Kawasaki H2 Dry Sump System
The single most important change you can make when putting an H2 engine in a car. Three-stage scavenge, consistent oil supply under sustained cornering load, and the sump depth taken out of your packaging problem.
A Geometry Problem, Not a Capacity One
The standard H2 wet sump is well designed for its purpose. A motorcycle leans into a corner, so the oil surface stays broadly perpendicular to the sump and the pickup remains submerged. Sustained lateral loading is simply not a design case for it.
A car does not lean. The same corner produces sustained lateral acceleration acting across the sump, and oil migrates away from the pickup and stays there for the duration of the corner — precisely when bearing loads are highest. Braking and acceleration add longitudinal displacement on top of that.
This is why baffling, a deeper pan or simply running more oil do not reliably fix it. The oil is not in short supply; it is in the wrong place. A dry sump removes the problem rather than mitigating it.
Why It Matters In Your Car
The severity scales with the car. A road-biased build on modest tyres will see far less of it than a light chassis on slicks sustaining high lateral g through long corners — which is exactly the sort of car this engine tends to end up in. Long-radius corners and banked or high-speed circuits are the worst case, because the loading is sustained rather than transient.
Oil starvation is the recurring failure pattern in car-installed H2 engines wherever the original wet sump arrangement has been retained or only lightly modified. It is also, unhelpfully, a failure that gives very little warning: the engine feels fine right up until the moment it does not. Our own development work on this platform began with exactly that failure, which is why this system exists in the form it does.
The full reasoning — including oil pressure characteristics on the H2 and why motorsport sensors often read misleadingly low on these engines — is set out in our H2 engine family reference.
What the System Does
- Maintains oil supply regardless of cornering load, braking or attitude
- Three-stage scavenge for effective crankcase evacuation
- Reduced windage losses, returning power otherwise lost to oil drag
- Removes sump depth from the installation, easing packaging in a low chassis
- External tank can be positioned to suit the car rather than the engine
Specified Around the Installation
- Tank position, capacity and line routing advised for your chassis
- Line sizing appropriate to the system rather than a fixed default
- Oil cooling strategy considered alongside the sump, not after it
- Compatible with our OE oil cooler blanking plate where remote cooling is used — available separately at £129 +VAT, not included in the kit
- Supplied with the uprated high volume oil pump gear set
- Requires an electric water pump — see below
What It Changes Elsewhere
Two consequences follow from the design, and both are better known before you order than after.
The mechanical water pump comes off. Our scavenge pump occupies the position the original water pump sat in — a deliberate packaging decision that puts the scavenge stage where it needs to be and keeps the installation compact. Cooling therefore moves to an electric water pump under ECU control.
In a car that is arguably the better arrangement regardless. Coolant flow becomes a mapped function rather than something tied to engine speed, so you get flow at idle when heat soak is at its worst, and no parasitic drag at high rpm. Any suitable pump will do and the choice is entirely yours — it does not need deciding before the sump is ordered, and we can supply one as part of a complete package if you would rather not source it separately. The MBE 9A9 carries a dedicated electric water pump output, so the control is already provided for.
The uprated oil pump gear set comes with it. Our scavenge pump is built around the high volume gear set, so it is effectively standard on these builds. Specifying the sump without it means machining the scavenge pump as a one-off, which on a part of this kind will typically cost more than the gear set itself. You end up paying more for less oil pressure — so we would rather explain that now than have the conversation afterwards.
Engine Fitment
The crankcase architecture and sump pan mating arrangement are shared across the supercharged H2 family, so this system fits the Ninja H2, Ninja H2R, Ninja H2 SX and Z H2. The differences between those variants — compression ratio, camshafts, cylinder head and supercharger — sit above the sump and do not affect fitment.
If your engine has been previously rebuilt, modified around the sump area, or fitted with an aftermarket wet sump arrangement, tell us before ordering and we will confirm compatibility. If you are unsure which variant you have, our engine reference explains how to identify it properly — the engine number prefix alone will not tell you.
Discuss Your Installation
Tell us about the engine, the car and how you intend to use it. We will advise on tank positioning, line routing and cooling strategy alongside the system itself.
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