Propane enrichment for diesels 5

[sportster]

I recently read about an after-market kit for electronic injection turbo-diesel automobiles which injected propane into the intake manifold. This proportedly improved emmissions (gaseous and particulate), power, torque, and fuel-economy. The system ran on a maximum 15% propane (15% of caloric imput I presume). Economy must have been computed as % ultimate efficencey of the combined fuels(?). The kit seemed to rely on the electronic diesel-fuel management system to lean out the charge to achieve appropriate exhaust O2 levels. Unfortunately, I've forgotten the name of the company and have had no success searching the internet...

I am interested in finding independant studies or documentation of this type of "dual-fuel" system and verifying its benefits. Does anyone know of application of this system?

 

[BigH]

All interesting stuff. LPG availability no problem in UK, though mileages are a tad smaller! Italian LPG bits are cheap and every man and his dog are converting petrol vehicles ( no legislation at present!)
Diesel fumigation is newish here, and I have been playing with a 160 bhp cummins B series using vapouriser,power valve and simple 10mm pipe mixer in turbo intake, pressure switch bringing gas on at 3psi.Setting is finger in the air stuff, and suggestions would be appreciated.I have been adjusting the inline power valve on the move, while turning the gas on and off, and monitoring the sudden increase in boost pressure. A point is reached where the pressure rise peaks for increasing amounts of gas, eg 5psi at 70mph --- 9psi + acceleration.I am assuming this represents max. power but at what % lpg I have no idea. I would also have thought that the injection pumps boost enrichment should be reduced with gas applied,but not sure about main fuel adjustment Any thoughts? I know some outfits reduce main diesel adjustment to prevent engine and transmission going bang. I am monitoring transfer box temperatures, and they soon start to climb with gas on!
I have toyed with the idea of a motorised power valve ( lambda control type) but no clue as to what to monitor to control it, excess lpg in exhaust?, use electronics to continually maximise boost pressure?
The vehicle is a 6x6, 5 tonnes camper, I have built based on a Land Rover 101 ex mil. tractor unit, and power is what I am after. In the UK this engine is usuallly 130 or 160bhp and 210s are not that common
Now I am rambling,need to get out more! Must go
Regards
BigH

 

Another problem I see with propane fumigation is in trying to increase power output in the modern electronically controlled diesel engines. Such engines control output power electronically. Caterpillar, for example, “Sells Horsepower”. What they mean by this is they will sell you a 3126B engine rated at 860 lbs of torque and 200 horsepower for thousands of dollars less than a 3126B engine rated at 860 lbs of torque and 300 horsepower. Same exact engine, just different programming in its computer, which limits its output power. Later on if you decide that you want a higher horsepower engine, you pay Caterpillar a few thousand dollars and they will “Flash” the computer chip to turn it into a 225, 250, 275, or 300 horsepower engine. More horsepower = more dollars for the upgrade. It seems that if you were to try to increase power output on such an engine by introducing propane fumigation, the computer chip would merely command a corresponding reduction in diesel fuel flow to keep the maximum horsepower from exceeding what it is programmed to deliver. Correct me if I am wrong about this. Torque is another matter, and I am not sure how the computer would control that.

 

[franzh]

Its easy to dump a lot of fuel into a diesel engine, even an electronically controlled one. The onboard computer has no way of knowing how much power the engine is producing, as long as the diesel profile is not altered, and the RPM is still within governing limits. When the governed RPM is reached, the electronic control system simply backs off on the diesel and allows the other fuel to take over. As long as the amount of fuel and RPM control are within the tolerances, the computer doesnt know (or care).

The problem is as I mentioned earlier, a little power is fine, but soon, the driver wants a LOT more, and its available often by a twist of the screw! This is dangerous and can lead to EXPENSIVE non-warrantable repairs. The TV shows and on-line advertisements do not disclose the possible side effect, only that a BUNCH of power is available.

Lastly, NONE of the web-advertised LPG-Diesel fumigation kits are EPA or CARB approved, therefore illegal to install or sell commercially. Treat it the same as an aftermarket camshaft or intake system on a gasoline (petrol) product. It was not emission tested or certified by the manufacturer, therefore, not permissable to install on over the road vehicles, your own or for a consumer.

Caveat Emptor (there have been more than a few dissatisfied owners so far!)

Franz

 

[charliebPE]

"The onboard computer has no way of knowing how much power the engine is producing, as long as the diesel profile is not altered, and the RPM is still within governing limits."

