Airboat build #44: How loud is it?

Measuring decibels at idle and full throttle until a head gasket lets go. Turbo 5.3 LS, megasquirt.
For my other airboat build videos, check here:
Airboat build #43: Test drive on snow
• Airboat Build #43: Tes...
Airboat build #42: Fuel Filler
• Airboat Build #42: Fab...
Airboat build #41: Turbo oil drain issues
• Airboat Build #41: Tur...
Airboat build #40: Starting it up again
• Airboat Build #40 - Le...
Airboat build #39: Update June 2022
• Airboat Build #39: Upd...
Airboat build #38: Tie down hooks and steering
• Airboat Build #38: Tie...
Airboat build #37: Trailer Modifications
• Airboat Build #37: Tra...
Airboat build #36: Rudder Mounts
• Airboat Build #36: Rud...
Airboat build #35: Painting Vinyl Seats
• Airboat Build #35: Pai...
Airboat build #34: Transom
• Airboat Build #34: Fin...
Airboat build #33: WhirlWind Super-Wide Prop
• Airboat Build #33: Ins...
Airboat build #32: The Cage
• Airboat Build #32: The...
Airboat build #31: Floor
• Airboat Build #31: Floor
Airboat build #30: Seats
• Airboat Build #30: Seats
Airboat build #29: Throttle Pedal Fabrication
• Airboat Build #29: Thr...
Airboat build #28: Megasquirt
• Airboat Build #28: Meg...
Airboat build #27: 14Point7 Wideband O2
• Airboat Build #27: 14P...
Airboat build #26: Wiring update and dashboard build
• Airboat Build #26 More...
Airboat build #25: Wiring harness
• Airboat Build #25: Wir...
Airboat build #24: Radiator and heater tubing
• Airboat Build #24: Rad...
Airboat build #23: Battery box
• Airboat Build #23: Bat...
Airboat build #22: Engine Paint
• Airboat Build #22 Engi...
Airboat build #21: Cam swap and valve springs
• Airboat Build #21 Cam ...
Airboat build #20: Fuel Lines
• Airboat Build #20: Fue...
Airboat build #19: Boost referenced FPR on 5.3 fuel rails
• Airboat Build #19: 5.3...
Airboat build #18: Fuel Cell
• Airboat Build #18: Fue...
Airboat build #17: Turbo Oil Lines
• Airboat Build #17: Tu...
Airboat build #16: Turbo Cold Side
• Airboat Build #16: Tur...
Airboat build #15: Exhaust:
• Airboat Build #15: Exh...
Airboat build #14: Turbo hotside:
• Airboat Build #14: Tur...
Airboat build #13: Turbo Mount Revised:
• Airboat Build #13: Tur...
Airboat build #12: Turbo Mount (#1):
• Airboat Build #12: Tur...
Airboat build #11: Radiator and intercooler:
• Airboat Build #11: Rad...
Airboat build #10: Turbo planning:
• Airboat Build #10: Tur...
Airboat build #9: Power steering pump delete:
• Airboat build #9: 5.3 ...
Airboat build #8: Engine stand part 2:
• Airboat build #8: Engi...
Airboat build #7: Engine stand part 1:
• Airboat Build #7 - Eng...
Airboat build #6: Finishing the deck
• Airboat Build #6: Fini...
Airboat build #5: Mediocre dolly
• World's Most Mediocre ...
Airboat build #4: Rudders
• Airboat Build #4 Rudders
Airboat build #3: UHMW Poly installed the hard way:
• Airboat Build #3 - UHM...
Airboat build #2 - Hull assembly:
• Airboat Build #2 - Hul...
Airboat build #1 - Planning and materials:
• Airboat Build #1 - Pla...

[@davidsonger3476]

Awesome boat! Youre my new idol. Im sure you've forgotten more about mechanics than i ever learned and i've never been on an air boat but i bought an old 17' hull and want to follow in your footsteps. From what i've read, the more blades the quieter it runs...surely that 5.3 would push a 4 blade? They say it gets even quieter when you run counter rotating blades....? Looks like you're running direct drive? Wouldn't a reduction gear make it quieter? Do you think the turbo may have contributed to the gasket failure? i doubt the LS i end up with will have a turbo but if it is an option i wonder if its worth adding. My hull is only 6 ft wide. have a great day.

[@dr.dansgarage]

Thanks. More blades might be quieter in certain circumstances. Keeping the propeller rpm down is important. From what I understand, if the tips exceed the sound barrier they get louder and less efficient. I am running a reduction drive, 2.5:1 reduction. That helps a great deal.
I don't know about counter rotating blades. Typically those a very high hp applications. The prop manufacturers (like whispertip) will give good advice for the ideal prop for each application.
I think these 5.3 are good motors for this. The LS platform is easy to work on. The turbo likely stressed the headgasket but it should've been able to take it. My tune likely wasn't perfect but it should've been reasonably close. These motors can usually take a fair amount of boost.
Good luck with your build!