Propane BaBy!!!

[race4fn]

Looking for some advice on kits that are out there and available for a sbc, the motor is a stock 350 with vortec heads running an edelbrock performer intake, full lenght headers....maybe 300 hp or so..
I have been looking at the got propane kit thats good to 420 hp, any advice on this kit, how much tuning etc...

[twiztedzuki]

nashfuels is best place to buy, impco 425 mixer, model e convertor and a vacuum lockoff if u choose to run a lockoff

[yellowjacket]

X2 on bill nash.... he can set u up w everything. Or like me, u can mix and match. I dident need the goofy chrome air cleaner or regulator mount, but I did want a splitter and fttgs for 2 tanks, and electric shutoff vs vacume.
If for some reason u do buy from him, be kind and tell him u know me(rob mickelson) as I'm running nash fuel flags werock '12 ..

Sent from my LS670 using Tapatalk

[race4fn]

Iam a complete newb to propane, what will I need besides the kit and a tank?
What about how much propane does it use compared to gasoline? I would use between 6 and 10 gallons of gas on a typical weekend.....

[Hope Springs Hauler]

Propane use is almost equivalent. So in you use 6-10 gallon of gas, you'd probably use 7-11 gallon of propane. The common tanks (forklift) are 33lb and are roughly equivalent to 8 gallons. At a minimum, I would think about carrying 2 tanks on the vehicle and having 2 spares on the trailer.

[race4fn]

thats not bad at all, what about tuning the propane system, is it anything like a carb? or is it just install and your ready to go?

[Hope Springs Hauler]

For me it was 2 screws/adjustments. There is an idle mix and a main. For the main on offroad use, keep turning it richer till you get no more power then turn it back a fuzz. This method wasn't scientific, just seat of the pants and it worked for my micro 1.3l

[race4fn]

Sounds easy enuff...lol
Where do you get your tanks filled?
I called cincinnati propane and they said about 35 for a 33 pound tank like what's on a forklift....is that about normal? Over 4 dollars a gallon?

[Hope Springs Hauler]

Originally Posted by race4fn

Sounds easy enuff...lol
Where do you get your tanks filled?
I called cincinnati propane and they said about 35 for a 33 pound tank like what's on a forklift....is that about normal? Over 4 dollars a gallon?

Last time I went to Uhaul. It was $3.5ish a gallon

[carwash]

Propane sucks... the advantages do not outweigh the pain in the ass that it brings.

If you are running a 14:1 compression engine that needs race gas, it's great cuz it's rated at about 110 octane. That makes it worth the 3.50-4.00 a gallon since you can't get 110 gasoline for lest than at least 7.00 a gallon. If you have propane heat at your house, you can get a wet tap installed on your tank and pull from there, and get it from whatever your lock-in rate is. (mine is about $2.25 a gallon). That can save you a lot of money, but still is a pain.

It only runs at about 85% the efficiency of gasoline. So it takes you 10 gallons of pane to get you what 8.5 gallons of gas does. This also means that a 300hp motor becomes a 245hp motor, etc. And that's only if you have your mixer tuned perfectly and have no vacuum leaks anywhere at all. With any vacuum leaks or an improperly tuned mixer, it will drink the pane about as fast as you can imagine. Also, it doesn't run at high rpm's like gas does. Even if your mixer is rated at 600 cfm, etc, that is only for short spurts, like 20 seconds, etc. YOu will find that on serious hammer down hill assaults, you will be starving for fuel. That's also not good for your motor to run lean like that, especially at higher rpms.

Other pain is having to carry a **** ton of fuel with you when you go on a 3 day wheeling trip, especially when running it on a small block V8. You will have to run 2 tanks on the rig for sure and have at least 4 at camp if you want to wheel for more than 2 days. There is something to be said for being able to run to the local gas station and filling up.

