1950s Alumacraft Deep C Upper Transom Drains

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79XS

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Hello, I have a late 1950s Deep C. Windshield and steering wheel are up front, not mid mounted. Currently, I run a 1961 Johnson 10HP and a 5gal tank. If I go in the very rear of the boat to pull-start or fix the engine, my 230lbs weight is enough cause the upper drains to take on a bit water, mostly if the boat is rocking a bit, see the picture below. I do not have a photo to post, so I used one off Google Images, forgive me if its a boat owned by someone here. I would like to switch to a 1950s 30HP motor. I am worried about the added weight of a battery plus a larger motor. Does anyone else have this issue? I'm not sure if I would survive losing a battery and 20HP worth of weight over winter...🥵 😁

Thanks.

IMG_20170522_184238448.jpg
 
Very odd scenario. I also have a Deep C and have had no experiences of that nature. The boat is rated 60hp and designed to accept twins. It also has an aft bench originally designed for a seatback - implying family seating. All equating to a design meant to accept some rearward weight. (it is a *deep c* hull after all, in my experience an extremely stable design built for bigger water)
That being said, a larger motor is going to offer electric start options that would circumvent the rearward journey.
Once equipped with more HP, your planing experience will be much different and allow a reconfiguration of your fuel, gear, and people to maximize balance.
Ultimately, one could mount an upper bilge pump to more quickly evacuate the Aqueduct Transom, as well, if it's not emptying quick enough. (your selected pic shows a non-factory hole size. There were originally 12-14 smaller 3/16in holes.)
 
The water empties out pretty quick. I wasn't sure if it was normal for them to be so low. I'll have the boat out on Saturday, I'll take some pictures. Again, it tends to happen when I am messing with the motor, maybe looking over the back or unlatching the cowl.

Any recommendations on engines? I really like the look of the 1950s OMC engines. My 1961 looks a bit too modern. I have been eying up a local 1957 Evinrude Lark 35. I'm not worried about doing mechanical work, but I know parts can be a wildcard.
 
The water empties out pretty quick. I wasn't sure if it was normal for them to be so low. I'll have the boat out on Saturday, I'll take some pictures. Again, it tends to happen when I am messing with the motor, maybe looking over the back or unlatching the cowl.

Any recommendations on engines? I really like the look of the 1950s OMC engines. My 1961 looks a bit too modern. I have been eying up a local 1957 Evinrude Lark 35. I'm not worried about doing mechanical work, but I know parts can be a wildcard.
For the most part, I suspect you're simply dealing with the downfalls of a 15" transom.
In my experience, shutting things down too quickly will often get an uninvited following wave, too. lol
The Aqueduct Transom does a nice job of mitigating that whole scenario, in my opinion.
I have a few other boats like the early Crestliner Speedsters that have no stern deck at all and the whole following wave thing makes for an interesting day using a part of the brain that usually stays dormant.

As far as engines, I love the early magneto omc motors. Super simple and all the consumables are still readily available. Except for the thermostat, most of the parts on the '57 are identical to your '61.
Personally, I have a garage full of them and I often switch them out just for giggles.
On the Deep C, I've run multiple omc 35s and a '62 40hp. This winter, I'm geared up to mount twin '56 30s.
It's a really versatile boat. It's becoming one of my favorites, to be honest.

*fwiw, I can tell the difference in the 35 vs the 40, but only because I've done them back to back.
Ultimately, I think you'll love the Lark. It's one of the best looking of the era with direct ties to the Raymond Loewy design house.
(also, for what it's worth, I would personally pick the '57 over the '61 mechanically, too, as the '60 / '61 40s had a few known weak spots with using the smaller 35 crank design.)
 
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For the most part, I suspect you're simply dealing with the downfalls of a 15" transom.
In my experience, shutting things down too quickly will often get an uninvited following wave, too. lol
The Aqueduct Transom does a nice job of mitigating that whole scenario, in my opinion.
I have a few other boats like the early Crestliner Speedsters that have no stern deck at all and the whole following wave thing makes for an interesting day using a part of the brain that usually stays dormant.

As far as engines, I love the early magneto omc motors. Super simple and all the consumables are still readily available. Except for the thermostat, most of the parts on the '57 are identical to your '61.
Personally, I have a garage full of them and I often switch them out just for giggles.
On the Deep C, I've run multiple omc 35s and a '62 40hp. This winter, I'm geared up to mount twin '56 30s.
It's a really versatile boat. It's becoming one of my favorites, to be honest.

