Rodknock Some one on the SCCA forum is either getting jerked around or just doesn't know anything about motors. LS motors from GM, we are told they should last a min of 200,000 miles, this is gas. Duramax is a 300-500K milage motor with the correct maintainance being done.
I have 12 years of racing of SCX#58. It is on the 2nd build. I went from a 452 motor to 482 stroker. The leak down was 5% on 7 cylinders and 7-8% on cylinder that has a scratch in it before honing. This cylinder is back to 5%. This is a race motor built for endurance and torque, not 700HP. Max rpm is 6,500. I see no problems with cylinder or core shift in this block.
I don't quite understand the over maintainance by Jack?
Oil and filter get changed every 3rd race. The car gets autocross, roadracing and some 1/4 mile. It gets ABUSED HARD. I have a 12 quart oiling system in the car 8 in the
oil pan, 1 in the lines and cooler and 3 in the accusump for preoiling and high "G" turns to maintain good
oil pressure. HVHP oil pump with 100 psi spring. Racing pressures are 70-80 psi. This motor needs and like alot of oil flowing. 15W-40 11 quarts, 1 bottle of EOS and Lucas oil suppliment.
Demending on the Al;uminum block you are talking about, (5) different ones I have heard of over the years. Shelby is the strongest for design and strength. Every thing is tighted into the main cap area. HP rating on this block is over 2,200 hp. the others are in the 1,300-1,500. This is more than enough for most people and cars. Shelby block also cost 1K more that the others.
Does a aluminum motor need to be rebuilt in 8-10K miles,,,,,,,,,,,maybe if heavy abused and overheated a couple of times. No oil changes. A leak down check is the easiest way to check a motor for how good the compression and valves are. I would say no to this question. Motors live and breath more so in Alumium than iron. Rick L