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MG MGB GT V8 Factory Originals Technical - Buick 215 startup questions, pertronix
|I am ready to fire a Buick 215 and have a few questions:|
1) With the stock Delco distributor and pertronix 1181 kit w/ Flamethrower coil, do I still need the external capacitor to attach to the coil?
2) Have a Edelbrock 1404 carb from D&D, I think he said to attach the vacuum advance hose to the timed port. Is this correct? In the manual it states this port is for 'emissioned controlled engines' vs using the manifold vacuum port. Does the Delco need vacuum at idle?
3) What is the procedure for setting base timing? I think you remove and plug the carb port and set to about 7 degrees from the #1 cylinder, correct? What rpm?
Thanks for the advice.
|Sorry, make that condensor instead of capacitor.|
|No. A condenser/capacitor (it's the same thing) is only needed with points.|
Carb vacuum is preferable to inlet manifold - if your carb has the appropriate port. Carb vacuum gives no vacuum advance at idle so you can set the timing with the port still connected. With inlet manifold vacuum you get near maximum advance at idle which is when this port must be disconnected and plugged at the inlet manifold before timing is set, otherwise you will get grossly retarded running timing. The only difference between carb vacuum and inlet manifold vacuum *is* at idle (and just off it), thereafter the two give the same signal. The type of distributor is irrelevant, some say that certain distributors *must* be used with carb vacuum and if you have inlet manifold vacuum you must use a different distributor, that is not correct. The reason for the move from carb vacuum to inlet manifold vacuum was purely emissions related - with inlet manifold and its high idle vacuum you get a high idle speed for a given idle screw setting, which means you can turn down the idle screw to get the correct idle rpms, which results in less fuel consumption and emissions. But it does make for slightly harder cold starting, which is why carb vacuum is preferable for everything except emissions.
Anything from 7 degrees to 10 degrees should get it running, thereafter timing is down to what fuel grade you are using and the driving conditions. For a high compression engine you want to be using the maximum advance you can without getting pinking at any combination of throttle opening, rpm and load. For a low compression engine pinking is less likely anyway, so you can either set it to stock for the engine or experiment and see which gives you the best performance.
|Paul Hunt 2|
External? On the original Delco distributor, the condensor was mounted internally (under the cap, on the same plate as the points.)
Hard to tell... but rather than capacitor (or condensor), it seems possible you meant to ask whether a ballast resistor is required. Most American cars, including 61-63 Buick Specials, had an external resistor (in a boxy, white, ceramic housing that measures about 1/2" by 1/2" by 3") mounted next-to and connected-to the ignition coil.
On the other hand, the original MGB wiring harness had "resistor wire" built into the wiring harness (and no external resistor), so that's why you wouldn't have seen a ballast resistor when you were pulling the MGB engine.
This thread was discussed between 22/11/2007 and 24/11/2007
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