Cam install...timing gear question
Thread Starter
Drifting
Joined: Jul 2009
Posts: 1,319
Likes: 64
From: Lakeville, MA
St. Jude Donor '10
Cam install...timing gear question
Probably a dumb question but just want to confirm before I proceed. When the crank sprocket dot is at 12 0'clock does that mean that the#1 piston is at TDC? Example, if I were spin the motor 360 degrees and cam dot is at 12 0'clock again, am I still at #1 TDC?
Placing my finger over #1 sparkplug hole tells me that air is being pushed out as the dot is coming up on 12 o'clock and that I'm at TDC. Just want to be sure as I am getting ready to install the cam.
Placing my finger over #1 sparkplug hole tells me that air is being pushed out as the dot is coming up on 12 o'clock and that I'm at TDC. Just want to be sure as I am getting ready to install the cam.
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 25
From: Austin Texas
If you "spin the motor 360° and the cam dot is at 12 oclock again". 360° of the crankshaft = 180° of the camshaft.
Remember that the #1 piston is at TDC at the top of the compression stroke AND at the top of the exhaust stroke.
2 turns of the crankshaft for one turn of the cam.
Remember that the #1 piston is at TDC at the top of the compression stroke AND at the top of the exhaust stroke.
2 turns of the crankshaft for one turn of the cam.
