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while ive got the head off my c20xe im gonna have a go at some simple head work. looked at a few websites and spoken to a few people about opening up the inlet and exhaust ports and nobody seems to give definate advise so my question is this ........

do you open up the exhaust ports to the same size as the manifold or do you just smooth them ??
and do you smooth the inlet ports completely or do you leave them a bit rough ??
 

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leave the exhaust ports unmatched - no benefit in enlarging them on an aspirated engine in low tune - leaving a step in section helps prevent reversion from the manifold reflections.

80 to 120 grit finish on the inlets, no finer.

concentrate your work on carefully matching and working the area from the valve seats up to the splitters in the inlet runners (the webbing where the port divides into two) - don't carve the top radius up into the head any more than is necessary to achieve a good match with the 'straight' part of the throats.
 

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cheers for the reply Gary :beer: seen a pic of a head that you did and was amazed at the quality !! im not after anythin special and i cant afford to pay £hundreds to get it done professionally but i want to try and do a proper job myself, hence its taken me a week to find out exactly what im doing lmao
 
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