Hot Rod Magazine - 340-HP 3.6-L Four-Cylinder LS-Headed Crate Engine

Steven Rupp - Writer | Hot Rod Magazine | December 19, 2022
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One of the hits of the 2022 PRI show was this oddball crate engine hiding in the corner of the Blueprint Engines booth.

When you're walking a trade show you never know what you will come across, and the 2022 PRI show was no exception. We definitely weren't expecting to stumble across a four-cylinder crate engine topped with an LS3-port head! Blueprint Engine's John Chrise told HOT ROD, "We were there to show off some new racing V-8s, and weren't exactly thrilled they wanted us to take this new four-cylinder from our R&D Department since we didn't think PRI was the place to debut something like that. We were wrong! Turned out that the 3.6-liter "LS" was a major hit at the show, and we constantly had people coming by the booth asking about it!" This explains why the small mill was hiding in a corner of the booth.

Chrise continued, "This combination starts out utilizing our tried-and-true heavy-duty block from our industrial division, Origin Engines. Similar engines are widely used in everything from industrial wood-chippers to airport tugs, forestry equipment, mobile equipment, power generation, and other applications. The block is rugged and designed for high-torque continuous use in extreme environments. We then slightly altered the block to successfully mate with our Blueprint Engines LS head." Blueprint brought the engine to see if there's a market, and they were flooded with ideas from attendees, including swaps into S10 trucks, early Jeeps, circle track cars, and more.

The engine block has external dimensions similar to a 3.0-liter GM engine. With dedicated piston-oilers and a large, full-loop-capable oil galley. The iron block is built for strength and the long-block tips the scales at around 300 lbs. In an industrial application, this small package, at only 1,800 rpm, will put out diesel-like torque numbers. If configured for a performance application, this bore and stroke combination could produce well over 300 horsepower and nearly 500 lb-ft of torque! The bore of 4.125 inches is the same as an LS7, and it can go bigger, but the "smaller" bore means the walls are super strong, and we think a single turbo or big shot of nitrous would be perfect for this half-LS. The Blueprint Engines 3.6-liter will accept any standard GM bellhousing, so the swap possibilities are endless. We are already imagining this engine with something like a Tremec TKX five-speed trans bolted to it!

The engine displayed at PRI was outfitted with one of Blueprint's LS3-style heads. That means the block could accept any LS head, although it's hard to beat the LS3-port design and aftermarket support. Blueprint also stated that the block will be able to accept a Ford Windsor head as well. This was an 11th-hour build by Blueprint's R&D department, so details are limited, but although we don't have a price or release date, the interest shown at PRI means that Blueprint will be fast-tracking this into production, and when it's ready, we called dibs on some power-adder dyno testing!