valve shrouding

[paul]

hi have not been on the site for a while now been dicconected for a while but anyway's...

i picked myslef up a vw golf gti the otherday and decided that im going to get it tuned up

ok the question is on porting and polishing a head.

im engineer so im that way inclined already and have quite a good knowelage of engine flow. but would really need an actuall guide that works best for a mrk 2 golf head

if anyone can dig me up some info then that would be great

the head has all the ports on the same side with the plugs and the injectors on the other face and the valve pits are of a dished shape

also wondering if it would be worth it to get angled vlaves and re cut the valve seats


thank in advance

Paul

[Quiggs]

Is it an 8v or 16v? The 16v already flows a decent amount of air. The 8v Crossflow head is very restrictive. It's really not worth putting money into the 8v head, but swapping to a 16v is relatively simple.

[paul]

its an 8v and they are ment to pull as well as the 16v's up untill the higher speeds then as you say the 16v's flow takes over and keeps on pulling

yes would change it for a 16v head but the problem is im only 19 and insurance is not too keen on the 16v so just going to make do for the moment on what i have got

picked up the head the otherday for a good price and just need to know what machining work , works best on that particular head

if not then ill do my best to follow a vauge guide for most head porting

[Quiggs]

I did some digging on the 8v heads, and if you're planning on just doing the P+P, it's not worth it. You'll only get ~4whp out of it. But if you plan on doing intake/chip/exhaust/cams, you'll see anywhere from 15-30whp depending on how much money you're looking to spend.

http://forums.vwvortex.com/zerosearch Search the 2.0 Liter forum under the Technical forums section.

[paul]

yes im going for high lift cam's and a really good port job

thanks for the info

would you happen to know what's the best high lift cam and chip setup for the golf?

[Quiggs]

For street use, most people don't go much past 268*. Techtonics Tuning sells a 272* cam, but that will set a CEL on a stock ECU, and will idle very rough. Keep in mind, most cams will raise your idle slightly. And with a longer duration/lift, it's a good idea to switch to heavy duty valve springs or you can float the valves.

http://www.techtonicstuning.com/ sells really good cams at really good prices, and they can burn you a custom chip that's mapped for your cam, exhaust, headwork. They're really good people. http://www.techtonicstuning.com/cams.asp is a direct link to the cam specs.

[paul]

so you would reccomend without a ecu alteration a 268*cam . and with a good headjob and improving intake flow , already got a nice dia exhaust on there at the moment

i would be looking at a neat 15bhp increase?

[Rockefella]

so you would reccomend without a ecu alteration a 268*cam . and with a good headjob and improving intake flow , already got a nice dia exhaust on there at the moment

i would be looking at a neat 15bhp increase?

Yes, roughly 15 bhp. Along with the engine upgrades, I would strongly recommend a set of rubber for the corners. You can't put power to the ground w/ no grip.

[hightower99]

Hey Paul.
great motor you have there and you abviously have abit of money to throw around (you have enough for cams and porting) Well the greatest advice and information I can give you is: Don't believe that making the ports bigger will gain power!

go to this website and read pages 15, 16, 17, 18, and 19 these will tell you about how a motor really works and it will tell you how to make your ports smaller and gain power! (Note: it is cheaper than "porting" the head and is completely reversable!) I have performed a similar tuning to my 3.8L ford engine and it really works. I would also advise that you read page 9, 21, 22, 23, and 24 to learn how to break in you motor to gain better mileage and power. (note: It doesn't follow the owners manual!)

If you learn what this website has to say and use it properly then I would expect at least a 10hp gain and if you re-break in your engine as well then you could get another 5-6hp ontop! I would go for a modest cam and better titanium valve retainers and better springs. Free flowing exaust is always a good choice and of course a K&N cold air filter is good for atleast 5hp.

good luck!

[paul]

cheers for the info there hightower , i have come across that site before but never read in depth...

making the inlet smaller increases flow??? sounds mad i can't explain it but can see how this would work!

so you say you have tried this theory out and it actually works...?

