Feature: End of E-TEC
Honda must have had a crystal ball when it stated the future of outboards would be four-strokes. Its first outboard, utilising an air-cooled side-valve engine, was released in 1964 and since then the corporation has never looked back.
Of course, other manufacturers jumped on the bandwagon, with Yamaha releasing small four-stroke outboards in the 1980s followed by the other mainstream manufacturers offering four-stroke alternatives to their bread and butter carbie two-strokes.
The ‘90s were a turning point with Mercury Marine, Outboard Marine and Yamaha offering direct fuel injection outboards in addition to four-strokes and carbie two-strokes, and Tohatsu followed in 2000 with its TLDI 50. Sensibly, Mercury and Tohatsu used a DFI system developed by Orbital in WA, while OMC opted for the troublesome German Ficht system (the final nail in OMC's coffin), and Yamaha a single-stage DFI from Mitsubishi, designed more for four-stroke automotive engines.
Orbital and Ficht systems used a combination of ‘stratified’ and ‘homogeneous’ combustion, where during low rpm operation the engines ran extremely lean air/fuel ratios, returning trolling fuel efficiency unobtainable in four-stroke engines due to the additional friction of powering camshafts and valves, plus the power loss of four cycles compared with two. Yamaha's HPDI used homogeneous combustion only, preventing it from gaining US CARB 3 exhaust emissions compliance, and it was the second of the DFI systems to be withdrawn from the outboard market after Ficht.
As the ‘90s closed Ficht had disappeared (thankfully) along with Outboard Marine, and when Bombardier Recreational Products took over the Evinrude name, it developed its own system known as E-TEC. As the competitors developed their four-strokes with a long-term view to axing their DFI offerings, BRP soldiered on with E-TEC, up until this year when the E-TEC and Evinrude names were finally killed off in a sad day for all of us who grew up with two-stroke outboards.
THE NITTY GRITTY
Orbital DFI systems used a mix of air (90psi or 6.1bar) and fuel (80psi or 5.4bar) injected into the combustion chambers, with a belt-driven air pump to pressurise the mix. Air and fuel injection pressures were increased slightly in later models but still remained relatively low. Unfortunately, the system required a hefty deep- cycle starter battery to power the engine management system, negating the lighter weight of DFI two-strokes over the four-stroke competition to some extent.
BRP got around this by developing the world's first battery-less DFI system, meaning just a normal starter battery could be used, and making the outboard/starter battery-package way lighter than comparable output four-strokes. Smaller E-TECs such as the 30 could be rope-started, opening up a whole new market of lightweight EFI engines that not only outperformed their four-stroke competition but used way less fuel when trolling.
Due to fuel being directly injected into combustion chambers, the E-TEC system ran much higher injection pressures, 600psi or 43bar. The stratified component (below 1800rpm) ran the same 14.7:1 air/fuel ratio as with the homogeneous stage, but because the fuel was sprayed directly at the spark plug, the overall combustion chamber air/fuel ratio was an incredibly lean 70:1. Above 1800rpm the normal 14.7:1 ratio was needed to provide the torque to plane a hull.
Apart from the leaner trolling operation, what really scored for E-TEC was the use of tuned exhaust gas megaphones in the leg that controlled where maximum engine torque was developed. The E-TEC V4 130 was a prime example of how this worked.
When the exhaust port closed in one cylinder bank, the energy wave raised pressure on the opposite bank before the exhaust port closed. As pressure waves travel at the speed of sound, the arrival time at the opposite bank is dictated by this speed. Below 4500rpm, a flap in the exhaust system made the waves travel further, increasing bottom-end torque, but about 4500rpm the flap opened for quicker delivery of the pressure wave and more torque — sort of like variable intake and exhaust valve opening time in a four-stroke engine but way less complex.
In more powerful models, the ability to alter the exhaust gas passages enabled maximum torque to be developed at lower rpm than comparable output four-strokes. The E-TEC 225 was a good example of this and developed maximum torque at 3000–4000rpm instead of 4500rpm for the closest four-stroke competition.
