good compression, correct timing= bent valves?

[Pyrice4]

Ok, Since I put my rebuild engine together I have had this horrible noise. I thought it might be the valves hitting the cylinders so I checked the timing, All marks line up pretty close to perfect. Then I did a compression check, 180 on every cylinder. So, i pulled the head anyway. Sure enough, there are small marks on the pistons and on the valves where all the valves hit(intake only not exhaust.) My questions is how can I have the valves hitting the pistons, but still have perfect timing and perfect compression?

 

[The_EE]

Did it look anything like this? I have the same question myself. Timing was dead on but when I pulled my head ( after a spun bearing ) this is what I had found.

Was your head resurfaced? Maybe over sized valves? ( Just throwing something random out there because I have no clue as to what would cause it )

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[absolute_DSM]

Better make those pics below 700x700.

My questions is how can I have the valves hitting the pistons, but still have perfect timing and perfect compression?

Like you said if youre marks are a "little" off, yet you still have valve to piston contact (posting a picture would sure help) then it sounds like your head was resurfaced beyond the service limit.

Also are you talking about the marks below? If you are, those are supposed to be there We call them valve relief cuts.

 

[The_EE]

No, I am talking about the ones on the other side. There was very slight hitting of valves to piston. Look again at those pictures and you can see from top to bottom ( 4th to 1st cylinder ) that they hit.

 

[Pyrice4]

The head was not resurfaced and worked fine before i put it on this block.

 

[outkastracing]

i dont see any valve marks or nicks. if you did you'd see sharp edges. ext you'd notice it those are valve reliefs.

 

[The_EE]

Trust me, there are slight indentations within the reliefs. I can feel them with my fingers.

If you look closely at the top picture ( cylinder #4 ) you can see that they barely hit, then look at the 2nd from the top ( Cylinder #3 ) and there is a tab bit more of an impact, then the 2nd from the bottom ( Cylinder #2 ) there is more of an impact and cylinder 1 at the bottom has the worst. You can see the shiny marks on it from where the valves lightly tapped the pistons. Cylinder #1 is the most apparent.

I would attempt to take pictures with a much better camera then I have but I already put the head back on the car for transport as I am moving 1600 miles away on Saturday. Perhaps when I get to my destination I will get some pictures with a better camera.

 

[luv2rallye]

My questions is how can I have the valves hitting the pistons, but still have perfect timing and perfect compression?

The ONLY way your valves can hit the pistons (assuming you have the correct parts) is to have the timing belt installed wrong or not adjusted properly (so it jumped teeth). Did you follow this proceedure EXACTLY on every step (http://www.vfaq.com/mods/timingbelt-1G.html)? Pay special attention to figures 11, 11b, 12 and the note under figure 11b. Also note all the shafts only line up correctly every 6 turns of the crankshaft (step 31).

 

[Pyrice4]

My timing is fine, tension is good, all marks line up. Its a 6bolt block with a 6 bolt head. Is there any way that it could be a jdm block thats different than a stock block?

 

[spyderturbo007]

All marks line up pretty close to perfect.

That's most likely your problem, since it doesn't take much at all to start bending valves.