What's the deal with Porsche's?
 

Why does virtually every Porsche have the noisiest valvetrain I've ever heard. It sounds like hell when I hear people revvin them out on the streets. What does the valvetrain consist of and why is it set up in such a way that it makes such a damn racquet?

I am going to watch this one.

I am going to take a guess and say stiff valvesprings, multivalves for cylinder, and lack of insulation to improve the driver's experience.

996, 996t 986 986 s 997 997t 987c
 

What models are you talking about? They all have the same basic horizontal 6 and thier are two blocks the 996t 997t and gt2 and gt3 share the same block, Its the air cooled block with water cooled heads. Then all the rest have a full water jacketed motor. As far as valve train there are 2 over head cams on each side that are driven by a vario-cam set up that can adjust when the valves open. There is also vario-cam plus which has two differnt lobes on the cam. Like v-tech. Small lobes idle and low rpm. Huge lobes for high rpm. So there may be some valve train noise there. The exhaust manifolds are more like headers which produce noise and the exhuat path is pretty short. And yes they sound like somethings loose when they rev. Now listen to the 5.7 litre v-10 in the carrera gt and try to say that that sounds like crap

I'm talking mostly about the older models, but some of the newer ones as well (the ones consumers buy, not referring to something like a GT3 that i've never heard).

The older ones had lots of duration and overlap for a motor that small. The air-cooling means there is no water jacket to dampen the sounds and the exhaust is kinda loud for a sports car anyways. There's an odd rasp, hairdryer on overload, racy sound all ground into one noise. You either love it or hate it. I have about 20% like, 80% dislike for the old noise. Rode in a friend's dad's turbo, a 996...beautiful.

I can understand why it's so noisy but why were they manufactured like that? I don't recall many (any) other cars of that era (other than the good old vw bug which made basically the same sort of ticking sound but through the exhaust) that sounds like that. I assume the buyers just took it in stride as a sacrifice for buying such a high end performance car?

If it's in good repair, you shouldn't be hearing valvetrain noise itself. If the lash isn't set up right, that sounds like what you're hearing. But on a properly setup Porsche, specifically a 911, you shouldn't be hearing anything excessive. Remember that you may be dealing with an older machine that may not have 100% the tune it needs. I doubt a lot of Porsche guys pop their valve covers and check the lash themselves every oil change. You hot rod Detroit, not Stuttgart. By the time you make that sort of cash, you either buy from the factory and don't tinker or have someone else do your tinkering for you.

Yeah they need constant lash adjustments on the older ones. Besides it's a sports car your supposed to hear some engine noise. Now that I think about it most all horozontal engines have some sort of valvetrain noise, look at all subarus, older corvairs and beetles they are all noisey even at low mileage.

I LOVE the noise! and the more rpm the better!

BMW had to make the enxhaust note sound all tinny (and loose!!!) to get the same rasp that the 911's have!

great sound if you ask me! :)

Chris.

please find a Porsche forum. This forum is reserved for LSX technology :)