReycleBill]

+1 for what Hugh said.

And you can run the bike at more extreme angles for that offroad rock crawler bobber you have been wanting to build.......

I too worked at a custom offroad shop for many years building tube buggies and jeeps. The propane injection fad came and went pretty quick.

Were you building 100% propane engines or engines that were supplemented with propane?

Also, why did propane fall out of favor?

 

[mouser]

interesting concept! I'll be watching this thread!

 

[ReycleBill]

I'm thinking propane could be injected via a tube that runs through the air filter into the carb throat, via the vacuum tubes on the intakes or into the threaded holes on the sides of the carbs. But right now I'm wondering how to build a throttle feed that won't freeze.

 

[Cafe-Dave]

 

[Punkskalar]

I'm thinking propane could be injected via a tube that runs through the air filter into the carb throat, via the vacuum tubes on the intakes or into the threaded holes on the sides of the carbs. But right now I'm wondering how to build a throttle feed that won't freeze.

You will also want to figure out how to properly mix your air with the added fuel... It can be done, but it will be more complicated than a simple injection system... Metering propane isn't tough, but metering Gasoline/Propane/Air will be interesting for sure...

 

[hotrdd]

I know lost of guys that are still using propane injection on their diesel's but I'm not sure what would happen on these bikes. Would be interesting to try.

 

[ReycleBill]

You will also want to figure out how to properly mix your air with the added fuel... It can be done, but it will be more complicated than a simple injection system... Metering propane isn't tough, but metering Gasoline/Propane/Air will be interesting for sure...

Life has taught me nothing is ever as easy as it seems.

 

[Patches]

Sorry, I've been out. To answer your question: the few propane kits that we did were full propane and for "off road use only". One was a fairly simple kit on a SBC. Pretty much a bolt on kit for the most part. Right before I left they were going to do a kit with a "switch" that would allow the driver to switch between gas and propane. Gas for street use and propane for off road. I never heard how that turned out.

The propane allowed the vehicle to overcome steeper approaches and climbs giving it some of the advantages of fuel injection.
Carbs tend to cut out during steep climbs just when you don't want them to.

 

[ReycleBill]

Sorry, I've been out. To answer your question: the few propane kits that we did were full propane and for "off road use only". One was a fairly simple kit on a SBC. Pretty much a bolt on kit for the most part. Right before I left they were going to do a kit with a "switch" that would allow the driver to switch between gas and propane. Gas for street use and propane for off road. I never heard how that turned out.

The propane allowed the vehicle to overcome steeper approaches and climbs giving it some of the advantages of fuel injection.
Carbs tend to cut out during steep climbs just when you don't want them to.

Do you think they fell out of favor because fuel injection became so widespread making the propane unnecessary? Or was there some other reason(s)?

I went to an event in California 20+ years ago where all the major diesel engine companies competed with independent owner-operators on a huge chassis dyno. The manufacturers showed up with engines that couldn't even be bought at the time but an independent took home the big money prize using a 20 year old diesel that was half the size of the factory teams but with propane injection. Cummings, Cat and Detroit all went home with their tails between their legs. The next year propane injection was outlawed at the event.

The Independent truckers who developed the process did it so that they could run smaller, more fuel efficient engines but still have the power to make the grades.

Only recently did I learn it was also used on gasoline engines. Check out this video: http://dieselperformanceproducts.com/gasoline.html

 

[XSLeo]

One thing is the propane tank you will need to go more than a few miles will be large and cumbersome. Look funny too.
Leo

 

[ReycleBill]

I think a lot are confused. What I'm thinking of doing is adding a tiny amount of propane to the air and gasoline mixture. A 1 pound can might go a long way.

 

[DirtyErnie]

Propane burns clean and fairly slow. For those wondering, it keeps the burn going a bit longer to help the main fuel 'finish' better. This is why it is so effective in a diesel, in stead of blowing massive soot out the stack, the propane helps burn more of the fuel to make more torque. It can get a little dicey on the modern turbo diesels, LP does have crazy high octane, but it does have limits... 25psi and 15:1 can get you there. This is why the water injection systems are so popular now, especially with methanol. In a clean burning engine it couldn't be as effective a booster as it is in an old dirty one.