The phrase "as an essential engine" is correct and usable in written English.
It can be used to describe something that plays a crucial role or function in a particular context or system.
Example: "Innovation serves as an essential engine for economic growth and development."
Alternatives: "as a vital driver" or "as a key component".
The company's main technology and product is called Payment Engine, and by way of an API, this sits as the essential engine behind a number of other services such as Azimo, TransferWise and xe.com and many others, over 125 in total, who have built businesses around the idea of moving money internationally.
Electric, hybrid and fuel cell engines were acknowledged as essential engine technologies with major importance for future transportation by more than half of the experts.
The basic instruction set of the microprocessor -- a chip's essential engine -- will remain tightly controlled.
Cabin updates include a 10.25in infotainment screen plus a dual cockpit display showing essential engine and performance data.
As clubs became workplaces and nightlife the essential engine of cultural evolution, they liberated music, design and, especially, ambition.
This is one of the basics of back-linking, an essential search engine optimization practice.
Nowadays most advanced search engines like google considers URL as an essential criteria in search algorithm out of various other factors.
As to the essentials, engine and chassis, the car starts and it goes, and as long as it does I don't go out of my way to lift the hood or crawl under the body.
As an essential power conversion system for vehicle propulsion, the technology of internal combustion (IC) engine is the focus of attention for attempting the improvement of vehicle efficiency.
Charles Babbage's design for his so-called Analytical Engine, the first general purpose programmable computer, relied on cardboard as an essential part of its apparatus.
