CONTINUOUSWAVE

[As a follow-up to an earlier thread discussing maximum engine weight for a 22 Whaler Drive boat] I wanted to let everyone know I installed two new E-TEC G2 three-cylinder 150-HP engines on my 1989 Outrage 22 Whaler Drive boat. The boat runs like a champion and is super smooth and dry. [The combined weight of the two engines at 794-lbs] is the limit of what I would put on the Whaler Drive. I will be moving the batteries forward into the console at the earliest opportunity.

I was going to get the E-TEC 140-HP engines, but the Evinrude dealer at Cape Romain (whom I have dealt with often and is an incredible guy) told me that the E-TEC G2 150-HP engines that he would install weigh 397-lbs and the 140-HP engines weigh 390-lbs. The price different was very small, so I took his advice and installed the twin E-TEC G2 three-cylinder 150-HP engines.





Thanks so much to everyone on this forum for their advice and knowledge.

The twin Evinrude E-TEC 150-HP three-cylinder engines with three-blade stainless steel propellers give:

RPM   MPH   GPH   Comments   
5400  47    --    Full throttle 
3900  31    14    Cruise; very smooth and controllable
900   6-7    2    Troll

GPH is for both engines combined.

Congratulations on the re-power with the twin 150-HP E-TEC G2 three-cylinder engines. And thanks for the follow-up from the prior discussion about engine weights.

What was the top boat speed before the re-power when the boat had the twin 150-HP carburetor engines?

What was the weight of those engines?

Are the new E-TEC engines a standard rotation and a counter-rotation pair?

What propellers are on the new engines?

What was the engine mounting height in number of hole above lowest?

The Evinrude power steering is a bit complicated. Please explain how your twin engine rig is set up for steering

Is there a mechanical tie-bar?

Does only one engine actually have hydraulic steering input?

ASIDE: when you move the engine batteries to the console, be certain that you use the appropriate engine battery cables. I believe Evinrude has strict specifications about the wire gauge for longer cables. Excessive voltage drop in the battery cables from using wire with insufficient gauge will cause problems.

What [is the manufacturer's recommended full-throttle engine speed range for an E-TEC G2 three-cylinder 1.9-liter 150. H.O.]

Is a top engine speed of 5,400-ROM too low?

A maximum boat speed of 47-MPH looks good, but [should the E-TEC be] getting closer to [an engine speed of] 5800 to 6000-RPM [at full throttle]?

The OP does not provide prop make, model, diameter and pitch.

Assuming the boat was tested with a full load of gear and fuel, I believe he could go down in pitch by 2" in the same make/model/size that are installed now, gain ~200-RPM, and get closer to the maximum WOT RPM for the engine, which is 6000-RPM.

That said, it appears the current rigging and propeller are in the ballpark of performance expectations.

To get information about the Evinrude E-TEC G2 150-HP three-cylinder 1.9-liter engine, visit

https://www.evinrude.com/en-US/e-tec-g2 ... html#tab=0

--or--

https://www.evinrude.com/content/dam/ev ... tboard.pdf

The manufacturer's recommended full-throttle engine speed range is listed as 5,000 to 6,000-RPM.

Stayinstrewn wrote:...[should the E-TEC be] getting closer to [an engine speed of] 5800 to 6000-RPM [at full throttle]?

You are probably influenced by the behavior of four-stroke-power-cycle engines which tend to develop their maximum horsepower at or very close to their rated maximum engine speeds. The E-TEC engines tend to develop their best horsepower closer to the upper-middle of the full-throttle recommended engine speed range. Evinrude publishes a list of the OPTIMUM engine full-throttle speed range, usually limited to a narrow range of about 200 to 300-RPM. The G2 150-HP engine is quite new, and I have not seen the Evinrude recommended optimum full-throttle engine speed range listed yet. A dealer who is really on top of his game should have this data. Usually the information about the optimum engine full-throttle speed range is provided in the Service Manual. (I do not have a copy of the service manual for the new G2 150.) But each E-TEC is different, so there is no telling exactly what the optimum WOT engine speed might be without guidance from the manufacturer.

An article I wrote in REFERENCE gives the full-throttle engine speed range and the optimum full-throttle engine speed range for many models and model years of legacy E-TEC engines, but I don't have similar data for the G2 engines, particularly this new three-cylinder model.

With twins I would want to be closer to max as it would make planing the boat on one engine more efficient.

NICK — good suggestion.

I am interested in the top speed of the 22 Whaler Drive with 300-HP. I also have a 22 Whaler Drive, but with 225-HP. My boat is not an OUTRAGE but a REVENGE, so the original hull weights are not the same; the REVENGE is heavier by 300-lbs. The OUTRAGE in this situation has a T-Top and twin engines, both adding extra weight. It is likely the OUTRAGE 22 Whaler Drive with twin engines weighs as least as much as my REVENGE 22 W-T Whaler Drive, and perhaps may be even heavier.

