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Discussion Starter #1
When the cams both point up and you lock em down with a punch...that's TDC right?
 

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No...the TDC term applies to the block and pistons.

But, yes when the cam arrows are up and you have them locked with punches (or something).. The indicator and the flywheel mark for TDC should be lined up. Make sure it's the TDC mark and not the ignition timing mark.
 

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Discussion Starter #3
dano said:
No...the TDC term applies to the block and pistons.
I know that much....I shoulda said the cams in relation to the pistons.

dano said:
But, yes when the cam arrows are up and you have them locked with punches (or something).. The indicator and the flywheel mark for TDC should be lined up. Make sure it's the TDC mark and not the ignition timing mark.
Got it...Thanks!!

SInce I have never paid attention, what is the distinct difference between the 2? Any?
 

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If you are puting on a timing belt you may need to play with the cams a little bit to make the belt fit. Once the belt is on and the punches removed, don't forget to turn the crankshaft (counterclockwise of course) a little, like equal to 3 cam sprocket teeth before you tighten the adjustment idler pully bolt.
This moves any slack from the front side of the timing belt run to the back side where the adjuster spring will pull it to the correct tightness.
 

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top dead center is just a reference. top dead center for the crank would be when the #1 cylinder is at the top of its revolution, best way to find is remove the #1 spark plug, insert a long screw driver in place of the plug and turn the crank until the screw driver is pushed up as high as the piston will push it. once it reaches the top of its revolution its at top dead center, then set the cams to top dead center, then your cams and crank are in sync, and you are ready to install your timing belt. hope that answers your question.
 

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Are there a difference between the TDC mark and the timing mark ??

Hell yeah.. If you try to put the belt on by lining the arrow thing with the ignition timing mark you will find that it won't fit. If you do manage to get the belt on your valve timing will be way advanced and the engine will run like crap.

When you turn the crankshaft counterclockwise, the timing marks will appear first and the TDC mark ("T" or "+") will show up an inch or so later.

Don't turn the the crankshaft very much and don't hesitate to turn the crankshaft CLOCKWISE if you need to in order to find the TDC mark.
In other words don't think you can ONLY turn the crankshaft counterclockwise and turn it 360 degrees..
YOU WILL BEND VALVES if you force it.

NO the best way to find TDC is NOT putting a screwdriver in a sparkplug hole...use the TDC mark on the flywheel and the arrow indicator !! Of course if you have fitted an Accura flywheel, you won't have the marks.
 

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Discussion Starter #7
dano said:
Don't turn the the crankshaft very much and don't hesitate to turn the crankshaft CLOCKWISE if you need to in order to find the TDC mark.
In other words don't think you can ONLY turn the crankshaft counterclockwise and turn it 360 degrees..
YOU WILL BEND VALVES if you force it.
I didn't fully understand that part, but to fully answer your curiosity, I am taking off the entire head to do a head gasket. I have done it before, just never really considered the timing thing before, but never had a problem...so I was double checking to make SURE I did it right.
 

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Ok gotcha.

I wouldn't advise having the crankshaft set at TDC when replacing the head.

Because after the head is torqued down you will be adding the cams back. As you torque the camshaft bearing caps down you will be opening some of the valves and you don't want to have them hitting to piston tops.

Say you now have the crankshaft at TDC. Turn the crankshaft CLOCKWISE so that the pointer is somewhat below the ignition timing marks. This will put #1 and #4 pistons down the bores a bit and out of harm's way. Now replace the camshafts and torque down the the bearing caps. Turn the cams (big cresent wrench and the hex section in the cams) to UP arrows up and lock them with punches or something.

Now turn the CRANKSHAFT ...COUNTERCLOCKWISE .. #1 and #4 pistons will now move back up the bores. Watch the flywheel marks. Turn past the ignition timing marks and then you will see the TDC mark. Line it up exactly with the pointer.

Now replace the belt.
 
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