I just got a TDC indicator from Summit and I'm not exactly sure how to use it. I know you make sure #1 piston is coming up on the compression stroke and then screw the indicator into the #1 spark plug hole. Then what? I assume you screw the inner part all the way in and when the piston touches it back it out as you raise the piston until it no longer touches the piston?? Some one throw me a bone here.!! Thanks, Todd
The old simple method is to place thumb tightly against No. 1 hole with plug removed. Bump the starter slowly until max pressure is felt (you will know). That is TDC, or damn close.
Which kind do you have,Is this for with the head of or on? Give us some info if you don't have pictures.
By hand (well wrench actually) turn the engine till #1 piston hits the stop. Make a reference mark on the balancer or note reading on the degree wheel. Reverse the direction and turn motor till it hits the stop again from the opposite direction. Make another reference mark or note degree wheel reading. True TDC will be halfway between your two marks or degree readings. Hope this helps.
What are you doing that you need to find TDC for? Could still mark the flexplate/flywheel to find it,but I'm not understanding the need too.
I changed the cam and want to adjust the valves. the motor is on a stand. It is rebuilt and is basically a long block. not water pump, flywheel, harmonic balancer ect.
OK, if you don't have the balancer on the crank, you'll have to bolt a degree wheel on the front of the crank snout. Screw the TDC tool in the sparkplug hole. GENTLY rotate the crank counter clockwise until the piston touches the tool and stops. Set the degree wheel on 0. Then GENTLY turn the engine clockwise until it stops. Half way between where the degree wheel is now and 0 is TDC. Look at post 3 and 20 might help with the degree wheel. Larry T http://www.jalopyjournal.com/forum/showthread.php?t=215715&highlight=swirl+valves
If your just adjusting valves try IC,EO. Learned from an old time aircraft mechanic 25 yrs. ago and he swore it would work on any 4-cycle engine. Always works for me. Works like this; while turning the engine in the direction of rotation as the "I"ntake valve is starting to "C"lose adjust the exhaust valve on that same cylinder. Continue your rotation and as the "E"xhaust valve starts to "O"pen adjust the intake valve on that cylinder. No problem remembering it,he taught us to remember IC as"internal combustion". The piston stop is mostly used to accurately determine TDC on a degree wheel when degreeing a cam,or verifying the TDC mark on the harmonic balancer lines up with the "0"on the timing tab.
...And on a Chevy it helps you avoid having to figure out if the timing tab you have is the correct one of the 43 available ones for your choice of the 16 different balancers, multiplied by random aftermarket parts mistakes!
if motor is apart (partially) , just put your finger on #1 intake lifter , rotate motor until the lifter is all the way down , roll the motor back & forth to be sure it is correct .............
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