TDC cam timing and distributer
08-26-2005, 03:40 PM
#1
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TDC cam timing and distributer
OK all this talk about this stuff on the forum got some of us talking and, yep, led to cornfusion 
...so, here is the $64K question...you put in a new cam...line up the dots at 12 and 6 on the timing gear, put the rest of the stuff back on the engine (timing cover, waterpump etc) and go to put the distributer back in...the question is, at this point do you drop the dist in with it pointing to the number 1 or do you turn the crank to ensure you are at TDC on the compression stroke on #1 and then drop the dist in with it pointing to the #1 spark plug wire
We had several smart people talking about this but the more we talked the more fuse'in it got...
...so, here is the $64K question...you put in a new cam...line up the dots at 12 and 6 on the timing gear, put the rest of the stuff back on the engine (timing cover, waterpump etc) and go to put the distributer back in...the question is, at this point do you drop the dist in with it pointing to the number 1 or do you turn the crank to ensure you are at TDC on the compression stroke on #1 and then drop the dist in with it pointing to the #1 spark plug wire
We had several smart people talking about this but the more we talked the more fuse'in it got...
08-26-2005, 03:50 PM
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But I one of my buddies (who is a member of this forum BTW) tell me that when he put his engine together he put the dots at 12 and 6 and dropped the dist in pointed to #1 and fired it right up.
08-26-2005, 04:26 PM
#5
Melting Slicks
I believe it's the brand of timing chain. I put in a Clyotes(sp) and the engine builder said that 12 & 6 was # 6 (as big g said), 12 & 12 was # 1. Either way you should be pointing at the terminal on the cap...
08-26-2005, 05:52 PM
#6
Melting Slicks
I always prime my engines using that tool which sticks down into the distributor hole. Thus, the engine is never at the same point as it was when I installed the timing chain. Check the thread on this page on finding the TDC, and when you drop the distributor in you don't want it pointing to #1 because the distributor will turn in a clockwise direction due to the worm gear of the distributor sliding into the distributor drive gear on the cam...thus, you really want to point it to #2 when you start to drop it in...then it will spin over to #1 when it reaches the bottom.
08-26-2005, 06:42 PM
#7
Le Mans Master
I have never seen any timing set that was not at #6 TDC Firing Position with the crank dot at 12:00 and the cam dot at 6:00.
Rotate the engine 360 degrees from that point and you are now at #1 TDC Firing position where the cam dot and the crank dot are now both at 12:00.
BUT... I will confess that I did get that wrong once (the first time). That is how we learn these things... the hard way.
-Mark.
Rotate the engine 360 degrees from that point and you are now at #1 TDC Firing position where the cam dot and the crank dot are now both at 12:00.
BUT... I will confess that I did get that wrong once (the first time). That is how we learn these things... the hard way.
-Mark.
08-26-2005, 08:37 PM
#8
Le Mans Master
Originally Posted by Rockn-Roll
I always prime my engines using that tool which sticks down into the distributor hole. Thus, the engine is never at the same point as it was when I installed the timing chain. Check the thread on this page on finding the TDC, and when you drop the distributor in you don't want it pointing to #1 because the distributor will turn in a clockwise direction due to the worm gear of the distributor sliding into the distributor drive gear on the cam...thus, you really want to point it to #2 when you start to drop it in...then it will spin over to #1 when it reaches the bottom.
08-26-2005, 08:39 PM
#9
Le Mans Master
For a fact...mine was at 12 on the crank and 6 on the cam sprocket (double roller) and I pointed the cap to #1. Fired immediately with no adjustments. More confused now??? 
???
???
08-26-2005, 09:33 PM
#10
Le Mans Master
Originally Posted by Jclgodale3
For a fact...mine was at 12 on the crank and 6 on the cam sprocket (double roller) and I pointed the cap to #1. Fired immediately with no adjustments. More confused now??? ???
???
08-26-2005, 09:43 PM
#11
Le Mans Master
Originally Posted by big_G
You must have one of those "Southern Hemisphere " engines....
maybe...but it didn't 
when it started and has run great since 
And watch it! I resemble that remark!
08-26-2005, 11:01 PM
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Originally Posted by Jclgodale3
maybe...but it didn't when it started and has run great since And watch it! I resemble that remark!
just think how much better it will run once you rotate that bad boy!
