318 LA Rotor position and TDC questions

Jeffry, stop sweating the timing, and stop sweating the cam. In fact just don't worry about it. Let's talk "simple."

"Let's say" you put the cam in correctly, that is, crank dot at 12 o'clock and cam sprocket at 6 o'clock. Let's say that cam turned out to be "optimum" there for performance. (Google "degree a cam")

"Let's say" you just closed your eyes and threw the distributor gear in there. It landed any old way.

"Let's say" you just closed your eyes and threw the distributor in there. It will only fit one of two ways, "you don't care" which

NOW we'll set the timing.

There are TWO ways to determine the no1 compression stroke. Pull the no1 plug, "rig" a way to bump the starter and stick your thumb in the no1 hole. Just a screwdriver or pliers across the starter relay is all you need.

One way, if either valve covers are removed, is to wrench the engine up to TDC. Now look at the no1 and no6 valves. One pair will be about equally open, the other pair will be shut. Whichever pair is shut is ready to fire

The way likely most used is.................

Bump the engine, feel the compression push your finger out, go around an extra cycle if you aren't sure.

AS SOON AS YOU start to feel pressure on your finger, look at the timing marks which will be shortly "coming up" towards TDC. DO NOT set the marks at TDC. Rather, stop (wrenching) the engine when the timing marks "come up" on the desired initial timing. For bone stock, maybe 8-10 BTDC. For a mild cam like a stock 340, maybe 10-12 BTDC and for a wilder grind, more, like 15 as much as 20BTC.

SO NOW you are on the no1 compression stroke, and have the marks set at desired initial timing.

Now rotate the dist. body until the vacuum advance has plenty of room to move. If you have breaker points, figure a way to monitor points open / closed, test light, ohmmeter, dwell meter with resistance scale whatever.

If you have breakerless, move dist. retarded (CW) and then advanced (CCW) until the pickup coil core and the reluctor are centered. You can get that closer with practice, I won't complicate that

If you have breaker points, rotate CW to close points, and rotate back CCW carefully until points open. That is the spark event. Snug down the dist. a little, so you can still turn it.

The distributor rotor will be pointing "somewhere."

Now determine which cap tower the rotor is "coming to" going CW. THAT IS WHERE YOU STICK the no1 plug wire, and connect the others in proper firing order going CW around the cap.