Engine Specs - 02 Boxster S M96.21

[Paul Goudas]

In the middle of an engine rebuild on my 2002 Boxster S. 

 

So the story is as follows - Got a boxster s with 2 engines.  Engine in car suffered a catastrophic failure when the IMS ( single row ) bearing blew around 35K miles.  The bearing appears to have been upgraded to a ceramic bearing and there is some slight deformation on the crank and IMS.

 

I also have a donor engine that was in an accident - mileage unknown - one head crack and unusable.  The second engine got some water in as evident by the amount of rust on the pistons rights, but mostly ok.

 

Both are M96/2167xxxxxx badged and the undamaged engine has in in tact dual row bearing - likely from 2001.

 

So was thinking of reusing the crank/bearing carrier from the original engine given it has less journal wear.  Main bearings measured 59.990 (newer) vs 59.986mm(older).  Is there a resource out there that lays out what is acceptable so I can move forward?  Or should I not risk it given there are smaller dents on the timing gear from where it was impacted.

 

Also any concerns with mixing the IMS from the older engine with a newer one.   ( Aside from the main timing chain and chain gears being different)?

 

Lastly, the heads were a disaster.  all of the intake valves hit and bent - 4 were completely sheered off and sitting in the cylinder.   Some damage to the top of the head, but nothing on the valve seats.  Also had to cut 5 of the intake springs to remove the valves.  Anyone know what is acceptable for valve wear or to verify if the valve guides need to be resleeved.

 

Any help would be much appreciated.

 

Disclaimer - this is my first bottom end rebuild.

 

 

 

 

[JFP in PA]

51 minutes ago, Paul Goudas said:

 

 

Also any concerns with mixing the IMS from the older engine with a newer one.   ( Aside from the main timing chain and chain gears being different)?

 

 

 

Extracting the IMS bearing from the shaft will irreparably damage it.  Get a replacement.

[Paul Goudas]

Sorry for not being clear - was not suggesting to reuse the ims bearing - rather use the actual full dual row shaft on an engine that came with a single row shaft.

[JFP in PA]

56 minutes ago, Paul Goudas said:

Sorry for not being clear - was not suggesting to reuse the ims bearing - rather use the actual full dual row shaft on an engine that came with a single row shaft.

 

I would check the chain designs and the gears on the shafts; Porsche changed design on the chains & gears, and they are not interchangeable, and also have to match the gears on the Vario Cam.