Focus Fanatics Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
336 Posts
Discussion Starter #1
Would you say that 4 valves per cylinder with the plug in the middle and overhead cams is the best configuration overall? I don't know how you could improve on this.
 

·
Registered
Joined
·
8,262 Posts
I remember a few years back VW had a 2.0L 4 cylinder 20v engine that had 3 intake valves and 2 exhaust valves per cylinder, but I don't think they ever built them in large production numbers.
 

·
Registered
Joined
·
139 Posts
Are you thinking of the VW 1.8T maybe? They made plenty of those. Also yamaha has had alot of 5 valve per cylinder engines. On paper the 5 valver is better for the larger bore engines because they can get more valve area with smaller valves thus allowing the engine to rev higher because of less mass. But in practice it didn't seem to help much I know atleast with the yamaha raptor they went back to a 4 valve setup.
 

·
FF's Night Security
Joined
·
28,766 Posts
cost wise its its exspensive. Performance wise its been used in formula 1's since way back 80's and maybe even the 70's. But for today cars yeah 4 vavles crossflow design with a pent roof combustion chamber is the norm for todays cars. Also Audi or VW whatever you wanna say has made lots of em' the little turbo VW and Audi's all used em'.
 

·
Registered
Joined
·
8,262 Posts
Well, I stand corrected. I recall VW made a bunch of noise about their five-valve per cylidner engines a few years ago and I figured it was some limited-run deal that fizzled out. So all of the VW 1.8T engines are actually 20v...interesting.
 

·
FF's Night Security
Joined
·
28,766 Posts
probably right next to the spark plug or like in a diesel same location. Though its the type of fuel injection not head design on those. The super high pressure of the fuel system atomizes the incoming fuel which make it more effective or efficient. Which in turn makes more power. some one correct me if I'm wrong I'm drunk right now.[goofydrunk]
 

·
Registered
Joined
·
139 Posts
Plus having the fuel atomize in the combustion chamber provides a cooling effect that you don't get otherwise with injection in the manifold. I have one of those new saturn sky redlines with this setup it works well. Plus it gets 32mpg.
 
1 - 9 of 9 Posts
Top