ste300

Could anybody tell me what tdc becomes in a boxer engine.
Thanks
Steve

5cby

not sure what u mean but tdc means exactly that
piston will be tdc when the piston is at the top of its stroke

steve

evander

iTrader: (1)

TDC is when any piston is at the top of its stroke, I take it your doing a cam belt swap so youll be looking to lign up the marks on the crank pulley in conjunction with piston No1.

ste300

no what im looking to find out if there is a further definition on tdc for horizontal pistoned engines such as the boxer. The 2 opposing pistons reach TDC simultaneously, which is also called 0° displacement but is there a specific defintion beyond this?

p1mark

No, it doesnt matter wether you have a single cylinder model aeroplane engine or Rolls royce merlin spitfire engine, When a crank pin (and hence piston) is at the the top of its stroke this is TDC on that cylinder.

Nearly all references on any engine are taken from no.1 cylinder, so if you see for example cam timing figures of Inlet 105 BTDC and exhaust 110 ATDC, then this is the angle (in crank degrees) that the relavent valves on no.1 cylinder are at maximum opening.

A boxer engine (180 deg opposed crank pins) is no different from a conventional 4 in that 2 pistons will be at TDC and 2 at BDC at the same time- with one on the compression stroke and one on the exhaust stroke.