[65coupe]

Okay guys...
please tell me what a 2v, 3v or 4v is when referring to a S197 Mustang?

Thanks,

Stoopid :lala

[HMUSN]

valves per cylinder.


and that goes for any mustang thats a 4.6

[MSO]

or any car for that matter..

[acehogg69]

197's are 3V and I believe the 04's and back are 4 not sure on the older ones.

[HMUSN]

96-04GT- 4.6 sohc 2v
05-07GT-4.6 sohc 3v
Cobra--year doesn't matter Dohc 4v

[65coupe]

Originally Posted by HMUSN 96-04GT- 4.6 sohc 2v 05-07GT-4.6 sohc 3v Cobra--year doesn't matter Dohc 4v

Riiiiiiiiight, thanks!
Got it. The more valves, the more potential for power (hence my V6 Vauxhall with only 2.5L and 24valves makes 225bhp)

[Regency 2007]

usually more valves equals more power but not always...

just think a 2v mustang gt makes 260hp
and a 4v mach1 makes 305 hp

[BWAL]

i have heard that the new 3v heads flow better than the older 4v heads though

[65coupe]

I suppose it's to do with valve size as well, isn't it. The exhaust valves on my engine are bigger than the inlet valves - one of the mods I WOULD have done if I wasn't getting rid of it was to enlarge the inlets to match the exhaust valves...

[LV51FER]

The purpose of having more smaller valves is to fill up the head area and make it more efficient. Being circular, the smaller the valve, the more you fit into the cylinder head area. Yamaha use a 5v design. 4v are two inlet, two exhaust.

That's not to say that if you've got a big engine to start with, 2 valves isn't adequate - see for example the C6 Z06 which remains a 2v as it can flow plenty of gas through large valves.

The disadvantage of 2v is the size and weight of the valves causing "valve bounce" at high rpm. This is partially offset by lighter valves and hollow stems and the fact that the Z06 revs to 7000rpm is proof it can be made to work.

The advantage of 2v is far less complexity in the valve train and therefore less weight in the head. It's also easier to operate them via a pushrod like the GM engines all of which contributes to a lower engine and lower centre of gravity.

AS for a Vauxhall having 225bhp from 2.0, in this day and age high specific output is fairly meaningless and your power actually comes more from a turbo than the 4v arrangement. You also have to put up with FWD, rubbish indicators and the fact it doesn't look like a Mustang.
http://www.auto-journals.com/blog/?p=189

[65coupe]

Originally Posted by LV51FER The purpose of having more smaller valves is to fill up the head area and make it more efficient. Being circular, the smaller the valve, the more you fit into the cylinder head area. Yamaha use a 5v design. 4v are two inlet, two exhaust. That's not to say that if you've got a big engine to start with, 2 valves isn't adequate - see for example the C6 Z06 which remains a 2v as it can flow plenty of gas through large valves. The disadvantage of 2v is the size and weight of the valves causing "valve bounce" at high rpm. This is partially offset by lighter valves and hollow stems and the fact that the Z06 revs to 7000rpm is proof it can be made to work. The advantage of 2v is far less complexity in the valve train and therefore less weight in the head. It's also easier to operate them via a pushrod like the GM engines all of which contributes to a lower engine and lower centre of gravity. AS for a Vauxhall having 225bhp from 2.0, in this day and age high specific output is fairly meaningless and your power actually comes more from a turbo than the 4v arrangement. You also have to put up with FWD, rubbish indicators and the fact it doesn't look like a Mustang. http://www.auto-journals.com/blog/?p=189

Bloody hell Wayne - swallow a tech manual or something?

Anyway, my Vectra's a normally aspirated 2.5 V6 and it hasn't got the stoopid indicators, but thanks for the lesson matey! :lala