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Engine 180 degrees out; 94 metro head swap
Topic Started: Dec 4 2016, 10:32 PM (389 Views)
mclovin_lucafer
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Sooooo, i made a mistake when positioning my engine at #1 TDC. I accidentally placed it at #1 TDC of exhaust and not compression. How do i put the engine in tdc for compression when i have it apart already? I have the haynes manual but it does not cover this occurrence. My new head (with a new cam shaft installed) is in the same position as the old head and cam was when i took it off. The lobes are in the same spots and all the valves are closed on the new head just like the old ones were. The notches on the cam where the distributor slide into it are also in alignment. My questions is, can i just put the car back together the same way it was when i took it apart being on the exhaust side of TDC for the #1 cylinder. :banghead

94 metro hatch 993cc 3 cylinder auto trans.
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David95237


If the head isn't on their is no exhaust tic. Its just tdc. You have to use the timing marks to do it properly no cheating.
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myredvert
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myredvert

Quote:
 
How do i put the engine in tdc for compression when i have it apart already?
By using the timing marks on the crank gear and cam gear.

Quote:
 
I have the haynes manual
You also have the manual written by the factory that built the car... ;)

Geo Metro Forum → The Garage → Factory Repair Manuals/Wiring Diagrams → 1994 library

SECTION 6A1 ENGINE MECHANICAL - 1.0 LITER (review the instructions for timing belt installation starting on page 6A1-16)
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mclovin_lucafer
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David95237
Dec 4 2016, 11:14 PM
If the head isn't on their is no exhaust tic. Its just tdc. You have to use the timing marks to do it properly no cheating.
I lined the mark on the crank pully to the "0" on the belt cover. I overlooked the position of the distributor tho when i took the head off. The #1 piston is all the way up right now but the cam is lobe positioning is different then the manual(it shows the lobes positioned differently than mine are, probably because that is what compression tdc would look like). How do i correct this? the old head is off the car and the new one is not on yet.
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mclovin_lucafer
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so if i line up the pulley mark to the "0" on the cover and the mark on the cam gear to the mark on the valve cover i should be ok provided that the two valves are closed on #1 and the #1 piston is all the way up?
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freegeo
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You need to use the mark on the crank timing gear with the mark on the oil pump. That will put the piston at TDC.
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Car Nut
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freegeo
Dec 5 2016, 01:04 AM
You need to use the mark on the crank timing gear with the mark on the oil pump. That will put the piston at TDC.
:gp
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Woodie
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David95237
Dec 4 2016, 11:14 PM
If the head isn't on their is no exhaust tic. Its just tdc.
:gp

If the head is off, then you can check TDC much easier. When the #1 piston is at the absolute top of its stroke, that's TDC. There's no compression, intake, or exhaust until the head goes on. If you want you can turn the engine one complete revolution and then bring it back to TDC. You won't have done anything at all, but it might make you feel better about having it right now. B-)

With the piston at the top, your timing marks on the crankshaft pulley should line up. If they don't, then your woodruff key inside the crank sprocket has sheared. It's something that happens sometimes when the big bolt is loose. Very easy to check at this point so you might as well check it.

Turn the camshaft until both of the #1 valves are closed and the lobes on the cam are pointing up away from the head casting. Now the head is at TDC, put it together and use the timing marks for the fine adjustment. With the #1 piston at the top, and the #1 cam lobes pointing up like Mickey Mouse's ears the timing marks should be VERY close to spot on.

Put on the belt, let the incredibly weak spring set the tension (doesn't seem like enough tension, but it is), then put a socket and ratchet on the crankshaft bolt and turn it over two complete turns clockwise. You want all the tension on the front (straight) side of the timing belt. Allow the spring to set the tension again, and tighten down the tensioner. Then, check your timing marks again. If they're right, then you've done it.


Edited by Woodie, Dec 5 2016, 06:40 AM.
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mclovin_lucafer
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Woodie
Dec 5 2016, 06:36 AM
David95237
Dec 4 2016, 11:14 PM
If the head isn't on their is no exhaust tic. Its just tdc.
:gp

If the head is off, then you can check TDC much easier. When the #1 piston is at the absolute top of its stroke, that's TDC. There's no compression, intake, or exhaust until the head goes on. If you want you can turn the engine one complete revolution and then bring it back to TDC. You won't have done anything at all, but it might make you feel better about having it right now. B-)

With the piston at the top, your timing marks on the crankshaft pulley should line up. If they don't, then your woodruff key inside the crank sprocket has sheared. It's something that happens sometimes when the big bolt is loose. Very easy to check at this point so you might as well check it.

Turn the camshaft until both of the #1 valves are closed and the lobes on the cam are pointing up away from the head casting. Now the head is at TDC, put it together and use the timing marks for the fine adjustment. With the #1 piston at the top, and the #1 cam lobes pointing up like Mickey Mouse's ears the timing marks should be VERY close to spot on.

Put on the belt, let the incredibly weak spring set the tension (doesn't seem like enough tension, but it is), then put a socket and ratchet on the crankshaft bolt and turn it over two complete turns clockwise. You want all the tension on the front (straight) side of the timing belt. Allow the spring to set the tension again, and tighten down the tensioner. Then, check your timing marks again. If they're right, then you've done it.


ok that sounds correct. So the pistons don't care whether the cam was on compression or exhaust when i took it apart? So as long as the number 1 is at the top and 2-3 are all the way down the block is good to go (provided that the mark on the pully and belt cover line up, which they do). I can just rotate the cam to the correct position until the lobes are up and the mark on the cam gear line up with the "v" on the valve cover and the crank pully. Then just make sure i put the distributor back on with the open metal side pointing at the number 1 spark plug. Then i should be good to go?
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Mrbreeze


Don't worry about the belt cover right now, that's for setting the timing AFTER its back together, right now you just need to line up the marks on the crank gear/pointer on oil pump, cam gear/notch in valve cover. Install belt, rotate 2 revolutions on the crankshaft and see if marks re-align at that point. If they do, continue putting it back together, if not, redo it..
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mclovin_lucafer
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ok sounds good ill try it when i get off shift. Thanks!
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