*fwiw, I can tell the difference in the 35 vs the 40, but only because I've done them back to back.
Ultimately, I think you'll love the Lark. It's one of the best looking of the era with direct ties to the Raymond Loewy design house.
(also, for what it's worth, I would personally pick the '57 over the '61 mechanically, too, as the '60 / '61 40s had a few known weak spots with using the smaller 35 crank design.)
Funny you bring up running dual motors. I was pondering the same idea. Right now, its just my grandpa's old boat, literally and figuratively. I felt a modern motor would be too boring. Then, I thought maybe dual late 1950s Johnsons, a pair of 10s or 18s. In part of that research, I was wondering how to handle the propellers. If I run the stock propellers, I will not gain any top speed, correct? All I gain is acceleration?
 
Funny you bring up running dual motors. I was pondering the same idea. Right now, its just my grandpa's old boat, literally and figuratively. I felt a modern motor would be too boring. Then, I thought maybe dual late 1950s Johnsons, a pair of 10s or 18s. In part of that research, I was wondering how to handle the propellers. If I run the stock propellers, I will not gain any top speed, correct? All I gain is acceleration?

"dual late 1950s Johnsons"

The would be cool.
 
Funny you bring up running dual motors. I was pondering the same idea. Right now, its just my grandpa's old boat, literally and figuratively. I felt a modern motor would be too boring. Then, I thought maybe dual late 1950s Johnsons, a pair of 10s or 18s. In part of that research, I was wondering how to handle the propellers. If I run the stock propellers, I will not gain any top speed, correct? All I gain is acceleration?
Not sure how it's going to work out, really. I suspect that duals will respond traditionally to diameter and pitch.
However, in some circles, dual motors must have counter-rotating props, no matter the diameter and pitch.
But historically, OMC and Merc were running duals without. Scott-Atwater was the first to counter the drives.
I figure it's just 60hp and they're simple drive pin props, not an off-shore performance package. lol
I have a crate full of Michigan Wheel props to play with, too. Should make for a fun time.
 
Two 18's will equal a good running 25hp apporox....people often choose duals for the security of having a backup if one fails. In the old days ( my youth) motors were only so big so if more power was needed you had to add another. And of course, the "cool" factor.
 
Two 18's will equal a good running 25hp apporox....people often choose duals for the security of having a backup if one fails. In the old days ( my youth) motors were only so big so if more power was needed you had to add another. And of course, the "cool" factor.

Cool factor for sure!



cool.jpg
 
Two 18's will equal a good running 25hp apporox....people often choose duals for the security of having a backup if one fails. In the old days ( my youth) motors were only so big so if more power was needed you had to add another. And of course, the "cool" factor.
true story.
...and if one was to actually hit the Deep C's 60hp rating in 1956, twins were the only way to do it. lol
 
here's a Deep C with a pair you don't see everyday...
(Apologies to the owner...I lifted the pic.)

1727178049350.jpeg
(
 
That is a slick looking boat. I'd be leery running it at WOT across the lake on anything but a dead calm day though. 75hp seems like a lot for that little tinny.
 
here's a Deep C with a pair you don't see everyday...
(Apologies to the owner...I lifted the pic.)

View attachment 122875
(


That's the same model/type of boat I own. I converted mine to modern steering. If I can't decide, I'll just need to go with the option to run either a single or duals. Maybe I'll buy a 35hp lark, then find a second match to my existing 10hp.
 
That is a slick looking boat. I'd be leery running it at WOT across the lake on anything but a dead calm day though. 75hp seems like a lot for that little tinny.
Might be more concerned with that weight on the transom.....lot of weight for a 15" transom...gonna need someone to ride up on the bow and hang on for dear life....lol...
 
The Deep C is rated 60hp and designed for the twins. 15ft with 5ft of beam.
Nearly 900 lbs of weight capacity.
(those Olivers are 125 each. That leaves 650lbs for the rest of the boat)
 
The Deep C is rated 60hp and designed for the twins. 15ft with 5ft of beam.
Nearly 900 lbs of weight capacity.
(those Olivers are 125 each. That leaves 650lbs for the rest of the boat)
In calmer waters you may be OK, but growing up on Lake Erie, having that much weight on a 15" transom in our choppy waters. Way to.much risk from my own experiences. Won't even go out in the lake unless I have a self bailing motor well in these small tinnies. My own tinnie is rated for 80 hp motor but at today's weight...not sure I would want that much hanging on the back. My is 16' long with an 80" beam and 1300 lb capacity, but I am safety concious, not just interested in flying across the water.
 
In calmer waters you may be OK, but growing up on Lake Erie, having that much weight on a 15" transom in our choppy waters. Way to.much risk from my own experiences. Won't even go out in the lake unless I have a self bailing motor well in these small tinnies. My own tinnie is rated for 80 hp motor but at today's weight...not sure I would want that much hanging on the back. My is 16' long with an 80" beam and 1300 lb capacity, but I am safety concious, not just interested in flying across the water.
Fair point. Great Lakes are a different kettle of fish than my TVA reservoirs.
 

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