Wanted to get some feedback from the motor guru's on some rebuild advice. We are a dyno shop and are not handling the rebuild but it is a friends car also and I want to make sure he is doing the smart updates during the rebuild while the motor is apart.
He had an unusually load knocking coming from the passenger side Cam and oil pump area. Lounder than the sound that some of the 996TT's make from that area. It was clear someone had been in there before trying to find the noise as the cam cover had some gasket sealer that was not stock. The car only has 16K miles also, and has stock turbos. Turns out after looking into the Cam area that when the Crank is turned by hand, the CAM chain that is driven off of the Intermediate Shaft would jump/slip about every 1/4 turn. This would in-turn cause the CAM to load-up and jump and also cause some knocking in Oil pump area. So only way to get to the Gear on the Intermediate shaft is to split the case and make sure there is no other damage and to see if the Shaft itself is ruined or the keyway that the gear is positioned with is damaged.
Turns out with the Intermediate shaft out and the Gear on the end there is play of about 1mm either direction that should not be there. The gear is slipping on the end of the shaft. Definately the cause of the noise, not sure why it happened to begin with, over-rev or valve spring that broke with previous owner, and maybe they tried to fix just in the head area which might explain the non-factory sealer around the CAM cover.

All Pistons , Rods, CAM's Valves and Springs look and spec out perfect. The question is that the owner is not going to go to 800 or 900 HP, they are putting on K24/18G turbos, tune, exhaust and Clutch. But while the motor is out and apart what parts would be wise to upgrade? Valve Springs and upgraded retainers? I've heard mention of GT3 oil pump upgrades. It is at a Porsche shop we trust and know the Mechanics, just want to make sure we are all on the same page for upgraded parts while it is going back together, without going overboard for his application. thanks for any advice.

 

Call Todd Knighton @ his shop (or Todd @ EVOMS, or Sharkey),

I believe anyone of these gentleman would help you out.

Good luck Vince, hope YOU are doing well!

MK

 

I think if I had it that far down already I'd do rods and maybe consider oiling upgrades. Rods are what everyone seems to sweat and while he may not be going for big power now he might consider it in the future and wish he'd done it. Worth considering anyway...