I fancy doing some porting and polishing over the christmas period - (better than the crap on TV) Does anyone know any good websites with examples/walkthroughs, as I've never attempted a Golf head before and its been a couple of years since my last go at porting!! any help appreciated cheers
http://www.sa-motorsports.com/diyport.shtm Sorry mate, can't hyperlink!! Its American so they talk about "Big Old V8 YoW" but don't hold that against them! Got some good diagrams though. Domma......
I'ev written loadsa good info on porting on this forum, have a search, you might be able to find something. Use a flap wheel, around 80 grit should do it. You can do near enough the whole job with these. Or some emery cloth on an extension (you'll have to make the extension yourself, they're actually iligal to have a solid one) The emery cloth will take out meat alot quick than a flap wheel usually. Better to go slow than to fast, and better to go to small on things like port size rather than to large. If you're not sure on the way cylinder head works and what effects what roughly then i'd say keep it minimal. Best thing ya can do is smooth the valve seat into the head and clean up the port walls a bit, but dont polish them. The way you hold the grinder is important, whatever feels comftable really but if you can grip it with two hands thats good for controll, especially with an extension. The tool must be a fair way out in the grinder, I usually leave a fingernail and a bit or so length left in the grinder, btu you have to be light handed remember. KEEP THE GRINDER MOVING if you don't, you'll grnd to much from one area and once you start getting into the 'oh crap, ground out to much here grind some out there to make it even' you're bolloxed pretty much. Oh, last but definatly not least, WEAR THICK INSULATED GLOVES, a dust mask and some eaer defenders. The gloves are super important, after a while of porting the vibrations and coldness of the griner in your hand will give you a condition called white hand..Shakey cold hands..really not nice.
im doing mine now iv taken alot out of the exsurst ports but not to much out the inlet ports this is using a set of gaskets!! been looking into head work and lots of people say to 3 angle the valve seats and a second one cut on your valve itself doing this makes the head flow loads better !!!! also going to have larger vavles fitted !!! oh and dont get a cheap rotory tool iv killed 3 now in the last 2 weeks only last 15 mins
depends on the kind of driving you are doing, cam, carbs etc read the cylinder head stuff on pumaracing website, just don't listen to his rolling road theories
Might be some pics of my 16v head on my site. http://gvkgti.free.fr/images/flowed_gvk_head/ Bloke that did that has been doing VW 16v heads since 1986 Edited by: G_V_K
adams is a driver tho dave walker wrote a write up of porting a vw head, in a 96 CCC magazine, it's got a 16v mini on the front if ayone still has a copy i might have one somewhere don't go too wild on a driver tho, or you'll lose power
flap wheel might do teh polishing part, but real gains get doen by porting. You will need a little more than 80 grit to do that over christmas. Get yourself down to machine mart and get a dremmel type tool with a flex extension. 30 all the tools and toys you could ask for, except perhaps a decent diamond tips grinding peice to really get busy
cheers for those, As Ian said its only a driver lump, so i won't be going to OTT. Looking for a decent hydraulic 8v gti head in the scrappers at the moment to go at. Are they all pretty much identical in terms of flow rate etc..? any advice on the best areas to work on for my application? or is it the usual valve seats, port walls etc..? and if you can find that mag you have Ian it would be very useful - let me know cheers
JC, flap wheels remove metal. Porting is the removal of metal. Dremels are pooe to, you want a proper air compressor and die gringer. For an 8V you don't really need an extension to do the head, or at least I havn't.. Don't even try to tell me you can't significantly reshape an ally head with a flap wheel. Porting isn't about going crazy taking out huge chunks at a time, it's about taking out metal from where you need to making small alterations. A 100 grit flap wheel will DEFINATLY decercate the valve guide shroudng more than quick enough. You have to think of the finish the tool your using will give to. Ideally you want to get the finish you want 1st time, but most times you'll have to go over again to get a final finish. Edited by: madmk4
Don't get me wrong, you can port an aluminium head with pencil sharpener if you want! I am not out to flame other people opinions just for the hell of it. We would all like to have a compressor and die grinder tools handy, chances are that the guy asking the questions (because he is asking questions) doesn't have a full gas flow bench and grinding tools. Most people who try to port a head with a flap wheel and electric drill don't get near the most important areas...the valve guide and the inner angle of the curve. There is a reason when you pay engine builders to do heads the majority use diamond tipped grinders of a small diameter on a flexible extension. Precision. A small "rotary grinding tool" is more than up to the job to a professional level and a good purchase for anyone looking to do a bit of DIY proting and polishing. IMO
