vinyltop70
Oct 30th, 03, 11:52 PM
I have a 350. I found out that the cam is a high performance cam. I have it adjusted to a stock cam. Should I put the timing to 10, and then get the carb adjusted or should I put the timing to 13 and then get the carb adjusted?
Thanks
SWHEATON
Oct 31st, 03, 10:50 AM
Most mild to fairly stout perf cams require anywhere from 15-20eg btdc (most16-18) intial advance with vac advance plugged @ idle with no mech advance. The total advance including your mech advance with the motor at approx 3k rpms should be apporx 34-38 btdc. You motor must be running very sluggish/mushy because your initial timing is too retartded for a perf cam and needs to be advanced.
Stock timing settings are only for factory stock cams and can't be used for any perf cam. Perf cams always need to be dialed in via road testing,dyno,etc for the best timing setting for that particular setup. It's an oversite on many perf cam mfg that they don't tell you this in the
installation instructions that come with the cams.
Set your initial timing to lets say 15-16 btdc,hook up your vacuume advance when done and then road test to ensure it runs well and does not detenate/ping. If it runs well with no ping then advance it a few deg more,road test,and if it runs well with no ping leave it there because you would be at approx 18 deg btdc at this pint which should be sufficient. But if it pings then back off the timing 1 deg at a time until the ping goes away and that will be your sweet spot for the timing your motor setup and fuel quality will tollerate.
Now as far as your carb goe's it may or may not need to be re-jetted,it depends on your setup.
If your running headers with a free flowing exhaust,aftermarket intake,fairly hot perf cam then you could likely benefit from a slight inc in jetting.
Check your plugs at light throttle cruise and then after a full power run and if lean increase you jet size,same goes for if it's rich but you would obviously decrease the jet size then.
If any jetting adj are made then you should re-do the above timing test beccause this could change the point/timing at which the motor could ping.
Scott