[LotusLocost]

Hey Paul.
great motor you have there and you abviously have abit of money to throw around (you have enough for cams and porting) Well the greatest advice and information I can give you is: Don't believe that making the ports bigger will gain power!
go to this website and read pages 15, 16, 17, 18, and 19 these will tell you about how a motor really works and it will tell you how to make your ports smaller and gain power! (Note: it is cheaper than "porting" the head and is completely reversable!) I have performed a similar tuning to my 3.8L ford engine and it really works. I would also advise that you read page 9, 21, 22, 23, and 24 to learn how to break in you motor to gain better mileage and power. (note: It doesn't follow the owners manual!)

If you learn what this website has to say and use it properly then I would expect at least a 10hp gain and if you re-break in your engine as well then you could get another 5-6hp ontop! I would go for a modest cam and better titanium valve retainers and better springs. Free flowing exaust is always a good choice and of course a K&N cold air filter is good for atleast 5hp.

good luck!

Pleas hightower!! you have realy been bit of this high-velocity virus!
You can`t claim that biger inlet ports DON`T gain power!!!
There are to many engiens in the world with big ports to prove you wrong!!!

And to you paul: Your engien is a great engien to tune! But stick to the porting and new cams..
I have read the mototune pages myself.. and know the deal..

For your road use I think it will be cheaper in the end with good machine work.. Remember that this high-velocity porting is done on RACING engiens! they are rebuild after every race.. So they keep good control on the epoxy in the inlets.. there are some reliability issues conserning this methods.. I can imagien you have no plan of stripping down your engien everyother month or so

And second: there are NO proof anywhere that this will work on bigger engiens.. and certainly not with the result that hightower claims to have done... hightower has a very good skill of writing, and clearly a lots of knowledge about engiens.. but still no proof of actual results.. I haven`t seen one pic of one singel nut or bolt from his garage yet..

[Matra et Alpine]

hightower has a very good skill of writing, and clearly a lots of knowledge about engiens..

Both "facts" are in dispute

[Rockefella]

Both "facts" are in dispute

Haha, don't be a bastard.

[Matra et Alpine]

Haha, don't be a bastard.

Give me three good reason why not .......

[hightower99]

Pleas hightower!! you have realy been bit of this high-velocity virus!
You can`t claim that biger inlet ports DON`T gain power!!!
There are to many engiens in the world with big ports to prove you wrong!!!

I don't claim that bigger ports wont gain power. I believe in motoman's statement that bigger ports lose power. He explains all the reason behind this statement and points out that not a single engine has proof that it is only the bigger ports working to make more power. NOT A SINGLE ONE!

Also to Paul: You seem to have a slight misunderstanding lowering the volume of your ports will not increase flow. However You can fill in quite alot without effecting flow (this space is referred to as "dead space") Flow is not the most crucial element of intake performance. Velocity has a much greater importance, to understand why everyone should read Motoman's explaination of how a 4 stroke works in real life (with all 8 phases!) another interesting note is that polishing your ports will reduce flow and velocity! the surface you want is like shark skin (An explaination to follow soon, or you could just read Motoman's stuff)

I have read the mototune pages myself.. and know the deal..

either you have only glanced over the info or you just haven't understood what you have read!

For your road use I think it will be cheaper in the end with good machine work.. Remember that this high-velocity porting is done on RACING engiens! they are rebuild after every race.. So they keep good control on the epoxy in the inlets.. there are some reliability issues conserning this methods.. I can imagien you have no plan of stripping down your engien everyother month or so

It will not be cheaper to get the porting done at all! And just to point this out the high velocity ports where tried out on normal motorcycles as well as racing ones and they have shown no reliability problems what so ever. I suggest you try it out with some epoxy, if it doesn't work you can remove it without any damage to your motor and then by all means you can take the normal path. If however it does work (It will) then if you are slightly paranoid of reliability then you can always replace the epoxy with weld material (I didn't)

And second: there are NO proof anywhere that this will work on bigger engiens.. and certainly not with the result that hightower claims to have done... hightower has a very good skill of writing, and clearly a lots of knowledge about engiens.. but still no proof of actual results.. I haven`t seen one pic of one singel nut or bolt from his garage yet..

This is unfortunately true I have no concrete proof (I didn't take many pictures when I was working on it, and the Dyno sheet I have proves nothing other than the gain ((which I could have used anything to get))) I might be taking the motor to bits again later this year and I promise to save some good pictures of the intake and exaust ports.

Give me three good reason why not .......

Being a bastard is not cool
Being a bastard does not serve the purpose of this website
Being a bastard does not protray a wise man of your years!

good enough?