LS 5.3 on propane?

I am interested in doing a got gotpropane kit on my 5.3. (LM7). i am currently looking at the edlebrock carb conversion kit with a timing module. that keep you coil on plugs. and uses cam sensor.. etc to control it and it come with 6 pre-programmed timing curve chips. but ive heard when using propane you have to sometimes change the timing up to 30 degrees. i think on the edlebrock site that it come with timing software. so you can make a custom timing curve. or change degrees. but i dont know if it would support the propane. timing change. has anybody had any experience with this. or can give me any info on it. i do not want to run the front distributor conversion. and i plan on decking the heads and raising the compression. so propane was my first choice. want to steer clear of spending money on a wiring harness for fuel injection and the tuning. and high octane fuel ;D. thanks, Nolan

do you already have the propane kit. it only a few hundred to do the factory harness and tune

Heres a few ways to look at it...

You will have just as much money in all the propane crap as a harness and comp.

You will still be limited to around 400 hp with pane, you can get 500 hp with the right mods on 93 octane.

Heck, u can get 400 hp with just a cam....so ive been told

Gas is on every corner 24/7, pane isn't

If u ride for a day u need atleast two pane tanks that will take up a lot more room than a regular gas tank

The Edelbrock LS manifold kit has a timing chip that works with propane. We have provided the fuel systems for several LS motors.


Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212
877-403-7827
205-591-2267, fax
[email protected]
[email protected]
www.alternatefuel.com

cash talks said:

do you already have the propane kit. it only a few hundred to do the factory harness and tune

Click to expand...

no not yet. im just looking at long run cost. since i will be making a high compression motor i will need high octane fuel. and it seems that gas prices are going to keep on rising. and i would have to figure out how to get a speed sensor for the fuel injection harness. and i will have to buy the harness and ecu. and intake. (a LS2 if i kept EFI) and fuel rails. since my motor is just a long block.

altfuel1991 said:

The Edelbrock LS manifold kit has a timing chip that works with propane. We have provided the fuel systems for several LS motors.


Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212
877-403-7827
205-591-2267, fax
[email protected]
[email protected]
www.alternatefuel.com

Click to expand...

how much does a dual mixer kit cost? and how much horsepower is it rated to? i should be making about 420-500.

A dual mixer setup will handle 650 horsepower. There are engines running 13/1 compression on propane. Check out the rail buggy photo on my website. He is running a 13/1, 235 hp stroker engine.
The cost is $1800.00 complete with all new components including new base plate, LPG hose, fittings and tank brackets. Tanks are not included but we do sell them also.

The Edelbrock LS intake kit costs $775.00 including the ignition control.

Let me know how I can help.


Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212
877-403-7827
205-591-2267, fax
[email protected]
[email protected]
www.alternatefuel.com


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That's a little to pricey for me. I think ill stick to edlebrock kit from jegs for $670. And the propane kit for $1000. And it will not support my engine. I guess. Ill just put the nitrous. To it. :****:. Lol. I don't need all that power anyways. Lol

That is a good price on the manifold kit. I make 10% on those and that is less than my cost.
A single mixer kit complete with one set of tank brackets runs $900.00 plus shipping. The standard kit is good for about 325 horsepower.
In most cases on a stock or mild 5.3 engine you are good for about 5500 rpm and the single mixer will work fine. I have a lot of small blocks running
single mixers with no problems. You can always upgrade to dual mixers later when your engine needs them. The torque on the low end is enhanced on propane either way.

In case you are wondering why the dual mixer setup costs so much, that dual mixer air cleaner is made for us from 3/16" aluminum plate and no one else has it. No other air filter assembly will fit on both mixers and use a standard air filter element. The dual adapter is also unique and expensive.


Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212
877-403-7827
205-591-2267, fax
[email protected]
[email protected]
www.alternatefuel.com

Okay. I have another question. The reaon. It will only support 325 hp. Is because it cannot supply enough fuel? (Propane) . I know you you can re-jet a carburator. To supply more fuel. Can the same principle be apply to propane as in the mixer? Or drill it out to supply more? Just wondering. If there would be any mods to be able to run 450 HP with a single mixer. Cause I am on a tight budget. Thanks. I'm a noob when it comes to propane

I have the Edelbrok intake and also a propane kit with a 425 mixer. I got it with a buggy but am going a different route.

