Steven Rupp - Writer | Hot Rod Magazine | December 19, 2022
Link to original article
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!
Blueprint Engines 3.6-Liter Four-Cylinder LS Specs:
- 4.125-inch bore
- Max bore 4.185 inches
- 9.145-inch deck height
- 4.05-inch stroke
- Cam Sensor
- Crank Sensor
- Could also run a distributor
- Additional capacity water jacket
- High-capacity water pump, capable of 38+ GPM
- 5.7, 4340 connecting rods, tapered pin end
- 351 Windsor main bearings
- SBC rod bearing
- SBC cam bearings
- Current crank is nodular iron
- SBC one-piece RMS-style flywheel flange
- Uses SBC flywheels or flexplates
- Uses SBC starter