<VV> Distributor....180 Degrees off

Chris & Bill Strickland lechevrier at earthlink.net
Mon Oct 23 19:58:26 EDT 2006


Jinm wrote:
> 
> four strokes- intake, compression, power, and exhaust.

in other words -- suck, squeeze, bang, and phooey. 

The piston is at TDC (and hopefully the timing mark matches) between the phooey & suck cycles (with the valves open) and between the squeeze & bang cycles (valves closed, iginiton fires)

One does not depend on the timing mark -- the balancer may be bad or mis-installed -- generally, when one is assembling the engine, one uses a dial indicator to measure piston tdc and one matches that to the mark (or your degree wheel) to make sure it is accurate. The "pencil method" (I use a screwdriver, carefully), is a good appoximation for finding tdc, but one must know what stroke it is on. Incidental to this, but equally important, one needs to know the cam is installed and indexed properly, ie, the valves are doing what is described -- "valve overlap" when both valves are just open a bit (exhaust closing, intake opening) occurs at the phooey/suck tdc, or should. This will be happening in a Corvair at #2 when #1 is at tdc of the squeeze/bang stroke.

Generally, when I'm indexing a distributor, a spark plug comes out, a screwdriver goes in, a valve cover comes off, the engine is turned over til it is where it needs to be, and then the distributor goes in in its proper place -- one might need to fiddle with the oil puimp drive engagement, but that is sort of like putting Tinker Toys together (and if you can't do that, get help!), but once it is dropped fully into the gear, the rotor should point to where you want the #1 spark plug wire to be.

If you have never held your thumb into the spark plug hole on on a cranking engine, it is something you need to do just for the experience -- doesn't have to be a Corvair -- go pull a plug out of your wife's driver and crank away. Heck, even F***'s and other GM's work this same way ...

Which brings up the question of "Is the Balancer good?"

Godspeed!

Bill Strickland




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