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Honestly, I think you're over-thinking this. If you put the crank gear's key at 12 o'clock, then cylinder #1 is at TDC.

Did you rotate the cams at some point? Given that your timing chain was still attached and functioning - the engine was running fine - everything should already be in approximately the right position. If you read the complete procedure that I linked to above, specifically steps 21-25, you'll see there's a step where it's necessary to rotate the exhaust cam about 45 degrees to get the dowl on the gear to pop into the notch on the end of the cam while keeping the chain in the right position. It also says not to rotate the intake cam at all. It's necessary to rotate the exhaust cam in order to get it in the correct phase and keep tension on the chain.

I'd be hesitant to spin the engine backwards. It'll probably be fine, though.
 

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There is always a concern in an interference engine with rotating any one component independently. If a piston is at TDC and a camshaft is rotated enough to open a valve in that cylinder there will be contact. Likewise if a valve is open and the crankshaft is rotated enough to raise that piston there will be contact. Rotating the engine in reverse raises concern because the chain drive is designed to only run forward and is tensioned on what is normally the slack side. Reverse rotation can load that part of the chain enough to deflect the tensioner, and if there is enough movement the chain can go slack enough to skip teeth. Absent that happening there is no inherent problem with reverse rotation.
 

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Another thing that should be obvious, but just didn't occur to me the first time I did a timing chain:

When rotating the cam, the valve springs will attempt to spin the cam after you've rotated it a few degrees. Use a long wrench on the cam and be prepared for it to try and get away from you.
 

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Discussion Starter #144
Sorry, I thought I had made it clear in my earlier post but looking back on it, it was not. The cams indeed shifted because of spring pressure when I took the tensioner out and was looking at the chain. Both cams rotated independent of the crank. I hope they didn't impact the pistons but in theory, the valves should be, on overall average, retracting from the spring pressure.

I have an entire new kit, so if the chain/tensioner/guides are the only reason for not turning the crank backwards, than there's no worries. I will just figure out which of the pistons are highest and rotate the crank in a direction that lowers them so that all 4 are in the middle (nowhere near the valves).

In theory, at that point the process should look like this:
1. Remove chain completely
2. Use extension/straw/etc to figure out the levels of each piston
3. Set piston levels near the middle
4. Set the cams to their TDC position
5. Set the crank to TDC position
6. Attach chain and align timing marks
7. Profit!

Does anyone see any flaws or misconceptions in that plan?

EDIT: Side question, our 4 cylinder's pistons move up and down in pairs, right? Like the outer 2 and inner 2 move together?
 

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Okay - that makes sense. Rotating the crank so that all of the pistons are mid-stroke should prevent valve-to-piston contact while timing the cams. Unless you're valves move by like 3", which would be both impressive and silly.

You're correct in that 1 and 4 move in sync, as do 2 and 3. So, if you rotate the crank so that the key is at 6 o'clock, everything should be in the position you're looking for. The question is which direction are you going to rotate, and will a piston hit the valves during the transition.

Shrug - sounds like you've got a well-considered plan. Go for it.
 

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Discussion Starter #147
Ok, second issue. I cannot get the timing chain on, it seems like everything is just a bit too tight. If I get the cams on, then I can't get the tensioner guide on (can't push it far enough to line up the bolt hole). If I put the tensioner guide on, I can't get the exhaust cam sprocket onto its shaft (let alone the into the keyed slot). I have tried rotating the cams and rotating the crank while trying to seat the cam to no avail. Does anyone know any tricks?
 

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Basically, you get the chain all lined up (without the tensioner installed), chain on the exhaust sprocket but with the sprocket not yet all the way on the cam.

There's an alignment pin on the back of both of the cam sprockets. You'll put a wrench on the hex portion of the exhaust cam and rotate it to get the sprocket on. Rotate the cam far enough that the sprocket alignment pin lines up with the slot in the end of the exhaust cam, push the sprocket all the way on, and then you can release the exhaust cam. The springs will cause it to rotate back and the pin will keep everything in the correct orientation.

That's all detailed in the AutoZone repair guide I linked to previously in this thread.

As far as the spacers go, I'm not sure what you're referring to. It's been awhile since I've done this.
 

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Discussion Starter #149 (Edited)
Basically, you get the chain all lined up (without the tensioner installed), chain on the exhaust sprocket but with the sprocket not yet all the way on the cam.

There's an alignment pin on the back of both of the cam sprockets. You'll put a wrench on the hex portion of the exhaust cam and rotate it to get the sprocket on. Rotate the cam far enough that the sprocket alignment pin lines up with the slot in the end of the exhaust cam, push the sprocket all the way on, and then you can release the exhaust cam. The springs will cause it to rotate back and the pin will keep everything in the correct orientation.

That's all detailed in the AutoZone repair guide I linked to previously in this thread.

As far as the spacers go, I'm not sure what you're referring to. It's been awhile since I've done this.
So the tensioner got activated at some point and I didn't notice, everything went just fine once i found that out. The engine is back together and running just fine. Now I have to put the radiator, intercooler, bumper, and trim back on and I should be good to go.

There are 2 very thin washers/spacers, one that go between the timing/balance sprocket and one goes between the timing sprocket and the crank pulley. I just omitted the one between the crank pulley and timing sprocket.
 
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