Anybody that says that doesn't sound like piston slap has never heard it. It's the same as when you have full floating pins with a tic too much clearance. Does the same thing. In fact, that's an old racer's trick. To run a little more clearance in the wristpins. The theory was it helps "unload" the pistons and allows them to "rock" a little in the bores and reduces a little friction. True? I don't know but I can tell you this. Some of the most serious engines I've ever heard run made that noise. A real HP engine is noisy. Solid lifters or hydraulics with a real fast rate of lift. Both make similar valve train noises. Bottom ends with loose HP clearances. Floating wristpins with lots of clearance. You ever heard a REAL Ford FE 427 High riser with the two backwards mounted Holleys? I have. I REAL one ORIGINAL. You'd think it was fixin to sling a rod but that bad boy was one hellish beast. A lot of these guys have never heard anything like that, don't know what it is and it shows. Yes sir. A REAL honest to goodness HP engine is not quiet in the least. It's like Don Garlits always said "Run um loose with lots of oil pressure" lol
