We are introducing the NEW! EC 263R Bottom-End Kit for racing go-karts and mini bikes.After many years of getting the right components together, you'll be able to assemble a low-buck 3-inch motor with a 58mm stroke crankshaft to build a 263cc or 16ci engine. During the development of the Tillotson R-Series Block, EC considered improvements and alterations to get a76mm or 2.99" bore to best fit in the block.
Some changes include removing the upper dowel holes and adding material around the jug, including the push rod galley, which increased the gasket surface area for a better seal.
When the Tillotson blocks were introduced, EC had a 76mm bore block made without the sleeve. However, changes in production meant Tillotson could no longer sell that version of the block. Instead, EC is boring and sleeving the 70mm & 72mm blocks.
Parts of EC's goal of a 263cc engine was to design a 76mm piston similar to the one they designed for the Tillotson 72mm bore block. They made a lightweight and affordable 76mm piston and a new rod slightly longer than the rod used in the 236R kits. The piston is significant in making the package less expensive.
Our kit includes a partial short block allowing you to add your current clone or predator parts, racing carburetors, and other components. If you want to build a brand new engine, we have many add-ons to make a complete engine. The short block does not come assembled.
76mm Tillotson Reinforced Block without Tank Mounts - This is the engine's core and allows most of the magic to happen. We designed these blocks to handle mid 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. A 76mm bores one of the largest bores possible in a factory block.
EC 76mm Lightweight Hypereutectic Piston - The piston is superior in performance and longevity over stock Chinese cast pistons used in other engines and kits. The piston uses the latest technology and design, utilizing a racing slipper skirt vs. convention barrel skirt design of other stock pistons. This piston uses an aluminum alloy with high silicon for a lower thermal expansion coefficient, allowing tighter tolerance. The low slipper skirt design also allows more clearance in the rotating assembly for larger stroke crankshafts. We also made the compression height shorter by moving the pin's location and using a smaller diameter wrist pin. These improvements allow the use of a longer rod while reducing weight in the rotating assembly.
58mm (2.283") Stock Stroker Crankshaft - This is the first-ever 58mm stock crank for a clone market. The crankshaft is significant because it has only .017" less stroke then the billet cranks made in the aftermarket and, more importantly, at les than a quarter of the price. With our kit, you will build an entire short block for just the billet crank alone. The Taper will fit any Honda-Clone flywheel (will not fit Predator 212 flywheels)
EC 8282 Forged Rod - Our new EC Forged Rods are designed to allow more stroke with standard clone journal crankshafts and bigger camshafts. The 8282 rod is explicitly made for this kit. It is 3.475 inches and brings the piston up to zero deck. This rod is made in-house and is unique to our engine combination.
These components are the core of the 266R "U-Build-It" Kit. It comes with the hardware gaskets to build a complete short block minus the camshaft.
Kit Includes:
- Tillotson 76mm Reinforced Block without Tank Mounts
- Tillotson 76mm Lightweight Hypereutectic Piston
- EC 8282 Billet Connecting Rod
- 58mm Stroker Crankshaft
- Stock Sidecover
- All hardware and gaskets included assembling the short block
- Stock Tappets
- Push Rods are not included (Chromoly Recommended for all builds)
To build a complete engine, we have many add-ons to build combinations based on your budget and goals.
The 263R Engine Kit is considered a racing product, and the final assembly is the builder's responsibility. We do not off any warranty on this engine package.
