There is no replacement for displacement. While the 236cc build is specifically for the 14.5ci open-kart classes, some don't have displacement rules. Using the 59mm crankshaft vs the 58mm will increase displacement, compression, and overall performance. We created a new short block kit that uses our new forged 72mm piston and 59mm crankshaft.
72mm Forged Flat Top Piston—The 240RX has been updated with our new forged 72mm piston, which replaces the hypereutectic Tillotson Piston. The piston's purpose is to further reduce weight while significantly strengthening it. 72mm Forged Piston(alone) weighs 122g, compared to Tillotson's 72mm hypereutectic Piston(alone), which weighs 131g.
The new 72mm piston also has moly-coated skirts to reduce friction and wear. The piston also has a shorter wrist pin height for a longer rod. We are also making oversized, including:
72.1mm(2.8385”) – 240.89cc(14.7ci)
72.25mm(2.8444”) – 241.89cc(14.76ci)
72.50mm(2.8354”) – 243.57cc(14.86ci)
72.75mm(2.8641”) – 245.24cc(14.97ci)
Forged Billet Rod — This rod is similar to our other forged rod, except we needed to make one longer for the new piston to get zero deck height. The 7075 aluminum forged rod has a realigned grain structure, making it superior to billet and cast aluminum rods. We've started anodizing our rods to enhance their look and appearance, but most importantly, to help protect them from oxidation and scuffing.
72mm Tillotson Reinforced Block - This is the engine's core and allows most of the magic to happen. We designed these blocks to handle mild endurance racing engines for Tillotson's 225RS/T4 Class. We made the block thicker and more robust to reduce flex and distortion; this prevents power loss through crank flex and blow-by between the piston and cylinder. At 72mm bore, it is one of the largest bore blocks straight from the factory. Still, with our background in modifieds, we couldn't pass the opportunity to build one of the best blocks for high horsepower applications.
59mm(2.323") Stock Stroker Crankshaft - The 59mm crankshaft is 1mm or .050" more than the 58mm crankshafts used in the 223/224 and 236cc engines. It is .023" more than the 2.300 Billet Crankshafts but will use the standard 1.180" crankpin, which is stronger than the smaller .998" crankpins.
Kit Includes:
- Tillotson 72mm Reinforced Block
- 72mm Lightweight Forged Piston
- Forged Connecting Rod
- 59mm Stroker Crankshaft - Pre-clearance for most camshafts
- Stock Side cover
- All hardware and gaskets included assembling the short block.
- Push Rods are not included(Chromoly Recommended for all builds)
To Build a Complete Engine, we have many add-ons that can be combined in many different ways based on your budget and goals.
We recommend upgrading our billet side cover if you're building to the higher echelon of horsepower. The billet side cover will help stabilize the crankshaft and further stiffen the block.
We are working on new combinations of cylinder heads, camshafts, and carburetors to maximize the power of this 240cc racing engine.
You can choose from our different color blower housings and recoils. Adding the blower housing will also come with the kill switch.
We hope you enjoy your new racing engine. You can ask questions on this page or call or email us if you need help with your combination.
The 240RX Engine Kit is considered a racing product, and the final assembly is the builder's responsibility. We do not offer any warranty for this engine package.
