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Old 05-28-2009, 03:09 PM
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cubed
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Old 05-28-2009, 03:58 PM
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TS1955
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That is correct. You align them up when putting the engine together, it makes it easier. But like you said, when it's on compression stroke on #1 cyl. both dots, crank & cam will be on top.

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Old 05-28-2009, 04:41 PM
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Old 05-28-2009, 10:31 PM
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Default Re: cam sprocket

Originally Posted by Sidracing
hi guys, when my chevy small block is on tdc on comp. stroke is the dot on the cam sprocket at the top? thanks.

NO, that is NOT correct.


The cam sprocket DOT should be at the bottom or 6 o'clock position and the crank sprocket DOT will be at the 12 O'clock position.
It;s reccomended to degree it in per the cam card, but dot to dot will get you pretty close.
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Old 05-29-2009, 01:25 AM
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TS1955
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Cepx, when you initially put in a cam you will align the marks up, BUT when you rotate the engine to "compression" stroke on #1 cylinder both dots will be at 12 o'clock.

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Old 05-29-2009, 02:20 AM
  #6  
johnracer
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Originally Posted by TS1955
Cepx, when you initially put in a cam you will align the marks up, BUT when you rotate the engine to "compression" stroke on #1 cylinder both dots will be at 12 o'clock.

TS1955
Yep, that's correct......
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Old 05-29-2009, 02:42 AM
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Default Re: cam sprocket

Originally Posted by cepx111
Originally Posted by Sidracing
hi guys, when my chevy small block is on tdc on comp. stroke is the dot on the cam sprocket at the top? thanks.

NO, that is NOT correct.


The cam sprocket DOT should be at the bottom or 6 o'clock position and the crank sprocket DOT will be at the 12 O'clock position.It;s reccomended to degree it in per the cam card, but dot to dot will get you pretty close.
Charles that position would be #6 TDC firing
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Old 05-29-2009, 06:49 AM
  #8  
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There are two TDC for each rotation of the camshaft. This may be what is confusing.

One TDC is compression, the other TDC is the overlap between exhaust closing and intake opening.

Always easier to install chain when the dots are close together.
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Old 05-29-2009, 07:30 AM
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I've wondered for ages why it's been done that way,one would think that the dots would be close when #1 is @ tdc compression.This position (6 tdc comp) also puts the fuel pump lobe on the heel IIRC.
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Old 05-29-2009, 08:44 AM
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