Check Out Your Favorite JDM Engine Swaps In Boats

Somebody on YouTube has cut a clip show of what sure look like some interesting car engines being used to power boats. The speed is impressive, the sounds are downright evil.

I couldn’t believe I’d never heard of these engines doing work in the water and at first I wasn’t sure any of these were real. But some cursory research seems to confirm that, yeah, at least a couple people are slapping huge turbos on Nissan Skyline and Toyota Supra engines and then using all that power to spin propellors.


JetSpeed Motorsport is even messing with rotary-engined racing boats, and a company called Sprintec has apparently put a 2JZ in a little single-seat boat and good lord does it look terrifying. I mean come on, this video has to be sped-up right?

Okay, one more... THAT SOUND.

So why aren’t car engines in boats more often?

Well, they are, sort of. It’s common to see V8 engines in familiar sizes in speed boats and offshore racers. But even though they might run a “Chevy 350” and use the same block as a Camaro, the marine engines use a different cam, starter, heads, carburetor, and other components dialed for aquatic use.

Architecturally, engine cooling is probably the most significant difference between car and boat engines. Most car engines are kept at a safe operating temperature by fluid that flows through a radiator and is consistently cooled by air blowing across fins. Boat engines generally use the water they’re surrounded by, sucking it up and spitting it out through an open system.

There are also major differences in fuel delivery and the electrical system to contain gasoline fumes and mitigate the possibility of them being ignited in a boat’s engine bay.

But how about you just promise me you’ll watch more than one grainy YouTube video before you try dropping a car engine into your own boat?

Anyway, I’m officially interested in five-cylinder supercharged Volvo-powered boats now. Send help.

Jalopnik Staffer from 2013 to 2020, now Editor-In-Chief at Car Bibles



The Mercruiser (Mercury) I/O engines are GM blocks that have been setup for marine duty.

My 18.5' bowrider has a carbureted 5.7 liter V8, it’s basically a Chevy 350, producing around 250 HP, and yes my boat can jump out of the hole with no problem and will do 45 MPH (would go faster but it’s an old hull design).

My FIL has a 35' Bertram with two 5.7 liter V8s.

GM 4 cylinder of 2.5,3.0L, V6s of 3.8,4.1,4.3L and V8s from 5.0L all the way up to 9.4L blocks have all been used in boats by Mercruiser as per this block identification guide.

The Volvo Penta engines are likewise based on the same 5 cylinder engine in many Volvo sedans.