both valves will be closed for quite some duration! Exact figures depend on the cam grind we're talking about, but we're talking about the majority of the compression stroke, plus most of the combustion stroke. This leaves an awful lot of scope for getting the timing horibbly wrong! Saying that it is accurate enough to set the engine up to run this way is inviting disater for your valves and pistons.

dialling a cam correctly is an involved process that I'm not about to try and explain in such a poor communication medium.

But you will be within safe running range if you set the cam up according to the factory timing marks. Get hold of a manual, or leave it to someone who knows what they're doing.

hi get # 1 piston tdc and valves closed then put chain and gears on......engine is now set up to run


SLY OLD FOX....

what is the best way to get the timing right, the motor has 2 t.d.c's
1) the duration when the cam closes exaust and opens intake
2) the duration of the power stroke

i want to get it right before i put it all back together and find that that i snap the valves off when i start it up