Just thought I'd let you know that at last there is a viable concept to cheaply and easily measure shaft torque, from which of course you can get power by combining with RPM.

It's not hokey, it's not snake oil, it can be retrofitted without altering a drive shaft, and it has the potential of being inexpensive. It has been patented overseas and a U.S. patent applied for via the patent cooperation treaty.

If interested, let me know.

 

[wixey]

This subject seems to be going a bit cold now with no responses for some time. I thought that I would try to get it going again by telling you guys that I have been working on dual fuel development for about a year now and have 15 R&D vehicles out on the road. The initial finding are very encouraging. We have fitted an electronically controlled vapour injection system to these vehicles and the first thing that you notice is the terrific power increase. We are having to "calm" them down. They are also showing fuel savings and are at present being tested for emissions. We have one van that is out with a delivery company and has covered 65000km since September and is going as well as day one. I hope to have it in soon for an engine strip down to check things over. I will keep you posted.

 

well hi people i have been fitting and developing a fumigation system for diesel for near on two years now with some great results.emmission testing is being carried out by qut in queensland.we have over 50 trucks on the system as of today with most returning greater driverability and fuel savings up to 7cents a klm.increased klms between oil changes and proven by oil tests every 5000k.we use propane as fuel.we have been working with australian epa and state government.our web site is under going a face lift and will be up and going soon complete with report copies photos ect.emmission test have shown reductions in greenhouse gases.i look forward to your input.

cheers mike michaeleve@bigpond.com.au

 

[sprintcar]

I'm curious if "Sportster" is really trying to build a diesel powered Harley and where the heck he's gonna hide the propane bottle!!
I did LNG (natual gas) powered golf car conversions in a former life - the Major pain was finding room for the gas cylinders and the safety issues. I'm not sure I'd want to be cruising down the highway at 75 with a big propane tank strapped in the bed of the Dodge Ram.
Of course it would be handy at the Tailgate parties.... Keep the wheels on the ground
Bob
showshine@aol.com

 

[franzh]

Just when we thought this thread was dead, it surfaces!

The propane tank in the bed of a truck is possibly the strongest item on the vehicle, excluding the engine block and possibly the frame members. The have an excellent safety history, far greater than either diesel or gasoline.

The propane tank is far stronger than the LNG dewar, and safer than 3600 psi NGV-2 cylinders.

In its place, propane can be excellent benefit to diesel engines, but with the proper use and ratios.

Franz

 

[bikejeremy]

hi,
I am wanting to assemble a toyota 22r engine to run on propane only..

does anyone know what compression ratio would be suitable???

thank you

bikejeremy

 

Interesting thread I just like to say my machine shop has built engines to run propane for 25 years as I live in B.C. Canada and every cab and most gas powered truck have been converted to run dual fuel or just propane. Propane is 29cents a litre and gas is 70+ I once bought propane for 1 cent a litre during a price war. 213 litres for $2.13 What a deal...
A few years back The factories got into act with propane powered cars and trucks. Dodge built a liquid injected 360. They heated the injectors to prevent them from freezing. Man talk about throttle responds, it was unreal.
I've turbo charged, supercharged, added nitrous, etc Added it to diesels. What I've found is its hard on pistons lands and rings especially if you get to much compression, I prefer no more than 9-1 on heavy truck and no more than 11-1 on light cars. Although I have turboed trucks with 9 to 1 and 20 pounds boost. I've also done 13-1 N.A.
They were high dollar custom stuff. It just not worth the grief to push the compression ratio to 12-1
Anyway its hard on exhuast valves and seats, Prefers cams with smaller duration than gas, likes lots of timing on lower compression engines,it will lug down low like a diesel
When added to big diesels,if you get carried away it breaks drivetrains parts like transmissions, rear ends,etc from the increase in power. As a side benefit to propane the oil stays clean so the interanal parts don't wear.

 

[franzh]

Thanks for the star guys, much appreciated.

One item that seems to be overlooked is that when a gaseous fueled engine goes lean, the exhaust temps also LOWER, and when the mixture goes rich, the temps RAISE. There is no evaporative effect with the gaseous fuel. I ran one 6.0 liter engine to L=1.9 and the exhaust temps were around 800 deg F! This was at 3000 rpm, 30 psi turbo boost, and about 290 bhp. Bringing the L ratio closer to 1.0 raised the power levels, but also the exhaust temps, and the NOx went through the roof!

