Serious power. Built by riders.

Built for riders

Riders first. Builders second.

Ride a Milwaukee-Eight (M8), Twin Cam or Evolution Harley-Davidson? We will get serious, reliable horsepower and torque out of it, proven on the dyno, not just on paper. Alpha Performance Engines (A.P.E.) has been building custom performance engines and bolt-on big bore kits in Gladstone, Queensland for more than 15 years, and every build carries that experience straight to your bike.

We're riders first, and that shapes every build. You won't get handed a one-size-fits-all kit. Your build is matched to how you ride and what you want to spend, so you get the right setup for your bike, not just the biggest number on a spec sheet.

Whatever stage your engine's at, we've got a path forward, from bolt-on kits to fully custom, ground-up builds. Want more cubic inches? Our big bore kits take 114ci and 117ci M8 engines out to 128ci and beyond, backed by performance camshafts, cylinders, forged pistons, engine covers and everything else it takes to do the job properly.

Whether you're chasing more grunt for a Breakout, Road Glide, Street Glide, Low Rider S or Fat Bob, or building a dedicated strip or track bike, we work closely with you to deliver a result that suits your style, your performance goals and your budget. Classic street character or full race attitude. We build both.

Wherever you are in Australia, we've got you covered: Australian-designed and Australian-built performance, shipped Australia-wide, with installation and dyno tuning available through trusted workshop partners. And because your warranty is built specifically for modified Harley-Davidsons, you're never left exposed for going non-stock.

Unleash more power from your Harley-Davidson: custom engines and performance built for the way you ride, from Alpha Performance Engines.