TOPIC: Barn find Fat Fifty

New to the site here. AOMCI member for ten years or so. I found this one on Craig's List in NH.Cosmetically its as good as it gets for 1958. I got the wiring harness, but no controls. Two weekends of fooling around with it, clean points, plugs, dist. cap contacts, carb, fuel pump. I replaced a couple of mouse chewed wires, and checked out the water pump and gearcase oil. All good. I hooked up some ears and a gas tank, and WOOO! she started on the fourth pull!
I remember seeing one of these when I was a little kid, and always thought it would be cool to have one. It'll go great on my Jet Deville project. Now go rebuild that transom...
Larry

Another pic. They don't make graphics like this anymore... Anyone have that little emblem that's missing?
Larry

Beautiful engine. No,they don't dress them up like that anymore.jim

sailor58,

WELCOME ABOARD.

Also NEAT engine!!!!
(Those old V-4 are TOUGH, though THIRSTY.)

yours, satx

Nice old V4. A good upgrade for the 50hp is a set of higher-compression heads from a later-model 60hp V4, and a set of pyramid-style reed blocks/plate from later models.

The old flat-style reeds have really bad airflow and it's almost like half the gas goes out the bottom of the motor instead of going thru it! Well, maybe not quite half but a pretty good oil slick for sure!!

It'll still be thirsty in comparison to more "modern" motors, but at least will have a few more ponies under the hood. A similarly-equipped Gale version was rated at 60hp.

I can't recall what other heads will fit (maybe 65hp?), perhaps one of the OMC Gurus can ring in.

Cheers............ed

Nice Fat fifty.
I have a 59 Fat Fifty.

Larry,
Yep good looking motor. I have a '59 also. The mid '60's 60hp heads will fit it. Don't know if will bring up the hp a that much. I tired to hotrod mine with a set of 60hp heads but I also milled them down but milled too far and I'd have to fill down the pistons a little to make the heads work. Definitely change out the reeds. Maybe just change the heads out with the 60hp and see how it does. Don't mill them just put them on.

Bob

Thanks for the warm welcome, fellas. You have a nice place here. I have heard of the bad reed design and would certainly entertain changing them to the later style. Could I just mill the heads that are on it to raise the compression?
TIA
Larry

sailor58,

ImVho, the later heads are designed better than those on the 1958. Also, a "junker" engine can often be bought,with perfectly functional heads, with the needed useful parts for less than 100.00.
(I bought a 75HP OMC for 25.oo some months ago & got ALL the parts that I needed to fix another Johnson, except new points/plugs/condensors from the local NAPA store! - Fyi, I am known to be "thrifty" here, as I regard Jack Benny as a "spendthrift".= CHUCKLE.)

yours, satx

Larry,
It would be better to use the newer heads since they cooled much better than the '58/'59's. The newer heads have a water jacket that flows through the head. This is the thread about hot rodding a fat fifty that I did. you can look at the top of the 60hp heads and see the difference. Keeps the heads much cooler, hence the ability to mill them slightly and raise the compression.

www.fiberglassics.com/fiberglassics-forums/home/j-e-g-o-s-place/hot-rodding-a-fat-fifty-a-lesson

Bob

Here's an eBay auction with the later-style reed plate assy so you'll know what to look for:



A little $$$, though, you can probably find an old parts motor off the Craigslist, with the correct heads, for not much more (maybe less, who knows!!!).......ed

That's a bute, I have 2 58's and just picked up a '59. (all long shafts). I ran one of the 58's last summer. A '59 Fat Fifty on a Shell Lake Rocket was the first boat I ever skied behind when I was a kid. I'm planning on a classic glass boat for a Fat Fifty, but still looking...

That has the be the cleanest Fifty I've ever seen. It is probably on of just a dozen or so with an undamaged set of face plates. Those plates alone are worth more than many of the boats on FG. I will send you a complete reed assembly for $40.00 - sent to your door. Any head from a gale V4 will work and an Evinrude 60 or 65 head will work. In either 1967 or 1968, the depth of the sparkplug hole changed. The heads can still be used, but a longer reach plug will be needed. I like the late heads because there are more threads and meat for the plug. You can certainly mill the heads, but be sure the shop that does it knows what they are doing. I advised Bob to have the ones for his engine milled .125" which he had done. The piston crowns hit the combustion chambers due to lack of clearance. I may have given him bad advice, but I have personally done this mod & have not experienced any problem. I suspect that the machine shop that did the milling cut too much from the heads. But the pistons in his engine may have been different than the ones that I have done. Either way, I still feel bad about it. The safest way to cut heads is to measure the squish area. I've decided to make a new post about this and it is found above. Good luck with the motor - it's a beauty

FYI, I checked both of my '58 Fat Fifties, neither cover has an emblem on the pull start door, nor does it look like they ever had one...???

