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Head question??

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Old 31-08-2011, 04:31 PM
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mk2rstaff
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Default Head question??

My 3 dr head is now at the machine shop being checked over, whats the lowest measurement i can go too on it skim wise before it's too far gone???

would this matter if i plan to fit a wrc metal gasket to make the compression ratio back to standard, as in could i skim past the lowest level then add the multi layer wrc to increase the gap again???

in advance thanks Tabetha lol
Old 31-08-2011, 05:34 PM
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chrisa3
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Originally Posted by mk2rstaff
My 3 dr head is now at the machine shop being checked over, whats the lowest measurement i can go too on it skim wise before it's too far gone???

would this matter if i plan to fit a wrc metal gasket to make the compression ratio back to standard, as in could i skim past the lowest level then add the multi layer wrc to increase the gap again???

in advance thanks Tabetha lol
think ford spec'd the minimum as 138.6mm i believe.
Old 31-08-2011, 05:44 PM
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mk2rstaff
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thought that was its new measurement???
Old 31-08-2011, 07:54 PM
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Originally Posted by mk2rstaff
thought that was its new measurement???
Nope, I think they were 139 new ish. Just checked workshop manual and its a minimum of 138.68mm.
Old 01-09-2011, 12:22 PM
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There,s been a few threads on here about this with some heads doing fine under Fords tollerances i believe, also unfortunately for some Tabetha wont be answering as he,s been banned not long ago
Old 01-09-2011, 12:43 PM
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Originally Posted by opposite lock
There,s been a few threads on here about this with some heads doing fine under Fords tollerances i believe, also unfortunately for some Tabetha wont be answering as he,s been banned not long ago
Do you know why he was banned, he always seemed so polite and very helpfull bloke??

so in answer to my question it would be ok to skim the head past them measurements and add a wrc gasket to replace the comp ratio gap?????????
Old 01-09-2011, 01:02 PM
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Originally Posted by mk2rstaff
Do you know why he was banned, he always seemed so polite and very helpfull bloke??

so in answer to my question it would be ok to skim the head past them measurements and add a wrc gasket to replace the comp ratio gap?????????
Youd be better giving one of the tuning companies a call for advice.
Old 02-09-2011, 01:07 PM
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Tabetha was banned for abusive behaviour towards a mod afaik. He knew the rules i,m sure , bit of a shame really but its he,s fault .
Have a search in here regarding head thickness lots of info given by pro,s already .
Old 02-09-2011, 05:50 PM
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Originally Posted by mk2rstaff
My 3 dr head is now at the machine shop being checked over, whats the lowest measurement i can go too on it skim wise before it's too far gone???

would this matter if i plan to fit a wrc metal gasket to make the compression ratio back to standard, as in could i skim past the lowest level then add the multi layer wrc to increase the gap again???

in advance thanks Tabetha lol
138.68mm is so say the lowest you want to go, however i have seen many many heads used beyond this measurement.

139.2mm was the thickness from factory.

most people think the head becomes too thin or alters the comp ratio, but the biggest problem is the area around the valve seats which becomes too thin the more you skim.
Old 02-09-2011, 06:06 PM
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138+ is fine to be honest, you won't get any problems unless it starts getting to the low 137s.
Old 06-09-2011, 11:15 PM
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Karl
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I have several original brand new unused Cosworth YB heads and each one measures between 138.90 and 138.95mm.
Old 06-09-2011, 11:19 PM
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Originally Posted by Karl
I have several original brand new unused Cosworth YB heads and each one measures between 138.90 and 138.95mm.
Whats the going price for one these days??
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