Engine Mounting and Bolt Orientation
Posted: Fri Apr 17, 2020 4:03 pm
[This topic has been separated from another repair topic. This topic is discussing the method of mounting an engine. To discuss how engine mounting height affects performance, please see the PERFORMANCE forum. This discussion is in regard to the process of mounting, particularly the location and oreintation of bolts, not the process of optimizing boat speed and performance from adjustments of mounting height. The FAQ discusses engine mounting height in detail. See
Q8: How Does the Engine Mount to the Transom?
http://continuouswave.com/whaler/reference/FAQ/#Q8
Q9: What is the Standard Transom Hole Layout?
http://continuouswave.com/whaler/reference/FAQ/#Q9
The FAQ discusses use of blind holes and elevated lower mounting holes, particularly in regard to Boston Whaler boats with shallow transom splash wells where the lower bolts would exit the transom on the inboard side below the splash well bottom. Reading the FAQ is highly recommended---jimh]
When I bought my boat it had a Mercury 60-HP c.1985 engine. The location of that engine's mounting holes were not even close to what I needed for my 1993 Evinrude 48 SPL. I filled the old holes and drilled new ones.
I rested the 1993 Evinrude 48 SPL outboard engine on the top of the transom for support. That location put the engine [anti-ventilation plate] where I wanted it [in relationship to some unspecified reference point].
I used two lower engine holes that [were not part of the notched slot that is located in the BIA recommend position range]. Using those holes put the mounting bolts safely above the splash well curved bottom.
Q8: How Does the Engine Mount to the Transom?
http://continuouswave.com/whaler/reference/FAQ/#Q8
Q9: What is the Standard Transom Hole Layout?
http://continuouswave.com/whaler/reference/FAQ/#Q9
The FAQ discusses use of blind holes and elevated lower mounting holes, particularly in regard to Boston Whaler boats with shallow transom splash wells where the lower bolts would exit the transom on the inboard side below the splash well bottom. Reading the FAQ is highly recommended---jimh]
When I bought my boat it had a Mercury 60-HP c.1985 engine. The location of that engine's mounting holes were not even close to what I needed for my 1993 Evinrude 48 SPL. I filled the old holes and drilled new ones.
I rested the 1993 Evinrude 48 SPL outboard engine on the top of the transom for support. That location put the engine [anti-ventilation plate] where I wanted it [in relationship to some unspecified reference point].
I used two lower engine holes that [were not part of the notched slot that is located in the BIA recommend position range]. Using those holes put the mounting bolts safely above the splash well curved bottom.