Number order of pistons

[Leyland]

This may seem a daft question but I just cannot remember.
Is number 1 piston the radiator end or the bulkhead end please.

I ask because I know on old Jaguar engines no 6 piston is the radiator end!
Many thanks

[les]

1 = rad end.

[oliver90owner]

Nothing to do with the rad, per se. Convention is drive to the engine 'brain' - the camshaft. No1 was always at that end of the engine, as were any rod cap markings, whether it were mains caps numbering, or rod markings which would denote the camshaft side of the engine as well as the hole/bearing number.

The adoption of overhead cams and transverse engines has somewhat muddied the waters, but the convention should hold true for almost all older engine designs.

RAB

[les]

I made the assumption the vehicle was a Minor.

[philthehill]

Not withstanding the timing gears / chain / bevel gears at the rear of the block or even in the middle of the block

[bmcecosse]

Does it really matter which is #1 ?? The engine rotates clockwise as we look at it from the timing chain end .

[Leyland]

It is a minor I am referring to. I ask because setting distributor drive and eventually timing, the manual says set piston 1 or 4 at TDC. So being a minor engine is no1 piston the radiator end please.
Thanks

[bmcecosse]

It can be either! But most of us would assume it is at the front.....yes - at the radiator. And unless there is something terribly wrong - both 1 and 4 will be at TDC at the same time...... Of course - what you really want is for #1 to be on the firing stroke... Put a straw down the spark plug hole and turn the engine till it reaches the high point - then look at the valves - both valves on #1 should be closed .

[Leyland]

Thanks bmcecosse, that is really helpful.