Top Dead Center...confirmation

[JPP]

I want to be sure I am at Top dead center, but with the timing chain cover on, I want to be sure.  So I am assuming that by removing the valve cover for cylinders 1-3, I can see the valves open and close.  I know the second valve from the front is the fuel valve, so as it closes I assume that the cylinder is at the top of its travel and therefore I am at TDC??  Thanks for any input..

[TodFitch]

There is a pipe plug on the cylinder head above the #6 cylinder. If that is removed then a stiff wire or small rod can be placed in the hole and you determing the piston position (#6 and #1 cylinders are on the same throw on the crank).

[Merle Coggins]

Yes, the second valve back in the intake valve for #1 cylinder, but when it closes you are at, or near, bottom dead center. The piston then has to come up on the compression stroke with both valves closed.

You should have some marks on your crankshaft pulley/damper. You may have to get down there and clean/sand the edge surface to find them. The largest mark should be TDC. Rotate the crankshaft so that the TDC mark aligns with the pointer, then check the valves. Both intake and exhaust valves for #1 cylinder should be closed. If one is open, even slightly, then you are on the exhaust stroke, not the compression stroke.

 

Merle

[Don Coatney]

[Todd B]

I thought you pull the #1 sparkplug and use a wire to feel the piston reach the top.  That's how I thought my dad did this 40 years ago.  (although, I have drank a lot of Windsor since then)

[Don Coatney]

The spark plug sits on top of the intake valve not on top of the piston.

 

[Charlie Stephenson]

What CID engine are you working on, Year, Make and Model ?

[ptwothree]

You could also pull #1 plug and rotate the crank slowly with a finger placed where the plug came out.  You will feel pressure as the piston comes up on the compression stroke.  At this point, the mark on the pulley should be about 45 degrees from tdc.  Just rotate the crank till it lines up with the pointer and you are there.  Btw, then pop of the distributor cap...rotor should be pointing at 7 o'clock if all is well.

[NiftyFifty]

The wire down the hole on #6 is truly the best way to get accurate tdc...there is also a certain position where you need to find the centre of tdc, at that point where it rises to the top and stops rising, and the between where it starts to drop again..should be a few degrees....but that accuracy likely isn't needed....just habit for me from years of timing 2 strokes