What did "setup" mean in 1958

[Texasmark]

We are always yakin about proper engine height and trim and all that setup stuff to maximize performance.

The last couple of days we have also been yakin about the "Fat 50", first American V4 engine produced by OMC back in the '50's.

Also still hammering the question (to me) of torq and it's application in propelling a boat.

So I'm quoting engine specs of the past (addressing torque) and obviously I am in the www.old-omc.de site getting my info so that it's accurate.

So I was in the spec chart on page ..../index2.html and scrolled down below the spec chart where the pictures are.

If you are into setup, you must go over there and check out the picture of the fat 50 with 5" extension (to make it 20"), hanging on the transom of a beautiful Mahogany boat, and look at where the antivent plate is located with respect to the bottom of the boat. Also notice the water pickup (one of 2)......the little plate with 2 screws in it just above the anti vent plate......the other one is on the front side of the exhaust deflector, where i'm told it was deliberately placed so that propwash could keep it swept clean of debris........but propwash, when you're stuck on the sandy beach, also cuts your impeller to pieces. I'm told that the one on the side is for removal if running in a tank of water or when backing up, as that manuever starves the one on the exhaust deflector.

So, I guess one of the reasons for the low mounting was to insure that the water pickup could pickup water.....but geez what kind of performance could they have gotten out of those old OMC's had they had water pickups like Merc on the gearbox housing.

Maybe that's one reason Merc had the speed on them, they were sitting higher on the transom and as a result were able to run faster with less drag......and the lower unit was sleeker, and the engines revved to 6000 rpm's.

So much for today's trivia.

Mark

 

[steelespike]

Re: What did

Re: What did

I tried to find your picture.Is it a catalog pic. or a posted pic.?The catalog pic is difficult to see but looks normal to me.
I'm sure no expert on the fat 50.But I think you may be confusing the shift rod conector cover for a water passage cover.I'm pretty sure there is only a single water pickup and it is very similar through the 58 lineup.
I never heard of reversing affecting cooling.The only problems I've heard is through hub exhaust causing veltilation from the exhaust in reverse.

 

[F_R]

Re: What did

Re: What did

Texas is correct when he mentions the side water intake plate (17) and screen (18) It's reason for living is to supply water when running in reverse. When running in forward, the prop wash forces water into the main water intake screen (30) in the exhaust outlet.

Just look at the shape of that gearcase. It's as streamlined as a football. Try to run it too high and it would cavitate like crazy. True, Mercs were better shaped. But the OMC would push a barge, Mercs wouldn't.

 

[Texasmark]

Re: What did

Re: What did

Steel

Go to the site and in the left margin get into the 1950 category and click on 1958. You will get a page of Johnny/rude specs.

Scroll down below the specs and find lots of pics, including the pic of the side view of the 50 and just the transom of the boat is showing....it's in the showroom on a trailer.

Click on it and when you get it, set your pointer to the lower right corner of the pic. May have to move your pointer around slowly to cross the right pixels to get illumination. You will get an expand box and clicking on it gives you an enlarged pic.

Mark

 

[WillyBWright]

Re: What did

Re: What did

It also has a lot to do with prop design. The Merc props were cupped inward, OMC props were swept back. The OMC design would've sucked bubbles into the thrust path if used with a thru-hub exhaust. The cupped-in design keeps the exhaust bubbles centered. But mostly, cupped-inward props don't ventilate as easily as swept-back props do. So you can run them closer to the surface.

 

[roscoe]

Re: What did

Re: What did

 

[Texasmark]

Re: What did

Re: What did

That's it Roscoe.

That's probably one of the prettiest engines Johnny ever produced as was the 35 also pictured there.

Thanks

Mark

 

[tashasdaddy]

Re: What did

Re: What did

the 50 looks like the long shaft, see the 5 " extension. just makes it look bigger for marketing.

 

[Chinewalker]

Re: What did

Re: What did

I've got a '56 Johnson 30hp short shaft that we run at 19-inches on an old racing utility. The AV plate is well ABOVE the bottom of the boat. Helps to have a 17-inch 2-blade bronze wheel throwing plenty of water into the intake screen on the exhaust outlet.

Although running them that high will not work on most applications, it DOES help to run the motor higher than is pictured in the old ads. Less unit in the water is less drag, which gives better performance and efficiency... Every rig is different, so the only way to find out is to cut up a wooden yardstick for shim sticks and have at it...
- Scott

 

[Chris1956]

Re: What did

Re: What did

I had two of those Fat-Fiftys, a '58 and a '59. Both were longshaft, but I converted one to a shortshaft, by buying a new driveshaft and shift shaft coupler at a junkyard ($15). I painted both of them all white, since I did not like the faded brown pattern of the '58, and the '59 came painted is some red-orange camoflage pattern. They always ran for me, although never had much top speed (25MPH), no matter what the weight of the boat was. Oh yeah, If the motor would overheat, the distributor shaft would expand, slightly cracking the plastic rotor. Now a bit of carbon would get in there, and short the rotor to ground, giving an intermittent spark. Anyone know how long it took me to find that? It was also a drag to adjust the two high speed carb needles, since you had to go full speed, and it took a bit of time to get them just right.

 

[steelespike]

Re: What did

Re: What did

Looks to me like they stuck a 20 in. motor on a 15 in. boat for the picture.
I think the flashiest looking V4 was the Gale Soveriegn
from 63 All white with black trim and what a sound.

 

[F_R]

Re: What did

Re: What did

Shows the gap between engineering and marketing, huh? Of course that motor is not compatable with that boat. They didn't count on anybody noticing, maybe.

 

[Chris1956]

Re: What did

Re: What did

I don't know if you can see it, but those Fat-Fiftys had four "Rocket-nozels" on the two spark plug covers in the rear of the cowling, kinda like my fathers '62 Colony Park station wagon, or the more famous '59 Caddy. The '58 had black inserts, but my '59 had fire-red inserts to represent the rocket exhaust that propelled you to that blistering 25 MPH.

 

[Texasmark]

Re: What did

Re: What did

So that's what those things were....rocket nozzles. I had forgotten that '58 was right in the middle of the make everything look like a rocket craze. DeSoto had a pretty good pair of tail fins as I recall....the Caddy Eldorado was one beautiful machine.

Was in the service and was enlisted. A full bird Colonel came over to the auto hobby shop and wanted someone to wash his baby blue Eldorado with a snow white top. I volunteered for a $5 bill.

You won't believe the feeling I had getting to wash that beautiful machine and afterwards having to drive it back to his residence.....will never forget it. That's back when chrome was king and that baby had plenty of it.

Mark