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Discussion Starter #1
So i'm about to pick up a cheap k20a2 head from a friend of mine who works at Acura but there is one problem, the head is warped and is out 6 thousands or 0.006. Acura won't machine a head via the Service Manual, but I know its been done before.

What is the maximum tolerance that I would be able to get the head machined since it is already out so much?
 

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Discussion Starter #2
I found out through word of mouth that the max you can mill it would be 0.008 in. It kind of answers my question but its nothing set in stone. Does anyone know for sure or have something to back this up???
 

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When you mill the head to remove a warp on a overhead cam design like the Kseries(.004 is the max allowed per Helms) you will cause the cams to ride off center in the cam saddles and cause greatly increased wear and clearance in the cam caps and possible cam snapping because the warp is still present for the cams, not to mention cam sprocket misalignment. The restriction cited in the Helms isnt regarding the material being removed from the head face, but the cam bore issue.
 

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In order to be able to use this head, you have to mill the head flat, take out the spark plug tubes, mill the top of the head, rebore and hone the cam caps and then reinstall the spark plug tubes.

All that will cost about $700 for a machine shop to do it. So its it worth it to do. Well that depends on how much you are paying for it.

But personally I would not use a head like that. You are asking for troubles.

Stefan
 

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Discussion Starter #6
When you mill the head to remove a warp on a overhead cam design like the Kseries(.004 is the max allowed per Helms) you will cause the cams to ride off center in the cam saddles and cause greatly increased wear and clearance in the cam caps and possible cam snapping because the warp is still present for the cams, not to mention cam sprocket misalignment. The restriction cited in the Helms isnt regarding the material being removed from the head face, but the cam bore issue.
That's what i was afraid of. I'm going to call my local machine shop today and see what they have to say about it but if its going to cost me more to machine it back to within standards I don't think its worth buying.
 
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