Timing Question

[multarnc]

I bought a '98 Eclipse GST a few months ago. I'm not new to turbo 4 cyl cars, but I'm not very familiar with this engine. I'm checking the timing because it is idling rough and running a little lean.
I noticed that the timing marks on the cam sprockets are lined up in the center, but not in a straight line all the way across. I've also noticed that the cam sprocket dowels are on the bottom as opposed to the top.
Based on everything I've read, and the Haynes manual, these should be in the up position. It almost seems like the cam sprockets are 180 degrees off. If this were the case, I would think it wouldn't even start, let alone run, right?

If it is 180 degrees off, do I rotate each one 3 times to get it right?

One mistake will mean ruining the head, so I really want to get feedback before attempting this.

Thanks in advance.

 

[WES_393]

You need to be able to see the crank timing mark to determine if the timing is off. The marks on the harmonic balancer are for ignition timing, you have to take off the black cover to see the timing marks.

 

[multarnc]

I have everything off. The crank and the balancer pulley are lined up with the marks. On the cam sprockets, the two marks that are not marked white are lined up in the middle. It's always been this way. But the dowels are at 6 o'clock and the white marks on the cam sprockets are on the outside, not the inside.
The car idles a little rough, but has seemed to run fine.

 

[Alan11]

Dowel pins always go up no matter what. Being 180* off will mess you ignition timing. If the dowel pins are facing down then the mechanical timing is off.
When timing is set the engine need to be rotated 6 times instead of 4 due to having the balance shaft.

 

[multarnc]

I would think it wouldn't run if it was off by 180 degrees.

To fix it, with the crank and balance shaft on their marks, do I rotate the cams 1 time or 3 times?

 

[Alan11]

I would think it wouldn't run if it was off by 180 degrees.

To fix it, with the crank and balance shaft on their marks, do I rotate the cams 1 time or 3 times?

You will -not- bend valves by them being 180* out. Your mechanical timing is off. Pull the belt and start over. You need to take the belt off and just line up the cams with the dowel pins up.

 

[multarnc]

So just turn them once, until the dowels are up?

I just want to be sure. This will be a very costly mistake if wrong.

 

[Alan11]

So just turn them once, until the dowels are up?

I just want to be sure. This will be a very costly mistake if wrong.

Yes, as long as the dowel pins are facing UP then you are fine.

Remember that in order to rotate the cams, the crank can't be at TDC. All 4 pistons should be at the middle of the block in order to give room for the cams to rotate freely.

http://vfaq.com/mods/timingbelt-2G.html

 

[multarnc]

How could it still run with the cams at 180 degrees off?

 

[WES_393]

You will just have to redo the timing completely if they are that off. Put the crank mark halfway between TDC and BTDC so that you can rotate the cams without damaging the valves. Turn them so the dowels are up and re-time the engine.

One thing you should pay particular attention to is the crank trigger plate. If it's flipped around, the car will not start. How the car runs with the marks being 180* off is beyond me.

 

[multarnc]

Can anyone explain how it ran while 180 degrees off?

How the car runs with the marks being 180* off is beyond me.

The fact that it ran with it 180 degrees off is what makes me nervous. Is it possible the sprockets were just put on wrong and it's actually oriented the right way?

 

[Alan11]

Having the dowel pins 180* out is pretty much the same thing having the CAS 180* out.
This doesnt mean you can just flip the CAS 180*. Is my math is right doing this will not work having the BS.

This is still a four stroke engine, so the strokes are in a given order.

When setting the timing belt it is based of #1 cylinder being on the compression stroke
Stroke 1 piston is at TDC, Both I&E valves closed,cam dowels at 12 O'clock, cam gear marks at E/3 and I/9

Stroke 2,power stroke, Piston moves to BDC,I&E valves closed, Cam moves 90*,crank moves 180*,Cam gear marks are E/6 and I/12, cam dowels are 3 O'clock

Stroke 3, Exhaust stroke, Piston moves up to TDC, Exhaust valves open, Intake valves closed, Cams move 90*, crank moves 180*, Cam gear marks are E/9 and I/3, cam dowels are 6 O'clock

Stroke 4,Intake stroke, Piston moves down to BDC, Exhaust valves close, Intake valves open, cams move 90* crank moves 180* , cam gear marks are E/12 and I/6, cam dowels are 9 O'clock

Now repeat.. again..again..again..

so it you drop the time belt on with the cam dowels at 6 o'clock and not 12, you set the time by the exhaust stroke on #1 cyl or the compression stroke of #4
At any time a 4 cyl engine has 2 pistons at TDC and 2 at BDC.

The fact that it ran with it 180 degrees off is what makes me nervous. Is it possible the sprockets were just put on wrong and it's actually oriented the right way?

Cam gears can only be installed one way. with the dowel pin guide hole into the cam's pin.

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[pauleyman]

You guys are killing me. Keep rotating the crank some more. All the marks will line up. It's takes six times for the marks to line up. Every three turns the dowels are down, three more and the dowels are up. Did you notice the cams are exactly double the amount of teeth from the crank? The front balance shaft and oil pump are also multiples of the crank.

But it is the newbie section......

 

[zack13277]

Did you line up the crankshaft pulley to the mark? Try rotating the engine 1 revolution with the belt on and line up the 2 cams in the middle then see if the crankshaft is liked up with the mark

 

[Alan11]

You guys are killing me. Keep rotating the crank some more. All the marks will line up. It's takes six times for the marks to line up. Every three turns the dowels are down, three more and the dowels are up. Did you notice the cams are exactly double the amount of teeth from the crank? The front balance shaft and oil pump are also multiples of the crank.

But it is the newbie section......

Did you line up the crankshaft pulley to the mark? Try rotating the engine 1 revolution with the belt on and line up the 2 cams in the middle then see if the crankshaft is liked up with the mark

Post #3 he said the crank and BS are lined up with the marks(I am asuming the oil pump too) while the dowels are facing down. Time to redo the timing.

 

[multarnc]

I redid the timing. When it was originally done, by the previous owner when the motor was replaced, they did not line up all four marks on the cam sprockets. I re-did everything. Everything lines up and the tension is perfect. I've never heard her sound so good! No more rough idle and no longer running lean!!
With the upgrades I've added, I've just revealed a new issue. Time for a new clutch!

Thanks for all the help!!

 

[pauleyman]

Post #3 he said the crank and BS are lined up with the marks(I am asuming the oil pump too) while the dowels are facing down. Time to redo the timing.

Just for anybody reading this post it may still not be necessary to redo. Just keep turning the crank. The marks line up several times while turning the crank but only once every six turns do all five line up with the dowels up. If only some of them line up (assuming it's right) then you just need to turn the crank some more.
To the OP glad you resolved it. Not sure if you had to redo or not but for reference notice this next time you're in there. Rotate it around a few times and you'll notice that the crank, oil pump and balance shaft line up but the dowels will be down. Rotate some more and they will be up. It's all about relative position.

 

[Alan11]

Yes sir you are very correct.
When the crank turns 360*
The cams turn 180*
So when the crank turns 720* the cams have gone 360*
Good job on fixing it op.