Some books say timing marks on a 318 are crank straight up and cam mark straight up. And others say cranks straight up and cam straight down. Whats best? And why. Is it just preferance?
One way it'll certainly be off 180 degrees and will not run at all!"Factory" gears have a dot marked at the top of the crank gear (12 o'clock), and the bottom of the cam gear (6 o'clock). When the #1 piston is at TDC the centerlines of the crank, cam, and these two dots must line up. Aftermarket gears may be marked differently, but I've never seen any that were different.
Think about it a little bit more fellas. Hint: The crank rotates at twice the speed of the camshaft.There is a potential drawback if you manage to leave the distributor installed as you replace the timing chain and gears. What is this drawback?
"Hint: The crank rotates at twice the speed of the camshaft."What is your point?
The point is the cam could be either staight up or at 180 degrees when you install the timing gears. The secret is make sure you leave the dist. in and note that the rotor is pointing at #1 cyl. If for some reason you pulled the dist. you can check for TDC by looking for when #2 intake valve opens, that is a much longer story.. Good Luck...
Install the cam gear with the dot up and rotate the crank 360 degrees. Where is the dot now? Install the cam gear with the dot down and rotate the crank 360 degrees. Where is the dot?Doesn't make any difference if the dot is up or down during installation. The cam will always be in the correct relationship to the crank. Just make sure, as Doc says, that you get the distributor timed so it is firing #1 cylinder when it is supposed to. If you leave the distributor in and have the rocker arms removed so you can turn the camshaft without the valves hitting the pistons, you could get the distributor 180 degrees off and number one plug wire would be firing number 6 plug and so on down the line.