How common is head warpage on EJ22 NA's?

[turboleg]

Hey guys just wondering how common it is for used EJ22 NA heads to warp. I have a 100K engine sitting on one of my stands with good heads...and a heads on the NA thats in my car that are all but done for. I would like to swap over the heads but if there one of the notorious heads that like to warp (I worked on a few quad fours ). I really don't feel like spooling up the mill to reface them. I would rather just replace the cam seals on the engine on the stand and swap engines. I could deal with the fried heads sometime in the future that way.

Suggestions?

[Manarius]

I can't think of the heads ever warping unless the car has overheated before. My car has 153k miles and no head warpage.

[turboleg]

Thanks!

[Psychoreo]

correct that, after spending some time at the local machine shop, almost all of our heads are warped. Nothign too major and most of which are in spec (under .005 for our aluminum heads.) They LIVE off the local subaru dealerships and have heads in and out of there all week long.

If you know what a quad four is, then you probably have access to a straight edge and a feeler gague. Check 'em and if it's under .005, they're fine.

[turboleg]

Yeah, I noticed that either the FSM or the Haynes (yeah I know it sucks) lists the warpage limit as .002". I figured that had to be a misprint. Thats a pretty crazy tollerance. I've used .005" for everything else.

That was the biggest reason for my concern.

Thanks!

[Psychoreo]

No problem