I am by no means a propane expert, but I have some decent first hand experience with it. I think it has its place on toyotas, samurais, etc. Smaller cubic inch engines that draw less fuel. I know toyota guys that swear by it and won't run anything else. But I have never heard of any one running it on a v8 for more than 1 or 2 seasons before getting fed up with it.

Just my 2 cents, take it or leave it.

[blazerbrad]

78Buford switched from a carb to propane a couple of years ago on his F-250 with a moderately built 469 (desktop dyno estimates 340 HP/525 FT-LB on the carb...take it for what it's worth but that is the best guess). The truck is probably 5,500-6,000 lbs. with 1-tons, 42" Swampers, and a C6/205/4.10 axle gear combo so not much gearing at all. He lost some top end power but the low end and throttle response are much better, but he contributes that from going from an almost 800 cfm 4-barrel carb to a 425 cfm mixer. However I did ride with him during a mud bog this last Memorial Day and the engine was able to spin the 42's through pretty thick mud around 5,000 rpm the entire 200' pit, so that is some pretty good wheel speed (about 1/3 the trucks got stuck, including a Super Duty on 38's with a wicked diesel).

He is very happy with the setup and has no plans to ever switch back after a couple of years of running propane. He has stated that in hindsight he would have built the engine with a higher compression rate and went straight to propane to begin with.

On a typical trailride he gets into the 2nd tank on the first day. We spent 2 days in Slade/Red River Gorge running all over on Booth's property one day and the "public" area (Sandlick) the next, so quite a few pavement miles also. Believe he was still on the 3rd tank at the end of the second day but it was close to empty. He carries 4 tanks on the truck all the time (he tends to be a little excessive on this, and has plenty of room) and another 2 in the tow rig. Granted, you can't count on having the tanks refilled when out of town so that is a concern, but has never been a problem.

Regarding this statement from Carwash:

"It only runs at about 85% the efficiency of gasoline. So it takes you 10 gallons of pane to get you what 8.5 gallons of gas does. This also means that a 300hp motor becomes a 245hp motor, etc."

This is only partially true. Technically propane has less energy content (BTU's) than gasoline so "efficiency" is not really accurate. You need to use more propane to equal the same power content as gasoline. So yes, the example of using 10 gallons of propane to equal 8.5 gallons of gasoline is accurate BUT the horsepower of the engine should remain equal regardless of fuel. The 300hp with gas but only 245hp with propane is only accurate if the fuel rate is identical (use 8.5 gal. of gas and only 8.5 gal. of propane)....increase the equivalent fuel rate when going to propane and you get the power back.

[race4fn]

lots of usefull info here, thanks to all.
I am going to propane simply because my carb sucks...lol
i would put on fuel injection but iam trying to make everything as uncomplicated as possible, last thing I want to do is add a computer and extra wiring.....hell the elec. choke scares the hell outa me....lol

[yellowjacket]

Your reasons are the same I had for going propane. I built a f/I harness and had no probs, but I always wondered if I did have issues w the ecm, or if I melted a specialty plug, or if it just wouldent run right, I would be at harlan and not wheelin w my buddies..

To me, having to run two bulky tanks and maybe(?)loosing some power is well worth it, cause if my motor wont run right, or start ,I can diagnose it w a timing light, a dcv meter, and a corn dawg in my other hand. And that is a big selling point to me.

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[race4fn]

K.I.S.S. kinda try to follow that a lot, anything iam taking miles back into woods, rocks, mud, water, and trees;) i want as simple as easy as possible..my motor, trans, drive shafts and axles i can get parts from anywhere, if the propane craps out my trusty, but sucky 4160 is always in my tool box...lol

[Nuts]

Had propane on the v6 in my last buggy and loved it. I had originally tried to set it up with FI but I'm cheap and wiring retarded so I went with lpg. Figured if I couldn't make it run at home in the garage there would be no way I could fix it in the woods. As for loss of power I can't say because I moved up from 4 to 6 cyls when I switched to propane.