Quote:
Originally Posted by DoozleD
(Post 228493)
...Hay Bushwacker!! what do u think of the new e-tech?
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This is what Doozle was referring to if you haven’t seen it.
http://www.evinrude.com/en-us/engine...etec_300_hp_g2 BRP unveiled their next gen 200-300 hp E-TECs due out this fall at a big dealer meeting last weekend in Milwaukee. Two BRP engineers got a big award from SAE last year for a “significant advancement in the state-of-the art of 2-stroke engines”! A lot of folks were expecting something radical like a lot more HP or duo-prop drives, etc., but it looks like they're saving more HP for the future. (They've already demonstrated ~200 HP/L from production Ski-Do engines with E-TEC technology, equivalent to 680 HP from the 3.4L block, but those are small very high rpm engines!)
Highlights include an integral hydraulic steering system (no external hydraulic cylinder req’d) and a much cleaner rigging system with fly-by-wire shift and throttle. Fuel burn is reported to be 15% less than current E-TECs and oil usage is also reduced because block was designed from scratch for DI and oil injection. Oil tank is on the motor; think it holds about 2 gal. They’ve standardized on the same 3.4L displacement for all motors from 200 to 300 hp instead of the old 3.3L for 200-250 and 3.4L for the 250 HO and 300. Looks like weight may have gone up some, but hard to tell because you’d have to add in weight of hydraulic steering hardware and oil tank to old motors to get a fair comparison. Prices are anybody’s guess, but you can be sure they didn’t get cheaper! Eliminating the steering cylinder will save some $ though! They also have a fancy large all-in-one instrument display panel that would eliminate many separate gauges.
I wasn't that impressed by the new styling, but the new cowling apparently provides great access to the most of the engine via a couple of easily removed panels, and the technical details are quite impressive. BRP has made a serious capital investment with an ALL NEW CLEAN SHEET design, with the V-6 block changed from 90 to a narrower 74 degrees, with extensive use of CFD. Since computers now have enough power to solve the complex equations in a reasonable amount of time, CFD has become a very powerful tool for flow visualization and BRP has clearly put that to use in designing the ports and combustion chamber. The jet engine folks have been using it for about 20 years to come up increasingly complex 3-D bent/curved airfoils that are significantly more efficient (and harder to make!)
I’ve been studying their patent
http://www.google.com/patents/US20140102400 for about a week trying to figure out the new porting and intake/exhaust manifold scheme! Both cylinder heads are IDENTICAL, and rather than exhausting into the center of the V as all outboards have done for over 50 years, they use complex external ductwork & manifolds to connect the crankcase to the intake ports and the exhaust ports to mid-section. Both heads have their exhaust on the port side, and intake on stbd side. The stbd. bank exhaust and port bank intake are located between the V and the port bank exhaust is on the port side of the engine, away from the block. Seems like that would add weight and pressure loss, but it also gives them the opportunity for some sonic tuning to improve mid-range torque and fuel economy, similar to what Chrysler did in the ‘60’s with their cross-ram intake manifolds and the tuned intake on the old slant 6. If you combine those ducts with variable area valves in the exhaust plumbing, it opens up a lot of tuning possibilities! The current V-4 motors have a 2-position valve in the exhaust duct to change tuning for better scavenging at both low and high rpm and the result is like a turbo kicking in at about 4000 rpm! The current I-2 motors use a variable water spray into the exhaust duct to do the same thing.
Although much of this 1+ hr video
http://www.evinrudenation.com/ClubEv...6b0b-171350521 is a bunch of marketing & styling BS talking about "colors, shapes and textures", you can skip all that by viewing the part from 44:00 to about 1:00:00, which contains some pretty impressive engineering info, like 600 ft-lbs of mid-range torque from the 250 HO that will probably embarrass the V-8 outboards, not to mention the 250-300 hp 4-strokes! Also check out the Aussie version of the Seafari at 1:07:00!
One word of caution, the fuel economy chart is a bit technical, as it's comparing BSFC (Brake Specific Fuel Consumption). BSFC is fuel flow divided by HP, so lower numbers are better, and it's the best way to compare engine efficiency.
For anyone looking for more info, there is a long discussion thread on the G2 motors on the E-Tec Owners web site with more info from dealers Seahorse and Huey at
http://www.etecownersgroup.com/post/...665?&trail=135. The useful info starts on about page 10.