ON THE WATER
In 2007 BRP was able to prove the torque difference to me when I toured the Ralph Evinrude Test Center in Stuart, Florida. An E-TEC 225 was mounted alongside the industry-leading four-stroke 225 of the time on a 9m Angler 2900 Centre Console built by Angler Boats in Miami. The hull had a 3m beam, a 19-degree transom deadrise and carried 750L of fuel aboard. The total displacement with three crew including my hefty bulk was 3.8 tonnes.
Having tested the four-stroke 225 on other hulls in Australia, I knew it was correctly propped and BRP wasn't trying to snow me. With both engines running and the four-stroke reaching 5800rpm and the E-TEC reaching 5700rpm we averaged 44.3kt.
However, when the E-TEC was tilted up, the best the four-stroke could achieve was 8.2kt at 3600rpm, whereas with the four-stroke tilted up the E-TEC averaged 29.5kt on 5000rpm with no sign of stress, just smooth power delivery out to Wide Open Throttle. I fell in love with two-strokes all over again!
I had already tested the RE-TEC 225 the year before on a Seafarer Victory, in my opinion, the finest offshore 6m hull I tested. Swinging a 21in pitch prop and pushing a total of 1.7 tonnes, the 225 cruised us at 33kt and 4000rpm using 37.1L/h, but at WOT averaged an eye-watering 52.1kt and 5500rpm using 75.7L/h. At this speed, the Victory was rock-steady with no sign of chine walking. In comparison, a four-stroke 175 I tested on this hull barely reached 43kt.
At the other end of the scale, in 2011 I tested an E-TEC 30 on a Savage 435 Jabiru vee nose punt and swinging a 12in alloy prop it was the perfect successor to the old carbie Johnson 30. The twin-cylinder powerhead was smooth running across its entire rpm range compared to the old 30 that was a bit chuggy down low, and pushing a total of 550kg trolled us at 1.5kt and 650rpm using a mere 0.3L/h, less than what a two-stroke five uses. Cruising at 17.2kt and 5000rpm, the 30 used 5.1L/h and averaged 22.9kt and 6100rpm using 9.3L/h, whereas the old 30 would have used around 13L/h.
Other stand out models (for various reasons) I've tested in the E-TEC range were the twin-cylinder 40, 50 and 60 and three-cylinder 90, plus, of course, the 130 mentioned earlier. With its massive 2.67:1 gear ratio that generated tonnes of prop steer torque, the E-TEC 40 was perfect for muscle building — better than Yamaha's Enduro 60. After all, boating should provide more experiences than just running out to a favourite fishing spot and back. Good one, BRP!
The three-cylinder 1.9L E-TEC 100, 140 and 150 released late last year also looked very interesting in online US reports, especially as they weigh only 119kg, not much more than the old carbie Johno 70.
Tohatsu followed in BRP's footsteps with its battery-less four-stroke EFI 25 and 30 in 2005 and four-stroke EFI 15 and 20 in 2017. Other Japanese manufacturers have followed suit in their smaller four-strokes.
By opting for plastic engine pans in addition to plastic cowls plus plastic air intake manifolds (not Tohatsu), Japanese manufacturers have been able to reduce weight to comparable DFI two-strokes.
The trouble with all these technologically clever four-strokes is that they lack the inherent simplicity of two-stroke outboards, whether carbie or DFI. Sure they run nicely and are quieter than the two-strokes, but to me, they still have drawbacks such as requiring more servicing and a careful break-in when new, whereas E-TEC’s simply doubled the fuel/oil ratios for the first five hours. Even in early models servicing wasn't needed for the first 300 running hours, though I still recommended changing the gear oil annually and removing the prop every six months to check for stray fishing line wrapped around the prop shaft.
As for the Evinrude name, has it ended after 111 years since the first outboard was marketed? Even if it has, it remains the longest-running brand name in the history of the outboard industry and a name old farts like me will remember forever, even when dementia sets in.
Goodbye E-TEC, we'll miss you.