big valve head ..... pros and cons?

[matthew172]

can anyone please tell me the pros and cons of big valve heads,

would it be worth putting +1mm wasted stem valves in a big power let engine??

or is this more for the n/a motors?

[Adam]

The better flowing you can make a turbo engine the less work the turbo will need to do(as there will be less restriction to flow...(which is what pressure is), so yeah its worthwhile.

What spec is the engine? Im assuming its not still on the std inlet/tophat?

[ck]

if u can afford it then go for it. u will be needing to have it ported/polished aswell otherwise the +1mm wont exactly do much to gain performance.

u gotto think about things like this. the more you do the the entire engine means you can run the same power but with alot less boost. meaning it runs cooler, will be ore reliable, more drivable ect ect

[matthew172]

ok thanks guys, engine will be running a inlet plenum etc, im thinking of having the head cnc'd but this is quite expensive so just have to save abit lol

[philip]

i can spec a full head for you if wana drop a pm. prices for all parts, porting, polishing, machining, shimming etc etc, advise on what you can/should use depending on what power you want, how reliable etc etc.

btw you could get a comfy 400+bhp out of stock inlet, just need an enlarged body.

btw do not bother having the head cnc ported. presume your looking at cnchead.co.uk? the only good cnc head are done up scotland way i believe. and thats info from a very gopod mate of mine who supplies swindon engine with heads, martin bowyer with parts etc etc