14 mm bolt piston stop question
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
You would need about 3" of thread on it....
but I would not do it that way,....in fact, you can use a piece of coat hanger about 6" long and poke it down the plug hole.. spin the crank slowly to feel the piston come up, and then note by feel the absolute highest point of piston travel, very carefully, back and forth....divide that differance of feel, and that is TDC.....wether the valves are open or closed is another question....you should see your timing marks line up, andif they are off, you got problem with the harmonica balancer slipping....it should be dead nutz on....I done it this way a brazillion times over the years....this is for CRANK position, not CAM position...
gotta remember 72184365 is your firing order....
but I would not do it that way,....in fact, you can use a piece of coat hanger about 6" long and poke it down the plug hole.. spin the crank slowly to feel the piston come up, and then note by feel the absolute highest point of piston travel, very carefully, back and forth....divide that differance of feel, and that is TDC.....wether the valves are open or closed is another question....you should see your timing marks line up, andif they are off, you got problem with the harmonica balancer slipping....it should be dead nutz on....I done it this way a brazillion times over the years....this is for CRANK position, not CAM position...
gotta remember 72184365 is your firing order....
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
I wouldn't use a bolt due to possibility of damage (you just need to forget it's in there, or somebody turns the motor over.....). I use a TDC gauge like this one http://cgi.ebay.co.uk/TDC-TIMING-TOO...QQcmdZViewItem , taking readings at the extreme end of the scale (where it's more accurate). You can make your own gauge by using a short 14mm bolt (that doesn't hang into the cylinder any more than the spark plug) & drilling a hole through it. Make sure that whatever you use as the plunger has some means of preventing it from falling right through the hole & into the motor. It's a real pita pulling a head to get your plunger back!
Le Mans Master
Joined: Oct 2001
Posts: 5,943
Likes: 3
From: Wildwood IL
I bought one...that would not thread into my heads AND was too short to reach the piston on my AFR heads. 
So I broke off & drilled out the center of a spark plug leaving just the metal...then tapped the center. Ground off the head of a long bolt leaving a nice smooth tip and it worked great. Also wrapped some felt on the bolt tip so it wouldn't scratch the piston.
Eddie
So I broke off & drilled out the center of a spark plug leaving just the metal...then tapped the center. Ground off the head of a long bolt leaving a nice smooth tip and it worked great. Also wrapped some felt on the bolt tip so it wouldn't scratch the piston. Eddie
Team Owner
Joined: Jul 2004
Posts: 40,412
Likes: 792
From: Redondo Beach, California
I bought one made out of brass from the GM Performance Parts catalog. It has a hole drilled through the center of it to allow air to escape as the piston comes up to TDC. A little pricey, I think it cost a little over $30.
