Bought my first propane van

Propane, Butane, LPG, GPL, C3H8, C4H10
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themorb
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Joined: Thu Mar 07, 2019 3:04 pm
Location: Victoria, BC, Canada

Bought my first propane van

Post by themorb » Thu Mar 07, 2019 4:33 pm

Looking to get some advice from forum members for my 1991 Dodge B350 high roof camper van which came with a OHG system:

-Can I ever hope to get better than 29 L/100km (8 mpg) on my high-roof 7000 lbs 360 powered van on propane?
-I am concerned about having a range of only ~400 kms for a road trip from BC to Baja...
-Does anyone have any advice to source larger tanks in the Victoria, BC, Canada area?
-Are there better carbs/foggers than my OHG which could increase efficiency and range?
-Am I crazy to consider converting my vehicle back to gasoline for ease of filling on road trips? With the price of propane only ~80% the cost of gasoline here, I don't think I am saving much if anything.

There are very few shops locally that deal with propane, and they are mostly geared to maintaining old systems or converting modern fleet vehicles. I have received conflicting information regarding which has better mpg, which is cheaper, which will give more HP, etc.

Thanks in advance!!!

Tom68
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Joined: Mon Jun 18, 2018 2:46 am
Location: Australia

Re: Bought my first propane van

Post by Tom68 » Thu Mar 07, 2019 5:13 pm

I wonder if the engi e has been built for propane i.e high compression.
If not, dual fuel would seem a logical option.

themorb
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Joined: Thu Mar 07, 2019 3:04 pm
Location: Victoria, BC, Canada

Re: Bought my first propane van

Post by themorb » Thu Mar 07, 2019 5:48 pm

I highly doubt they changed the compression. I think in the 80s and early 90s here the shops just slapped on Impco and OHG systems and maybe advanced the timing. I remember people saying propane will give 20% less power but back then it was way cheaper so it was worth it.

I am a pretty good diesel mechanic but I am new to old V8s... dual fuel, can I stack the propane carb on top of a normal carb? This year came with TBI, so if I get the correct throttle body with injectors, I would need to reconnect the computer (currently the computer wires are cut and connected to a little black box labelled "propane computer fix.") But then the computer would need to get switched on or off depending which fuel I am running........

Or I forget TBI and forget computers and get a regular carburetor from an older model V8? But what is the point of running dual fuel if they are the same price? I realize propane is cleaner and easier on the engine but is it really worth keeping it for a camper van (ie. not my daily driver?)

Tom68
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Joined: Mon Jun 18, 2018 2:46 am
Location: Australia

Re: Bought my first propane van

Post by Tom68 » Thu Mar 07, 2019 8:19 pm

I can't answer a lot of that.

I thought it'd be worthwhile keeping the propane since it shouldn't be too expensive to do so and you'll have the range from both fuels.

20 odd % less power. I reduced that loss by using a spreadbore holley. Lp Gas through the primaries and petrol through the secondaries.

I have another car on separate rate dual fuel. The LP Gas has never been good on it, so between the time and money trying to get it right on top of the the power loss, fuel injection v vapor gas carbie, I'm thinking of pulling it off. So I understand your issue.

Frank
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Re: Bought my first propane van

Post by Frank » Fri Mar 08, 2019 9:18 pm

The propane system should not affect your gasoline economy so I would leave in place, especially since the previous owner invested a significant amount to convert your van.

Propane tends to be more expensive from places that sell low volumes of it. If there are any taxis or airport limousines still running on propane, I would check with them to find out where they refuel. I would also check with your local propane supplier (Superior Propane?) to see if you can get an account with them.

As for the propane tank, I would think that whoever converted the van installed the largest that would fit so I don't think there would anything to be gained by replacing it.

What is the model number of your the propane controller? I might have a copy of the installation manual that I could send you.

Since you have an OHG mixer, you might want to get the Franz Hofmann's Diagnostic Guide to Alternative Fuels. It includes a section devoted the tuning and maintenance of the OHG X-450 mixer.

C3H8
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Location: Winnipeg, Canada

Re: Bought my first propane van

Post by C3H8 » Sun Mar 10, 2019 3:33 am

I'm going to assume you have the 5.9L engine in that van. Let's face it, you just described it as a raised roof and weighing in at 7000 lbs. Realistically you aren't going to get great mileage from that vehicle no matter the fuel. The same set up in a 1/2 or 3/4 ton truck weighing 5500 lbs could only achieve 12 to 15 MPG empty on gasoline. Your best choice would be to locate some additional tanks if possible. From there you can do the necessary checks. New plugs and wires. Plugs gapped at .035 thou. Check the timing. You don't say what the computer fix model number or manufacturer is. Some fixes modified timing. Mixture check by a shop with a gas analyzer.

Tanks by the way, brand new are expensive. Probably 1000 to 1500 dollars. Good used ones are available. You just have to search. There are propane shops in BC still. Get them to check the fuel mixtures for you and clean the OHG mixer. Like most mixers they get gummed up. New tanks are available from a company called Maxquip. look them up. They have warehouses across Canada. Also National Energy (NEE) is another. Proquip Sales Inc. in Calgary may have some leads on new or used. They would all require specific measurements to suggest a compatible tank size. Lastly you can check the junkyards. They offer them cheap but be careful. The tanks need to be re-certified and any rust will be a reason to deny re certification.