08-26-2005, 11:24 PM
#13
Le Mans Master
Originally Posted by vettepilot68
Dude...the Puke is awesome...but I just looked in another engine manual and it says the same thing everyone here AND the crane cam instruction manual says...we must have rotated your...er, you must have rotated yours...I dont see any other way.
just think how much better it will run once you rotate that bad boy!
just think how much better it will run once you rotate that bad boy!
08-27-2005, 01:19 AM
#15
Melting Slicks
[QUOTE
I always prime my engines using that tool which sticks down into the distributor hole. Thus, the engine is never at the same point as it was when I installed the timing chain. Check the thread on this page on finding the TDC, and when you drop the distributor in you don't want it pointing to #1 because the distributor will turn in a clockwise direction due to the worm gear of the distributor sliding into the distributor drive gear on the cam...thus, you really want to point it to #2 when you start to drop it in...then it will spin over to #1 when it reaches the bottom. QUOTE]
Every primer I ever saw, store bought or homemade made from an old distributor, only spins the oil pump.
Unless I see proof of one being capable of spinning the cam and crank (they are connected with a chain) I would say the above statement is misinformation.
I always prime my engines using that tool which sticks down into the distributor hole. Thus, the engine is never at the same point as it was when I installed the timing chain. Check the thread on this page on finding the TDC, and when you drop the distributor in you don't want it pointing to #1 because the distributor will turn in a clockwise direction due to the worm gear of the distributor sliding into the distributor drive gear on the cam...thus, you really want to point it to #2 when you start to drop it in...then it will spin over to #1 when it reaches the bottom. QUOTE]
Every primer I ever saw, store bought or homemade made from an old distributor, only spins the oil pump.
Unless I see proof of one being capable of spinning the cam and crank (they are connected with a chain) I would say the above statement is misinformation.
08-27-2005, 08:09 AM
#16
Le Mans Master
Originally Posted by glen242
[QUOTE
I always prime my engines using that tool which sticks down into the distributor hole. Thus, the engine is never at the same point as it was when I installed the timing chain. Check the thread on this page on finding the TDC, and when you drop the distributor in you don't want it pointing to #1 because the distributor will turn in a clockwise direction due to the worm gear of the distributor sliding into the distributor drive gear on the cam...thus, you really want to point it to #2 when you start to drop it in...then it will spin over to #1 when it reaches the bottom. QUOTE]
Every primer I ever saw, store bought or homemade made from an old distributor, only spins the oil pump.
Unless I see proof of one being capable of spinning the cam and crank (they are connected with a chain) I would say the above statement is misinformation.
I always prime my engines using that tool which sticks down into the distributor hole. Thus, the engine is never at the same point as it was when I installed the timing chain. Check the thread on this page on finding the TDC, and when you drop the distributor in you don't want it pointing to #1 because the distributor will turn in a clockwise direction due to the worm gear of the distributor sliding into the distributor drive gear on the cam...thus, you really want to point it to #2 when you start to drop it in...then it will spin over to #1 when it reaches the bottom. QUOTE]
Every primer I ever saw, store bought or homemade made from an old distributor, only spins the oil pump.
Unless I see proof of one being capable of spinning the cam and crank (they are connected with a chain) I would say the above statement is misinformation.
08-27-2005, 10:31 AM
#17
Melting Slicks
Originally Posted by Jclgodale3
kinda what I was thinking...
That said, I always have nightmares about finding TDC. I try to make sure there is NO WAY the motor will turn any time I have the dist out or the timing gears off. I remove battery, mark and take pictures of all moving parts, etc.
08-27-2005, 12:04 PM
#18
Le Mans Master
Originally Posted by Star79
That said, I always have nightmares about finding TDC. I try to make sure there is NO WAY the motor will turn any time I have the dist out or the timing gears off. I remove battery, mark and take pictures of all moving parts, etc.
08-27-2005, 05:07 PM
#19
Melting Slicks
A word of caution - you have to separate the wheat from the chaff when taking advice from forum members. If you have been here a while and followed posts on various subjects, you will learn who knows what they are talking about, and who doesn't have a clue.
08-27-2005, 06:37 PM
#20
Le Mans Master
Originally Posted by glen242
A word of caution - you have to separate the wheat from the chaff when taking advice from forum members. If you have been here a while and followed posts on various subjects, you will learn who knows what they are talking about, and who doesn't have a clue.
