CloseDec 12, 2007 3:35:44 PM
Quote:
GatorBite said:
The benefit
Quote:
BlueApple said:
According to official Porsche website, the Cayman and Cayman S engines do use dry-sump lubrication system!
http://www.porsche.com/usa/models/cayman/cayman/indetail/drive/
Quote:
Moogle said:Quote:
BlueApple said:
According to official Porsche website, the Cayman and Cayman S engines do use dry-sump lubrication system!
http://www.porsche.com/usa/models/cayman/cayman/indetail/drive/
Thats exactly what they want you to believe. However, everyone know's it's not true.
Quote:
GatorBite said:
I wish I could agree with you on the dry sump thing, but the integrated dry sump really isn't a true dry sump. The oil IS stored in the bottom of the crank case, making the sump wet, not dry.
In a true dry sump system, the oil will be stored seperately from the engine, usually in a tank. There will be a feed bump that delivers oil to the engine and then one or more scavenge pumps that return the oil to the sump. The 987, 996, 997 models store the oil in the crank case, sort of, in an extended sump. There are scavenge pumps (2) that return oil from the heads to the sump. So it's has elements of a dry sump, but it's not really a dry sump.
The benefit of having a dry sump are:
1. Oil can never reach the crank shaft. When seeing strong lateral forces, like from aggressive turns on the track, the G-Forces can make the oil shift or move. A dry sump engine can work upside down, sideways, with any G-forces and this is not a problem.
2. By removing the oil from the crankcase, you reduce the contanmination caused by blow-by.
3. By removing the oil from the crankcase, you can more easily cool the oil and keep it cool.
Dec 17, 2007 4:27:17 PM
Dec 17, 2007 6:18:50 PM
Quote:
easy_rider911 said:
However, from the link below, PCNA seems to have gond one further. There is no mention of "integrated" anymore. It just says "Dry sump lubrication" and then it goes on to describe the operation of the oil scavenging mechanism.
Dec 18, 2007 10:45:53 PM
Quote:
GatorBite said:
It is a shame. The marketing angle is questionable...
So, what models have an integrated dry sump? 986, 996, 987, 997. Am I missing any?
Dec 20, 2007 2:30:41 AM
Dec 20, 2007 3:49:59 PM
Dec 20, 2007 7:00:43 PM
Dec 20, 2007 11:05:42 PM
Quote:
cibergypsy said:
You're missing my point. I am not saying the M96 or M97 motors are superior to the GT3, as that would be absurd. I was just stating that, even with the lack of a true dry sump system or not being developed for racing, the M96 or M97 are not all bad and perhaps better than most are willing to give them credit.
Quote:
dreamcar said:
I agree Grant. When the original Boxster came out in 1996 it was head and shoulders above everything else, but unfortunately Porsche sat back on their laurels, the bean-counters that seem to make every decision at Porsche watched the money roll in and took their eyes off the competition that has caught up and literally overtaken in the process. The 987 replacement for the 986 was not nearly enough of a step forward, mainly because of the 911 sacred cow,which itself in 997 form though a great car isn't enough of an advance over the 996.
If they are not careful, the arrogance and complacency will ultimately cost them dear. Am I sounding like nberry?
Dec 27, 2007 1:40:45 PM
Quote:
Grant: That's correct. All the sportscars that cost less than $100k have a wet sump (Carrera GT has dry sump too).
Prior to the 996, EVERY 911 had a dry sump (1964-1998) and could be driven on the racetrack with racing slick tires (or on banked tracks that can cause oil starvation with wet sump)
Quote:
cybergypsy: While it is dissapointing that we no longer have a true dry-sump motor on the Carrera line, I know of at least one fellow in my PCA Region who races his 1999 996 with racing slicks even at Daytona and has had no issues whatsoever. His car is all out race prepped but the motor is stock, except for the questionable Fabspeed cold air intake kit. If I am not mistaken, his motor is over 60,000 miles now. Another PCA member I know also has a 1999 996 fully race prepped and has over 20,000 miles of track time on it with PCA racing. I don't think the wet sump of the M96 or M97 engines is much of an issue.
