Propane Timing

[altfuel1991]

I have had quite a few inquiries lately about the proper setting for timing a propane engine so I am posting this to help anyone that needs this info. I also attached it as a document that can be downloaded.

Setting Timing for a Propane Engine



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.
__________________
Propane Systems: Buddy: 877-403-7827
www.alternatefuel.com [email protected]

 

[Rokcrler]

Re:

Awesome tech!
Thanks Buddy

 

[Eddyj]

 

[mikemounlio]

Now who wants to come show me how to do all this? Brand new to tuning here.

 

[altfuel1991]

It is easier to perform this operation if you have an adjustable timing light since only the zero mark needs to be painted on the balancer.

 

[gsell]

It is easier to perform this operation if you have an adjustable timing light since only the zero mark needs to be painted on the balancer.

You can use this tape from Summit as well.....

http://www.summitracing.com/parts/sum-162591?seid=srese1&gclid=CjwKEAjw0-epBRDOp7f7lOG0zl4SJABxJg9qisRGaFhuboMUAeuh0gEKA0n_2XzikSG_XOClcft95xoC8Jbw_wcB

 

[zukimaster]

Wow, kinda the opposite of what I was thinking, I have never had any dealings with propane, kind of thought is was a slower burning fuel, that would need more timing instead of less.

 

[altfuel1991]

You basically have to disregard what you know about gasoline timing when working with propane. It has a very flat burn rate meaning there is less need for gradual timing increases as rpm goes up. It is ready to burn when it enters the engine unlike gasoline that enters as a liquid droplet and is sucked into the cylinder where is is compressed and heated up. At that point it converts to vapor and is ready to burn. That is why less overall timing is needed for propane even though it is a higher octane fuel.

 

[mikemounlio]

I got the timing to a total of 35. I have a bracket in the way of the distributor so i cant get it down lower until i get a new style bracket. It is running very good tho. Just a bit touchy to get going. Once fired up its golden.