Draining coolant from the block

[n1gzd_plymouth]

Spark plugs are over by the valves. The plug Don pointed out is over the piston.

hence L-Head. This is my first flathead and I guess I never thought about this before (piston not under spark plug hole).

Why did they not put this hole for detecting top dead center over the cylinder 1 piston?

Rebecca

[n1gzd_plymouth]

Thermostat housing area???????

That must be the reason. Thanks.

Rebecca

[TodFitch]

hence L-Head. This is my first flathead and I guess I never thought about this before (piston not under spark plug hole).

Why did they not put this hole for detecting top dead center over the cylinder 1 piston?

Rebecca

The #1 and #6 cylinders are on the same throw of the crank so they are both up and the same time. (#2 and #5 are another pair on the crank as are #3 and #4. With that information you can figure out that there are only two possible firing orders if you want the engine to fire uniformly: 1-5-3-6-2-4 and 1-4-2-6-3-5. All 6 cylinder engines I have worked on (not very many) use the 1-5-3-6-2-4 firing order.) Anyway, shel_bizzy_48 has as good a reason as any for putting the hole/plug over the #6 cylinder rather than the #1.

[n1gzd_plymouth]

Thanks for the info. Such good information. Thanks a lot.

Rebecca

[greg g]

Just remember that the TDC position for one and six are opposite. So while the pistons ar in the same position one is on compression and the other is on exhaust. So you can find TDC on Number 1 by removing the number 1 plug and the access for number 6. Withthe coil wire off put your thumb over one and crank he motor till you fell compression pressure, then insert the wire in the access hole over 6 and bring it up to its TDC position. then 1 will be at TDC on compression.

[n1gzd_plymouth]

Thanks. I needed to know that.

Rebecca