Tdc #1 heads off?

36tudordeluxe

36tudordeluxe

Well-known member
Am adjusting valves and thought I would go through them a second time before I put the heads back on, as soon as I checked the valves on #1 I discovered the adjustment was way off. I understand the cam runs at half speed so why are the intake and exhaust valves both on their seats and piston at TDC #1 whenever I turn the the crank to TDC #1 as marked on my pulley? I know everything is working as it should because every time I come around to TDC #1 the gap on the valves changes. What should I also look for to confirm TDC on compression cycle?
 
At TDC on the firing stroke, both valves are closed. You need to make two revolutions of the crankshaft to get back to the same condition
 
There probably is a better right up.
Watch the intake open turn to TDC both valves closed, now adjust #1 ,
Then turn 90 degs and do next cylinder by firing order.
The intake will be just opening the next TDC is compression stroke.
 
Put a steel strap across the cylinder with a bolt in the center to hit the piston. Turn engine by hand in one direction until the piston stops rotation and mark pulley location, then turn engine the other way until piston hits and mark pulley again. TDC is exactly middle of the two marks ......the most exact method geting or finding exact TDC..
 
After the compression stroke the next time the piston is at TDC BOTH valves are open. This is called "split overlap" and is a good way to check if the cam is in right.
 
You must log in or register to reply here.
Back
Top