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Original Message
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| RE: Timing problems |
| By Gerry Proctor - 06/07/2002 8:59:29 AM; IP 207.133.188.254 |
When you watch the timing mark on the crank, you are reading the timing event in crankshaft degrees. No mathematical manipulations are necessary. Running a distributor on a machine does require some math but are you sure your timing numbers aren't already converted to crank degrees? 26-degrees of vacuum advance is very high. I've never heard of a vacuum can giving more than 20-degrees. Most are in the 10 to 20-degree range.
There is no one size fits all when it comes to ignition timing. You want to allow for a margin of error...give yourself enough headroom that you won't destroy your engine by having your timing on the sharp edge. Many factors contribute to optimal timing. They include the vehicle, driving style, engine components, fuel quality and octane rating, cooling capacity, and other related items.
It's always hard to say where to start, but for the best driving situation, you want to run as much initial advance as you can and control your total advance with the centrifugal by tuning the rate of advance and the amount. The rate is important because having full centrifugal advance too soon can cause detonation and surging. I can't say that having it all in by 2,000 rpm is bad for you since I know nothing about the other elements, but I can guess that it is probably a bit too early for full advance. If your vacuum advance is connected to a ported source, then you will see your vacuum advance come in when you begin to open the throttle. Vacuum advance cans, regardless of ported or manifold, have a range of operation. They generally don't contribute advance below 8"hg and contribute the most advance in the 15 to 20"hg range.
Now, it is very common for the outter inertial ring to slip on elastomeric dampers. This means that unless you use a degree wheel, you don't know what your true timing numbers are. In this case, it is best to tune for best operation with that safety margin and use the numbers off the balancer as a reference rather than a true reading. In other words...don't worry, be happy.
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