74 vert

Last week I set my timing at 12 degrees after installing my mallory system. Thing is, my Haynes manual says that it should be set at 4 degrees, should I have set it at 8 degrees for performance? The engine seems to me running ok at 12 degrees. Should I leave it at 12 or back it down?

lars

Initial timing is irrelevant. You need to set it up for 36 total (with vac advance disconnected). At 36 total, your initial will usually come out to about 12-16 degrees.

Vetterodder

If you're not having any problems with it at 12º, it's probably ok as long as it hasn't pushed your total timing too high. Keep in mind that what you add to your initial is also added to the total. Generally, total in the 36º-38º range will provide the most power. Going much higher than that can cause power to fall rapidly and in some cases causes serious damage to the engine. A lot of guys are fooled by the increase in low rpm power and don't realize how much total power they actually lost to get it. Ideally, curve the distributor so you can run both optimum low rpm advance AND optimum high rpm advance and have it come in as soon as you can without experiencing any problems like pinging or surging.

wayne_69_427

The more timing the better until the starts to ping. More timing gives the air/fuel mixture more time to burn in the combustion chamber.

Vetterodder

Not necessarilly. Many engines will allow much more than optimum total timing without any pinging. An example of this was a 396 Chevelle I had years ago and race at the strip weekly. Looking for lower et's, I played with the initial timing and cranked it up some. It "felt" more powerful so I added even more initial and it "felt" even more powerful in normal driving. No pinging or any other problems resulted. I just knew that my next trip to the strip would yield my best times ever. Instead though, my et was off by over .2 secs and my mph was way down. Some more experienced racers helped me out and, upon learning that the only change to the car had been timing, had me reset it to where it had been before. My next run had me back to where I'd been before. I finally figured it out and recurved the distributor so that I had all the benefits of increased timing at lower rpm AND the right amount of timing at high rpm. The end result was better performance under all conditions and in all uses. BTW, this engine was pretty much identical to an L36 except for it's smaller bore.