Quote:
Grant: I think GT3 Cup motors are good for 100 hours (of all-out racing). That's more than 2 seasons for most race classes (typical race is an hour or less 15 days a year or so, right? + qualifying + hard practice).
Quote:
Grant: Are they as good as a BMW M-series motor? No, they make less power and torque even though they have more displacement (BMW 3.2L makes 333 hp and 269 ft-lbs of torque compared to the Cayman's 3.4 which makes 295hp and ~250ft-lbs).
Quote:
GatorBite said:Exactly how are you measuring the 'Goodness' of an engine? I don't get it. Are you hanging that solely on hp/liter? That's not a very good test. There are many other characteristics of an engine that I would consider. Reliability, torque delivery, center of gravity, usability, etc.... Heck, by your measure we might as well install 2 stoke engines into our Porsches. The deliver far more horsepower per liter so they must be better. Right?
Quote:
GatorBite said:Let's not forget that all of those prior engines were also air cooled. The last of them, the 993 engine, had a relatively short life span because of it's soft valve guides.
Quote:
Grant said: How about the fact that they make more power and torque (not just per liter - more period) and contain more technology for less money?
Quote:
Grant said: Some (not all) 993 motors (as well as many 911 motors from 1974-1998) suffered premature valve guide wear. This was definitely a problem, but it was not indicative of a "short life span", since these motors could be rebuilt (or in this case receive a valve job and fixed).
An M96 motor that has internal issues has to be discarded - they are not rebuilt or repaired. Instead, you have to buy a new (or reman) motor. Those are the motors with the short life span. An aircooled motor meant that you could have a "matching numbers" car basically forever (replacable pistons/cylinders meant they were easy to upgrade to larger displacement too). Not true with the wet-sump motors - they're basically disposable...
Quote:
GatorBite said:
Wait a minute? Am I reading this right? Your signature says that you own a 73 Carrera RS 'Replica'? Does that mean your car does not have matching numbers? I thought this was somehow a big drawback. I'm confused.
Quote:
GatorBite said:I came real close to buying a used 993. Before purchase I went to my local Porsche shop whom I had a 10 year relationship with. They told me about the 993 valve guides that were prone to early failure and o2 passages that were prone to clogging. In their estimation, it wasn't if but when the car would need a top end overhaul and in their experience that was between 60-80K miles. A comprehensive overhaul would cost $8,000 - $10,000. Guess what? You can buy a whole new M97 engine for that.
Quote:
GatorBite said:
That's got to be one fun damn car to drive. Too bad you're in CO. I'd love to ride shotgun on a drive.
My Porsche sales pro owns a '73 Carrera RS 3.0, completely original and mint. I've only seen pictures. I'd love to see it in person.
Quote:
Grant said:
I know an older M96 motor used to cost $10K, but they don't anymore and an M97 costs significantly more. With the Dollar vs. Euro getting weaker all the time, I think by the time a new M97 motor gets replaced, we could be looking at a MUCH higher number.
Fortunately for the 993 motors, the valve guides themselves cost almost nothing and the only real cost is labor (which is relatively static). A reasonable valve job from a Porsche specialist (not a dealer) on a 993 costs around $5k. That number is not likely to increase dramatically for many years.
Also, while there are certainly 993's that needed new guides by 60k, there are MANY that are way past 100k miles with no sign of wear at all.
I'm sure you can find a mechanic who will tell you it's inevitable that you'll need to replace the RMS on an M96, but we both know that it doesn't afflict nearly all the cars (just as valve guides are a much less common problem on 993's than is sometimes represented).
I've sincerely enjoyed chatting with you - you certainly know some Porsche history
About Rennteam | Help | Terms of use | Privacy Policy | Support | Contact | Imprint | Archive
Powered by
Community
and
