Cams Backwards/Upside down?!

[want_a_gsx]

The rebuilt motor does not turn over when I try to start it; it cranks about close to one whole rev and then it stops violently. Someone suggested the cams are on backwards; I tool some pics, wondering if someone could help me out.

Not sure if it's possible to tell, since the cams aren't lined up after cranking the motor, but I figured I would give it a shot.

Thanks in advance.

 

[starsthensun]

Put a 1/2 inch socket wrench on the crank pulley and line up the timing marks. If you can't line the marks up because it all of a sudden stops before you can line it up or the timing marks don't line up, you will need to re time the motor. Don't try to start the car, what is happening is the valves are hitting the top of the pistons and locking up.

 

[want_a_gsx]

The timing marks line up . Everything seems to be turning normal...

 

[tkelly27]

Check your crankshaft pulley to see if it's at TDC when you see that.

Even if it is, I'd pull it apart again. The only other thing it could be if the pistons aren't hitting the valves would be a loose bolt in the transmission area.

 

[moto x]

Check all your timing marks.

Did it spin freely before you put the head on?

 

[want_a_gsx]

The motor did spin without the head.

Here are some pics of the crank pulley. Where is the timing mark on the pulley?

 

[SOADweskey]

To see the timing marks on the crank and on the oil pump sprocket you need to take off that pulley and the lower timing cover.

Check the timing belt how to articles at http://www.vfaq.com for pictures of them.

 

[Quasimondo]

You have to pull the crank pulley and lower timing cover off to check the marks on the crank. There's a static timing plate that's sandwiched between the cog for the balance shaft belt and timing belt. That plate has a notch in it that should line up with an arrow that's stamped on the oil pump cover and points to the timing plate at the 2 o' clock position.

An easier way to check is to take a long screwdriver and insert it into the #1 cylinder. Turn the crank until the cam gears line up, and then give it another quarter turn. If the screwdriver continues to move up, then that static timing plate was installed backwards. If the screwdriver moves down, then your problem is elsewhere.

 

[Epic904]

Take the rank pulley off and check the timing marks on the crank shaft and balance shaft. It does sound like the valves are hitting the piston and locking up the motor. Did you turn the motor counterclockwise at all?

 

[Quasimondo]

Another wild thought. Pull that half-moon off the head and see if there's a notch on the end of that exhaust cam.

 

[crensinivon]

The timing mark on the crank pulley is on the back half of the pulley and line up with the TDC mark. I would also check the battery there might not be enough power to spin the brand new motor as there are a little tighter than a used motor.

Also were the ridges on your block reamed this could cause a similar issue.

 

[want_a_gsx]

An easier way to check is to take a long screwdriver and insert it into the #1 cylinder. Turn the crank until the cam gears line up, and then give it another quarter turn. If the screwdriver continues to move up, then that static timing plate was installed backwards. If the screwdriver moves down, then your problem is elsewhere.

The screwdriver moved down...

Take the rank pulley off and check the timing marks on the crank shaft and balance shaft. It does sound like the valves are hitting the piston and locking up the motor. Did you turn the motor counterclockwise at all?

No, I did not turn it counterclockwise.

Another wild thought. Pull that half-moon off the head and see if there's a notch on the end of that exhaust cam.

 

[peypey's ride]

From the pic of your exhaust cam, it looks like your cams are in the right place. The notch is on the intake side and that is where your CAS will mount into. I would check your timing and make sure your crank timing mark lines up and at the same time check to make sure your cam gear timing marks are lined up to!

 

[blcknspo0ln]

It could very well be that your timing is still off. As you saw in my other tech article, there is more than 1 timing mark that needs to be aligned when everything is at TDC. Check that the cam gear timing marks, oil pump gear, and crank sprocket plate are all timed correctly. I know it's frustrating to remove everything since you just put it back together, but removing the lower timing cover will tell you (or at least give you peace of mind) about what's going on with your motor.

I also hate to be the bearer of bad news, but if your timing was off by more than 2 teeth, valves and pistons may have collided and by that second of it being on (as in you turned your car on) it could have bent your valves. Again, definitive way of checking is to remove the lower cover.

 

[TurboAnything]

If you put the lower timing indicator on backwards then you will have a no start or hard start condition. Its the round shetmetal with the notch in it. When its on backwards your timing will be off but the motor will still seem like it wants to run and it uselly will bend the #1 cylinder intake valves.

 

[DSMopar]

Doesn't really matter anymore, the head has to come off. This is why you should always roll the motor over a few times by hand before using the starter...

 

[tkelly27]

Doesn't really matter anymore, the head has to come off. This is why you should always roll the motor over a few times by hand before using the starter...

While the probability of bent valves is nearly 100%, getting it in time and doing a compression check will save a lot of time and energy if it turns out to be OK. Additionally, learning how to get it in time with bent valves is a better idea than learning the hard way with fresh ones again.

 

[blcknspo0ln]

While the probability of bent valves is nearly 100%, getting it in time and doing a compression check will save a lot of time and energy if it turns out to be OK. Additionally, learning how to get it in time with bent valves is a better idea than learning the hard way with fresh ones again.

While you're probably right, I don't think it's fair to say that the valves are absolutely bent until timing is checked. Once that is done, a compression test is definitely in order.

 

[tkelly27]

Haha, that's what I was trying to say. Mornings are bad for me To the OP, get on AIM, it will be faster for me to send pictures that way. There are more than a few things that can be out of alignment and they need to be gone through from the crank all the way up to the cams.