LPG for vehicles

[QC]

Re: LPG for vehicles

I need to clarify a few things, so some will understand why I post in these threads when I see them. For the last 15 years of my career I have done 100% alternative fuel application for heavy trucks. Primarily CNG and LNG, but actually a tiny bit of experience with Methanol and some more with LPG. Our technology is Dual-Fuel which is compression ignition (diesel engine) but we use natural gas as our primary fuel. We use the diesel injector to ignite the natural gas. It acts sort of like a liquid spark plug, but it is still compression ignition. I am not going to share company name as I am not trying to spam in any way. Just wanted to explain my background. Prior to that 100% Caterpillar diesel engine experience for 20 years.

I am our lead salesman, and I have applied these things on 5 continents. I have nothing against LPG at all. But methane (natural gas) has an even higher octane rating (140ish) which allows us to use in high compression engines. We have applied LPG as well, and we just have to back off peak torque too much to make them practical. Some have been successful with 20% LP use. We aim for 80% gas use on our systems as the primary driver is economics. VERY hard business, and VERY hard technology, but we get it done. I follow all alternative fuel vehicle projects daily. I have worked with almost all major truck manufacturers, and this is why I am very confident regarding the availability of these products in the marketplace. They are my customers and competitors. This is what I do

 

[aerobat]

Re: LPG for vehicles

i,ve heared w?rtsil? had or has some lpg applications on large medium speed engines. there are indeed two styles of engines : spark ignited otto cycle for pure lpg or compression ignited diesel cycle where a small amount of diesel was injected for ignition. they called it "pilot fuel" .

 

[glenn property of pam]

Re: LPG for vehicles

they did convert about 200 large trucks to run on gas as a experiment payed for by the goverment in the uk so they are out there on the roads somewhere. The trucks had the compression lowered and the heads drilled to take spark plugs so techincally they are unable to run on diesel as they lack the compression for self combustion so realy they are just realy big gasoline engines that use to be diesels. As these were designed for depo refills they may be lpg or some other form of gas. I know we are off subject but its nice to learn whats in the market as the outboard/inboard designs are going to be heading in the same direction in the future. The other thing that seems strange is how the name gas is used in the uk lpg is liquid pertroleum gas and it may be propane or butane or a mix depending on the weather and cost.

 

[rbh]

Re: LPG for vehicles

We have three vehicles on propane ford f150-5.8 lt and 2 E150s with straight six 300, all imco systems
As long as you had the hardened valves and seats and I believe we had to retarded?? the timing, you were good to go.
85 liters = 400 + KMs running empty.
When the price went over 85c per LT, went back to gas/diesel.

 

[QC]

Re: LPG for vehicles

i,ve heared w?rtsil? had or has some lpg applications on large medium speed engines.

I know Wartsilla has natural gas dual-fuel engines, nit sure about LPG. Sometimes "pilot" is used. We use that term when specifically discussing the shot of diesel.

 

[QC]

Re: LPG for vehicles

they did convert about 200 large trucks to run on gas as a experiment payed for by the goverment in the uk

I believe those were Scanias and they were Impco systems. Yes, spark plugs and lowered compression. Not available anymore. We are currently delivering systems on Volvo trucks in the UK.

 

[aerobat]

Re: LPG for vehicles

qc, on a lng / lpg diesel with pilot fuel the gas is sucked on the 1st stroke and the gas air mix is compressed and then ignted by a diesel shot when i understand it right. but the gas will disperse oxygen so cylinder filling will get worse - does it make any economical sense in regards to engine efficiency ( g/kwh or lb/hp/hour) comparing that to a similar "pure" diesel ?

what amounts ( in % ) are we talking here for the pilot fuel in gerenal in regards to total fuel consumption? is the diesel used entirely to ignite the gas or is the amount tweaked to balance overall power output ?

i guess such installations are mainly used in countries with attractive prices / taxes on such fuel combinations

interesting !

 

[QC]

Re: LPG for vehicles

Yes, we displace some air with gas, but air is usually more controllable with a turbocharged engine than a naturally aspirated engine. Sometimes we need less air than the diesel, sometimes more. One of our biggest challenges. Efficiency can be very close to the diesel, so we always compare as you have noted. One engine we have worked on we actually improved efficiency. Typical swings are within 2% either way.

