Aussie GSi
Member
Registered: 5th Aug 02
Location: Sydney, Australia. Drives: Corsa B GSi 16v
User status: Offline
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Hey guys,
Well, seeings as my valve stem seals are on their way out, and it seems the head has to come off my X16 to get to them, was thinking about perhaps fettling with the head a bit. What kind of gains could I be looking at from porting? What about skimming? Have many people done this? If so, how'd she go?
Aus
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broster
Premium Member
Registered: 6th Dec 02
Location: Drives: E39
User status: Offline
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not many gains to be had from skimming, just a better higher compression ration, gains of 4-5bhp i belive can be had on a goos job. get the manifolds matched to it
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James R
Member
Registered: 4th Feb 03
Location: 205GTi16/306GTi16
User status: Offline
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Courtnet give a 15% gain as quoted, but I thikn that's unrealistic, It's more like 10% (ish) depending on what you have done. Also to get the long radius on the exhaust port the exhaust guides have to come out ( to do the bes job possible) I had this done and took the oppertunity to have bronze high flow guides put in.
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JJ
Member
Registered: 20th Apr 00
Location: Northern Ireland
User status: Offline
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When i was doin mine i was told not to polish... so i just ported it... Also fitted the bronze guides 
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James R
Member
Registered: 4th Feb 03
Location: 205GTi16/306GTi16
User status: Offline
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You should highly polish the exhaust ( in theory) and leave the inlet slightly rough to add turbulence in the inlet tract, but by rough it's more like the finish of 1200 grit wet and dry, virtually smooth.
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Aussie GSi
Member
Registered: 5th Aug 02
Location: Sydney, Australia. Drives: Corsa B GSi 16v
User status: Offline
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Hey fellas,
Yeah, that's what I've been told also, leave the inlet ports rough. If they're too smooth, they fuel mixture can form large fuel bubbles, which isn't optimum. Rough ports keep the mixture fine.
Aus
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masterx81
Member
Registered: 7th Oct 04
Location: Asti - ITALY
User status: Offline
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I'm also need to say if there is any optimization to the x16xe cylinder head...
I have one engine (from a crashed corsa) to exchange with my actual...
So there isn't any modify to make better this head?
I'am thinking minimun to do a gasket mathing, intake ports rough and chamber & exhaust polished and rise the cr (lowering the head) to 11:1 (like the c16xe), and exchange the cams and giude valves (if they aren't too expensive, with broze ones), an surely changing all the gasket...
I wont to run the head always with original tappets (hydraulic, for the maintenance free operation) and i don't think to pass the 8000 rpm line, if possible a good torque from low rpm...
Is possible?
Enlarge ports?
I have also read to restrict the intake port to increase the air velocity (I have also an open thread on the argument on migweb...)
Any comment?
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masterx81
Member
Registered: 7th Oct 04
Location: Asti - ITALY
User status: Offline
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Ops, I think that i have forgotten more hard coil...
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