MLS head gasket prep

[Grrrrrrr!]

How smooth does the head and block need to be to get a good seal with a MLS head gasket?

Just picked my head and block up from machining and the machinist says its all good to go, but it feels pretty rough to me.

[Malcolm]

I found a surface roughness guide once but buggered if I'd remember where. You could always lovingly sand them with some wet/dry and something very flat. For what its worth I was concerned when I got mine done but it seemed to seal fine.

[Grrrrrrr!]

Yeah, I have a set of parrallels around somewhere so i could hit it up with some 400grit to knock it down. It just adds more work that i'd rather skip.. Sanding, cleaning. cleaning, more cleaning. Grrrrr!

[Dell'Orto]

Laminated (multi layer) steel type gaskets with rubberised coatings - less than 0.50 micrometers RA

Laminated (multi layer) steel type gaskets without rubberised coatings - less than 0.75 micrometers RA

So fairly smooth

[Malcolm]

Laminated (multi layer) steel type gaskets with rubberised coatings - less than 0.50 micrometers RA

Laminated (multi layer) steel type gaskets without rubberised coatings - less than 0.75 micrometers RA

So fairly smooth

The machine shop I got to do mine had surface finish sample cards to allow a comparison to be made to determine the finish quality, might be worth seeing if your machinist has some of those you can check

[rx7guy]

Could try copper spray?

[Grrrrrrr!]

Laminated (multi layer) steel type gaskets with rubberised coatings - less than 0.50 micrometers RA

Laminated (multi layer) steel type gaskets without rubberised coatings - less than 0.75 micrometers RA

So fairly smooth

Seems weird to me that the one without the rubberised coating can handle more roughness. Thinking i'll just go with the composhit gasket if it measures up too rough.

[Malcolm]

I'll be keen to unsell mine if you change your mind