Approx HP gain from boring 40 over on a 572?

Question

My uncle has a jet boat that he installed a 572 chevy create motor in. The one that runs on pump gas and is advertised at 620hp. The motor blew and for some reason and he had to bore it 40 over. So that is now going to be 612cu in? Correct? He is running it with a 1050 dominator carb, is that enough info to gage the new APPROX hp of this engine?

Answer 1

About 15 to 20 more. HP.

Answer 2

Horse power gain will be so nominal, you'll never notice any difference.

By boring 40 over, it still remains a 572 CID engine. It just becomes a 572 CID bored 40 over. It just means they bored it 40 thousanths of an inch to remove scratches, etc to get the cylinder walls smooth again. Then they replace the piston rings with rings that are 40 thousanths of an inch over sized to make up the difference.

The CID difference is only 320 thousanths of an inch and it doesn't change the horse power.

Answer 3

incorrect- boring 40 over doesnt mean adding 40 cubic inches- it means .040 inches (forty thousandths of an inch) of metal was removed from the cylinder walls to clean up the bore- that will add about 5 cubic inches. horsepower gain will be insignificant