Specs and Power Differences between 1981 Merc 1400 140 HP & 1993 Force 150 HP

[aricstoner]

As my long winded subject line indicates I am hoping to get the power specs (cylinder bore size, prop HP rating etc) as well some feedback as to which motor is going to produce better speed for my boat.

I have been told that the 140 is actually more powerfull. But I find it hard to believe that an older motor with a lower HP rating can produce more torque. Can someone please shed some light on this for me. Much appreciated.

 

[Silvertip]

Re: Specs and Power Differences between 1981 Merc 1400 140 HP & 1993 Force 150 HP

Prop RPM (prop speed) and pitch ultimately determines what the theoretical top speed of a boat will be. HP and torque will determine how much prop speed the engine can produce with a given prop and how much prop pitch the engine can twist using a given lower unit gear ratio. So it isn't all about HP and torque.

 

[aricstoner]

Re: Specs and Power Differences between 1981 Merc 1400 140 HP & 1993 Force 150 HP

Well thats what I thought...So in theory a boat with a higher HP rating in the Engine, should produce more torque to the prop depending on the gearing in the lower end gear case. BUT...I was told that somwhere between 1982 and 199? they changed how they rate the HP in motors. They used to rate them on the HP at the flywheel which translates to the raw HP of the engine. But now they rate it based on the HP output at the prop? Maybe Ive heard wrong but thats what I interpreted as to what they told me. Furthermore that still doesn't explain how a 140 HP engine that has in theory 115-125 prop rating is going to be faster than a newer 150 HP engine that was rating under the newer system. So I am very confused