We do vary pilot fuel percentage a lot. At idle we usually run 100% diesel as diesels are very lean there and the gas simply won't burn. We get pilot down to as small as 8% in some engines at full load. We refer to the "substitution" as the percentage of gas vs. diesel. We end up with a 70 - 80% overall gas.

Yes on geography as well. We look for $1 per US gallon equivalent difference, of course $2 is better and we are approaching that now here.

 

[CharlieB]

Re: LPG for vehicles

I'm in the middle of Missouri and have seriously considered converting my pickup to use LPG. The cost of conversion is a bit, fuel costs savings will eventually pay off. My local LPG supplier allows me to 'pre-buy' fuel for home delivery, saving me a bundle every winter when the price rises.

My biggest draw-back in making the conversion is the lack of refill stations for vehicles. Sure, you can get a BBQ tank filled at any # of locations, none of them will touch a vehicle. The nearest vehicle filling station is about 25 miles out of my way. Definitely not convenient.

One possibility is a home filling station (pump) drawing off my home tank. This could work out fine as pre-buying my fuel I can take advantage of that mid-summer price break and if running low on fuel too far from home simply hit the switch and run on regular gas. However when you start adding the cost of the home station to the cost of conversion, and that I have since retired and don't drive near as many miles. It simply isn't worth it now.

 

[DirtyOldBoat]

Re: LPG for vehicles

My biggest draw-back in making the conversion is the lack of refill stations for vehicles. Sure, you can get a BBQ tank filled at any # of locations, none of them will touch a vehicle. The nearest vehicle filling station is about 25 miles out of my way. Definitely not convenient.

Huh? Anybody that can fill a BBQ can fill a vehicle tank. It's exactly the same as filling up an RV with built in tanks.

 

[WIMUSKY]

Re: LPG for vehicles

Huh? Anybody that can fill a BBQ can fill a vehicle tank. It's exactly the same as filling up an RV with built in tanks.

When I was a kid, way back when, I used to work at a gas station(full service), I filled RVs all the time, along with 20 -100# portable tanks....

 

[jimbo_jwc]

Re: How many miles per $

Re: How many miles per $

Haven't heard mention of Otto cycle engines in a long time is it the one with the least moving parts next to rotary ?

 

[QC]

Re: How many miles per $

Re: How many miles per $

Otto is typical 4 stroke. Spark plugs, four cycle and a throttle are the required components. Almost all modern gasoline cars are Otto

 

[glenn property of pam]

Re: How many miles per $

Re: How many miles per $

Haven't heard mention of Otto cycle engines in a long time is it the one with the least moving parts next to rotary ?

are you thinking of a sterling?

 

[QC]

Re: How many miles per $

Re: How many miles per $

Or a Miller? I think there are some Miller's being sold today. I think Mazda was playing with those. Miller Cycle

 

[jimbo_jwc]

Re: How many miles per $

Re: How many miles per $

Maybe a Bourke
http://bourke-engine.com/ani.htm

are you thinking of a sterling?

 

[jimbo_jwc]

Re: LPG for vehicles

When I was a kid, way back when, I used to work at a gas station(full service), I filled RVs all the time, along with 20 -100# portable tanks....

When I was a kid, way back when my Grandpa had me filling a wood burner in the back of the bed of his truck barely burning, and he could run his 6cyl chevy but that was all it could do to haul that contraption .

 

[glenn property of pam]

Re: How many miles per $

Re: How many miles per $

Maybe a Bourke
Bourke-Engine : Animated GIF

i had seen this when i was in school. Intresting read

 

[jimbo_jwc]

Re: How many miles per $

Re: How many miles per $

i had seen this when i was in school. Intresting read

There is a turbo Mazda rotary video speed ski pulling boat that's amazing and out of site of land and seems to keep adding more rpm .
They were not fuel efficient and had to have a second plug just to burn excess fuel .

wankel turbo ski race boat - YouTube

 

[glenn property of pam]

Re: How many miles per $

Re: How many miles per $

There is a turbo Mazda rotary video speed ski pulling boat that's amazing and out of site of land and seems to keep adding more rpm .
They were not fuel efficient and had to have a second plug just to burn excess fuel .

wankel turbo ski race boat - YouTube

thats what i love on the rotarys you can just keep stacking them to make more power
rotary engine 4 rotor - Yahoo! Search Results i dont like that they feed engine oil into the rotar to protect the apex seals especially as its from the engine oil but it can be converted to run on 2-stoke premix