Dodge RamCharger Central banner
1 - 7 of 7 Posts

·
Registered
Joined
·
140 Posts
Discussion Starter · #1 ·
i was looking into doing a propane conversion for my amc 304 and was looking for advice and a place to find parts. i would like to be able to switch between gas and propane (like switching tanks). also any thoughts.
 

·
Registered
Joined
·
31 Posts
Its possible to do that. I have an impco system on my V10 and it works fine. I got it installed at the local propane dealer cause of the complexity of the system. On my 440, I have a straight propane system by OHG (it was duel fuel, but I have too much compression to run gas). I found the OHG at a wrecker and installed it myself. It needed to be rebuilt, but a mixer is easier to rebuild than a carb, and cheaper. To run both gas and propane, they build a switch that shuts off the gas and turns on the propane or vice versa.
 

·
Registered
Joined
·
1,560 Posts
Hey there fellow Bc guy. Me and Robo are both putting our engines together for propane. As to the question that was asked, if you can avoid going dual fuel you would be doinhg yourself a favour. IMPCO 300 is a dual fuel "carb" (I got a spare one) but with dual fuel you will not get the best of both worlds. Propane should have the heat risers blocked, higher compression is nice (if your rebuilding anyway), and the ignition curve is a bit different. More advance at the start and lower (<2500) rpm but less overal advance at higher revs. That's your biggest drivability problem with dual fuel. Cam is livable with dual fuel and 9.5:1 or less compression is livable too, but ignition is not good as a compromise. And sometimes the switching from one fuel to the other can be a problem if everything isnt done right.
 

·
Registered
Joined
·
140 Posts
Discussion Starter · #4 ·
thanks what needs to be done to a stock 304 to go straight propane. the reason i was looking at dual was the availibilty of propane here is kind of sparce
 

·
Registered
Joined
·
1,560 Posts
Dont know much about those engines (if it was a Internation Harvester 304 it would have hardend seats already) but you will likely need to do the heads with hard seats (or stock induction hard seats if there is such an animal), and probably new guides while your at it. Whatever you can do to inprove the comp ratio up to maybe 10:1 (if the bottom end is healthy), and maybe upgrade the ignition a little and change the curve a bit. Get a book from the library or on line for more details.
 
1 - 7 of 7 Posts
Top