Tdc ?
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Tdc ?
TDC on Compression stroke for # 1 cylinder is "dot" on CAM Gear at 11:00-12:00 position, and "dot" CRANK Gear at 6:00 position.
When "dot's" are above each other CAM at 6:00 and crank at 12:00 then # 6 cylinder is at TDC COMPRESSION stroke. CORRECT?????
When "dot's" are above each other CAM at 6:00 and crank at 12:00 then # 6 cylinder is at TDC COMPRESSION stroke. CORRECT?????
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
Dave - You should install the cam when the crank sprocket's dot is at 12 o'clock. Set the cam sprocket dot at 6 o'clock. Then install your lifters, pushrods and rockers and adjust your lash with the intake manifold off so you can see when each lifter is on the base circle. Rotate the crank with a wrench, with the sparkplugs out. When the lash is set, look for both #1 lifters on the base circle and then your timing marks should be close to zero. Put the manifold, etc back on, drop in the distrib and advance it a few degrees. That should be close.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
To install the new set, forget about TDC 
and align the dots (with pushrods removed or rockers loose) to meet at 12 and 6 oclock as palmbeachvette76 pictured and 63mako described. This position is not #1 TDC on the firing stroke.
To get the #1 firing stroke after gear set installation, continue to rotate the crankshaft another full turn so the dots are both at 12 o'clock and install the dist so the rotor meets #1 on the cap. No need to check the piston position for TDC when you can see the gears.
and align the dots (with pushrods removed or rockers loose) to meet at 12 and 6 oclock as palmbeachvette76 pictured and 63mako described. This position is not #1 TDC on the firing stroke.To get the #1 firing stroke after gear set installation, continue to rotate the crankshaft another full turn so the dots are both at 12 o'clock and install the dist so the rotor meets #1 on the cap. No need to check the piston position for TDC when you can see the gears.
Burning Brakes
Joined: Jul 2008
Posts: 914
Likes: 10
From: Brooklet Ga.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Burning Brakes
Joined: Jul 2008
Posts: 914
Likes: 10
From: Brooklet Ga.
If the cam and crank gears are set right and 1 is at TDC it dosen`t matter where you put the rotor as long as it is wired correctly. You just have to be sure the vacum advance has room to swing for timing adjustment and the tach cable isn`t pinched.
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