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timing help


zguyincali

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Hi I took my engine in to get rebuilt about a year ago and I just now got it in the car. I found out that the camshaft is 180 degrees out. What is the easiest way to correct this? Do I have to pull the head or can I just remove the rocker arms? Also if I pull the oil pan will I be able to see the timing chain where it connects to the crank?

Edited by zguyincali
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2 possible scenarios here.

 

1) If the camshaft is 180 degrees out from the crank, it is fine. If #1 piston is at TDC, and the cam lobes are pointing down when they should be point up, or vice versa, then just rotate the crank one full revolution (360 degrees) then the cam will have rotated 180 degrees and the #1 piston will return to TDC just as before.

 

2) Now if the crank is 180 degrees out from the cam, (90 degrees of cam rotation), then you may have big problems when the head was bolted on with rockers in place or if the crank was rotated as valves could have contacted pistons bending those valves, (L-series is an interference engine).

 

If #2 is the your scenario, need to verify no valves are bent, then with the rockers removed clock the cam to the correct position using whatever service manual you have handy, then reinstall the rockers, readjust valves, etc.

 

 

 

Side note, be sure to read the forum rules linked in the upper right corner of the page, this forum has a few rules not common to most car forums, one being capitalization is expected. :wink:

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Thanks. Right now I have the crank at tdc so that the rotor is pointing at the 1st spark plug terminal. But the camshaft lobes are facing down when i think there supposed to be facing up. Is there any way of checking if I have a bent valve stem? Or do I have to run a compression test on each cylinder to check it?

Edited by zguyincali
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Sounds like your distributor is out 180 degrees. Thinking practically, a camshaft can't be 180 degrees out from the crankshaft, it just moves your place in the engine cycle by two strokes. Your options are to either move the spark plug wires around correctly and use a timing gun to properly set ignition timing, or to drop the oil pump and rotate the distributor.

 

I'd say the former is pretty simple to do...

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***edit***

Leon beat me to it.. :2thumbs:

 

Thanks. Right now I have the crank at tdc so that the rotor is pointing at the 1st spark plug terminal. But the camshaft lobes are facing down when i think there supposed to be facing up. Is there any way of checking if I have a bent valve stem? Or do I have to run a compression test on each cylinder to check it?

Sounds like you are seeing this all wrong. Your cam and crank are fine!

Does your plug wiring match this picture?

1stGenDist.jpg

a) If this matches your plug wiring and your rotor is pointing to the #1 in the picture with #1 piston is at TDC and #1 cylinder cam lobes facing down, then your plug wires are just clocked incorrectly on the cap, re clock the wires on the cap and enjoy.

b) If with rotor is pointing to towards the firewall with #1 at TDC, #1 cam lobes pointing down, then your dizzy is 180 degrees out, NOT your cam or crank!

If the answer is b), you have two options. Start out by getting #1 cylinder at TDC firing stroke by rotating your crankshaft 360 degrees, (one full revolution). That will keep #1 at TDC and your cam lobes up indicating TDC of the compression/firing stroke, (the point from which all timed aspects of the engine are referenced in most if not all shop manuals).

1) Just rewire the plug wires on the cap 180 degrees out, i.e. #1 at the #6 position, and so forth. It wont match the service manual, but it fire the correct cylinder at the correct time, the engine wont know the difference, only you or anyone else that works on the car.

2) Remove the oil pump and drop the dizzy drive shaft/quill shaft. Reinstall the quill shaft orientated properly per the service manual lining up the dots.

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Great pics. :2thumbs: Dizzy quill shaft is 180 degrees out, crank-cam is most likely fine.

 

Either of these 2 solutions will spark the plug at the correct time;

1) Just rewire the plug wires on the cap 180 degrees out, i.e. #1 at the #6 position, and so forth. It wont match the service manual, but it will fire the correct cylinder at the correct time, the engine wont know the difference, only you or anyone else that works on the car. :wink:

2) Remove the oil pump and drop the dizzy drive shaft/quill shaft. Reinstall the quill shaft orientated properly per the service manual lining up the dots. That way if anyone else services the car, it will match what the service manual says it should. :wink:

Edited by BRAAP
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