3.0L gear swap

[Todd D]

Will a set of 1.47 alpha 1 gen 2 gears fit in a Mercury 3.0L sportmaster. Will these gears hold up as well as the stock gears?

[transamz9]

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Todd D &raquo;</TD></TR><TR><TD CLASS="quote">Will a set of 1.47 alpha 1 gen 2 gears fit in a Mercury 3.0L sportmaster. Will these gears hold up as well as the stock gears? </TD></TR></TABLE>

This would be a "mute subject".... since the overall "gear ratio" of the Mercruiser drive is "primarily" determined by the UPPER CASE GEAR RATIO.

The actual gearing ratio of the lower case used in the Mercruiser A1G2 sterndrives (for 1.47, 1.62, 1.84, and 1.94 ratio outdrives) is 1.62:1 (which is one of the two ratios already available as a gearset for the Sportmaster).

[esdbass]

Don: I think Redline was right and secretly you just used to be a freaking engineer for Mercury! Amazing answer, I had no idea that was the "case" LOL!

[Todd D]

Thanks Don, hadn't even thought of that. Any ideas what I can do?

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Todd D &raquo;</TD></TR><TR><TD CLASS="quote">Thanks Don, hadn't even thought of that. Any ideas what I can do?</TD></TR></TABLE>

What precisely are you trying to accomplish? Current setup and ratio..... and your "target"?

[Todd D]

sent IM

[EuropeanAM]

And replied....

[JAZII]

Come on!
Post info so we all can learn.

JAZII

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JAZII &raquo;</TD></TR><TR><TD CLASS="quote">Come on!
Post info so we all can learn.

JAZII</TD></TR></TABLE>

Your wish is granted......

The only "viable" ratios at this time for this gearcase are: 1.75:1 and 1.62:1

There are other gearcase options (such as the Speedmaster), but they are simply not suitable for a bass-application (there is no REVERSE GEAR).

Suggested adding PITCH and/or CUP to bring the engine RPM's into spec. Also suggested "care and caution" when operating with higher pitched props. As pitch increases (especially on a "surface run" gearcase), so does the tendency of the prop to "paddle-wheel" across the surface of the water!

[esdbass]

Don: So more pitch adds lift inherently ?

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by esdbass &raquo;</TD></TR><TR><TD CLASS="quote">Don: So more pitch adds lift inherently ?</TD></TR></TABLE>

Not necessarily. The concern is that as pitch increases, the blades become at a greater angle to the propshaft, causing a higher likelihood of the prop "paddle-wheeling sideways" across the surface of the water (to RIGHT or STARBOARD).

With proper setup (and some common sense), it's manageable. Just need to be aware that the "possibility exists" (for obvious safety reasons).