liquid propane injection 2

[geofire]

Hi, I've been thinking about liquid propane injection lately using nitrous solenoids as shown here:

http://www.diy-nitrous.fsnet.co.uk/nitrous-solenoid.htm

The setup I'm contemplating is a turbo motor and I would like to add liquid propane for its high octane and how it would lower the intake temperature as it phase changes. I may try to go pure propane eventually, but for now I want to use propane assist so to speak. I'm running megasquirtnspark extra so it would be easy to trigger the solenoids only when needed, and lean the gasoline maps to compensate so it doesn't get overly rich when the propane kicks in.

in order to ensure I will be getting liquid and not vapor when the solenoid fires I was thinking of setting up a fuel pump with return to circulate the propane and purge the vapors. The question is what kind of pump do I need?

http://www.caranddriver.com/article.asp?section_id=26&article_id=2279&page_number=1

That article says a corvette fuel pump, so does that mean I can use gasoline stuff?

 

[franzh]

This forum has discussed liquid propane injection many times.

Here is a very brief outline on LPPFI.
Fuel injectors must pulse width modulate to properly meter the fuel. Nitrous injectors have too much internal mass to modulate in the order of millisecond response time.

LPG vapor pressure is high, on the order of 8.5 BAR at 70 Deg F, and 17 BAR at 125 F. To keep LPG in liquid form at these temperatures on an engine, you must keep at least 3.5 BAR above vapor saturation pressure, or you will have a mixture of liquid and vapor propane. Now, add in underhood temperatures of around 225 F, and you can reach propane vapor pressures in excess of 400 psig (27 BAR). This is out of range for even the most advanced over the counter fuel injector. I have personally witnessed a production gasoline fuel injector blow apart at 150 psig. Not a pretty sight.

If you just want to use propane as an octane enhancer, remember that the liquid expands 270 times from vapor. Even the tiniest amount will quickly exceed the air fuel handling capabilities of many engines.

The article you refer to is a long ago project that never made it into production. The pumps discussed were indeed GM production fuel pumps, mounted inside the fuel tank (custom tanks) and plumbed in parallel.

Lastly, this type of project is NOT for the novice high pressure hobbiest (actually, nor is this forum). There are just a handful of companies in the world that even have the capabilities and expertise of this technology. Even mighty Ford tried it for one project run on a large Ford Excursion but pulled it almost as quickly.

Franz

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[DanEE]

I believe this article, that I found with google, names some folks and companies who are working on this...

http://www.kettering.edu/~lpgvan/SAE-LPG.html

 

[franzh]

That was an educational engineering competition program similar to the SAE competition programs, in 1996 and 97. Nothing on the production side came out of it. I was deeply involved with the competition as an organizer and technical and safety officer. The some of the companies mentioned in the credits are no longer in business.

Franz

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[geofire]

http://www.fas.ch/eCatFASBin/eCatFAS.dll/DisplayENTCATALOGUE?ID_ENT_CAT=830&ID_ENT_CAT_PUIS_BOB=788

Theres one of the solenoids I was thinking of trying this with.

responce time is 15ms, yes the typical fuel injector is what around 1.2ms, but that just means is won't be as accurate if my thinking is correct, and therefore wont be used as the primary fuel. As long as its consistant I think it would be useable.

Also as you can see the pressure range is up to 100 bar, so I don't think that would be a problem.

the Orifice size is 0.50 mm I'm not entirely what that means with propane, but from looking at this chart:

http://www.diy-nitrous.fsnet.co.uk/Jet_Sizes_2.25.pdf

With a .5 orfice at 3 bar with gasoline he's saying 40hp, but taking into account the higher pressures of propane, i'm just guessing between 60-100hp, but don't really know.

I think i'll just purge at first so I don't have to setup the pump and such untill I've proven it would work like I'm hoping.

Whatever the case, I think it will be a fun project asuming I don't blow something up...