Hey don't sweat it Bruce, no big deal. That's how we learn things and I learned a lot on this one. I'm working on restoring the '67 80hp in the '61 housing then I'll go back and possibly file down the sides of the piston crown so it doesn't hit head and see what kind of performance I get. Want to make sure I have a good running spare first.

Bob

The carb door did have an emblem it was a giant and bold "E" that fit into that recess on the door. I've never seen one , I'm pretty sure all of them fell off in the 70s or before that even.

Bob - Putting an old pan and hood on a later 75 through 100 motor is the smartest thing to do if you want go-go. "If you are burning a ton of gas - might as well haul ass"

That's what I did with mine. The 50hp mill only got me 28 MPH. The 1961 75hp gets me 35 MPH and uses the same gallons per hour at full throttle, about 5.5. While learning about a newer baot and motor I discovered the evinrude on my 64 sea ray is mounted too low producing extra drag. On the lake this summer I will adjust. I hope to have what looks like the fastest "fat-fifty" on castle rock lake this summer.

Bruce Gerard wrote:

That has the be the cleanest Fifty I've ever seen. It is probably on of just a dozen or so with an undamaged set of face plates. Those plates alone are worth more than many of the boats on FG. I will send you a complete reed assembly for $40.00 - sent to your door. Any head from a gale V4 will work and an Evinrude 60 or 65 head will work. In either 1967 or 1968, the depth of the sparkplug hole changed. The heads can still be used, but a longer reach plug will be needed. I like the late heads because there are more threads and meat for the plug. You can certainly mill the heads, but be sure the shop that does it knows what they are doing. I advised Bob to have the ones for his engine milled .125" which he had done. The piston crowns hit the combustion chambers due to lack of clearance. I may have given him bad advice, but I have personally done this mod & have not experienced any problem. I suspect that the machine shop that did the milling cut too much from the heads. But the pistons in his engine may have been different than the ones that I have done. Either way, I still feel bad about it. The safest way to cut heads is to measure the squish area. I've decided to make a new post about this and it is found above. Good luck with the motor - it's a beauty

Bruce, thanks for the kind words. I've sent you an email. Here's a question for you V4 guys,I was told that I could use a 75HP lower unit to get a bit more speed. The 75HP lower unit uses a different ratio, giving a higher prop shaft speed? Yes, I do have some understanding of prop design/gear ratios/shaft speed having repowered a number of inboards.
Larry

I can't attest to the gear ratio, but the original "Fat Fifty" lower unit (aka "Heavy-Duty" lower unit) is about as hydrodynamic as a log! It was meant to swing a large prop at low speeds, to take advantage of the motor's large amount of torque, for pushing heavy boats/loads.

Later motors had what was called a "High Speed" lower unit, with a much smaller gearcase diameter and a streamlined shape, which cut the water much better. It also carries a smaller-diameter prop and I'd expect swings it at a faster speed, so maybe there is a diff in gear ratios!

At any rate, the 2 lower units are interchangeable and if you get a late-enough one, the shift clutch is improved with spring-loaded balls which ensure the clutch snaps smartly into gear, and holds that gear better.

The biggest weakness on these old mechanical-shift V4's is the shift clutch/gear design, 'cause they depend on the tightness and adjustment of all the pieces in the shift mechanism to hold the motor in gear. Any wear/slop leads to slippage and damage of the dogs on the clutch and gears. Mostly on the forward gear since there's more stress on the dogs.

But I digress, there should be plenty of the High-Speed lower units kicking around, finding a good one is the chore. They are a bit harder to work on, since the case halves don't split like the Fifty.

There are 2 long studs holding the lower and upper case/housing together, and they can be a real bugger if run in salt. A fresh water gearcase should come right apart, with little persuasion (maybe a bit of heat if necessary).

Check your local Craigslist for dead V4's, there should be a couple or 3!

I found a pic of a 75hp V4 on eBay, for an example. The housing on top is the 5-inch extension piece for a longshaft and is just bolted on.

HTH.......ed