[AD removed for archives] ------------------------------------------------------------------- Are you a lottery player?Play smarter! Improve your odds and detect winning patterns. Access the best kept lottery secret on the Net. Easy to use! caadVJPbOyW3Na/Lottery Vault ------------------------------------------------------------------- Top dead center is when both valves are closed and turning the cam either way begins to open them. On BDC, both valves would be fully open. Most engines fire the sparkplug before the valves are fully closed @ tdc to get a scavenge effect to better fill the cylinder. The motor runs better on more advance, aka, 38 degrees btdc, but it will be very hard to start at such a setting. So a few degrees are built in (vacuum) to let it get going then the mechanical takes over and adds to the already added vacuum. ie; 7 degrees vacuum + 27 mechanical = 38 degrees total. At what rpm the total advance happens is very important on how the engine responds. The mechanical is built in and can be changed with different weight springs or altering the rotating weights within the distributor. The vacuum usually can be adjusted on some distributors via an allen wrench inserted in the vacuum canister. This is about my limit on timing adjustment. Earl and Don D have the skinny on this sort of thing. I usually can get a motor running without losing my eyebrows, but I'm a shade tree guy at best. Hope it helps. Joe [Non-text portions of this message have been removed] [AD removed for archives] ------------------------------------------------------------------- Buying or Selling a Home? Get the Facts Before Buying or Selling! Get a FREE Home Valuation TODAY! caadV2pbOyW3Nf/Home Valuation ------------------------------------------------------------------- ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html. bOyW3N.