Electronic Ignition = Cool?

[napa 1]

I installed a petronix elect ignit into my distributor this past weekend. The engine is very smooth and responsive. The interesting thing is that where before I'd seem to be running with the temp needle at the 3/4 mark (can't recall what that temp is).... since I installed the elec. ing. its been running closer to just above the 1/2 mark. A fair bit cooler. (generally the same outside temp, the same weather conditions, and same driving route). Is it possible that the car could run slightly cooler with electronic ignition? Or do I have something else going on?

 

[Nickodell]

The only way I can see this happening is if you corrected a late ign. timing at the same time. A late spark can cause overheating because a) the temperature of the exhaust is higher and b) because the engine is working less efficiently it needs more throttle for any given load; i.e. burns more fuel per minute.

Even so, I fail to see how the engine does not simply heat up to the thermostat opening temperature as before. The only way you might notice it is if it was running on the edge of overheating before and the late timing pushed it over the edge.

 

[napa 1]

When running my alpine, as I drive it generally slowly heats up to a point at about the 3/4 mark, and then I assume the thermo opens at which point the temp comes back down, difference is now it comes back down and settles at a lower temp than it did before. You're probably right about inadvertantly correcting an ignition timing issue - since I'm no mechanic the timing could have been way off. I'll have to go over the forum info on setting the timing (maybe try your vacuum guage method)

 

[Nickodell]

Possibly you have a faulty thermostat that opens at the right temperature (I'm not sure what "3/4" means; the opening temp should be around 85-90C, 185-195F) but then sticks open; i.e. doesn't cycle to keep the coolant at a reasonably constant temp.

Remember when you do the vaccum ignition timing that this only checks it at a fast idle, i.e. before the mechanical advance kicks in. It is a good start but to be correct throughout the speed range you need to check the advance at varius speeds. You can't do this with the vac. gauge, you need a timing light and degree marks on the crankshaft balance weight.