Warped head.

jorion · Post by **jorion** » 18 May 2011, 21:31

I have a cylinder head with .024 of an inch warpage. This is off of my 99 volvo s70. Any suggestions on what i should do? has anyone had similar warpage on a head? what about the cylinders warping?

Post by **Oly_850** » 18 May 2011, 21:35

Easy! It's an aluminum head and is entirely fixable and known for this issue. Take it to a machine shop that works on German cars and get the head "decked" flat or just rebuilt while you're at it. Should be like $250 for the complete job.

jorion · Post by **jorion** » 18 May 2011, 21:43

Is .024 excessive warpage though? Is it to much to just have the head machined? And if i have the head decked, the top of the head will still be warped. How does this effect the camshafts and the valves?
does anyone know the correct spec's for warpage?

Post by **Oly_850** » 18 May 2011, 21:52

Machined = Decked. Your head would be visably u-shaped to affect your cams. Are you sure you've got .024 warp over at least a 6" Span of the head? The spec is .003 so yours is way off straight. Threy usually warp between the middle cylinders. Not to fear. Machine shops fix these heads everyday, even if thy're cracked.

jorion · Post by **jorion** » 18 May 2011, 21:58

I was just interchanging machined and decked. The measured warpage was with a straight edge across the length of the head.

Post by **Oly_850** » 18 May 2011, 22:01

Yep way too much to put it back on. You could fix yours or find one in a wrecking yard (which might or might not be straight), but new ones are ridiculously priced.

Post by **Ozark Lee** » 18 May 2011, 23:09

The book spec on warp limitation "for acceptable use" is 0.0196" lengthwise and 0.0078" across. A good machine shop should be able to fix you up with the head that you have so long as the valves are all OK. If you also have damaged valves you might want to compare prices between the local machine shop and a place like Clearwater Cylinder Heads. Clearwater sells refurbished heads that are plug and play but they want your old head back and it is thus double the freight on an item that has some significant weight .

...Lee

jorion · Post by **jorion** » 18 May 2011, 23:20

Wow, that seems like a lot for an acceptable warp limit
.

Post by **Ozark Lee** » 19 May 2011, 00:28

Wow, that seems like a lot for an acceptable warp limit

If it were a cast iron head it would be but aluminum has some conforming properties as it is torqued down. For all of the work that replacing a head gasket is I want the thing dead flat when it goes back on the car. The warp spec can also get a bit misleading if it is all at one end rather than the middle.

...Lee