Sep 16

Sep 16 Mercury Racing 360 APX: A New Competition Engine and New Direction

The most exciting part of Mercury Racing’s latest announcement, the new competition 360 APX Competition, is not the engine itself but what it means for the future of Racing engines along with potential consumer performance engines. Mercury Racing is showing how far they can take the V8 platform and there is a strong indication that this is just the start of the APX platform but what does that mean?

For anyone other than an F1 race team, the 360 APX is something you will probably only see from a distance, which is fine, it’s purpose built for tunnel boat racing. That said, squeezing 360 HP at the prop out of the versatile 4.6L DOHC V8 is cool and intriguing.

Do we think Mercury is working on a naturally aspirated 350 HP consumer engine? Possibly. Is Racing going to add different competition engines to the new APX platform? I think so and I think it might be at least one more. A 400 ROS replacement with an applicable midsection to replace the existing 2.6 ROS is most likely, depending on that race class. And, maybe there will be an even smaller lighter engine, but if the APX platform is race specific, I’m not sure where that would fit.

What makes the 360 APX special? The key things are the weight improvement, ability to rev to 7,000 RPM, and the unique overdrive gear system. By removing parts from the 300R, adding carbon fiber everywhere, and running a 12” mid section bring the big V8 down to a respectable 430 Lbs. And another trick is the 24 volt starting system, with a low inertia flywheel for quick starts.

The unique overdrive gear system allows for optional gear ratios to spin the prop shaft much faster; made possible because of the incredible torque, allowing to match the prop shaft speed of the much higher revving 2.5L current race engines. That’s a neat trick. The SSR gearcase is updated, the midsection is very cool and built just for this application but again, this is an engine you won’t see if you don't’ hang around the race circuit. For race teams, I suppose running normal fuel and greater engine longevity are huge cost savings in the long run.

We talked at length about the business case for the V6 platform to be more utilized, and being perfect in the 200, 225 and 250 HP class, sharing many parts with the V8 platform. I’m actually surprised they didn’t use the V6 for the the 360 APX program, because of the inherent advantages of the lower CG, and weight. The 360 V8 is an impressive achievement though and I’m sure the open exhaust on the V8 sounds incredible.

Here is the speculation and hope for Racing’s road map. Like I mentioned, a 400 ROS replacement based on the V8. Since the 300R is a popular platform, I think they might introduce a 15” mid version of the 300R but that’s speculative. A consumer V6 200, 225 and 250 R engine, also speculative but is actually a no-brainer business wise. Maybe Mercury Racing could offer carbon fiber cowls for the other engines too, that would be cool as an aftermarket item.

I rarely do news and this isn’t really another news article about the 360 APX but more of a fun look at what the APX program might be hinting at. I think we have a couple new announcements form Mercury Racing in the next six months and I can’t wait to see what’s next.