TDC

[NES304]

Whats the easiest way to find Top Dead Centre in a 138?

[craiga]

Find the position where no1 cyl is rising on the compression stroke, you can do this by removing the plug and have an assistant put their finger in the spark plug hole while you manually rotate the engine. You will hear air start to escape past their finger while the piston rises. Watch the rockers, intake should open, then slowly close, once it is nearly closed watch out for the timing ball on the flywheel, keep rotating engine until the ball lines up with the timing mark. This is TDC no1.

If you go to far you will see that the exhaust valve opens. Keep rotating till it closes, then the intake will open and its coming back to where it all started.

Cheers,

Craig.

[Dr_Terry]

Hi Guys.

Craig, the ball on the flywheel of Grey motors is for ignition timing only & is several degrees before TDC (BTDC). The actual number of degrees varies with model, FX/FJ - 7 & FE to EJ - 2.

The actual TDC is when the harmonic balancer keyway is at 12 o'clock & the piston itself is right at the top of its stroke. This can be felt, approximately, using a screwdriver (or similar) down the spark plug hole. There are other methods if you need to know.

Dr Terry.

[craiga]

Thanks for the correction Dr Terry.

Cheers,

Craig.

[NES304]

cheers guys