How good were racing the OMC lower units

**Powerabout** · 01-20-2010

from the 60's i.e. the non thru hubs.
40, 50, 75's 100Hp etc
Did they survive surfacing?

Any style better then others, split through propshaft versus split higher versions?

Cheers

**Ron Hill** · 01-20-2010

I only know about the 45 SS, SST 100, CC, CCC, and V-8 gearcases.

These units were well designed. I have personal knowledge that they'll stand up to the engine horespower they are suggested for and some more.

I also know, that in the HEAT of he "Outboard Wars", Mercury hired at least one engineer away from OMC to assist Mercury in inproving their gearcases. This was circa 1979.

Sea Marine has the rights to make OMC gearcases at this time. AND I wish they'd build a few of each!!!

**Skoontz** · 01-20-2010

Far as I know, the only racing lower units OMC made were for the X115/GT115 race motors prior to the Stinger/SS motors.

They were smaller diamter than Mercury which pissed Carl off royally, they also were shiftable cases, F/N/R. The exhaust opening could be plugged and placed on the bottom end of the cavatation plate.

We had several of the race engines running on the river anfd did not have too many issues, I did however hear they were only good for about 15 hours of use before they scattered. I never saw a scattered one apart.

Others may know different.

**Mark75H** · 01-20-2010

Not sure I understand the question ... racing using the gearshift pleasure units or race only units?

**Roy Hodges** · 01-20-2010

I think he's asking about the gear shift units , like those on the 70.7 cube 60 horse v-4 and 90 cube v-4 (75 horse) from 1960-68, before the prop -exhaust units came out . You know, the pointed nose units with the 20/23 gear ratio .

**Powerabout** · 01-20-2010

yes
the old pointy consumer models.

**wolfgang** · 01-21-2010

Originally Posted by Skoontz

Far as I know, the only racing lower units OMC made were for the X115/GT115 race motors prior to the Stinger/SS motors.

They were smaller diamter than Mercury which pissed Carl off royally, they also were shiftable cases, F/N/R. The exhaust opening could be plugged and placed on the bottom end of the cavatation plate.

We had several of the race engines running on the river anfd did not have too many issues, I did however hear they were only good for about 15 hours of use before they scattered. I never saw a scattered one apart.

Others may know different.

In `67 or `68 we received from Bruges one of the first 55hp loopers with a racing lu which externally looked the same as the GT115 ones. A hot works SE engine, received in `69, was unable to grenade a like unit within the 40 hours, during which we used it for testing on the Rhine river, as well as the Liege and Berlin 6 hour races, which Helmut Tinscher and I won in that year (Jimbo won ON).
We never had water in the oil or noticable radial shaft play. Only, I cannot remember ever having used a shifter on those motors.

**Powerabout** · 01-21-2010

Prior to the X115 lowers
were the V4 engines raced with stock lower units?

**Skoontz** · 01-21-2010

Originally Posted by wolfgang

In `67 or `68 we received from Bruges one of the first 55hp loopers with a racing lu which externally looked the same as the GT115 ones. A hot works SE engine, received in `69, was unable to grenade a like unit within the 40 hours, during which we used it for testing on the Rhine river, as well as the Liege and Berlin 6 hour races, which Helmut Tinscher and I won in that year (Jimbo won ON).
We never had water in the oil or noticable radial shaft play. Only, I cannot remember ever having used a shifter on those motors.

It is quite possible that the OMC back room boys installed a spacer where reverse gear was and you in fact had the X115/GT115 unit on the three banger.
Spacer kits to replace reverse gear were routinely sold for the manual shift pointeed gear cases that Powerabout is referring to, and they would get you marginal incements because the drag of reverse gears flipping through the lower unit oil robbed power.

We were considering extending the lower pice on the pointed cases once so we could get more prop diamter, but nixed the idea when the gear ratio was what it was.

We did have a 75HP V-4 running a 17" 2 blade cupped bronze Johnson-Oakland prop on a 14' Yellow Jacket. It loved eating big black grain silos but we are talking river racing here, not any sanctioned events.