-------------- Original message ---------------------- From: "Larry Shouse" <[EMAIL PROTECTED]> > As a follow-up question, please explain to me the pros and > cons of vacuum vs. mechanical advance.
All OEM-style distributors have mechanical advance (the weights and springs under the rotor). Vacuum advance provides additional advance when the engine's under light load (high-vacuum situation) for economy purposes. Many race-only distributors don't have a vacuum advance canister because it would serve no benefit. I'll bet that at least one list member with a stock/original car has only mechanical advance because the vacuum canister's failed and he doesn't know it. Changing the cap and rotor is a good time to check it. Brad O.
