Elgin Outboard Impeller swap

[Buccaneer]

Just wanted to show a seemingly successful Elgin impeller
swap, replacing the original 10 vane rubber impellers (one inch plus tall)
with two Mercury impellers stacked together.
Slight modifications were required, such as drilling the driveshaft
for two impeller drive pins, to drive the Merc impellers.
The original Elgin impeller was driven by the driveshaft splines.
The driveshaft is “very” hard drilling by the way!
Thanks to Brian Wilcox for “tips” on doing this conversion!

My camera was aimed a little “low”, but it appears to be pumping water
plenty good. How it will hold up will be the real test.

https://youtu.be/Do6N6ho9gaY

Prepare to be boarded!

[Al]

buccaneer

can you share the part number for the mercury impeller your using in the elgin outboard thanks AL

[seakaye12]

Some of those driveshafts are hardened steel.  Was it difficult to drill?

[bobw]

Buc – looks like it works great.   Glad it worked out!

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[Buccaneer]

Al wrote:

buccaneer

can you share the part number for the mercury impeller your using in the elgin outboard thanks AL

I used Mercury 47-89981 impellers.
Sierra 18-3039

They’re a little loose on the driveshaft, but I fit the
drive pins tight to compensate.

Prepare to be boarded!

[Buccaneer]

seakaye12 wrote:

Some of those driveshafts are hardened steel.  Was it difficult to drill?

I spot drilled them with a machinist “center drill” on the milling machine,
the switched to the size drill bit I wanted. I managed to drill the first
hole to depth, about .200, but the drill wouldn’t touch the other
hole, nor the other four bits I tried, lol.
I ended up using the center drill to go to depth, which worked okay,
but I had to use a larger diameter pin than I intended, which
may have been better anyway.

Prepare to be boarded!

[billw]

You had mentioned that you also had ordered the Sierra equivalent of 47-89980. Did you end up feeling that they were too tight on the shaft?

Long live American manufacturing!

[Buccaneer]

billw wrote:

You had mentioned that you also had ordered the Sierra equivalent of 47-89980. Did you end up feeling that they were too tight on the shaft?

Those ended up being “bigger”.
The 47-89981 I used had a center bore of .453
and the 47-89980 were .457.

Someone mentioned they had to bore the hubs ever so slightly
to fit over the driveshaft. Not sure what make or number those
impellers would have been.

All the impellers I got were Chinesium, so “fit” may not be as
good as the OEM impellers.
When I ordered the impellers, I ordered six all together, not
being sure if I was fixing two motors or one, or which impellers
would work out.

Prepare to be boarded!

[The Boat House]

Including the pictures you posted in projects
might be helpful for others needing a substitute
for their Elgin.
Tubs.

[Buccaneer]

The Boat House wrote:

Including the pictures you posted in projects
might be helpful for others needing a substitute
for their Elgin.
Tubs.

Thanks for mentioning that Tubs.

Photos, including the impellers swap, in Current Projects…….
https://www.aomci.org/forums/topic/1951-elgin-7-5-hp/

Prepare to be boarded!

[Author]

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