Find top dead center

How to find the end of the piston stroke to set the distributor or adjust valves

Category:

Autos & Vehicles

Tags:

• Engine
• motor
• adjust
• valves
• TDC
• top
• dead
• center
• corvair
• car

[MrVhandi]

K, now I'm assuming that you put that napkin into the FIRST spark plug hole, as when you adjust your timing, you clip your reader to the FIRST spark plug wire.  How does this work? if the hole were plugged, and the piston starts to go up, there isn't enough pressure half way up to pop the napkin out? It's like a potato gun. ..just don't see how this is absolutely accurate. interesting though.

[Richardlwt]

@MrVhandi

No, the pressure builds quickly and if tapped in right, pops out when it hits max. Separates the compression stroke from the end of the exhaust stroke - that many people confuse.

You can then fine tune a bit with a screwdriver if you want to.

[Richardlwt]

That is a little beyond my scope........

[vseae15o]

air still leaks with a napkin in the spark plug socket....not very accurate but that's just me.

[Richardlwt]

@vseae15o

you need to wet the napkin more and compact it a little more

[fiddlerpin]

Are you sure about that? You could be a little off doin it that way. I would use a small steel rod or screwdriver or a piston stop

[beercoolie]

Please post video of how to degree a cam using the napkin method. 

:-)

[hp11208]

@ort4815 lol

[Wombosi24]

It works, and strange as it sounds, it's quite accurate.

[ort4815]

YOU HAVE GOT TO BE KIDDING ME!!!