This is perhaps the most interesting use we’ve found yet for an LS engine – and it’s an LS7, no less – the cream of the crop of GM’s fleet. This wild kit ‘copter from Vertical Aviation Technologies, Inc. uses a specially-designed LS7 that’s been modified for use in a helicopter application.
The camshaft has been changed to provide the most torque and horsepower at a continuous engine speed of 3,250 RPM – the “sweet spot” where the engine is most effective in this application. In addition, a new oil pan, specially-modified cylinder heads, and a helicopter-specific exhaust system were created for the unique fitment.
In fact, most notable is that the engine is placed at a near-45-degree vertical angle to get the rear of the crankshaft facing skyward and in the proper position to drive the rotor shaft. The engine still relies on a dry-sump oil pan to ensure that the critical flow of lubrication is not disrupted in flight, and the engine has been optimized for use with fuels ranging from 87 octane all the way up to 100LL aviation fuel. The exhaust system was developed to optimize the power curve at the operating level of the engine and required extensive testing time.
At the 3,250 RPM level, the engine pumps out 280 horsepower all the way up to the max 12,000-foot vertical limit on the helicopter. As it runs on regular pump fuel, it can be imported into many parts of the developing world that don’t necessarily have access to leaded aviation fuel, and that alone opens up a whole new market for the company.
It’s an interesting use of an LS engine, and one that appears to have many merits.