New awm head, question about valves

[ShogunR32]

I bought a reman OEM AWM 1.8t head from a seller who had the head refurbished at the machine shop. I know that all the valves do not need to sit flush but was just wondering if these 3 open valves on cyl#3 look normal to everyone? One appears to stick out a little further than the other two.TIA!

[diagnosticator]

The intake valves (and exhaust valves,) all have the same timing and lift as designed. You can rotate the cams to lift other cylinders valves and compare. I agree, that does not look right.

[ShogunR32]

*edit.Damn, now im worried. Are you saying those valves should be open the amount?

[ShogunR32]

Couple more pics

[Furly]

The one in the center looks more open than the rest. When I set mine they were all evenly open (about the same as your other 2)

I'm guessing the machine shop installed it on the wrong groove or something.

[diagnosticator]

*edit.Damn, now im worried. Are you saying those valves should be open the amount?

Yes correct, the same lift amount and opening/closing timing. Do the other cyliders center intake valves lift more/open earlier than the two side intakes like the one shown?

[Kevin C]

any chance the lash adjusters on the out valves are bottomed or have a different set point? Any head that been sitting with the valves open is likely to have bottomed lash adjusters. You can try rotating the cams to make sure the valves fully seat and the buckets don't have a gap to the cam.

FYI Also, there might be a subtle timing difference on the center port, just not as much as is shown in the photo. My understanding is that the three cam buckets are not perfectly lined up ( the center bucket is offset). That would make for a slight difference. I have wanted to get a 1.8t head on the bench to measure it. If i remember right Audi has a patent for adding tumble by opening one of the three intakes before the others. I don't know if they ever implemented it.

This looks more like an assembly error or a bottomed out lash adjuster.

[ShogunR32]

Idk what to do now. I contacted the seller about it and he said this "That's normal you have a hydraulic lifter that's charged with oil more than others, when the engine starts they will automatically adjust." Does that sound right to anyone?

[redline380]

There's nothing wrong with that head. There will always be some valves open at any cam position. Look at the intake cam lobes.

And yes, that center valve will be open a bit more. Again, look at the lobes. The center one contacts the lifter first.

And yes, the seller is not lying to you. Those valves will look funny without proper oil in the lifters.

[ShogunR32]

There's nothing wrong with that head. There will always be some valves open at any cam position. Look at the intake cam lobes.

And yes, that center valve will be open a bit more. Again, look at the lobes. The center one contacts the lifter first.

And yes, the seller is not lying to you. Those valves will look funny without proper oil in the lifters.

Thanks for the response The seller does seem like a stand up guy and I dont believe he would lie to me. I was worried I needed to bring this to a machine shop again to check the other machine shops work.

[redline380]

Post up a closer pic of the cam timing. That is really the only thing that matters. It looks right but is too far away for me to tell 100%.

[ShogunR32]

Is this ok?

[redline380]

No, that does not look ok. At least from the angle. Plus, they marked only 15 links, it needs to be 16.

[ShogunR32]

Is that something that can be taken care of by the person who will install the head aka swap cct from my original head in? Do you see anything else that would stop you from installing the head on the car?

[redline380]

I would need to see the head in person to determine if it is usable. Looks fine from the photos though.

If you are swapping CCT's, then it is not an issue and when a new one is put in, the correct cam timing can be applied. The chain timing will be lost anyways when a new CCT is put in, so it can just be reset.

[ShogunR32]

If you count from 1 on the exhaust cam to the intake cam, it looks like 16 if you include the pin just to the left of the mark on the exhaust side.

[redline380]

Like I said, it is tough to tell from the angle your picture was taken. But if a machine shop put it together, I would trust them. They do that sort of thing for a living.

[diagnosticator]

Any variation due to the hydraulic lifters being compressed, is why I suggested rotating the cams to check the other cylinders. The engine assembly instructions require the engine not be rotated or started for a defined time, to allow the lifters to compress before pressurized oil pumps the lifters up fully. There is no difference in valve lift or valve opening/closing defined in the specifications for the three intake valves. Only one valve lift and opening/closing timing value is specified for all three intake valves. Even with the lifters extended fully to the mechanical travel limit, the valves should not be able to contact the pistons, unless there is a basic cam/crank timing error.

The intake cam drive chain has 16 link pins between the vertical alignment of the intake cam timing marks with the 1st link pin, and the 16th link pin offset 1/2 sprocket tooth toward the exhaust side past the vertical alignment of the exhaust cam timing marks.

[redline380]

The engine assembly instructions require the engine not be rotated or started for a defined time, to allow the lifters to compress before pressurized oil pumps the lifters up fully.

Pretty sure the time period you are speaking of is so short, it would be impossible to take it apart and put it back together in that time. Think it is around 30 minutes.

[diagnosticator]

Pretty sure the time period you are speaking of is so short, it would be impossible to take it apart and put it back together in that time. Think it is around 30 minutes.

Sure, that is the practical matter involved. Without rotating the cams, it is unclear why the middle intake valve is open more than the two outside valves. It could not be that way if the cams have not been rotated recently because the middle valve lifter would compress to equal the two outside valve lifters.

In the end there is a technically correct reason to explain why the middle intake valve is open more than the two outside valves. Only by examining the question will the situation be fully understood.

[redline380]

Sure, that is the practical matter involved. Without rotating the cams, it is unclear why the middle intake valve is open more than the two outside valves. It could not be that way if the cams have not been rotated recently because the middle valve lifter would compress to equal the two outside valve lifters.

I bent valves last spring. After I got my head back from the machine shop, the valves were much more variable than the one shown here. I was a little uneasy about it. Everything worked out fine.

A cylinder head is going to look much different statically than while in movement.

[diagnosticator]

I bent valves last spring. After I got my head back from the machine shop, the valves were much more variable than the one shown here. I was a little uneasy about it. Everything worked out fine.

A cylinder head is going to look much different statically than while in movement.

I agree. Regardless, if the cam has not been rotated recently, the middle valve as shown cannot remain open more than the other two valves, because the lifter would compress to equal the other two.

Even though there is practically little chance the head is not assembled right, it is worthwhile examining the question for full understanding of the technical situation involved.

[diagnosticator]

Is this ok?

The intake cam drive chain timing does not look right here. There is 16 links between the 1st link and the 16th link, but the 1/2 sprocket tooth offset specified past the exhaust timing marks, is instead divided between the timing mark alignment at the intake cam chain link #1, and the exhaust cam timing marks. All of the offset should be at the exhaust cam timing marks. The alignment of the timing marks and the 1st chain link and the intake cam timing marks must be vertically aligned with no offset at link number 1.




It doesn't matter witch direction the chain links are counted, as long as the 1/2 sprocket tooth offset exists at the exhaust cam timing marks.

As long as the cam timing marks are aligned, the intake cam timing with the chain links counted according to the red lines is correct.

[ShogunR32]

Thanks! You guys have been a huge help. It looks like everything appears good to go for an install then .