Hot rodding the HEI distributor
(Add text) |
(Add text) |
||
| Line 264: | Line 264: | ||
So say the mechanical advance at 2000 rpm is 12 degrees. The max mechanical at 3000 rpm is 18 degrees. The "missing" 6 degrees can come from the vacuum advance. One thing to watch out for by using more vacuum advance is the engine can 'surge' at elevated advance settings and also there's the chance it will have a transient ping when hitting the throttle quickly when the vacuum advance is all in. That said, being as how we're only talking about 6 to maybe 8 degrees added vacuum advance, there's a good chance there will be no problems at all from using more vacuum advance. | So say the mechanical advance at 2000 rpm is 12 degrees. The max mechanical at 3000 rpm is 18 degrees. The "missing" 6 degrees can come from the vacuum advance. One thing to watch out for by using more vacuum advance is the engine can 'surge' at elevated advance settings and also there's the chance it will have a transient ping when hitting the throttle quickly when the vacuum advance is all in. That said, being as how we're only talking about 6 to maybe 8 degrees added vacuum advance, there's a good chance there will be no problems at all from using more vacuum advance. | ||
| − | + | ==Disclaimer== | |
| + | Because this article came from several authors besides myself, the statement of having about 50 degrees combined advance (initial, mechanical, and vacuum) at cruise rpm is a bit misleading IMHO. That's the max I would ever want to see, and personally speaking I use less- somewhere around 46 degrees combined advance would be perfectly acceptable in many cases. | ||
But any way you slice it, it's still trial and retrial to get the curve dialed in. No matter what we do (short of digital control), the timing curve is always something of a compromise. And all engines and vehicles (and all the other considerations) are different, case to case. So don't be surprised if you end up w/a curve that is a bit different than what's presented in this article. | But any way you slice it, it's still trial and retrial to get the curve dialed in. No matter what we do (short of digital control), the timing curve is always something of a compromise. And all engines and vehicles (and all the other considerations) are different, case to case. So don't be surprised if you end up w/a curve that is a bit different than what's presented in this article. | ||
Your Privacy Choices