Top Dead Center
- Thread starter gmf502
- Start date
Robert Lone
MUTANT
Re: Top Dead Center
The voodoo way is to pull the sparkplug out of #1 and insert a small scewdriver into the plug hole. Have someone turn the crank bolt by hand and feel for the piston to stop at the top of the stroke. Make sure that the crank is being turned the same direction as it would while running and before you put the screwdriver into the hole, place your finger over the plug hole while the crank is being turned. When you feel positive pressure escaping, you know that you're on the compression stroke. Then you're ready for the screwdriver.
The voodoo way is to pull the sparkplug out of #1 and insert a small scewdriver into the plug hole. Have someone turn the crank bolt by hand and feel for the piston to stop at the top of the stroke. Make sure that the crank is being turned the same direction as it would while running and before you put the screwdriver into the hole, place your finger over the plug hole while the crank is being turned. When you feel positive pressure escaping, you know that you're on the compression stroke. Then you're ready for the screwdriver.
critical
meltdown
Re: Top Dead Center
Finding TDC on all cylinders for a leak down test is really a bitch.
Since our motors are 90* v6`s there are 3 places on the damper that reference tdc on all 6 cyls.
Simply rotate the engine [w/ valvecovers off] and watch the valves close on compression stroke.
Find TDC and mark the damper. Keep a note of witch cyls share the same mark, and things will be a lot simpler next time you pressure test the engine.
Remember to use the correct timing mark on #1 tdc.
Finding TDC on all cylinders for a leak down test is really a bitch.
Since our motors are 90* v6`s there are 3 places on the damper that reference tdc on all 6 cyls.
Simply rotate the engine [w/ valvecovers off] and watch the valves close on compression stroke.
Find TDC and mark the damper. Keep a note of witch cyls share the same mark, and things will be a lot simpler next time you pressure test the engine.
Remember to use the correct timing mark on #1 tdc.