Lean burn and NOx control are also different with gaseous fuels. Going a tad rich (A/F .97) will lower NOx, but will also raise them again due to exhaust temps).

It takes a different mental picture of the combustion process when operating with gaseous fuels than with liquid fuels.

Its also kind of addicting! I am sure RacerRick will agree!

Regards

Franz

 

Franzh Seeing you have done tests with propane. What do you think about combustion chamber shapes?
Is it possible to have to much quench turbulance in the chamber?
It seems to decrease the octane of the fuel if you do. I've found you need some but not to much.
It seems like the reaction rate of propane increases at higher piston speeds due to increased turbulance within the chamber which can cause some high quench chambers to detonate even though they have the same CR as a more open style chamber.
In other words the more open the chamber to a point the less likely it will detonate at higher rpms. Is that generalization what you have found?
It reacts, kind of opposite to gasoline

 

[franzh]

Hmmm.
I have personally liked open chambers with unshrouded valves. Seems like the trend with gasoline is to small kidney shaped chambers to promote fast burning.

I tend to agree with all of your comments. One thing additional is that Propane tends to have low fuel sensitivity compared to Natural Gas, thus more critical as to compression and ignition timing.

Been a while since I have seen the high speed photography with a propane combustion front, but at some of the pistion travel speeds in the 6000 rpm range, the flame held together equally as well if not better than liquid fuel applications.

I would like to see a direct comparison on equal engines between open vs closed chambers, possible one engine with two different styles, one for each bank. This might shed some light. Research funding anyone?

Franz

 

[autogasmarine]

Hi,
I just came across this thread. I'm doing some research on propane(lpg) fumigation of diesel engines. I intend fumigating a pair of normally aspirated Perkins 4-236c.i. direct injection diesel engines presently rated at 84bhp @2800rpm. These are on a marine installation and run almost exclusively on cruise and full throttle speeds.
To what extent would a fumigation system be beneficial on such an installation?
Look forward to comments from you all out there.

Thanks and regards
Autogasmarine

 

[franzh]

Re-read this thread, no sense in beating a dead horse.
Franz

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[rmw]

The thread is an interesting read and should be made into a FAQ. Great input Franz. Thanks for relating your experience in understandable language.

I was introduced to the fumigation topic 20 or so years ago in the heavy duty trucking industry. There were several people pushing it. That was before the days of electronic engines and the fine control that they offer.

As a ME that had survived Thermo 101, I saw potential, but I also saw some of the drawbacks mentioned here. Since I had a passing interest in the topic, and an associate who had an industry connection, I inquired about the progress/status of the concept. The only answer I got was that fumigated HD diesel engines had suffered an inordinate amount of stretched head bolts, and that it was a no-go.

This would go to verification of some of the problems mentioned herein.

My contribution to a very old, but none the less interesting thread.

I think your third star is long overdue, Franz.

rmw

 

[franzh]

Thanks, again, much appreciated!

There is an FAQ on propane, been there a couple of weeks now.

Ages ago, I heard of truckers using Cummins Big Cam engines, and others with Detroit 671's with a propane tank behind the cab, a hose and barbeque regulator, with a ball valve in the cab, dumping propane vapor directly in the air intake. Reportedly, it would allow for hill climbs without dropping into the low split box (old over the road trucks would have dual boxes with twin shifters). Stretched head bolts, cracked heads, blown pistons and sleeves, blown exhaust manifolds and early turbo's, burned underhood rubber parts from glowing exhaust manifolds, were all stories from old truckers I've heard.
Franz

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[GregLocock]

I'm surprised they didn't blow the intake apart as well - any flame at all in the header and you've got a bomb. A pressure relief flap in the intake is a wise investment.



Cheers

Greg Locock

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[rmw]

I saw the FAQ on propane, but was suggesting one for propane fumigation per se.

The big rig systems I was mentioning were not just jury rigs, they were store bought systems. If I think long enough, I will remember the name of the company in the Los Angeles area that was a big promoter. I visited their place, but didn't have the $$ to do it to my pickup. Later I just added a turbo, and had that 6.9 Ford IDI diesel doing about it could anyway.

rmw

 

[franzh]

The name Red Hat or Red Top rings a bell. I'll work on a FAQ on diesel fumigation when I return from an assignment and get some spare (HAH!) time. Right now, my project Mustang is taking most of my left over time.
Franz

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