Hot rodding the HEI distributor
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However, the scope of this article at this juncture doesn't include a full run-down of modified computer-controlled or aftermarket HEI distributors, but is instead primarily aimed at reworking a stock-type HEI for performance duty. | However, the scope of this article at this juncture doesn't include a full run-down of modified computer-controlled or aftermarket HEI distributors, but is instead primarily aimed at reworking a stock-type HEI for performance duty. | ||
| − | == | + | ==Finding/verifying TDC== |
*You will want to begin by knowing the timing tab and line on the damper are accurately indicating [http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center TDC]. | *You will want to begin by knowing the timing tab and line on the damper are accurately indicating [http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center TDC]. | ||
*On the SBC there were three different combinations of damper lines and timing tabs that go together. [http://www.crankshaftcoalition.com/wiki/Timing_tabs_and_damper_TDC_lines_SBC This page] describes them. | *On the SBC there were three different combinations of damper lines and timing tabs that go together. [http://www.crankshaftcoalition.com/wiki/Timing_tabs_and_damper_TDC_lines_SBC This page] describes them. | ||
==Plug gap== | ==Plug gap== | ||
| − | Don't be tempted to excessively widen the gap. The correct gap is 0.035" for the majority of cases | + | Don't be tempted to excessively widen the gap. The correct gap is 0.035"- 0.040" for the majority of cases. Using plug gaps wider than that is unnecessary when using a basically stock HEI ignition. Wider plug gaps (or faulty ignition wires) cause voltage spikes in order for a spark to occur. This in turn causes the cap to fill with ionized air, and this can cause erosion/degradation to the components along with spark scatter and/or voltage bypassing to the distributor advance mechanism, shaft, etc. It is hard on the secondary ignition components in general and just isn't needed in the vast majority of cases. |
The large diameter of the cap helps to prevent this and it works well enough in a passenger car, even with the wider gaps that were used for some applications. But once the RPM goes up and the cylinder pressure increases, the chance of a misfire increases dramatically with a wider plug gap. | The large diameter of the cap helps to prevent this and it works well enough in a passenger car, even with the wider gaps that were used for some applications. But once the RPM goes up and the cylinder pressure increases, the chance of a misfire increases dramatically with a wider plug gap. | ||
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A gasket can be used under the shims. But do not use paper distributor gaskets stacked together as shims. They will soak with oil and compress more than when dry. | A gasket can be used under the shims. But do not use paper distributor gaskets stacked together as shims. They will soak with oil and compress more than when dry. | ||
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| + | ==Rotor phasing== | ||
| + | *[http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Support/frm28392_tech_bulletin_rotor_phasing.pdf Checking and correcting rotor phasing] from MSD | ||
=Ignition advance= | =Ignition advance= | ||
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