How big can it get?

[EPorsche]

I was just wondering about the size of 911 engines and wanted to know if porsche could go bigger than the 3.8 flat six or would they move to a flat eight. The reason I wondering is because 911 engine a limited more than most because of the location of the engine.

[Joe Bob]

Air or water cooled?

Because they went with water cooled due to emissions, noise and horsepower limits....

[EPorsche]

Both but since water cooled is in today, let's go with that.

[Dantilla]

I suppose the limiting factor will be the spacing between cylinder bores. Hasn't changed from the 2.0 litre in 1965. There needs to be either cooling fins or coolant passages squished in there too.

[HawgRyder]

Or they end up with paired cylinders like some of the chevy engines.
Liquid cooled, but no space between the cylinders.
Bob

[EPorsche]

What about the space in the engine bay? The 997 does have a lot of junk in her trunk but how wide or big will be too wide or big?

[Carrera3.5L]

The GT3RSR based motor being used in the Grand-Am DP series is bigger than 3.8L.

Ralph

[livi]

I hope the flat six concept is considered heart and soul at Porsche in Stuttgart and that they are aiming to keep it that way in spite there need to up rate performance each year. They have probably asked themselves the same question several times since the 2.0 liters engine. IMO, it they moved to eight cylinders a big part of the Porsche signum would be lost.

[randywebb]

A V-type engine has substantial advantages in terms of rigidity.
An opposed 6 is a fundamentally balanced design.
V-8s have unbalanced characteristics (2o IIRC) but there is something appealing in that "rumble."

The # cylinders is a separate question and relates to factors like frictional losses, esp. from the rings, size of the flame front in large cylinders, pumping losses, etc.


They've always used what was best...