I worked for several years as a mechanic on a fleet of CNG/unleaded police cars. Did not see the valve seat problem some have mentioned here. However I would stay as for away as possible from any conversion to CNG. It works fine on an engine designed for only CNG fuel.
A conversion will work but most likely you'll be unhappy with it. If you must do it here is my advice:
#1 you will need to advance the timing an additional 8-10 BTDC. If you don't it won't run for crap.
#2 You will need to change your plugs every 10k miles and only use top quality plugs, wires & coil. CNG fuel needs every bit of fire you can get out of it to run well.
#3 DON'T pump the gas when starting!!! It will have a tendency to backfire through the carb(injector depending on what system you use). Our shop record was about 100 ft from the car where the airbox landed.
#4 If you have to pass a state emmisions test switch it over to unleaded for the test. Unless the ignition system is perfect CNG runs in a constant state of misfire & will fail the emmisions test for excessive HC. switch it to unleaded & it will sail through. I lost count of how many cars the cops brought in for emmision test failures that I just switched fuels & retested OK.
#5 Look up GFI or Mogas. they are 2 of the major manufactures of conversions. I think they are both out of Canada. they should have some good info on how to make the systems work. Of course they will blow lots of sunshine up your skirt to make you think the systems are the greatest thing since sliced bread. :rolleyes:
#6 Pray always. You may even make it home from your drive occasionally!! :p
Good luck
