Starting a new thread so I don't hijack.
Pismo posted a note about relatively cheap, reliable HP. The dyno #s for the setup are at this link.
http://www.offshoreonly.com/forums/a...502mpidyno.jpg
All of which makes me wonder something, though I'm not sure anyone is likely to really know. When an engine is hopped up like that (from say, a stock 502 making 415 HP @ 5000 RPM to about 500 HP @ 5000), how large is the cut to engine life if you only CRUISE the motor and don't run it wide open?
An example makes it clearer. Let's say you propped your 415 horse stock 502 for max speed at 5000RPM, as most people would. 65 mph, say. Then, suppose you propped your 500HP 502 with a steeper pitch, so that it ran that same 65 mph down at 4100 RPM, where it makes 415 horsepower. And you never ran it above 4100. (Dream on, I know...)
1. If you stayed below 4100, and ran at the same speed profile (x hours at 6 mph, y hours at 35 mph, z hours at 50 mph, t hours at 65 mph) with the two engines, is there a big difference in engine life? Which engine wins? (The 500 will have more power behind each explosion, and thus more loading on some parts. But it will have about 20 % fewer explosions, running at 4/5ths the RPM ALL the time.)
2. Are you likely short on torque at low rpm with the 500HP motor, such that getting on plane with the steep prop could be a challenge?
Put another way, can your performance upgrade dollars be used to add engine life instead of extra speed, such that you can drive the boat the same as with the stock motor, but make it last longer? Or is that only (or much better) done by adding cubes, dropping rpm further, and burning more gas?