As for fuel. Getting it in the US is not too hard but you do have to go off the main drags and find the local propane supplier. You can also get locations of filling stations on line. One location is here.
https://afdc.energy.gov/fuels/propane_l ... t?fuel=LPG.
Usually the best pricing is the local supplier over the actual highway fueling station. Baja will be where you may have a real problem getting fuel.

Lastly, you want better mileage. Slow down. Your type of vehicle and the 5.9L Dodge engine gobble fuel at higher speeds. 90 KM max. Anything over and it begins to really create drag. The mountains also will cause heavy use. The flat highways of the US will likely help but only if you are diligent in maintaining a reasonable speed.

Converting back to gas. An option, but I wouldn't expect a huge mileage increase. Also you probably have to buy new(used) equipment and the cost will not be cheap. You will need a complete system including lines, tank with pump and filters, maybe new injectors unless yours are still there and they may or may not work. Yes a carb setup would likely be cheaper to install.

themorb
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Location: Victoria, BC, Canada

Re: Bought my first propane van

Post by themorb » Mon Mar 11, 2019 11:38 am

Thanks for the replies everybody. I will do plugs, wires, cap and rotor as soon as possible. My computer fix is an Autotronic 8789, which I gather does not do timing control. I'm not sure what this means -- does my original Dodge computer still control timing, based on RPM and vacuum?

I found one shop so far on the island, North End Automotive in Nanaimo, who says he can help tune up my OHG system and can help me look for a used tank to add. But I am in Victoria, so it might be a while before I can get my van to him.

I have signed up for a Superior Propane cardlock account, so when the cards arrive in the mail I will see how much that saves me. Although that isn't going to help me on a road trip through the USA and Baja.

I realize that this van will never be "cheap" to operate, and will never get a long range between fillups. But there is a difference between looking for gasoline every 400 kms and looking for propane every 400 kms in an unfamiliar area with possibly no cellular coverage and a different language spoken.

If it turns out not to be feasible to fit another propane tank I might still consider switching back to gasoline. I picked up an original 360 throttle body with injectors and sensors for $50 off Craigslist, and I will keep my eyes open for a tank. The fuel lines are still on the van, and a new fuel pump is about $150 online. So that route might not be so bad after all. Although I do agree it would be a shame to pull off a perfectly good propane system which the previous owner went to considerable effort and expense to install.

C3H8
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Re: Bought my first propane van

Post by C3H8 » Mon Mar 11, 2019 1:26 pm

Whoops? A bit of a problem here. An Autotronics 8789 is made for GM vehicles not Dodge. Are you sure you got the number right. Depending on what they intended on the installation I guess you could adapt it to work on your vehicle as an O2 fix. That would be the only function the 8789 could be used for. It's other functions include a knock sensor and EGR fix which were't required on a Dodge.

Yes, timing is still controlled by the OEM computer taking into account RPM, TPS, Vacuum, etc. On that model of vehicle the timing is not affected even though the gasoline injection system has been disconnected. If you do have a code that turns the check engine light on it would likely be for injector circuit problem if the injectors have been disconnected, however that code might only apply to the newer styled port injection.

I'm told Murray Auto in Victoria still works on Propane.

themorb
Posts: 4
Joined: Thu Mar 07, 2019 3:04 pm
Location: Victoria, BC, Canada

Re: Bought my first propane van

Post by themorb » Mon Mar 11, 2019 3:01 pm

Yes, I noticed it that too, it says GM right on the module. Maybe that's all they had on hand, and they just used it for the O2 function? My CEL hasn't come on yet.

Murray Auto was one of the many shops I called and I can't remember now if they said they don't do propane, or if they don't do OHG... whatever it was they couldn't help me. I did find Searles in Victoria which said they could tune it up, but they couldn't help me with a used tank and he quoted me around $2k for a new one which is too much for me to justify.

Frank
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Re: Bought my first propane van

Post by Frank » Thu Mar 14, 2019 10:02 am

I found some Autrotronics 8789-6 (Super Fix 1) installation manuals and have emailed them to you. Autotronics recommended the PN5952 for 88-92 Dodge vehicles and you might come across one on sites like eBay. The 5952 only did fuel mixture control and interfaced with the engine to prevent CELs. There are probably some fuel efficiency gains to be made by optimizing the ignition timing but I'm not sure how easy it would be to change the factory advance curve. One alternative might be to use an aftermarket system like MicroSquirt for timing control.

If you're planning on travelling through the USA, truck stops like Pilot/Flying J and Loves have bulk propane. You can plan your trip by checking truck stop fuel availability and prices online. Pilot has a RV Plus charge card that gives you 10¢/gallon discount on bulk propane but you need a Good Sams Club membership to get the Pilot charge card. The longer term Good Sams cards include a merchandise certificate but it looks like you can only spend them at their stores (like Camping World). Pilot's MyRewards card only gives a 3¢/gallon fuel discount on gasoline and diesel. Either card is available to Canadians.

Another site you can try for propane stations is AltFuelPrices.com. This site used to work really well but it looks like the owner needs to make some coding upgrades.

The price of propane at these 2 truck stops is higher than that of gasoline right now but the situation might improve by summer with the reduced demand for heating fuel.

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