Not Ranked
The Basics
Let me start by saying that this could be pretty long if we tried to cover all the variations from stock to highly modified engines with various advances so I will try to be brief and start will some generalities for now.
Light cars can really benefit from a quicker advance because they are carrying less weight and have less risk of pinging or detonation. Many of the old stock engines did not fully advance until the high 4k rpms. By changing the advance springs you can make your advance come in a lot quicker which improves performance as you are giving the engine more time for combustion. Generally, it is good if we can get all the advance in from 2,500 to 3,000 rpms. Mildly modified engines seem to run pretty well with around 10-12 degrees initial advance. Highly modified engines can run up the high teens of initial advance. Initial advance plus advance built into the distributor equals total advance. Initial advance aids idle quality. Let's leave vacuum advance out of it for now.
FE engines seem to run well from about 32-36 degrees total advance. SBF engines can run a little higher, and in some cases I have seen them run 41 degrees. It all depends on the cam duration, type of heads and combustion chamber design, compression ratio, and other various factors. But cam duration seems to be the biggest factor.
Since we were working on a very mildly modified FE engine with a low duration cam our target initial timing is going to be 10 degrees. We were also shooting for a total centrifical advance of 35-36 degrees. So 36-10=26 degrees that we would like to be built into our distributor. I say 26 degrees but I need to clarify that is crankshaft degrees. The distributor turns 1/2 the times of the crank shaft so that means we are looking for 13 distributor degrees.
Jeremy had purchased some Mr. Gasket Ford Springs, part number 925D, that sell from 5-10 bucks. Next post is when we get started.
Wayne
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