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Head and engine block skimming
bikecarbfred - 29/4/17 at 07:42 PM

If you can't slip a feeler gauge strip under a straight edge ruler on the the head and cylinder block then why is there need to re-skim?

If the straight edge ruler shows all parts on engine block is straight is it worth skimming.

And if that's a yes, I feel comfortable doing it the DIY youtube way. Sand papers stuck onto 10mm thick glass and place the head on there and give it a few minutes to skim.

coozer - 29/4/17 at 08:12 PM

Any reason why think it might need skimming then?

What motor you on about and has it boiled or chucked a head gasket?

britishtrident - 29/4/17 at 08:46 PM

Sounds like the head needs a skim, block should be OK , but if it is a wet liner engine it is generally better to have the liners up to 0.006" proud of the block.

bikecarbfred - 29/4/17 at 10:40 PM

quote:
Originally posted by coozer
Any reason why think it might need skimming then?

What motor you on about and has it boiled or chucked a head gasket?


1.4 16v AFH engine. No it has not boiled. It is just an engine from a crash damage car that I bought that I am rebuilding as part of a learning project.

I just read everywhere on the net , when putting on a gasket, always skim the head.

I think I might just skim the head and leave the block. Will double check the block with straight edge ruler and torch to make sure ever where is blocking light.

minibull - 30/4/17 at 03:09 AM

Only reasons to skim a head are if it's warped out of tolerance or suffered corrosion around the waterways. Alloy heads seem to warp for fun hence it's become more or less standard practice, regardless if it isn't warped or corroded it doesn't need skimming. As to skimming with sand paper on glass no real reason it won't work as it's basically only lapping and been an engineering process for many years. Check glass is actually flat though as it often isn't. Problem is that if head needs skimming it will need a lot more lapping than a couple of minutes, if a couple of minutes does the job it didn't need it in the first place! Still it's your engine and your time.

snapper - 30/4/17 at 05:05 AM

quote:

I just read everywhere on the net , when putting on a gasket, always skim the head.


More nutsack from the web, by all means check it, you could even blue the faces and scrape a rule over but as said before a straight edge and a bright light will show you if there is an issue

bikecarbfred - 30/4/17 at 08:56 AM

quote:
Originally posted by minibull
Only reasons to skim a head are if it's warped out of tolerance or suffered corrosion around the waterways. Alloy heads seem to warp for fun hence it's become more or less standard practice, regardless if it isn't warped or corroded it doesn't need skimming. As to skimming with sand paper on glass no real reason it won't work as it's basically only lapping and been an engineering process for many years. Check glass is actually flat though as it often isn't. Problem is that if head needs skimming it will need a lot more lapping than a couple of minutes, if a couple of minutes does the job it didn't need it in the first place! Still it's your engine and your time.


Yes - Would probably need alot more than 2 minute of sanding if skimming was required. That did flash through my brain as I posted 2 minutes . Yes glass has to be true flat.

quote:
Originally posted by snapper
quote:

I just read everywhere on the net , when putting on a gasket, always skim the head.


More nutsack from the web, by all means check it, you could even blue the faces and scrape a rule over but as said before a straight edge and a bright light will show you if there is an issue


I will check it over and let you guys know what's happening. Thanks alot again.