What is the maximum advance the distributor can move between mechanical and vacuum advance?
What is the maximum advance the distributor can move between mechanical and vacuum advance?
The maximum is about 14 degrees of vacuum advance. If too much advance is added, the engine will either start to knock or ping or perhaps it may surge slightly at very light throttle opening with high vacuum.
Do all distributors have mechanical advance?
Not all distributors are equipped with vacuum advance, but for a street engine it can be very useful. Engines operating at part throttle require more ignition timing to light the fire in the chamber because the cylinder contains only a portion of the total charge that is present at wide-open throttle (WOT).
Which way is advance on a Ford distributor?
Turn the distributor in a counterclockwise direction to advance the ignition timing. Do not over-adjust the distributor, as even a slight movement will yield a significant change in the ignition timing.
What is the purpose of the mechanical advance on a distributor?
Mechanical advance uses the weights and springs in the distributor to rotate and alter the timing sensor shaft’s position relative to the engine’s position.
How do I check my mechanical advance?
Timing LightsThe best way to measure total mechanical and vacuum advance is with a dial-back timing light. These more expensive lights use a dial on the back to place the TDC mark on the harmonic balancer at the zero timing mark on the engine. Then you merely read the total amount of timing on the dial.
What is mechanical advance distributor?
The mechanical (or centrifugal) advance is an Ignition Timing control mechanism built into most distributors. It is made up of: An advance plate or cam attached to the trigger mechanism inside the distributor, and. Springs that control how fast the weights are flung outward.
How does the distributor work in a Duraspark?
As the distributor shaft spins with increasing rpms, the centrifugal force acts on the weights, which begin to force outwards against the springs. This movement rotates the shaft and thus advances the timing. The slotted arm controls how much the weights can move the assembly, and the springs control how fast the assembly reaches that limit.
Where is the distributor pin on gofastforless distributor advance?
There is a pin that sits in one of the slots to limit travel. To change slots you simply remove the armature assembly turn it 180 degrees and reinstall it so the pin is in the other slot. The slots are numbered as to how many distributor degrees it will pull in, double it to find the amount of crank degrees.
How much mechanical advance do I need on a Ford distributor?
If you have a total of 36° and want to run 12° initial then you need 24° mechanical advance. Aftermarket distributors will have replaceable bushings to adjust mechanical advance. Stock Ford distributors have two slots. There is a pin that sits in one of the slots to limit travel.
When does the distributor advance add timing based on RPM?
The mechanical adjust timing based on RPM where the vacuum adjusts timing based on load. Under high load, WOT, performance conditions there is almost no manifold vacuum so the vacuum advance does nothing. The only time the vacuum advance adds timing is at part throttle, low load conditions when there is manifold vacuum.
What are the changes to a Duraspark distributor?
The biggest change, apart from the control box redesign, was the large distributor cap to handle the increased spark energy. The system consists of a magnetic reluctor and pickup in the distributor, and an ignition module to trigger the coil. Typically, the distributors have both mechanical and vacuum advance mechanisms.
When was the Duraspark II ignition system used?
Duraspark II electronic ignition was used on 1977 to 1984 Ford V-8 passenger car and light truck engines.
What kind of bushing does Duraspark II have?
This article refers to the Duraspark II control module with a BLUE strain relief bushing, one 4-pin connector, and one 2-pin connector. Another version of the system has an additional 3-pin wiring connector, and two YELLOW strain relief bushings. Discussion of that “dual mode” system will be added later.
What kind of oil pump does a Duraspark 2 have?
They are a direct fit on older 200/250 engines built after 1964 with the 5/16″ oil pump drive shaft. If you want to get one from the auto parts store, make it easy on the clerk and just ask for a distributor from a ’78 or ’79 Fairmont.
