mercury 45 hp classic 50 hp classic

[riverboy39]

what did mercury do to make up hp difference between 45 hp classic and the 50 hp classic ( port location , bigger carbs ) just curious .

 

[racerone]

Nothing but the rating of power at the propshaft verses power off the crankshaft.------Engine is all the same parts !!.

 

[riverboy39]

Thank you for the response. great way to save on the budget .

 

[riverboy39]

mercury crossflow boostport how did this increase hp our did it ?

 

[Faztbullet]

Its called " direct charge" and the additional port aids in increased crankcase pressure. The result is a more forced introduction of fuel mixture and removal of burnt charge. Adds about 10HP overall....

 

[Chinewalker]

But the boost port was never used on the 44 cube motors.

 

[Faztbullet]

This I know...…...:bounce:

 

[jimmbo]

The Power Port was used on some production engines starting in 73(it was used on competition engines prior to that. It added an extra Transfer passage directly from the crankcase(in addition to the regular transfer passage, thru a one inch hole in the Piston to a Trough in the cylinder wall that was exposed shortly before the Piston reached Bottom Dead Center

It was used in the 1973 and up 49.6 blocks(65 and 70 hp), the 66.6 block(85, and post 1981 80, and 75hp), also the 99.9 blocks, the 1500s, the 1978 1400, the 79 - 81 140s, and finally the 1982 and later 115s

A non Port Block engine could not be converted, as the block casting was different

 

[Texasmark]

I had it on my '88, sold as a '89 115 tower. One fine engine, on a Ranger pad boat and a Laser prop, turning 6k RPM, one fine experience. And the efficiency of which they boasted was very true. I couldn't believe how much fun I could have on so little fuel. Wayyyyyy better than my earlier 125 Johnson cross flow......different rig.