-
Help Support Hardline Crawlers :
350 chevy on propane
- Thread starter shawn213
- Start date
altfuel1991
Well-Known Member
- Joined
- Mar 28, 2010
- Messages
- 271
Here are some general guidelines for setting the timing.
On most applications, the timing should be a total of 30 degrees(base and centrifugal) with all of it in by 2500 rpm. What we normally do is disconnect the vacuum advance, run the engine up to 2500 rpm, set the timing at 30, lock it down, then let it idle with the vacuum advance disconnected. See what your base timing is running. If it is low,4-10 degrees for example, you can alter the centrifugal to lower that number and increase the base, still keeping a total of 30 degrees. As you increase the base timing check to see if the engine spins and starts smoothly when hot. If you reach a point that the engine bucks or loads the starter, back off about 3-4 degrees and that is your base timing. Subtract that number from 30 degrees and that will be the advance you need to have. This will provide a good start, strong idle and proper advance curve. We have had some engines run as much as 20 degrees base timing but 14-16 degrees is normal. The vacuum advance should be connected to ported vacuum and have no more than 10 degrees. This helps fuel economy at light throttle positions.
The only adjustments to be made are on the idle mixture and idle speed. Set your timing first, then set the idle mixture screw for the smoothest idle and last set the idle speed at the throttle stop screw on the base plate. If you run into any issues, give me a call.
If you are starting with used equipment there might be other issues to deal with.
__________________
Propane Systems: Buddy: 877-403-7827
www.alternatefuel.com [email protected]
On most applications, the timing should be a total of 30 degrees(base and centrifugal) with all of it in by 2500 rpm. What we normally do is disconnect the vacuum advance, run the engine up to 2500 rpm, set the timing at 30, lock it down, then let it idle with the vacuum advance disconnected. See what your base timing is running. If it is low,4-10 degrees for example, you can alter the centrifugal to lower that number and increase the base, still keeping a total of 30 degrees. As you increase the base timing check to see if the engine spins and starts smoothly when hot. If you reach a point that the engine bucks or loads the starter, back off about 3-4 degrees and that is your base timing. Subtract that number from 30 degrees and that will be the advance you need to have. This will provide a good start, strong idle and proper advance curve. We have had some engines run as much as 20 degrees base timing but 14-16 degrees is normal. The vacuum advance should be connected to ported vacuum and have no more than 10 degrees. This helps fuel economy at light throttle positions.
The only adjustments to be made are on the idle mixture and idle speed. Set your timing first, then set the idle mixture screw for the smoothest idle and last set the idle speed at the throttle stop screw on the base plate. If you run into any issues, give me a call.
If you are starting with used equipment there might be other issues to deal with.
__________________
Propane Systems: Buddy: 877-403-7827
www.alternatefuel.com [email protected]
Nuts
Well-Known Member
There should be a "sticky" propane tech thread, seems like once a week somebody is asking about it. :****:
tommyswheelin
Well-Known Member
- Joined
- Dec 21, 2011
- Messages
- 230
What about troubleshooting. Mine just got hard to start. Sometimes I have to bleed off the line before it will start. Also it sounds to its leaking pressure by the cone in top of the carb mixer after I stop cranking the motor. Any idea's
altfuel1991
Well-Known Member
- Joined
- Mar 28, 2010
- Messages
- 271
tommyswheelin said:
It sounds like the vaporizer needs to be rebuilt. There should never be any propane coming out of a vaporizer if the engine is not running or if the vapor hose to the mixer is disconnected. Impco(as well as other) vaporizers require a vacuum inside the vapor hose to move the secondary diaphragm and push the lever down and allow fuel to flow.
