Thursday, 17 December 2015

CGI set to take off in new application

A new and exciting high-performance diesel engine application for compacted graphite iron (CGI), together with its British connection and offering 105 bhp/litre, pushes out the boundaries of conventional CGI use into demanding areas where safety, reliability and performance are paramount.
Engineered Propulsion Systems (EPS) of New Richmond, Wisconsin has leveraged the strength and stiffness of CGI and seamlessly blended this with a ‘flat V’ water-cooled design, to create a new benchmark for general aviation applications.

Based on a CGI cylinder block, the 4.3-litre, eight-cylinder design (with a cylinder vee-angle of 180 degrees) results in a compact, low-profile engine package that provides ease of installation, durability and low aerodynamic drag.

Initial testing of the pre-production engine has demonstrated specific power of 105 bhp/litre (77 kW/litre), resulting in an output of 450 bhp (332 kW). For comparison, most US NASCAR racing teams use CGI cylinder block or liners - a Toyota Racing Development engine of 5.8-litres for example has achieved 650 bhp, or 112 bhp/litre (83.5 kW/litre).

This compares, for example, with a Mercury Marine outboard engine of 370 bhp (272 kW) based on the well-known Audi 4.2-litre CGI V8 diesel engine which Mercury claims “leads the world in power/weight ratio”.

This puts the 4.2-litre Audi engine on 88 bhp/litre or 64 kW/litre, figures that demonstrate the strides that EPS has achieved in performance in the demanding world of aviation where there is no room for failure.

The use of CGI enabled EPS to engineer a clean sheet aviation diesel engine that sets new standards in weight, size, reliability, and most importantly, fuel consumption.

Initial testing of the pre-production engine has demonstrated an installed wet weight of the diesel engine package is within 45 pounds (20 kg) of alternative 350 bhp (257 kW) air-cooled turbocharged engines currently used in aero applications.

Heralded as the potential for a new era in aviation engines, the Graflight aero diesel promises to be more fuel efficient than any general aviation engine currently on the market.

The diesel combustion process, together with the design freedom provided by high strength CGI coupled with steel pistons, has enabled EPS to realise between 30 and 50 per cent lower fuel consumption and emissions compared to conventional aero engines.

With much improved fuel economy users of diesel-powered aircraft therefore can fly further or carry more payload. Also with the prospect Avgas (leaded aviation gasoline) could be prohibited in future, the ability of the EPS engine to use widely-available, low-cost jet (Jet A and JP-8) and diesel fuels provides a significant global growth opportunity in regions such as China, Africa and South America.

Engine and flight tests are currently underway and EPS expects Federal Aviation Authority (FAA) approvals during 2017.

The volume production contract for foundry products has been awarded to Grainger & Worrall’s UK foundry in Bridgnorth, Shropshire, which uses SinterCast process control technology and has been responsible for producing prototype engine blocks.

As the engine is intended for use in single- and twin-engined aircraft, small helicopters, unmanned military aircraft, as well as potentially some marine applications, production volumes are likely to be in the region of a few thousands per year.

Engine build so far for the flat eight-cylinder stretches to two complete engines for testing and EPS is working on manufacturing multiple engines that will be used in the first step of the process to FAA certification.

Although EPS has a pilot manufacturing plant in New Richmond it is sourcing any of the critical parts from "world class" suppliers with resources to produce "top-of-the-line" components like BMW, Porsche, Audi, Bosch (fuel injection and engine control), Mahle Konig of Austria (steel pistons), Hoeckle GmbH (crankshaft – the company also makes V8, V10 and V12 crankshafts for Audi, BMW and Mercedes-Benz) and Grainger & Worrall (cylinder blocks and heads)  - names familiar to readers of this newsletter.

“Building on our design experience with automotive diesel engines, we knew that Compacted Graphite Iron was the optimal material for the crankcase of our Graflight V8,” said Michael Fuchs, president of EPS. “The aero-engine industry has been relying on outdated engine technology and fuels for more than 20 years. Our use of modern technologies such as CGI, steel pistons, common rail fuel injection and electronic engine control form the basis of our competitive advantage, our contribution to the aviation industry, and our market opportunity.”

He added: “Our partnerships for the supply of critical components and technologies, with proven world class suppliers like Grainger & Worrall and SinterCast, are a key element of our ability to meet the necessarily stringent requirements set by the aviation authorities.

Together, Edward Grainger, business development director at Grainger & Worrall and Dr Steve Dawson, president and chief executive officer of SinterCast said: “We are pleased to contribute our experience from more than 10 years of joint CGI product development and the launch of more than 50 state-of-the-art CGI engine programmes to this exciting project, both for the development phase and for the future series production. The EPS engine provides a high profile application for CGI and further reinforces the benefits of CGI in demanding modern engine applications.”

EPS’s venture into aviation applications of CGI must give added re-assurance to current users of the material, as well as those working on the sidelines to bring their own engine applications to fruition, and to maximize the potential benefits of CGI.

In addition, it is worth bearing in mind that it is surely far safer to push CGI to the limits on road or in the water than it is in the air.

Meanwhile in the UK, the new CGI volume will add useful business for the UK foundry in Shropshire which, among other work, specialises in CGI prototyping with one of its most recent jobs being the CGI vee blocks for the Ford EcoBoost 2.7-litre turbocharged gasoline engine that in 2016 could see applications beyond the F-150 pick-up truck and the Lincoln Continental.

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