HPBCANADA.COM

WOW!

https://www.mercuryracing.com/outboards/engines/360apx/

The Mercury Racing 360 APX is a potent competition outboard designed specifically to power Formula 1 tunnel boats in the premier class of the UIM F1H2O World Championship. The 360 APX is tuned to deliver amazing torque from a durable, low-emissions four-stroke V8 powerhead that sets a new benchmark for circuit-racing performance.

A 4.6-liter V8 powerhead is naturally aspirated and features deep-breathing dual overhead cam/four-valve architecture with a short-runner intake manifold mated to a cold-air induction system. An 11:1 compression ratio boosts torque output while the 7000 RPM redline extends the power curve. A dynamic oil pickup system is designed to maintain critical engine oil pressure under high-G loads. A cut-down flywheel, deleted balance shaft and carbon fiber top cowl optimize weight.

I don’t get it......
Why a 4.6 litre V-8......
Yamaha’s R-1 bike engine has been around for years.
Very similar motor now used in sleds...
4 cylinder 1000cc
Depending on the level of tune and the use of a turbo or blower....400 reliable horsepower easy.
I’m not being critical of Mercs new creation I just can’t figure out why it takes that much displacement & 8 holes.....

I promise you that there is much more power there, by upping boost and tweaking cam & ECU. With the 10% rule from BIA, it probably puts out closer to 400hp now. How much more power can a F-1 boat handle?

There's no boost on this one. N/A 4.6L....I just love the idea of shorter midst being a thing again.

Thanks. Apparently, no super charger on that model.

I think it's longevity. I think the Yami 1000 is a great motor too, but it's mostly used on platforms that weigh the same as it does. To produce the kind of torque it would need for marine use wouldn't be as easy as adding cylinders. Yamaha had a four stroke 1000 cc outboard, not sure if it was the same platform, but I think it topped out at 115 HP? Now that motor is a 1.8l. I'm sure Doc will correct me if I'm wrong on that lol....