Excerpts
from: KERMATH - A TRUE CLASSIC By Jim Aamodt
Originally published in "The Boathouse".
Buzz words, such as "Overhead Cam," "4 Valves Per Cylinder...... Hemi-Head," "Dual Ignition," and "Dry Sump Oil System" are all contemporary terms for high performance engines. The Kermath "Sea Wolf" and "Sea Raider" Marine Engines began production with the above features in 1926!
Kermath Engines introduced the overhead valve (and cam) leading to the "Sea Wolf" Series in 1926. It surprisingly incorporated many of our contemporary design items. Let's consider how the Kermath Company formulated those designs.
The overhead valve ("Sea Wolf" type) was introduced in 1926, sharing the oil pan, oil reservoir, distributor, pistons, and crankshaft of their flathead 150 H.P. predecessor. The new engine was initially rated at 150 H.P. at 1800 RPM, displacing 648 cubic inches. A later 1928 version, the "Sea Hawk" was rated at 175 H.P. Late in 1928, the 5" bore was retained, with the stroke increased to 5 3/4" to produce the 200 H.P. 678 cubic inch version. Within a few months, the slightly higher compression 225 H.P. version was marketed, which is the highest production model (through 1943) and known, as the "Sea Wolf".
The earliest 678 cubic inch engine, I have seen, used dual 11/2 " Schlebler S Models, and later a Holley DDV-5 downdraft unit. The stabilization of design to twin updraft carburetors occurred after 1930. Initially they were 1 7/8" and later became 2" Strombergs. The addition of an oil cooler also appeared about 1927. Later engines also used 1 7/8" Zenith updraft dual carbs.
The "Sea Raider" V12 Series was added in the 1930's. It was simply two six cylinder Sea Wolfs sharing a common crankcase, thus becoming a 1414 cubic inch V12! Originally rated at 300 H.P., most units sold in the 1930's were 450 H.P.
The early 1940's saw the stroke of the "Sea Wolf" six cylinder increased by 1/4" to produce the 275 H.P. "Sea Raider 6" The V12 was also stroked to 1560 cubic inches and became the "Sea Raider 12 " up to 580 H.P. Counterbalanced crankshafts, internal rod oil passages, and several minor changes also occurred in the late 1930's.
Chris Craft, Sea Lyon, Garwood, Mathews, and many other builders utilized Kermath Sea Wolf engines. One of the largest supporters of Kermath was John Hacker. Hacker Craft Boats used the 200 H.P. and 225 Sea Wolf in their 26' through 30' runabouts, and promoted the 450 Sea-Raider in their 33' models. John Hacker always preferred engines designed for marine use, and avoided earlier aircraft conversions, and in smaller boats, automotive conversions. He also designed two 450 H.P. Sea Raiders into his famous Tahoe boat, "Thunderbird."
The Kermath Company was a great company with a tremendous contribution to pre-war engine design. We will certainly remember its popular phrase, "a Kermath always runs."