[RKDinOKC]

Them parts is all purdy. Is that blue from cc'ing the heads? Any porting or fancy valve grinds?

When I did my valve job, the big power 928 builders told me I should spend about $23K on super lightweight valves, custom springs, and some fancy super lightweight lifters with some kind of special coating. Thought that was unnecessary because more aggressive cams I put in were from the stocke 5.0 liter 928 GT. The GT and the GTS use the same heads, lifters, springs, valves, etc from the factory. The GT cams alone produce from 35 to 40 more hp across the entire rpm over the GTS cams on the 5.4 liter motor.

There were 3 more aggressive cam options, but the increased cost of those cams plus the additional need for lighter weight lifters, and custom valve springs to match the cam would have doubled the total cost of my engine rebuild. The slightly used, (40,000 mile) GT cams I got were the same cost as one new GTS cam to replace the broken one. With the GT cams, port matching the intake to the head, x-pipe exhaust, and some ECU tweaking I went from 350hp to 420hp. It's enough increase that I'm a little over 80% duty cycle on my injectors WOT and should go up a size.

Did NOT have any flow work done on the heads or intake because the word is Porsche did a pretty good job and any flow work that's been tried ends up decreasing the velocity filling the cylinder and kills power. The stroker and supercharger guys claim all but the stock intake go well over 600 hp. Above 500hp the 6 liter and over stroker guys replace the intake with Individual Throttle Bodies.

The only thing I wish I had done WIWIT was to go ahead and pull the pistons and drill out the oil ring relief holes. Porsche left them undrilled so the oil wiped from the cylinder wall does not have anywhere to go, gets burnt, carbons up the top of the piston, and sometimes causes preignition. Porsche claims it was to make the motor last longer. When the GTS was new, if you complained about the oil usage, Porsche would replace the motor with one that the only difference was those oil relief hole were drilled in the pistons. The mechanic did clean all the carbon out and found the valve crash just chipped the carbon and didn't even mark the tops of the pistons.