Big Valves

[Sandy 191]

Some builders/sellers love big valves, because it makes sense in simple terms to increase sizes, increase flow and hence power. The work and parts involved is nicely chargeable, the business case is strong.

What really makes good engines it moderate, considered choices in all areas, pragmatic sizing of things like valves, bores etc and having it all matched and set up really well.

 

Repeating myself, but there's alot more background and testing to my point than you'll ever know... the standard valve sizes are more than adequate for all but the most extreme engines. You're more likely to make your build worse than better, by increasing the valve sizes.

Edited September 21, 2011 by Sandy

[petert 588]

anyone know whats the best size valves to use for big valve 2.0 mi16/s16 head that i want to build and what car they from??

 

I know of an engine builder who bought a set of 36.4mm valves from my supplier and turned them down to 35.5mm as he didn't want the hassles of shrouding. Like Sandy said......................

[Josh_Quant 27]

well i was looking today at work in our valve book and the 2.0 hdi runs 35.6 x 6.0 x 107.1 and stardard 34.6 x 7.0 x 106.4 inlets i was thinking would a bit easier to fit and got a hole hdi engine at work doing nothing, would need more valves and to change valve guides to 6.0mm

 

also got catcams inlet cam and vernier pulley at work, would port and polish the head same time while it was off to

 

what you reckon??

 

and would be running with superchip ECU, uprated fuel reg (4 bar) and gti6 inlet manifold which is already in my 205

 

cheers GUYS (:

[stefan 4]

Well hell, go for it! And do report back how it goes, will you?