Hi all, I'm new, please be gentle. Ive tried the search engine but it doesnt appear to be working atm. Could anyone tell me the std inlet and exhaust port sizes are for a 1990 mk2 GTi 16v? One of my mates has just had his GTi head rebuilt and the bloke doing the work says he took the head to a company for skimming, porting and polishing. I want to try and make sure my pal isnt being ripped off! Any help would be greatly appreciated. The car is quite a distance from where I live and the Haynes manual is in the boot of the car so I cant check that at the moment unfortunately. Thanks, Chris Edited by: Digita1dragon
Hello and welcome! the search facility is a bit like that, search in seperate forum sections sometimes helps but not always. You want the dimension at the valve seat? This thread answers lot of questions about the 16v, if it doesnt I'll measure one but mine has been ported already but someone must have a standard one off the car.
Thankyou for the quick reply! Ive already been looking at the 2.0 16v threads! you guys have SO much info on here its fantastic!!!! Makes me almost wish I had a GTi myself! Havent seen any port sizes specified in the threads yet, its all interesting reading though! I did keep my search within the engine section but there was a timeout error each time # cheers!
really? I thought the polishing was making it smoother and porting was enlarging the port itself. ** Got a result on the search! cheers for the tip Andy! It came up with this thread and one with no answers! [:^(] *** did a better search! have lots of reading to do now! seems lots of you guys do some DIY! ive always wanted to but was scared off by people saying it would probably make it wrose Edited by: Digita1dragon
It's difficult to define a port size. I know the combustion chamber on my flowed 16v head is 47cc. On the VW 16v head they usually take material from the exhaust port as the design isn't the best. Here's some pics of my 'man in the shed' head. http://gvkgti.free.fr/images/flowed_gvk_head/
Well Im used to 8v myself. I know when 8v (like on my XR2 for instace) are ported, the port is opened up to some extent, and matched with the inlet manifold. Then valve seat is smoothed back for better flow. With a 16v I am aware that the "throat" splitting into 2 makes things more complicated, I had only my assumptions to run with at the time! All I really want to do is give my mate something to say to the bloke building his head back up, to the effect of "I know what Im talking about" just incase he gets his pants pulled down! My mate doesnt know much about cars, this is his first one really so he knows plenty less than me and I only really know a bit about fords
Dunno about a 16v, but on the 8v the ports on my PB head were hardly any different in size from the gasket, so there wasn't a lot of scope for making them any bigger.
ok well cheers for the help fellas! Ill be back when the search fails me again Ive been trying to convince him to get a 2L in there. We will have to see how well she goes when shes back i guess! Edited by: Digita1dragon
there is a bit on the PumaRacing website detailing what to expect for your money when getting a head done, plenty more reading...
Oi u !!! No snails allowed here Search engine never works unless its sommink pretty specific (eg selecting which forum topic to look in). Add me on msn again... XRtwo forum getting boring? Or tired of rust and wanted to get a real car
Porting heads yourself can make it worse. Until you get it on a flow bench your really not going to know if you done the head any good. There's alot more to flowing heads than people think. Your altering the chracteristcs of the head as soon as your start to remove metal. Porting and polishing is not just 'bigger is better' but to get the gases to flow smoother and quicker. Make the ports too big and you've lost velocity, make them too smooth and the fuel/air won't mix properly. Don't get me wrong, I do my own heads and they SEEM to work, but without a flow bench I could have done more harm than good.