 

[turbocohen]

Here is a link to a cng injector and an lp liquid injector that is available to oem's.

http://www.siemensvdo.com/products_...stems/alternative-fuels/alternative-fuels.htm

Add 4bar boost over tank and thermally isolate the fuel from engine heat as best you can. If you happen to solve all the system design issues then you will stil hit the wall with deposits forming inthe fuel system.

Good luck, Turbo

 

[franzh]

Hello Turbo! Long time no hear! Glad to hear things at Siemens are still kicking around.

Franz in Texas

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[turbocohen]

Franz, they are kicking alt fuels to the EU since the alt fuels vehicle sales here in the US are so weak.

 

[dieselgas]

There are currently few European manufacturers of 'liquid LPG' injection systems – required mainly for large engine Petrol application, I'm new to these forums - and I’ve got to ask - why not just use a standard LPG conversion kit?
I have been converting both petrol and diesel vehicles for some 4 years now and cannot believe the lengths some people will go to convert vehicles – if you need more basic info check my site

http://www.meagan-ve.co.uk

if you need access to complete vapour or liquid injection systems let me know.
Most skilled technicians would be able to fit the equipment with some guidance/instruction.

 

[franzh]

dieselgas:
Consumers want less expensive fuel, BUT, are not willing to adopt any newer refueling infrastructures. The US has a nice distribution of LPG refueling outlets, but they are predominantly oprated by privately own companies with strict operating hours. CleanFuel USA is opening a number of self serve outlets with very user friendly dispensers, but still, the consumer balks.
The US vehicle base is currently not very conversion friendly, and the new EPA OBD-II requirement is making it all that more difficult. Note I state the NEW OBD-II, not the one instituted in 1996.
Ford had the last production vehicle with LPG and it was a disaster. GM has not had a production LPG vehicle is a couple of years, and Chrysler has not had a LPG vehicle in at least 5 years. A number of private companies have tried to partner with the OEM's with little success.
Our industry wonders too, why in Australia, Asia, South America, and parts of Europe, there are wonderful and very successful alt fuel systems in partnership with the OEM's, even to the point of cooperative warranties.
Currently, and for the future, the EPA only authorizes vehicle conversion systems which have been emission tested and approved by the EPA. One drawback, besides the OBD-II issue, is the EPA does not address warranties or the durability of components. The EPA does require no emission degradation for 80,000 miles, and by default, that requires a componenet warranty, but I have not seen any systems go that long without requiring component overhaul or replacement. Blame it on the fuel, or the technology, its a fact we have to deal with.
Personally, I would love to see the concentration of alt fuel vehicles here in the US like other parts of the world. That now leads to geo-political and socio-economic discussions, and we WILL NOT go there!
Regards
Franz

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[turbocohen]

dieselgas, "standard LPG conversion" is an outdated term. EPA and CARB have done a good job of keeping high pollution alt fuels vehicles off the road and allowing the few available validated systems to make it to market.

Aside from poor fuel detergency issues, yesterdays LPG conversion systems do not demonstrate low emissions due to poor fuel management optimization and poor demonstrated durability relative to modern fuel injected engines. Most and I mean 99% of the later model converted engines I have tested or witnessed pollute nausiatingly worse than the same engines that were running on petrol. A few years back there was interest in port injected liquid metering due to the low cost potential of meeting emissions and the commonality to gasoline systems. A client demonstrated a fuel injection system that my firm fabricated that metered gasoline or LP liquid through the same rails and bottom feed injectors and the system allowed an oem to deliver an LPG ready vehicle that could have the gasoline tank removed and a dedicated LP tank installed which connected to the same fuel lines and electrical connections. A new calibration could be flashed in a few minutes.. Commonality of components and storage tank hookups simplified hence cut costs for dealer retrofit. The underhood cost to the vehicle buyer was barely $100 above a dedicated gasoline vehicle. I still drive one of the test mules to this day. A typical technician could perform the retrofit from gasoline to LP in about 45 minutes. Including parts and labor bout $600 per vehicle US. It aint gonna happen here across the pond unless the LP industry execs at the top decide they want to implement availability of motor grade fuel to the automotive market.

