Topic: Impeller fab – if you had your druthers – Antique Outboard Motor Club,Inc

This topic has 24 replies, 9 voices, and was last updated 4 years, 2 months ago by green-thumbs.

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March 11, 2020 at 1:34 pm #197147
kirkp
Participant
So going to attempt fabricating a impeller for my KE3. If you had your druthers would you rather:
-work with a impeller that has the correct OD and thickness but the bore needs to be reamed out or
-work with a impeller that has the correct OD and bore but needs to be thinned down.

Don’t have a drill press but have access to one. What’s the best way to ream out the bore?

Thanks
Kirk
March 11, 2020 at 1:51 pm #197149
frankr
Participant
US Member
Have you checked with Brian Wilcox? He makes new impellers, using your old hub.
March 11, 2020 at 4:34 pm #197153
Mumbles
Participant
It’s probably easier to resize the bore than shave the vanes. I have thinned impellers before by using a belt sander and constantly checking the thickness with a pair of digital calipers. The bore can be opened up a bit with a sanding drum.
March 11, 2020 at 5:53 pm #197169
lindy46
Participant
US Member
Resize the bore.
March 11, 2020 at 6:57 pm #197170
green-thumbs
Participant
US Member - 2 Years
Joe Brincat’s article in recent Antique Outboard shows some reall
outside the box thinking. His Wizard WD3 has same pump as
your Mercury KE3. There are a number of alternatives ,but, I think
Joe has found one that is hard to beat. The real problem is creating
slots for drive hub. Joe’s solution was way out of the box thinking
Recent thread here about KD3 has the article.
I was present when Joe fired up WD3…srarted right up, ran strong and
pumped water like a fire engine.
Atta boy Joe!
Louis
March 11, 2020 at 8:35 pm #197171
Buccaneer
Participant
US Member
I read that article, and thought about doing the same on my KD4, melting the
slots in the new impeller, but when I held up the drive piece, the lugs just
about went across the whole diameter of the new impeller.
I ended up making a new drive bushing for the new impeller,
using the single slot.
I have not tried it out yet though. To make it work, the drive key, that’s part of the bushing
is a lot thinner than I would have liked.

Prepare to be boarded!
March 13, 2020 at 11:21 am #197266
geary
Participant
US Member - 2 Years
Kirk,
Another way is to thin down an impeller that the diameter is correct for but is too thick ! What I’ve done is to make an arbor using a bolt and large flat washer, It takes a bit of time to fabricate but works great keeping the thickness uniform !

Using a piece of steel round stock or an old bolt about 2-3” long, assuming you have access to a lathe, turn it to the diameter of the bore of the impeller a little less than the thickness you need. I drill and tap a small brass screw to go in midway in the impeller thickness and file it to use as the drive key ! You will have to fit a fender washer against the shoulder on the shaft before you install the screw key, make sure the washer is a bit bigger than the impeller diameter.

install the impeller on the shaft against the washer, then using a drill press with a nice flat piece of wood you can bump the impeller against a piece of course (80grit) sandpaper and thin it down very easily to the exact thickness you need ! Good luck which ever way you chose to go !

Gary
March 13, 2020 at 2:25 pm #197281
kirkp
Participant
Appreciate all the replies.
Frank, I hadn’t when you posted but have since reached out to him. I should have said initially that I was THINKING about doing this. Most things I’ve seen lately were geared around doing a mod so didn’t even think of him. Actually it was hard to find his contact email but got it done. I think.

Louis, read Joe’s article with interest. You’re right of course that my KE3 uses the same impeller per the parts list. When I pulled the old impeller which was pretty old, I quick measured the approximate OD at 1.5″. The tips of the vanes were really worn but they still seemed to contact the housing pretty good. I see where the 18-3072 impeller has a 1.835″ OD which is quite a bit larger. I’ll have to measure more accurately.

Buc, that replacement drive piece is a work of art. I need to look at my impeller closer to see how far the recess for the pin goes on the bushing. Joe’s article didn’t address this but zooming in on his pics doesn’t reveal an issue that I can see.

Gary, sounds like a slick way to do this. Had to chuckle about the lathe, I don’t even have access to a drill press. 🙂

Kirk
March 13, 2020 at 2:32 pm #197282
fifty20ne
Participant
US Member
Try the easy way first!
Call Joe.
http://fergusonpoolemarine.com/enginecoolingsystem.html
Or
https://www.oldmercs.com/category_s/37.htm
March 13, 2020 at 3:25 pm #197285
Buccaneer
Participant
US Member
I think I’ll try Gary’s way next time. I’ve done it on the belt sander,
but there was always the concern about sanding it “out of whack”,
or the free and bloody manicure.

I may need to do this for my current Flambeau project if
I can find the suitable cadidate impeller.
Wish Mr. Schopke was around to ask.

Prepare to be boarded!
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