Crank rated HP's

[HighTrim]

I would really like this one answered. I always thought that prior to about 85 all makes measured HP at the crank, and then over about a 3 year period all makes switched to measuring HP at the prop. Now I read in a post by Mr Reeves that as far back as 62 OMC would advertise in promo videos available to dealers that their hps were rated at the prop, which was their selling point over the Mercs.

So now I am confused?? Anyone have some factual insight into this? Im sure that Seahorse5 would know for sure.

 

[JB]

Re: Crank rated HP's

I hadn't heard that before.

I thought that Suzuki forced the issue on other makers by going to prop rating sometime in the 70s.

However, if Joe Reeves say so it is probably true.

 

[seahorse5]

Re: Crank rated HP's

Back in 1983, all the then outboard manufacturers agreed on the International Council of Marine Industry Association(ICOMIA) Standard 28-83 for rating power at the propshaft for the model year 1985 or 1986.

Prior to that the old BIA powerhead dyno testing was the industry standard for power output for American manufacturers. Foriegn companies used either procedure during the early days.

 

[steelespike]

Re: Crank rated HP's

I think the basic outcome is that without a gps your not likely to be able to tell the difference.

 

[Dhadley]

Re: Crank rated HP's

The difference is that everyone is focused on horsepower. That's a small part of what moves a boat. A crossflow and a looper may indeed both make the same horsepower with the NMMA guidelines but everybody knows the looper has more power potiental. Torque is a much bigger part than horsepower.

 

[HighTrim]

Re: Crank rated HP's

Tks guys.

 

[coolguy147]

Re: Crank rated HP's

would rather have ur operating rpm at 4500( older evinrudes and johnsons) with massive torque or the newer motors that operate at like 5000-6000 rpm

 

[BSDenning]

Re: Crank rated HP's

would rather have ur operating rpm at 4500( older evinrudes and johnsons) with massive torque or the newer motors that operate at like 5000-6000 rpm

I don't know if that is a question or a statement because there is no punctuation.

 

[Dhadley]

Re: Crank rated HP's

Not really sure either. The older E/Js sure didn't have a lot of torque. Even "newer" old crossflows can't hold a candle to the same hp looper as far as torque goes.