Three cylinder outboards ... pleasure & racing

[Mark75H]

Without going thru Peter Hunn's Old Outboard Book, the first 3 cylinder that comes to mind was built by Thor ... the predecessor to Merc

1938 & 39

[Mark75H]

About the same time Rudolph Konig made a 3 cylinder 2 stroke radial motor in Germany that had a successful racing version



Notice a cylinder pointing off to the left and another to the right at the back; the third cylinder faced forward

[Mark75H]

Dieter Konig, son of Rudolph Konig ... added a cylinder to his 2 cylinder racer to make a 3 cylinder 30 ci racer


The bottom carb is missing its float bowl.


This motor was unique in its day, using the exotic "Curvic coupling" segmented crankshaft ... fully "tinkertoy" piece together construction. You could literally take the motor apart and remove the center cylinder pieces and reassemble it as a 2 cylinder or a single.

Decades later OMC would use Curvic couplings in the prototype rotary race motors

Another uncommon feature of this motor, there are no reed valves. The carbs feed up into the crankcase, timed by an internal disk valve called a rotary valve.

[Mark75H]

Another "add a cylinder" twin to become a triple was Scott-Atwater's 40 hp ... becoming the 60 hp triple. Nothing exotic inside this motor, reed valves and a solid crank.

[Mark75H]

In 1961 McCulloch, the sucessor to Scott-Atwater improved the 60hp triple to 75.2 and introduced a gearshift racing lower unit for it ... the 75hp "Custom"


The differences between the 60 & 75 were piston & head shape, carbs and transfer port covers

The 40 & 60 used a wedge shaped combustion chamber, the 75 uses a hemi shaped combustion chamber

[Mark75H]

Crescent ... sometime division of Electrolux and Volvo in Sweden ...

Introduces a 3 cylinder triple 30ci race motor



No reeds or rotor for this motor, this motor uses "piston port" intake controlled by the piston skirt

[smokin'joe]

I ran one of these, too briefly, in Aug., 1961. It was my last summer with outboards before going off to the univ. That Sunday I had my dad's Mark 78 on our 14' Allison, a little over 50 mph. Our local Scott dealer, Dave Rogan, who always wanted to outrun me, showed up at the island excited, wanted me to run his new outfit: the motor below on a 15' Norris Craft (we were on Norris Lake). I'd never turned the key on a Scott before, they were the enemy (we sold Mercury), but I somewhat reluctantly hoped in, hit the key and planned off. Dave said it had showed 55 mph on his speedometer. I looked back, surprised, there he was driving my Allison right behind me! He was curious about the Mercury, never having run one (and I was the fastest boat on the lake), and he also wanted to see his Scott pull off and leave the Allison. Well, his 75 missed and sputtered in an unhealthy way as it broke 50 mph, then wheeeeeeeeeeeeeeeeeeeeeeeeeeeee. I shut off the key. He hadn't retorqued the gearcase bolts, the beautiful racing gearcase was in 40' of water. Unfortunately, Dave never brought that outfit to the lake again.

PS The differences between the 60 and 75 were very likely present in the 'Scott 60' that set the NOA unlimited record at nearly 52mph ca. 1959 on a 13' Rose boat (the boat that Paul used to mold the first fiberglass Allison in 1961). J.C. Leatehrwood, the Scott dealer who set up the Rose, had heavy McCulloch support.

In 1961 McCulloch, the sucessor to Scott-Atwater improved the 60hp triple to 75.2 and introduced a gearshift racing lower unit for it ... the 75hp "Custom"


The differences between the 60 & 75 were piston & head shape, carbs and transfer port covers

The 40 & 60 used a wedge shaped combustion chamber, the 75 uses a hemi shaped combustion chamber

[Mark75H]

Dieter Konig, son of Rudolph Konig ... added a cylinder to his 2 cylinder racer to make a 3 cylinder 30 ci racer


The bottom carb is missing its float bowl.

You may have noticed that my HRE did not have the original ignition or cylinder head.

Well, I found an original HRE cylinder head. I've been wondering the whole time I've known about this motor whether it actually ran with the battery ignition or whether it was a work in progress that was never completed. Now I'm pretty sure it was run with the battery ignition ... when I removed the bottom head - the piston ring was imbedded in the head. The piston did not seem to be damaged, nor was the bore.

[powerabout]

I remeber working on some volvo outboards...cast iron block and heads..
what were they (th)sinking?

[goodride]

my little 12 footer is a homemade hull....a buddy pulled 12 feet off a boat and made a couple hulls for 35 horse omc's

i traded for a hull and asked my friend to make the transom extra strong because I wanted to put a sport ..e...... motor on it...........66 mph the first day with a titus cut 23 sst rx, that was now a cleaver with a smaller diameter to clear the sprint gearcase..
.so 1 day at a boat show I met up with the old service manager from evinrude... and showed him a picture of my little 12 footer i named....".step on it"

he said give me your business card i'll get you 10-15 miles an hour just bolt on my old nitrous system

I was so proud of getting 66 mph, and just put a hustler 3-1 hedder dry stack out the side crazy noisy and no hole shot, open exhaust on the little beoutch.
.a touch over 70, but you had to milk it to plane off.
. we ran the era 1970 nitrous for a couple weekends at the races,

and called chuck at nitrox..he said send me what you have..........i'll get you more !!.
with the right enrichment fuel, and finallly methanol with castor oil...we found 82 at 8200 running a seebold 25 solid hub cleaver....

and that little homemade 12 footer runs straight as an arrow with no bad habits
my little 12 footer sure did...................."step on it"

[powerabout]

Great bit of history
many thanks

[rwk]

Hello
I'm new to the forum. I have a hydro from the 60"s, has what look to me from the pictures here a McCulloch 603. The boat was a full race team, 2 complete engines and lower units, 6 blocks, props, cranks....I was told it was used out west for top speed runs, owned by an artist. If I put pictures up could you help ID, boat, engines?
I think it's time to get it back together. Thanks Bob

[joelsob]

COOL rwk put up the pictures, I always liked small machines with big engines, and you have what seems to be a lot of cool stuff...
and welcome to the scream and fly website and forums.
I just come here to share some of my racing and boating stories, thinking the guys that read my ramblings had similar experiences. and maybe we ran against each other, or were at some of the same races

and I really liked where you said time to get it put back together

picture of 49 cube ...little boat running against 427 cubic inch jet boat.

and the winner was yep!!!

joel

goodride

[rwk]

Hello
I will get pictures of the hydro soon. It is 14 Feet I think. Papers stuffed in one engine block is from 1967. What year are the engines from? Any Idea what class it would have run in? Any help would be great, Thanks Bob

[Powercat]

McCulloch 590