3.8 Replacement Motors

[Jager]

I am always on the hunt for another Porsche and I have noticed an alarming number of 2005 and 2006 Carrera S models with replaced engines. What is going-on with the 3.8L motor? Are the factory/dealer replacement engines better?

[Jake Raby]

They lose cylinders horribly die to longitundinal bore scuffing. Big reason for it, called improper skirt clearance with a forged piston.

When I see people" upgrading" to an OEM 3.8 I just shake my head.

[pk2]

Originally Posted by Jake Raby

They lose cylinders horribly die to longitundinal bore scuffing. Big reason for it, called improper skirt clearance with a forged piston.

When I see people" upgrading" to an OEM 3.8 I just shake my head.

Whats your take on an 02 3.6 Carrera upgrade.

Regards, pk

[Jake Raby]

Originally Posted by pk2

Whats your take on an 02 3.6 Carrera upgrade.

Regards, pk

Upgrade? The 02-05 engines have the worst issues of all.

[The Radium King]

I was just reading on another forum where the 997 guys were referring to 2000 rpm as the "bore-scoring" zone. any truth to this? apply to us m96 guys too?

[pk2]

Originally Posted by Jake Raby

Upgrade? The 02-05 engines have the worst issues of all.

Like what?

[pk2]

Originally Posted by The Radium King

I was just reading on another forum where the 997 guys were referring to 2000 rpm as the "bore-scoring" zone. any truth to this? apply to us m96 guys too?

How sloppy are these things that you get piston slap (scoring) at 2k. Is this a case where you hear about the 1% of disasters LOUD and all the other happy drivers are mum?


Regards, PK

[Jager]

Originally Posted by Jake Raby

Upgrade? The 02-05 engines have the worst issues of all.

Hmmm... Making me think more about a Metzger motor car.

[Jake Raby]

Originally Posted by The Radium King

I was just reading on another forum where the 997 guys were referring to 2000 rpm as the "bore-scoring" zone. any truth to this? apply to us m96 guys too?

An M97 is just an M96 with a different name.

[Ian c]

Originally Posted by Jake Raby

An M97 is just an M96 with a different name.

So the m97.70r and the m96.05 are just different numbers , right jake ???

[The Radium King]

another reason to keep the revs up.

[Ian c]

Originally Posted by The Radium King

another reason to keep the revs up.

[Jake Raby]

add stroke and put a shorter connecting rod with the combination. No way to better wipe out cylinders than adding rod angle!

Then, add a larger bore and multiply the issues. Yeah.

[The Radium King]

that makes sense. interesting read here too:

Bore scoring on refurbished engine - PistonHeads

where they suggest piston and cylinder coating changes may also play a role. they also state that low rpm, high torque situations are the culprit (situations facilitated by improvements to variocam, and another reason why forced induction cars have such finite lifetimes); I presume your increased displacement builds offset potential damage from increased rod angle by using improved linings?

[Jake Raby]

Originally Posted by The Radium King

that makes sense. interesting read here too:

Bore scoring on refurbished engine - PistonHeads

where they suggest piston and cylinder coating changes may also play a role. they also state that low rpm, high torque situations are the culprit (situations facilitated by improvements to variocam, and another reason why forced induction cars have such finite lifetimes); I presume your increased displacement builds offset potential damage from increased rod angle by using improved linings?

Our exclusive use of Nikisil plating in all engines eliminates cylinder scoring and accelerated wear. This is not a coating, like others, it is a very hard, wear resistant, friction resistant plating process that couples Nickel, Silicon and Carbide into one super durable wear surface.

This is not new, Porsche has utilized it for decades with all the engines that do not fail, the ones without radiators and even the Mezger based GT3 and TT engine use it, along with the Cayenne TT engines.

Its just expensive.

[pk2]

Originally Posted by Jake Raby

add stroke and put a shorter connecting rod with the combination. No way to better wipe out cylinders than adding rod angle!

Then, add a larger bore and multiply the issues. Yeah.

Are you saying that is what was done for the stock 2002 3.6l Carrrea motor? Do they all fail?

Regards, PK

[Mark_T]

Originally Posted by Jake Raby

Our exclusive use of Nikisil plating in all engines eliminates cylinder scoring and accelerated wear. This is not a coating, like others, it is a very hard, wear resistant, friction resistant plating process that couples Nickel, Silicon and Carbide into one super durable wear surface.

A request for clarification... Are you quoting someone, Jake, or are you claiming exclusive use of Nikisil?

[The Radium King]

or, he only uses nikasil in his engines. ie, he uses it exclusively. the other interpretation seems off, as anyone can have there cyls lined with nikasil from lne.

of course, I am neither jake nor do I speak for him, but I am an honorary cadet with the grammar police.

[pk2]

Originally Posted by The Radium King

or, he only uses nikasil in his engines. ie, he uses it exclusively. the other interpretation seems off, as anyone can have there cyls lined with nikasil from lne.

of course, I am neither jake nor do I speak for him, but I am an honorary cadet with the grammar police.

OMG Please don't proof my posts, I'm dyslexic as all _ell.

Guess the question remains, are these early 3.6s crap?

Best regards, pk

[Perfectlap]

Originally Posted by pk2

OMG Please don't proof my posts, I'm dyslexic as all _ell.

Guess the question remains, are these early 3.6s crap?

Best regards, pk

Porsche needed to make a profit. They're over-building of engines days nearly put them into bankruptcy. The early water-cooled would have been decent engines if you removed the Porsche premium and priced them like the short-cutted engines they all are.

If I had to do it again, I probably would have put my Boxster money towards a 996 GT3 (once depreciation set in of course).
At end of the day, the monetary value of a Porsche comes almost entirely from its engine. But I'd still need to Boxster/roadster which the GT3 will never be. But as a powerful, good for the long-haul, converted grand touring? it has its merits.