From what I can tell, people feel almost as strongly about their cars engine model as they do about the actual model of their car. So far, what I understand (which is most likely wrong), is that the Turbo's shares an engine with the GT3's. The GT3 engine is a dry sump, while the 997.1 Carrera is a wet sump and a different engine all together. The 997.2 Carrera tho is a hybrid wet and dry sump, which is again different from anything before. All of these are now water cooled and at least 3.6L in size.

I was wondering if anyone more informed then I could provide me with a breakdown, strictly for curiosities sake, of what engine is in what car, and what makes them all different. If anyone also knows exactly what kind of sump is on a 997.2S engine (dry or wet), I'd be interested in hearing about that as well.

 

The 997.2 has an "integrated dry sump", just like the Carrera motors before it, and that's just Porsche's way of trying to call a motor with and oil pan something other than what it is. Though it is not a draw back by any means. The 997.2 has a variable pressure oil pump, which is new to Porsche. You'll notice you're no longer cruising down the road at 4.5 bar but rather like 2.5 if I remember correctly, helps conserve energy, and lower oil temps.

 

All 996 and 997.1 Carreras as well as Boxsters and Caymans up until 2009 have variations of the M96 engine which came in 2.5L form all the way up to 3.8L. Think of the M96 like the M50 platform that BMW uses.

All GT cars and TT's up until 2010 use a variation of the GT1 derived 3.6L. So all GT3's, GT3 RS's, GT2's, and TT's have some version of this engine. This engine is very closely related to the engines found in Porsche's various 911 based race cars.

997.2's and 2009 and later Cayman/Boxsters have a totally new DFI engine that among other things, does not have the famed IMS that is a weak point in the M96.

Jason

 

i'm probably wrong on this but i thought the 997.1 had an integrated dry sump system?

EDIT: yeah, i see on the old 997.1 brochure that an integrated dry sump system is standard on 911's

however, i know that this is not a true dry sump system

 

I have noticed the oil pressure gauge, and actually went to the dealer thinking there was something wrong with the car because it varied so much. My understanding of dry vs wet sump was that a dry sump, although more complicated, allowed for greater stress on the system in terms of force, while still maintaining operation. What benefits does the Porsche system offer over a traditional wet sump?

As for the GT3 engine vs the Carrera engine, what exactly is different between them? I was told that the engine in the GT3 Cup car needs to be rebuilt every 25 hours, so I am assuming that too is a different engine from the GT3.

 

Typically, the value of a dry sump system is twofold
Consistent pressure under high g's: during high speed cornering, g-forces can force oil in the pan to slide to one side - though modern baffled systems can mitigate this somewhat. The effect is a temporary reduction in oil pressure as the sump intake is sucking air rather than oil. Hugely bad. A dry sump is really a (virtually) no sump design in which circulated oil is accumulated and pumped to a reservoir from which the oil is recirculated (or passed through a cooler and then recirculated). The reservoir is tall and narrow and not subject to the effect of high g-forces.
Lower CG: since there is no oil pan, the designers can lower the engine in the frame while retaining the same ground clearance. The engine mass being quite significant enables a measurable lowering of the center of gravity of the car. Hugely valuable.
One of the experts on this forum will have to inform us as to whether the Porsche dry sump cars in fact have lowered engines. I just don't know.
But I have a dry sump system on my Ford GT. Quite a nice piece of plumbing requiring the oil level to be checked within one minute of warm engine shutoff. But the FGT is famous for having an extremely low CG.

 

It is common to rebuild engine in a race car after each session, it does not mean engine went bad, it is just a procedure. But it is generally logical to presume that race engine will not be able to run as long as regular M96 otherwise Porsche or any other manufacturer would never spend so much time developing different engine types - balance between power and longevity is always a challenge.

 

As I understand 2010 Turbo engines are no longer based on the GT1 block but the 3.8 DFI from the regular S, is this correct? Lower compression?

The engine capacity of the 997.2 (non-S) 3.6 increase to 3614cc from 3596cc of the 997.1 3.6 (and 996.2), while the 3.8 of the S stays the same at 3824cc.

But from an early issue of GTPORSCHE magazine listed 997.2 S as 3800cc?

 

As I understand 2010 Turbo engines are no longer based on the GT1 block but the 3.8 DFI from the regular S, is this correct?

Correct!

 

I'm interested in the tunning potential of the new 3.6 DFI. Porsche obviously had to keep the power level down in order to please the previous 997.1 S owners.

Current 3.6DFI: 3614cc Power 345hp 6500rpm, Max Torque 390Nm at 4,400rpm

997.1 S 3.8: 3824cc Power 355hp 6600rpm, Max Torque 400Nm at 4,600rpm

Both max power and torque of the 3.6DFI arrive in lower rpm than previous 3.8. The 10hp and 10nm deficit was obvious for marketing purposes like Porsche had always done in the past.

 

According to an article I read on a previous GT Purely Porsche, the M97 engines on the 997.1 Carrera Ss have been tested to 1.4g without suffering oil starvation. If this is not so, it's not me that came up with it but a statement made on that magazine. Therefore, I think the M97 engines have an adequate oiling system for their intended purpose. The M96 on the plain Carreras (I didn't really inquire too much so they may be Carrera Ss with the M97 instead) are raced albeit not by the factory (I saw them this year at Daytona) so that should say something about that, shouldn't it?

I've seen detailed pics of the M96/M97 engine without the oil cover (it's not really a pan but a flat piece with baffles on top of it) and you cannot see the crankshat from under the engine. It seems that the crankshaft is not partially or totally submerged in oil but separated from the integrated oil reservoir. Forgive me if I am mistaken as I am not an expert but it seems to me this is different than a true 100% wet sump also so the "integrated dry sump" Porschespeak seems to me to be a hybrid - neither one nor the other - but a mix of both and probably fine for what the car's intended use is.