Wow... where did the summer go? Can’t believe how quickly it went... didn’t make as much progress on the Nova as I had hoped over the summer. Kids activities seem to dominate the schedule and I also spent a lot of time finishing the new garage/sport court addition we built over the summer.
We finally got the LS7 on the engine dyno... nothing ever seems to go as easy as it should, and this was no exception. Motor first went on the dyno in July and didn’t produce near the power I was expecting - it topped out at 580hp when I was expecting 700+hp. Turns out the dyno operator used an incorrect pilot bearing when connecting the engine to the dyno which caused significant forward pressure on the crankshaft. So much pressure that it burned up the thrust bearing and damaged the crankshaft. The dyno shop paid to fix the crankshaft, new bearings, fresh hone on the cylinder walls, new rings, etc. Really frustrating, but at least they owned up to it.
The rebuilt motor went on the engine dyno in late August and results were great - 705hp and 604tq. The torque curve is insane - a little over 500ft lbs of torque starting at 3,500 rpm and it never drops below that. It holds peak torque (~600 ft lbs) for more than 1,300 rpm, from 4,900 rpm to 6,200 rpm with a gradual fall off after that. You can see on the attached dyno graph how the torque curve is like a table top in that rpm range. Since horsepower is a function of torque, the motor’s ability to carry its torque like that is what allows it to top 700hp in naturally aspirated form.
As I stated in earlier posts, Tony Mamo has a lot of these head, cam and intake combinations on LS7s across the country and they are, in many cases, breaking dyno records when put on the rollers. He obviously knows his stuff - that’s an impressive power curve. This dyno was done on 91 octane, but I will have it tuned for 93 octane after its in the car, so I suspect final numbers to be closer to 720hp at the crank with 93 octane. Really amazing and probably a little over kill for the Chevy II... I can’t wait to experience it in the car!
