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Original Message
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| Click on the "Engines" button for 390IP details. |
| By Dave Shoe - 06/02/2001 11:25:15 PM; IP 216.243.158.47 |
The IP stands for "Improved Performance". The 390GT was called a "High Performance" motor, but decamming it necessitated that the marketing department come up with a catchy name for the lower cost version of the performance 390. The change was principally "price point" driven by Ford beancounters.
Fomoco.com has a "specs" page for your engine. Just click on the gray "Engines" button on this page and select your engine.
As for the Thermactor air pump, Ford claims it provides "auxiliary exhaust manifold oxidation". Heating of the intake manifold is not the same thing. Intake heating relates to emissions in that it assists atomization of the fuel, but it does NOT relate to exhaust oxidation. If I recall correctly, EGR is a third method of using the exhaust to reduce emissions.
Performance cams have more overlap than mild cams. This extra overlap allows some fuel to be scavenged directly from the intake runner to the exhaust runner without ever being combusted. Performance cams also tend to require a richer fuel-air mix, so partially burned hydrocarbons are also an issue. Pumping fresh air into the exhaust runner allows the unburned and partially burned (carbon monoxide) to be more completely combusted.
Shoe. |
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