5 replies to this topic

[mattkjsmith]

Hi,

My mate, who's an apprentice mechanic, told me to send away my cylinder head for skimming. All well and good, but i don't actually know what skimming is and what it does?

What's good and bad about getting this done?

Cheers, Matt

[Big_Adam]

Take a thin amount off the bottom (cylinder to head side) of the head to make the surface smooth and perfectly flat.

Also, sending it away? You sure you not got a local place that will do it, if not it is like £13 postage.

[lrostoke]

Any particular reason he's said get it skimmed ?? Have you had head gasket problems, is it a non standard head for your engine.

[Turbo Phil]

Unless the head face is uneven or you're trying to raise the compression then there's no need.

[dklawson]

To add to TurboPhil's comments, skimming is usually done to flatten a warped head. When you want to remove more material to raise the compression, that's typically referred to as shaving.

If your friend is suggesting shaving the head to boost the compression ratio, this isn't an arbitrary process. You're supposed to CC the cylinder head to determine how much to take off after calculating the volume you need/want for a given compression ratio.

[01smartc]

We have a lot of people sending heads for skimming.. its usually just to get a nice finish before rebuilding.. not always necessary but worth it for peace of mind. A 5 thou skim will not alter the compression very much, and even that is in the right direction.

I say for peace of mind during a rebuild you might as well skim it.

Just for the record we charge £25 to skim a head casting so that about the price your looking

Chris @ Smart Performance