OK, so I am sure there must be a hundred threads about this. This evening I dropped a distributor in an sbc, and after cranking on it, checking the firing order, checking the fuel, and so on I fnally 180ed the motor. I know, I should have done that first. But here is my question; What is the definitive way to know that the motor is on tdc and not the 5th stroke, or 180 off?
Check the valve positions under the rocker...if TDC and one valve open, its 180 off....Hyd rockers make this a little more difficult...
TDC on exhaust is valves open, TDC on compression is valves closed. So feel compression with your thumb or other means, when compression is building you are on compression stroke. Preferably turn engine over by hand, or bump very slowly with starter, to find this.
An easy, down and dirty way to do it without much disassembly is to take number 1 spark plug out. Hook up a remote starter button, and bump the starter with your finger over the plug hole. When it makes pressure, the next time the timing mark comes up, it's firing number one. Never fails, as long as you BUMP the starter so you don't go flying past the timing mark on the balancer and miss seeing it. Bud
5th stroke? There are only 4, you want compression and not exhaust. It's explained about pretty well...
Stick your finger in the #1 spark plug hole and bump it over. When #1 is coming up on the compression stroke it will blow your finger out. Then line the timing mark up on about 10 degrees then see which way the rotor cap is pointing.
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