I am looking at a truck that has been refitted with a 460 the runs on dual fuel.

I have no clue on what type of motor mods have been done.

If I decided to remove the propane componated is this going to be a big problem, or is having both on it a plus?

Never owned a dual fuel, so I have no clue on what I am getting into.

Any help would be nice?

 

Sorry to see that your post is 6+ weeks old----I don't monitor this forum on a regular basis. You have probably done whatever you are going to do by now.

Should be no problem switching back to straight gasoline by removal of the LP system. You may have problems with dried out or gummed up carburetor and/or fuel pump if the truck has not been randomly run on gasoline. LP is a clean burning fuel---should be a clean engine. Probably need to reset timing and check plugs to gasoline specs.

Late response----but good luck.

Delta Dirt

 

What are plug and timing specs for propane?

 

I would have to go back to some of the older spec/reference files to offer you specific propane ignition information---but seems like we always retarded the timing 2--3 degrees from the gasoline setting. You also need to run a colder range plug than for gasoline (NAPA can reccomend the right plug).

I just bought a 89 model F-700 with a factory propane 429 engine this summer----have not run it much, but it runs so good I haven't checked anything on the ignition, etc.-----so I haven't gone back and refreshed my memory.

I would reccomend checking with most any reliable propane supplier (distributor status----not filling station)----most all of them have someone in service that can furnish reliable service information. Not many trucks running on LP at present----so hopefully you will find an "old timer" that's still into it.

If you don't find out what you specificaly (that ain't spelled right)-----holler back at me. If nothing else----I'll check the plugs in the 429 and also check the timing for you. I've been sorta down in my back here recently---and haven't been doing very much. I'll also be looking for some of my old service manuals and hopefully notes. (just might not get to it to quick)

I used several different mixers and vaporizer set ups----settled in on the Imco 425 mixer (carbreutor unit) and Imperial Model E vaporizer. That's the same set up that's on the factory 429----you will need these higher volume units on a 460 for sure. Make sure you have a large size air cleaner-----and keep it clean. Biggest problems I found through my experience was lack of air supply (no doubt with the 460, you will need plenty of air and gas). Really, at today's fuel prices---the propane economics look pretty good----especially if you already have your equipment.

Where are you located???-----Scott Petroleum at Itta Bena, Mississippi should have someone that could give you this information. Mauldin Supply (on Hwy. 80) in Jackson, Mississippi is a major LP equipment supplier----they used to have some real knowledgable people working with them (haven't had any contact in years with them).

Delta Dirt
Avon, Ms
662 335-5213

 

When I bought my truck it was propane only. I have since converted it back to gasoline using an aftermarket carb. But it is true that a propane engine is a clean engine. Probably last longer.

I had thought the ignition timing could be advanced with propane from what I remember. You can also run higher compression with propane. Do a search in the net to find out some info. Good luck.

 

If it is a true factory propane engine----it most likely is a higher compression set up----to make use of the higher compression on gasoline, you would most likely need to run a higher octane gasoline----if you are experiencing troubles on the new gasoline set up---the higher octane might be worth a try.

I may be wrong (may be thinking backwards) on the timing???---know we went one way or the other just a little.

I haven't fooled around with LP in several years---ran up on the used F-700 this summer and it rekindled my interest. We did operate a F-750 with a 361 on LP pulling a 700 bu. grain trailer for several years. "With enough air" and everything set right----I always felt like we got just as good power and mileage off of the LP as we did on gas runnning the Imco 425 mixers. I also ran several GMC pickups (350 engines) off of LP.

None of these engines were a match for the 429---let alone the 460. I always wanted a 460----but was tickled when I ran up on the 429 (they've got a real good reputation also). From an economy situation----we both probably need a .460 in a motorcyle.

Good luck---

Delta Dirt

 

Forgot to mention----but yr. model could also play into to whether you have the higher compression engine for factory propane----I am not sure when factory propane became available, but I do know the 1989 was the higher compression engine.

Maybe somebody else can give us some info on this----I'm thinking maybe late 70's or early 80's???? (just guessing---I don't know).

Delta Dirt