 

[dieselgas]

“Turbocohen” – I assumed that “standard LPG conversion" would be using modern equipment!? I can understand that some U.S. kits are unacceptable and are now outdated but European Petrol LPG conversion ‘kits’ do comply with ‘our’ Euro4 emissions and are fitted by several OEM’s, also many of our ‘diesel-blend’ systems are currently/have been evaluated and are showing signs of a acceptable reduction of ‘harmful’ emissions – do you know of anyone installing a European style Petrol/LPG injection kit’s within the U.S.?
As a company we have converted many U.S. and Jap imports and have all been passed off through our ‘regulatory’ body.
Refuelling issues have now become acceptable here in UK and across Europe – I concur that the refuelling infrastructure is always the largest hurdle - but as Franz stated that leads to geo-political and socio-economic discussions, and (I’ve got to ‘cut and paste it’ never mind spell it) we WILL NOT go there!

Just out of interest where can I find emissions standards from the U.S. to compare with Euro Standards?
;-)
Regards

 

[franzh]

Take a look at the European Working Group studies, plus the term Euro 4 in Google and be prepared for some time spent. The EPA has the same info. Be prepared for some terminology translations. As a whole, the Euro, Japanese, and US Tier 2 are pretty close, but are testing using different methods and protocols. The US still uses the FTP 75 and a modified US-O6, while the Europeans use a modified Euro Drive cycle.
While I'm at it, I want to mention that "turbocohen" brings a unique perspective to this forum, he's one of those "been there, done that" folks, more times than we care to mention. Our paths have crossed many times. His words add credibility to this issue.

Franz

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[turbocohen]

Dieselgas, The last oem evaluation I was involved with systems took place in California a couple of years ago. The vehicles and systems were from automakers out of Holland, Japan, Korea, Australia, Canada and the US.. I will not mention the brand names. All of the systems meet the smog requirements in the country where they are sold.

The systems were tested as part of an oem show and tell of sorts but a couple of aftermarket retrofit systems were also present. After operating all of the vehicles using a known blend of problematic LP for a predetermined time through several urban cycles with complete cool down for two full tanks of fuel all vehicles were smogged. None of the aftermarket injection systems passed tier2 and only one of the Canadian oem systems made it to LEV in spite of the goop coursing through the fuel system.

Forget refueling infrastructure issues. The big problem is that the vast majority of LP is not additized for use as motor fuel. As systems are evaluated then the truth eventually comes home to roost and the oem's have to decide if it makes economic sense to take on the financial risks involved with maintaining compliance with emissions laws that are toughest in California and epa. It appears that the EU has not taken smog compliance through the life cycle the way the US does. Correct me if I am wrong but a lot of the "approved" systems from across the pond as tested here did not test well after exposure to contaminated fuel aka high sulphur and propylene, etc.

As for diesel fumigation, I am not impressed with the results when compared with modern clean diesels fueled with low sulphur fuel. In fact, the latest clean diesels when fueled with low sulphur high cetane fuels with basic keep clean additives often beat dedicated CNG angines in fleet use. What data can you offer that shows what your diesel blend systems are capable of?

Respectfully, T

 

[franzh]

From reports I receive from overseas, across the pond to the west and the east, the US appears to have a more aggressive sludge problem. We analyzed fuel injected options for the 2007 advanced forklift study and all of the FI participants withdrew their systems from the technology study because they were concerned that if their system was chosen for the program, it would not survive the testing due to sludge buildup.

The sludge appears to be plasticizers from hoses (problem solved when type 3 hose is used across the board) and pump lubricants (not miscible with liquid propane, tends to settle when heated and the lighter gases vaporize). Not sure what Europe, Asia, and Oz uses, but the reports I get from there does not support the same conclusion. The US motorfuel market is only about 17% of the total LPG consumption where it would be hard to justify a fuel quality tighten up.

