Wildcat 240RS Race-Spec Engine
The Wildcat 240RS is a unique engine that stands out in the market. It offers the largest displacement in a small block, combined with the best initial upgrades used throughout the industry. This means you get a high-performance engine without immediate part changes or teardowns. The Wildcat 240RS is designed to meet all your needs, from spec kart racing to highly modified racing to mild and wild minibikes. And the best part? We've made this level of performance accessible to everyone by keeping the price low. You won't find another engine that offers the same performance at this price.
Warning Read Before Ordering:
1. Each engine is dyno-tuned before shipping. The engines are tuned using a karting fuel tank with a 1/4 vent and fuel pump. If you are not using the proper fuel tank, especially stock fuel tanks or aftermarket mini bike fuel tanks that vent through the fuel cap or have a check valve in the vent. In that case, it may pressurize the carburetor, causing an untunable rich condition because the fuel tank is trying to vent through the carburetor. Do not attempt to tune the carburetor, as the issue is not the carburetor tuning. You may need to replace or modify your tank by adding a 1/4 fitting venting to the atmosphere.
2. The engine has been started and run before shipping, and in some cases, the violent shaking during shipment may cause the float to stick. If you are still having a rich condition after resolving fuel tank issues, remove the float bowl move the float up and down, and ensure the needle goes up and down.
3. The engine works on flat or up to 8-degree mount. If your machine has increased engine angle when mounted either by the motor mount or rake of the machine, this may cause a stumble or hesitation at low speeds.
4. Do not use stock mufflers, screw-on style mufflers, weenie pipes or other small restrictive exhausts. Only use headers with .900 ID or larger. Small Pipe ID and Restrictive Mufflers will cause the engine to run rich.
Dyno Comparison Video, https://www.youtube.com/watch?v=njZrP3ITHQc
Dyno Comparison Blog, https://www.eccarburetors.com/dyno-testing-wildcat-240cc-racing-engine
Displacement: The WC240RS is a small block engine with a ¾ output shaft that is 240cc. 240cc is the same size as the smallest "big block" that Honda makes, which means you get big block displacement from a small block engine. We like to think of it as the 427ci/7.0L LS of the mini bike and karting world. To achieve this displacement, the bore is 72mm like the Tillotson 225, 228, and 236cc engines, but the Wildcat has a 59mm stroke crankshaft, which is a first for a complete engine.
The Wildcat 240RS is built with high-performance components that set it apart from the rest. The 240RS features the Wildcat WC946 head, equipped with 31mm Intake and 25mm Exhaust stainless steel valves. These larger valves give the engine a lot more potential than the smaller valves used on other small blocks, ensuring top-notch performance and reliability. You can learn more about the WC946 head on our website.
Carburetor - The Knock-Off VM22 carburetors are easily one of the most popular carburetors for upgrading your Predator, Tillotson, or Wildcat engine. The WC22 is an updated version that has been expertly blueprinted and tuned here at EC's. The carburetor has proven to be better than other brands' similar carburetors, as seen here with real dyno results.
Camshaft - The Wildcat 240RS comes with the Banzai 265 camshaft, which has set the standard for camshaft upgrades on your mini bike and kart engine builds. This camshaft is included in the engine, which means you have a great cam out of the box, and even better, you don't have to worry about clearancing to make it fit around the 59mm crankshaft. This upgrade can significantly enhance your engine's performance, giving you a competitive edge on the track.
Flywheel/Ignition Coil - We are using the lighter cast aluminum flywheel that is rated for 8500rpms of safety and performance. Instead of using a mechanical internal governor, the Wildcat 240RS is rev-limited by a 6100rpms coil like the Ghost 212. Adding a billet rod and changing the coil is all you need to have an engine that can run over 7000rpms.
Spark Plug - We are the first to offer a fine-wire iridium spark plug on our engines. In our testing, the fine-wire iridium plug performed the best, making .2-.3hp more than most other plugs. As cylinder pressure increases and fuel mixtures are richer to produce more power, the spark plug is challenged to ignite the fuel. The fine-wire iridium concentrates the spark and fires more consistently. We can see the air-fuel mixture read more consistently on our O2 sensor, which indicates a more efficiently running engine.
Side Cover - The side cover is identical to the Ghost 212, which features an oil fill on the top cover. The oil fill on top makes it easier to access when adding engine oil. You can also use this as a spot to add a Pressure Control Valve(PCV) to help vent crankcase pressure without modifying the block, side cover, or valve cover.
Top Plate/Fuel Pump - The engine is set up to be nearly turnkey by including a top plate and fuel pump. This setup is chosen to work best with the WC22 carburetor since the stock fuel tank is not elevated enough to work properly. It also makes it easier to install for racing go-karts. Those who have an elevated tank and plan to gravity feed the engine may need to bypass the pump for optimal tuning.
Soft Grip Pull Rope - While it's a minor detail, we wanted to include the best options for our engine. The pull rope handle is not cheap plastic but a sturdy soft-grip handle.
Break-in Oil - To break in the engine, we include the Maxima Racing Oil Break-in oil with every engine. To break in the engine: The engine must have a load. Do not free rev the engine! If you have a tach, keep the rpms between 3500-5500rpms, and if this is on a mini bike or go-kart, you can run the engine like normal for 15-20mins. A practice session or two works well to break in the engine. Just keep the engine below the rev limiter during the break-in.
Switch to the Maxima Racing Oil RS 0w-20 or 5w-30 for optimal performance.
For more in-depth information about the Wildcat 240RS, check out our blog.
Specs:
- Displacement: 72mm Flat Top
Piston x 59mm Stroke Crankshaft = 240.11cc
- Cylinder Head:
Wildcat WC946 18cc Cylinder
Head with 31/25 Stainless Valves, 26lbs and Billet Retainers
- Compression: Approximately 11:1 Recommend 91+ octane gasoline (non-ethanol if available)
- Carburetor: WC22 26mm slide carburetor with Short Port Matched
Intake
- Camshaft: 265 Lift Banzai Camshaft on the new 224 core(no more
clearance-ing of the compression release to clear the crank)
- Ignition Coil: 6100rpms Limited Coil (No Internal Governor)
- Other Parts: Reinforced Block, Cast Aluminum
Flywheel(safer than cast iron), Cast Rod, Side cover with top side
oil fill(can use pulse fitting or 280 PCV), Top Plate with Aluminum
Fuel Pump
- Other information: Small Block(Same as GX200, Predator 212, Etc) with ¾ output shaft, No warranties expressed or implied(You are buying at your own risk)
Recommended Stages of Upgrades:
1. Billet Rod and Non-Rev Limited Coil—The billet rod is designed to handle rpms above 6100 rpms. The non-rev limited coil will allow more rpms, but it also improves ignition timing and spark to produce more power. The Wildcat 240RS will use the 8270 Billet Rod.
2. Billet Flywheel—Our SK201 is a lightweight billet flywheel with 34° ignition timing and a stronger magnet for improved spark. It's highly recommended that you unlock more potential from the engine if you regularly exceed 7000 rpm.
3. Head Porting—The WC946 has 31mm intake valves and offers a lot of potential, so use it. Porting is the WC946's greatest strength and can greatly improve engine performance without changing any engine parts.
4. PWK24 Flat Slide – Our PWK24EC-1K offer a little more performance than the WC22. While it may be a small change, it doesn't require getting inside the engine. If you decide to use more camshaft/rocker arms after porting the head, we recommend a 28mm flat slide carburetor.
5. Once you reach this point, you'll need to modify the head to support dual valve springs for bigger cams and ratio rockers. You'll also need to switch to chromoly push rods, which must be cut to length.
