jaetee

I'll let you know after I pay for this engine build... LOL!

Nina (the black Cab) was my first, and will likely ever be my only convertible and I figured out in that time that I'm not a convertible guy. My family could care less, too. Had a great winter in the car and drove it top down quite a bit, but my son and wife were more of the "can we put the top up" types. And in the summer, it's actually too flippin' hot here to drive with top down too much. It was good while it lasted, and I'm satisfied with the money I got for it when I sold it on BaT. I got the replacement car for considerably less than I sold the cab for, so this build isn't hurting "TOO" much... (still hurting though).

I really wanted a coupe all along and I love the paint/interior and feature rich appointment of the Millennium edition. If I pony up to punch it out to a 3.6 and get some extra oompf out of the engine to make my C4 match the performance of my prior C2, then I'll definitely not regret it. The Black convertible was noticeably faster off the line than the Millenium edition.

jaetee

I completely understand where you're coming from, and if I were attempting to re-use my old crankshaft, I'd let engine lab handle it. But I've bought from the seller before, and they have a very fair return policy. Engine Lab will magnaflux and check all the necessary C/Shaft specs before we spend any time installing a bad shaft. Shaft & basket are coming from a wrecked car, and with the miles and visual condition apparent from the photos, I feel really good about this purchase. Beyond magnaflux and measuring, this crank should need nothing more than a routine cleanup and maybe a light polish.

Pdyson4

Hi guys, this is my ‘99 3.4L

Main journal with particle break out. How bad is this?

crank. It’s straight and crack free but surface particles are breaking out at 4 main journals. I’m not sure if I should should:

- build it back up with new bearings.
- get it polished.
- get it ground and re-nitrided and fit undersized bearings.

Any advice would really be appreciated!

bazhart

Crankshaft hardness is not deep enough for a hard surface after re-grind.

Crankshafts can be ground and nitride but nitriding adds a small amount to the diameter (usually 0.00025 to 0.0004) and leaves a dull slightly bumpy surface that has to be polished afterwards.

We have done this and they have run perfectly for years ever since but up to now managed to find enough used ones to cope and a bit worried about the consequences of the re-hardening and re-grinding process if it did go wrong and we were held responsible and had to pay for a whole rebuild again - so do not now offer the solution (may have to re-think as good used crankshafts are becoming less available).

We have made new cranks with deeper hardness that would allow regrinds but they are a bit more expensive than a new original Porsche crankshaft - so for most - they would prefer the standard replacement.

When "new bottom ends" were cheap it was a source of pistons and crankshafts but as the price went up and Porsche insisted on associated engine numbers that too has become uninteresting.

Run out of 0.002 to 0.004" is common and probably more to do with stress relieving than anything else.

The Cayman S, 3.6 and 3.8 engines have bigger main bearings than the previous smaller capacity examples.

Baz

jaetee

Wow... four years since I posted this thread and I've been quite absent from here.... This is deserving of an update...

My rebuild took a lot longer than it should have, due to really slow work from my mechanic and my life forcing the car rebuild to the back seat... Mechanic had to move his shop twice while we were rebuilding and it took over a year to get it running properly again. I had full intention of writing up and documenting a rebuild thread here, but since this went all down I have been laid off from my job of 19 years, got divorced, and moved into a different home. No sorrow here, so please don't reply with a bunch of "sorry to hear that" comments. Life happens and we define ourselves by how we handle moments of adversity. The divorce was lawyer-free and we are on very amicable terms, my kid is not screwed up over it and I now live in a nice townhome where I don't have to maintain a pool or do any exterior maintenance. Onward and upward!

Best of all, I still have my M.E. 996, and boy does she run and sound great! I had Engine Lab do the machine work to the heads and reassemble the rotating assembly/block, and my mechanic (mostly him) and I put it all back together and made her go again...

Here's the list of what has been done to the engine since:

• The crank and basket from the 3.2L Boxster S with same part number was practically pristine and saved the day...
• Engine is now somewhere between a 3.5L~3.6L with Darton ductile iron sleeves,
• New pistons & rings from Woessner for those new sleeves
• LN Dual row IMSB bearing installed
• Heads rebuilt and gasket-match porting performed on the exhaust side
• I bought two additional IMS Shafts to have them all spun, so I could use the one with the least amount of rollout. (.002)
• All moving parts of the rotating assembly have been dynamically balanced prior to reassembly.
• Installed a lightweight flywheel
• Installed Agency Power underdrive pulley
• Added 200 cell sport cats to the Agency Power headers & sport mufflers (sounds fantastic)
• Installed Tarret Engineering Oil Sump baffle
• Basic ECU tune from innovation motorsports.

Engine runs smooth as silk, and the car went from "quick" to "wow, this thing is quite fast"

I've put maybe 12k miles on her since then... Engine is reliable.



Happy motoring!

Formerly996fried

Yes.......,What comes out of engineering is rather different than what comes out of marketing