Thread: hot ballast resistor and timing with LPG

Originally Posted by jasper110

is it normal for the ballast resistor on a distributor to get real hot (ie; finger burning) and do you have any suggestions as to where to mount it and the numpty garage fitted it near to the rad. should it be away from the coil?

also what do you set your timing to when using;
3.5 low comp V8 with LPG (i believe its 8deg BTDC at 1000rpm vacuum disconnected and pluged.)

NO!.....it certainely shouldn't get that hot!

For running a low comp 3.5 on unleaded 91 RON octane.....setting should be 6 BTDC @ <800 rpm vacuum plugged.

But.....LPG will run heaps better with more initial advance than that , so.....

set the timing to 12 BTDC @ <800 rpm vacuum plugged ......

But then that's too far advanced for 91 RON octane , so fill with Ultra Premium 98 RON octane [such as BP Utimate or Shell Ultra etc]


......a friend of mine has this same engine and that's the way we've found it runs best.

check and make sure you have the right coil......it should say on the coil if it needs a ballast......

depending on the type of ballast resistor they are ment to get hot as some have a direct voltage/resistance co-efficient so that the more voltage you apply to them the more they resists. If you have one of these and your voltage regulator is set high (14.2v+) it will get hotter as its working harder to drop the voltage back to where the coil needs it to be.

If your resistor is near another hot spot it will get hotter again. It doesnt really matter where Its mounted physically but the shorter you make the wiring run the better of you'll be.

Ive never had one so hot that I couldnt hold it with bare fingers but

Not knowing how deep your pockets are...
The best thing for LPG is to fit a good electronic ignition module and a matching coil.
The spark gap is then increased dramatically which gives much better combustion.
Most will not utilize the ballast resistor as they need a good 12v