Power comparision I6 merc vs Etec& newer outboards

[sourbsted]

Just curious on what the power differances are between the I6 150hp vs the Etec 115. Obviously the Etec is more efficent .The I6 has a light weight advantage, where Etec weight is not so good. . Is it the power to weight that give the tower its name or shear power it puts out.

 

[wired247]

Re: Power comparision I6 merc vs Etec& newer outboards

Just curious on what the power differances are between the I6 150hp vs the Etec 115. Obviously the Etec is more efficent .The I6 has a light weight advantage, where Etec weight is not so good. . Is it the power to weight that give the tower its name or shear power it puts out.

The etec is a little heavier. Other than that its 10X the motor the tower is. 150HP from the tower is probably equivalent to 115 HP on the etec given the differences in rating systems but the subtle differences make the etec a far superior platform.

I often hear that the tower has the best power to weight ratio of any boat motor. In 1973 that was probably true. A lot has happened in 40 years.

 

[sourbsted]

Re: Power comparision I6 merc vs Etec& newer outboards

It's hard trying to find specs on the towers, which makes it hard trying to compare with all these newer motors.
Cheers

 

[Chris1956]

Re: Power comparision I6 merc vs Etec& newer outboards

The inline 6 Merc 1500 packed a lot of power into a lightweight package. At 300# including PTT, it's power/weight ratio is tops. However, the 99 Cu In displacement is less than newer motors of 115HP or greater and the torque is only gained on the IL6 at mid-range and above. I have had both a Merc 1500 and a Merc 135HPV6 on the same boat. The Merc 135V6 weighs a lot more, so much more that I an concerned about water over the transom. However, it has a lot more low end power. Both the IL6 and the V6 have about the same top end. The mid-range on the IL6 "rolls-on" much more sharply than the V6 which is more linear.

My bottom line: If you have a boat that cannot handle the weight of the V6, the IL6 is a real good idea. However, if the boat can handle the V6, it is more powerful across the RPM range, and more predictable. With the IL6, you needed full throttle out of the hole, and when the boat planed, it would pull from 25MPH to nearly 50MPH in a few seconds. This made it hard on the skiier, who could get launched.

 

[wired247]

Re: Power comparision I6 merc vs Etec& newer outboards

At 300# including PTT, it's power/weight ratio is tops.

A 400 lb 280 HP 2.5 puts out .7 HP per lb. Even the pedestrian 200 HP 2.5 carb'd fishing motor does .5 HP/LB.

A 150 HP inline ( actually 120 at the prop ) at 325 lbs with the trim cylinders and pump puts out .36 HP per lb.

I wouldnt say the inline is "tops" in hp per lb by any stretch.

 

[coolguy147]

Re: Power comparision I6 merc vs Etec& newer outboards

A 400 lb 280 HP 2.5 puts out .7 HP per lb. Even the pedestrian 200 HP 2.5 carb'd fishing motor does .5 HP/LB.

A 150 HP inline ( actually 120 at the prop ) at 325 lbs with the trim cylinders and pump puts out .36 HP per lb.

I wouldnt say the inline is "tops" in hp per lb by any stretch.

Compared to motors from its time period, it might.

 

[roscoe]

Re: Power comparision I6 merc vs Etec& newer outboards

A 400 lb 280 HP 2.5 puts out .7 HP per lb. Even the pedestrian 200 HP 2.5 carb'd fishing motor does .5 HP/LB.

A 150 HP inline ( actually 120 at the prop ) at 325 lbs with the trim cylinders and pump puts out .36 HP per lb.

I wouldnt say the inline is "tops" in hp per lb by any stretch.

The 150 generally was more than 150, thats what they had such an advantage on the race circuit.

And the loss in crankshaft rating vs prop rating is more accurately 5%, not 20%.

 

[wired247]

Re: Power comparision I6 merc vs Etec& newer outboards

5% ? Ive never heard anyone say the loss through the lower is 5% . Even Merc and OMC when they downgraded their number went to 115 from 150/140 albeit with slight compression losses. Best Ive ever heard claim on the 99 cube towers was 155 HP from the J blocks or the early circle C's. In anycase even if they were 150 HP at the prop which they certainly were not that would still not be even close to the real HP/Lb champions, the 2.5's.