In many tests with many propellers, the top speed of my 22 Whaler Drive boat with 225-HP is between 41 and 44-MPH. Let's use a figure of 42.5-MPH as a reliable top speed.

The increase in speed that would be anticipated if the engine power were increased to 300 from 225-HP (while the total weight remains the same) is proportional to the the power ratio to the 0.5 exponent. Thus the estimated top speed for such a power increase would be:

MPH = 42.5 × (300/225)0.5
MPH = 49

The reported top speed at 47-MPH is slightly less than expected, but this is probably due to three factors tending to reduce speed:

• the additional drag of two gear cases with the twin engine rigging
• the additional air resistance of the T-Top
• weight variations between the two boats

The engine weight differs by about 300-lbs, that is, about 500-lbs for a single engine and about 800-lbs for twin engines. The hull weight favors the lighter OUTRAGE by 300-lbs. The two boats should have similar weights The addition of the T-Top might bring the hull weigh of the OUTRAGE to be greater. Certainly the air resistance of the T-Top has an influence.

Let's repeat the speed estimate calculation, but allow for the OUTRAGE 22 Whaler Drive boat with twins to be five-percent heavier, based on a difference of say 150-lbs in boats that weight about 4,300-lbs The math looks like this

MPH = 42.5 × (0.95 ×(300/225))0.5
MPH = 47.8

Now the predicted speed is very close to the reported speed.

I have given some (idle) thought to re-fitting my boat with twin E-TEC 140-HP engines. When I look at my pattern of use of my boat the last five years, I cannot justify investing in new engines. But I do find speculating and analyzing the possibilities to be fun.

I think the twin 150-HP E-TEC three-cylinder G2 engines are a great choice for fitting twins on a 22 Whaler Drive boat. As remarked above, at almost 800-lbs the two engines are probably close to presumed maximum weight for a Whaler Drive boat. I would be particularly conservative about total engine weight on a Whaler Drive boat when the boat is NOT in the water. With a Whaler Drive boat on a trailer, the drive is supporting all the engine weight without the benefit of the buoyancy force the Whaler Drive creates in the water.

There is a flaw with that however. Most boats have a "max hull speed". To get over this hump requires a LOT more hp. You can only make a barge go so fast. If a hull with 100hp does 50mph and with a 50hp does 35mph, putting a 150hp engine on it does not mean it will go 15mph faster or 65mph. I have read where in some instances you would have to double the HP to gain another 10mph once max speed is achieved.

"I would be particularly conservative about total engine weight on a Whaler Drive boat when the boat is NOT in the water. With a Whaler Drive boat on a trailer, the drive is supporting all the engine weight without the benefit of the buoyancy force the Whaler Drive creates in the water."

I agree on being cautious about weight but if a whaler drive boat can get airborne and land on the stern repeatedly in it's lifetime, I doubt sitting on a trailer would be stressful to the hull.

biggiefl wrote:There is a flaw with [the analysis using Crouch's method above] however. Most boats have a "max hull speed"...

Crouch's Method is applicable for moderate V-hull boats on plane at moderate speeds. As mentioned, any speed increase is limited to the power to weight ratio to the 0.5 exponent. This means that to go twice as fast will require four-times the power with no weight increase. The method has been demonstrated to be very good at predicting boat speeds with different horsepower, as I demonstrated in my example, where it came rather close to predicting the observed speed.

biggiefl wrote:I agree on being cautious about weight, but if a Whaler Drive boat can get airborne and land on the stern repeatedly in its lifetime, I doubt sitting on a trailer would be stressful to the hull.

Sitting on the trailer is probably not awfully stressful. It's the lousy roads the trailer has to drive on at 55-MPH that give me cause to worry about the total engine weight on the Whaler Drive. The problem with a Whaler Drive boat on a trailer is there usually is NO support for the Whaler Drive because its bottom is 6 to 10-inches higher than the hull keel. On the trailer, the Whaler Drive is just a cantilever force on the transom, and that 800-lbs of engines has a 2-foot lever arm.

Also, Whaler Drive boats generally do not get airborne. The Whaler Drive acts like a giant trim tab and limits the bow rise. However, one particularly rough afternoon going to windward in Georgian Bay, the boat behind me later said they could see air under the whole hull. Some of those landings did feel a bit rough. But the Whaler Drive boat usually has a nice ride. Larry Goltz gave my boat the nickname "The Brougham," a Cadillac-reference.

"This means that to go twice as fast will require four-times the power with no weight increase."

I am still not sure that 160hp would be able to get a 13' classic hull to over 70mph. Who wants to try?

There is a prior discussion about really high-speed predictions, and the formula alters slightly. On really high speed boats where most of the hull is out of the water and the boat runs on a small pad, the prediction for speed changes from the Crouch estimate. Crouch estimates are for planing hulls with the hull still in the water.

The 13-footer with 160-HP still has to weigh the same as a 40-HP for the Crouch model to work as you suggest. Of course, that is impossible. Adding a lot of weight to get the 160-HP is going to reduce the speed increase significantly. Also, 80-MPH boats are not really in the range of Crouch's method.