There are only a handful of additive suppliers in the US, and when researching the products, it appears to come from only two or three producers. One issue is where to administer the additive, at the bulk tank, where everything is additized no matter where it goes, or during motorfuel refueling via a proprietary connection. Putting it in manually works but will not fly with the general motorfuel public.

We have several Ozzies on this panel, maybe they can share some insight on their experiences with LPG 'over there.

As for the diesel fumigation issue, this is one of the modern snake oil / witches brew topics. Almost all of the websites hawking the use of propane with diesel advertise increased power due to the "propane making the diesel burn more fully" or "acting as a catalyst to insure the full burning of diesel"! HAH! All that is happening is more fuel is being put in an engine that already has excess air. Call it BTU plus BTU plus air equals heat.

To my knowledge, there has not been one diesel fumigation system with propane that has been EPA approved for reduced emissions, although it appears that several have been tested.

Franz

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[turbocohen]

On the fumigation topic, the excess heat generated by using the excess air that is needed to keep pyro temps under control leads to premature engine failures and high nox. The operating cost efficiency is not there.

At the risk of violating the board rules regarding promotion I will mention that an additive that was reformulated specifically to accomodate LPG FI (vapor or liquid) was blended by Bell additives has been lab and field tested. No harm to materials was noted and the materials are chemically compatible. The work was done in conjunction with GFI who imo is best of breed as far as aftermarket systems know how. All of their fuel system materials exposed to fuel were exposed to dilute and saturated additive and none of the materials from current or past generation systems showed signs of incompatibility.
Franz, I think they are offering the stuff only to large scale customers but if you want a sample call 269-966-9182 and ask for JW. Tell him I sent you. My liquid injected truck depends on that stuff, no leaking injectors after 150,000 miles. The fuel rail and injectors were old when I put them in the truck, they were field returns that had about 300,000 KM from an old chrysler lp van out of Canada.

And it squeaked past LEV a year ago.. not bad for an obsolete ten year old test mule eh.

 

[franzh]

I am aware of this and similar products. They are being tested as we speak.
This borders on the edge of promotion, and risks being red-flagged.
Are you still with cox.net and I will write you directly?

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[GregLocock]

In Oz we have a factory fitted SF LPG system available, which is obviously calibrated correctly and passes emissions. We sell a reasonable volume of them, and although I am out of touch with the engine side of things, don't appear to have too many warranty/service problems. That uses a water heated gasifier. (Apologies for the grammar of that website, I will have a word).

http://www.ford.com.au/landing/egas/

We used to sell a factory fitted Dual Fuel system, basically a normal gasoline EFI intake with a barbecue plate LPG vaporiser thingy. It was too uncool, transitions between the two fuels were occasionally a bit rough, but I knew a couple of drivers who really liked it.

GM have just reintroduced a factory fit dual fuel conversion

http://www.americancarfans.com/news.cfm/newsid/2050912.001

which uses a very similar setup, ie gas injected direct into the manifold close to the intake valves.




Cheers

Greg Locock

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[turbocohen]

It is great to see oem support in your country and I hope it is successful.

The oem experiences here in North America indicated that there is a lot less trouble with LPG sold to markets supported by natural gas processors and a lot more trouble with deposits when fuel from refiners is available. Hopefully the industry leaders down under are more organized and responsive to supporting quality isses that affect motor fuel. That has been the underlying cause of reliability problems here in the US.

Lots of luck Greg, T

 

[patprimmer]

The willingness of the market to accept maintenance problems might be roughly proportional the cost difference in the fuels.

Currently LPG is selling here for about A$0.42 per litre while petrol is about A$1.25, or about US$1.12 and US$3.33 per US gallon. At 800 gallons a year thats about US$1600.00 savings. That justifies the occasional service.

Regards

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