Whilst mines sitting in the corner of my bedroom I thought I may as well get it tweaked before fitting. It's already a large port head, but can much more be done to these to improve airflow? And will I really notice any real gains in performance? Also, are there any good books on the subject? I rather fancy having a go myself, in the true DIY spirit. That and I don't have 400+ to pay someone else to do it for me. Cheers
They don't tend to do alot to the 20v heads. A little here and there is all they need. If you're going big power change the valves for something better. badger is the man to chat to about these.
there are +1mm larger inlets availabe now.. nimonic EV80 stainless steel inlets in one piece. inconel exhaust valves. (what my new motor is being built with now)
What will that increase achieve performance wise? And what sort of cost am I looking at? Also, is it the tappets and valves that tend to let go when getting close to 400bhp, or the block? Was told once, but I've slept since then and forgotten. D'oh! Cheers
The valves are a weak point of the 20vT esp when tuned for big power, the lighter weight of the new valves may give a performance advantage, but the main reason is so they don't fail and take the rest of the engine with them, it does happen. Is it the valve heads that drop off Bill?
I've heard from several totally diferent sources that the 20v valve heads fall off, from all sorts of 20v 4cyl variants. Mind you with modified engine it's not a surprise things like that will fail I guess, pushing 190bhp per tonne +
Yep they do... eg Donington in Golfy.. [:^(] inconel exhaust valves are a smidge heavier but inconel. nimonic stainless one piece inlet valves. Std valves are 2 piece and they seem to break at the transition of the head to stem grind point which is quite a sharp/abrupt edge. (usualy bad news, stress risers etc) 6mm stems and 2-piece! rev em, power em and they can fall apart. Not prepared to take the risk myself on new motor so pukka valves it is after a lot of research finding suitable reputable, motorsport proven source. Want to risk it or spend 375 instead.. I know which route I am taking. inconel exhaust valves will be a lot more tolerable to engine tuning being "off", something the std valves dont seem capable of living with. Bill Edited by: badger-bill
375!! That's for all 20, yeah? What sort of cost are you looking at to have the head machined to accept the new valves? Anything else that should be considered whilst in there? Valve springs? Tappets? Just out of curiousity - What pistons are used to make the lump 2.0? Cheers.
Subject to exchange rate but yea..~375 and all 20. (I get a better discount on these now) 12 x stainless one piece EV80 black nitrided inlets 8 x inconel exhaust Coming shortly Ti retainers & springs. These valves retain std collet dims (3 groove)so no need to buy additional collets, retainers etc (like you would have to with schrick for example) - I have been quietly supplying these to several VAG tuners here in the UK. They are as used by SEAT Sport in their Race SupaCopa's for a few years now with no reported failures. - Next order is about to be placed. Edited by: badger-bill
