Mechanical advance.....timming

[graham]

Running both petrol and LPG, I need to compensate the amount of advance for each fuel. Waiting for a reply from MSD on an advance controller.
Some people I've spoken to suggest that I do away with the Vacuum advance and use Mechanical advance. Counter weights and springs.
Can this be done on a breakerless distributor?
Has anyone done this?
How effective is the mechanical advance?
TIA.

[reddog]

While I don't know how one would set it up for dual-fuel, you already have mech advance in your stock distributor and it is just a matter of tweaking the advance curve with different springs.

Kerry

[graham]

<BLOCKQUOTE>quote:</font><HR>Originally posted by reddog:
you already have mech advance in your stock distributor and it is just a matter of tweaking the advance curve with different springs.
Kerry<HR></BLOCKQUOTE>

According to Haynes (50029) I have a Solid State Ignition (SSI) system. Page 5-11 shows some pic of my distributor, no mech advance. So I guess its either the MSD timing control or a distributor swap. Thats if mechanical advance will be effective :confused:

[reddog]

I don't have the Haynes book - you don't have the ford duraspark system??

Kerry

[andy d]

alot of cars in the old days 20s and 30s had cockpit controlled spark advance. the model t frinstace.say you backed off the retainer as you would do to adjust the timing. you turn the body of the dizzy, clockwise a bit and back.why couldnt that be done with a cable? i would think it would be possible to rig some sort of push /pull mechanical choke type cable to the body of a dizzy that would give cockpit controlled spark. saying it and doing are 2 different things. please post your results

[Sgt. Dave]

I'm pretty sure you have a mechanical advance, unless you have full computer controlled ignition. Easy check...Pull the dist. cap off, and see if you can twist the rotor \shaft. Should rotate about 20-30 degrees, and spring back when released. Either MSD or Jacobs omni spark controller will do what you want

[Sgt. Dave]

Thought I had this somewhere http://www.jacobselectronics.com/products/timingcontrols/timing.htm

[graham]

<BLOCKQUOTE>quote:</font><HR>Originally posted by andy d:
i would think it would be possible to rig some sort of push /pull mechanical choke type cable to the body of a dizzy that would give cockpit controlled spark. saying it and doing are 2 different things. please post your results<HR></BLOCKQUOTE>

Andy, I've done as you have suggested, Model T technology, not accurate enough for 82 Jeep technology. Though the principle works, its still not getting the best out of both fuels, which is the aim.

[graham]

<BLOCKQUOTE>quote:</font><HR>Originally posted by reddog:
I don't have the Haynes book - you don't have the ford duraspark system?? Kerry<HR></BLOCKQUOTE>

Not sure about the Duraspark, Haynes doesnt go into that detail. Pic's of the SSI system difinitely have no counter weights.
Can vaguely recall not seeing any mech advance on mine when I cleaned it out some time ago.
There is another breakerless dist pictured, in Haynes, that has mech advance. This has a large trigger wheel. This dist has quite a large vac advance setup. My dist has a quite small trigger wheel, and a smaller vac setup.

If your not :confused: I am :confused:

[Iron Horse]

Graham, I ran across Iwema LPG timing advance (http://www.iwemalpg.com/TAP.htm), while I was looking through the December issue of Land Rover Inernational (pg. 184) and I remembered your post. I don't know if this is what your looking for or not. Their main web page seems to have quite a bit of info on LPG systems.

[ December 18, 2001: Message edited by: Iron Horse ]