HKS Built a 1.75-Liter Closed-Deck Short Block for the GR Corolla's Three-Cylinder

The G16E-GTS three-cylinder in the GR Corolla and GR Yaris is one of the most tunable small engines Toyota has ever sold, and HKS has now built the bottom end for owners who want to push it well past factory boost. PASMAG reported on July 21 that HKS released the G16E 1.75L Low-Comp Step 3 closed-deck short block.

Displacement grows from the stock 1,618 cc to 1,746 cc, with an 88.0 mm bore and 95.7 mm stroke. The block gets a closed-deck design, which HKS says helps minimize cylinder deformation under high combustion pressure, plus machined water jackets and an added cooling jacket around the No. 2 cylinder for use with HKS's Grommet Head Gasket SUPER COOLING Pro.

What is inside

HKS machines the deck for flatness, bores the cylinders for cylindricity and cleans the main oil gallery after machining. The rotating assembly uses HKS machined low-compression BCD pistons from its BCD Piston Full Kit, STEP3 high-strength machined I-beam connecting rods that HKS says are 25 percent stronger than the factory parts, a machined chrome steel full-counter crankshaft and ACL main and rod bearings.

One catch: the factory balance shafts cannot be used with this setup. HKS recommends its Racing Pro 10W50 oil and pairs the short block with its Grommet Head Gasket SUPER COOLING Pro and HEAD STUDS KIT Pro.

Why it matters

GR Corolla owners chasing big power have mostly relied on built factory blocks. A closed-deck short block from HKS, with more displacement and a low-compression piston designed for boost, gives time attack and road course builds a known-quantity foundation. HKS did not publish a power target, and compression ratio and price were not in PASMAG's report. The product page is listed on HKS USA under part number 23011-AT009.