I recently purchased an engine from a wrecked 2004 GTO, it had been sitting for about a year. The engine has an overdriven Magnacharger MP 122 HH supercharger, 60 lb / hr injectors, AFR 1630 heads, Yella Terra 1.7 rockers, iron 6.0 block with an Eagle 4" stroke crank, Eagle 6.125 H beam rods and 4.01 bore Diamond pistons. The guy I bought it from claimed it made 580 at the tires @ 12 lbs of boost which sounds plausible from a 404 with the parts listed above. I pulled the front sump pan, to install a Holley pan and everything looked great. To be sure it is O.K., I leaked it down and got 30% on the first hole that I tested, virtually all going past the rings. I took it to my engine machinist, and we took the short block apart. The bearings look good, but the piston shirts show some minor scuffing. There was water leakage in one cylinder that caused pitting in the bore and you could see combustion gasses had gotten past the head gasket on that hole. As the pistons and rotating assembly are serviceable, I got another standard bore 6.0 iron block which is getting ARP main studs, align honed, decked and sized to the Diamond pistons for re-assembly. My question is camshaft choice, the cam in the engine has 232/236 14 engraved on the timing gear end and 51601 engraved in the back as well as 3310107 stamped in the back. I would assume (yes I know!) 232 is in. duration @ .050 236 would be the ex. duration @ .050 and 14 is 114 LSA. I may very well be completely incorrect in this assumption so if anyone can decipher the numbers that I listed please let me know. Also, while I may have the attention of people way more knowledgeable than myself, this engine had more carbon in the combustion chamber and on the pistons than I have ever seen. The engine machinist thinks it was not tuned properly and was fuel washing the cylinders ant low / mid rpm's. The intake ports are black with an oily coating as well. As the engine was removed from the vehicle when I purchased it I don't know if it used a catch can, which I would consider mandatory an a supercharged stroker engine. I notice much wider LSA on some supercharger cams, could some of the residue in the intake ports be from reversion? This may be a dumb question, but I know very little about supercharged engines and would rather not be looking at the same problem again once the engine is rebuilt.
Thank you for any help, Bob