Cylinder Head Cleaning

[johno90]

@dom14

Trust me I've built many engines from 4cyl through to 12cyl. Im not saying it wont work im saying it wont last.
Here is sorter the point Im making, there is alot more to metal work and gaskets and building engines then people think - its why a proper built engine is always expensive

"Don’t go smoother than 40 Ra (240 Rz) or rougher than 100 Ra (600 Rz) with a gasket. Rougher surfaces limit gasket conformance, while smoother surfaces increase the tendency for gaskets to flow, reducing the gaskets blow out resistance."

What ever you do dont spray the copper on anything other then a standard compo or paper gasket, spraying on mls or anything else is actually doing it harm.

Just trying to give you some experienced advice and save you money in the long term.

[dom14]

@dom14

Trust me I've built many engines from 4cyl through to 12cyl. Im not saying it wont work im saying it wont last.
Here is sorter the point Im making, there is alot more to metal work and gaskets and building engines then people think - its why a proper built engine is always expensive

"Don’t go smoother than 40 Ra (240 Rz) or rougher than 100 Ra (600 Rz) with a gasket. Rougher surfaces limit gasket conformance, while smoother surfaces increase the tendency for gaskets to flow, reducing the gaskets blow out resistance."

What ever you do dont spray the copper on anything other then a standard compo or paper gasket, spraying on mls or anything else is actually doing it harm.

Just trying to give you some experienced advice and save you money in the long term.

Thanx for the tips. Yes, I can't argue with that experience as I haven't been rebuilding engines on regular hobby basis.
Yes, I can understand the surface smoothness of the head need to have some perfect balance to match the particular head gasket. Too coarse or too smooth both can yield unfavourable results as you explained above.
Yes, I understand there is no saving in money if the head gasket fails within few thousand km's of engine running.
And yes, I can understand there is a difference between sanded metal surface and machined metal surface with a cutting tip.
The surface texture of a mill machine cut surface would have curved cut lines whereas sandpaper ground surface would have straight lines.
I guess for a particular type of head gasket, those surface texture pattern can negatively or positively affect.

Of course, there is no way backyard engine rebuilding can match with proper machine shop work.
It is fun to DIY and it's even more fun when I get it right.

[billyj]

as above even most composite gaskets are pre coated these days, spraying them with copper coat or hylomar etc will only reduce how well they adhear