I like my vehicles to look like junkers but run good. There is so much to worry about when I own a nice looking one seeing I'm a class "A" perfectionist. I try to fight against my condition, but if something isn't just right it bothers me. Now I'm getting better at ignoring less important stuff and I'm no longer a slave to a "list".
On mechanical stuff, I used to be a fan of ported vacuum advance, but now that I better understand vacuum advance I'm starting to respect vacuum advance from manafold vacuum. I tried it on my truck today and whoa what a difference. My exhaust fumes smell more like they should instead of that rich smell. My carb is from a 1976 firebird and there was a place for manafold vacuum I had to pull out the little screw blocking it and install a vacuum port.
I mentioned the year of my carb because it is an emission carb and ported vacuum is an emission thing. Most manufactors used manafold vacuum before the crackdown on emissions. The difference is ported hole is above the throttle plates and the manafold vacuum is below the plates.
Ported advances the timing when the throttle plate is cracked open a little. Vacuum increases to a certain point and then drops off before the mechanical advance takes over at a certain rpm and wot. Maniford vacuum doesn't increase, but is already there and then it drops off the same as the ported does. The manifold port gives more vacuum at idle and low rpm cruising speeds and causes the air/fuel ratio to burn more completely providing a snappier throttle response and better mpg.
Manifold vacuum isn't for newer vehicles and most of them are electronically advanced anyway. I used to think manifold vacuum just added to your initial timing adjustment and then just hung around, but that isn't so and that there was the biggest thing I misunderstood. You can double your initial timing without pinging and hard starting because it decreases. I'm just learning all this, so if I'm not explaining it quite right (why do I think I always need to explain things) please bare with me.
Overall though, my truck runs way better and I need to also replace expensive e3 snakeoil plugs with just regular plugs with a decent heat range. E3 plugs seem like they somehow advanced my timing a little- maybe because they have a smaller air gap than what is recommended and the gap isn't adjustable. Some of mine are misfiring and it threw me off temporarily. I got to looking on the web about e3 troubles and I found a fair amount. I'm glad I never had to pay for them and will probably be using mostly stock plugs in the future.
My 1980 LTD had rapidfire plugs in it when I got it 13 years ago. I never changed them because they seemed to be doing a good job, so maybe rapidfire isn't snakeoil.