The Impco mixer is designed to flow the correct amount of fuel and air to supply the BTU's needed for 325 horsepower. The fuel flow can be increased(richened) but that will not help since the air flow cannot be increased to match. The mixer is calibrated to maintain the correct air/fuel ratio throughout the rpm range.

The OHG X450 mixer is the same way.They even went as far as to remove the power mixture adjustment from the housings and made it stationary.

I would suggest running one mixer starting out and see how it performs. Unless you are running above 5500 rpm alot I think you will like how it performs. Lets say you do have 400 hp, the chances are pretty good that it will not make that kind of power below 5000 rpm. Below that rpm the torque is what moves you over those rocks and ledges.

Glad to see you asking questions. There is a lot of misinformation about propane that sometimes causes unnecessary grief. Propane is absolutely the most simple and trouble free fuel system there is for off-road use especially for the money and it is a clean domestic fuel.

well i think the highest ill go will be 6000 RPMs. and i may be on rev limiter every once and awhile. ill do the single and see what happens. ill keep your number if i need a second one. thanks.

one more question. say i get a propane kit. and it comes with a single 425 impco. like from matth_85. who has one and wants to sell. and say im not happy with it. and will not supply enough CFMs for my engine. if i make my own adapter for 2 impco 425s. what else will i need? another converter? and ive heard people talk about shut off valves. or line locks for the propane?

What about forced injection instead of dual mixers? I thought I understood that the 425 just can't flow enough air, but can supply enough fuel.

ih8mud34 said:

one more question. say i get a propane kit. and it comes with a single 425 impco. like from matth_85. who has one and wants to sell. and say im not happy with it. and will not supply enough CFMs for my engine. if i make my own adapter for 2 impco 425s. what else will i need? another converter? and ive heard people talk about shut off valves. or line locks for the propane?

Click to expand...

To change from a single mixer to dual mixers you will need a second mixer, vaporizer, extra vapor fittings and hose(unless direct mounted), additional fuel line and fittings to connect to the second vaporizer. Only one vacuum lockoff valve is needed. If you are already running an electric lockoff most of them will flow enough for two vaporizers.

The adapter can be made. We have them in stock. We also keep the dual mixer air filter assemblies.

Let me know how I can help.

Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212
877-403-7827
205-591-2267, fax
[email protected]
[email protected]
www.alternatefuel.com

Markrobinson said:

What about forced injection instead of dual mixers? I thought I understood that the 425 just can't flow enough air, but can supply enough fuel.

Click to expand...

I assume you are talking about propane injection. We install that on current model vehicles with fuel injection. The OEM power control module and sensors are needed as well as the harness just like on gasoline. We actually set them up as bi-fuel to run on gas or propane.

As far as the 425 or X450, richening up the fuel is the same as going to bigger jets in a gas carburetor. If the ratio is not correct you are just wasting fuel and causing excessive heat in your engine because that fuel is still burning as it goes out past the exhaust valves.

Buddy

http://www.ajusa.com/details/index/398/0/0/EDE%207518 check this out. i could use this and put dual mixers on it. and wouldnt sit so high.

ih8mud34 said:

http://www.ajusa.com/details/index/398/0/0/EDE%207518 check this out. i could use this and put dual mixers on it. and wouldnt sit so high.

Click to expand...

That looks like a much cleaner setup than that goofy think pictured above... But you would need 2 throttle plates and the appropriate linkage for them.

yes. i know everyone has said "Go EFI" or "they made those engine fuel injected for a reason" but i think propane will be nice and simply. and i wont have to worry about trying to hide wires. can tune it myself, at home! . . now all thats left is funds. lol

As far as the dual propane kit pricing it would probably be a little cheaper to use the dual quad manifold and would be about 2" lower profile. You would not need the adapter or air filter assembly just a second throttle plate. You would need to get a linkage kit to go with the manifold and standard air filters could be used.

You still can't beat a propane setup for the money or simplicity. The entire fuel system has no wires. Ever talked to anyone with an "electronic" engine that broke a sensor, wiring or connector in the woods?

Buddy