I am unable to find mention of narrow passages in this thread.
Until KE4 the cylinder exhaust ports were 3/8″ openings either
side of a 1/2″ opening. Most KE4 and all Mark 7 had
cylinders with 3 exhaust openings of 1/2″
The Wizard WF4 and WG4 had the old pattern cylinders with
the uneven exhaust ports as well as the old style reed block
and chankshaft. KE4 and Mark 7 were rated at 7 1/ hp while
Wizards twins (and Mercury KD4) were rated at 6 hp.
The difference in power between K1, WA2 and either the
1940 and 1941 Sea King was zero. They all had the poppet
valve fuel mixer. Up market models of Mercury and Wizard
singles had more power due to having a more efficient carburetor
The Kiekhaefr made Sea King single did not upgrade to a carburetor
as it was made to an entry level price AND Montgomery Ward
had OMC made models for up market customers.
Kiekhaefer may not have made much money from entry level
models, but, they added volume for economy of scale production,
Kiekhaefer was happy to make a range of models for Western Auto
and even to create a twin cylinder model at their request.
Postwar Mr. Kiekhaefr was in a better position to favor Mercury
over Wizard,
My opinion, which you are free to share or dispute.
Louis
edit
If you were Mr. K and you had some left over Thor lower units , would
you scrap them or cobble them into something that could be sold to
someone willing to buy odd but cheap outboards. I have seen a streamline lower unit with a Thor powerheade. Hard telling what
combinations of parts are out there, so I will only say most if not
all.
Horse power is a curious subject when it comes to Kiekhaefer…
Per MW ad 1940 Sea King 8820 2.8 hp rated @ 3500 rpm
Per Mercury Master Specification Chart
1940 Mercury K1 2,5 hp rated @3800 rpm poppet valve
1940 Mercury K2 3 hp rated @4250 rpm carburetor
1940 Mercury K3 3 hp rated @ 4250 rpm carburetor
1941 models had revised piston, rings, cylinders and crankcase
which may account for some improved power output.
MS series carguretors used in 1940 models and KB1A
while AJ series models were adopted for other 1941 models
Certified horsepower ratings were adopted by the industry to
put and end to imaginative claimed power. I am not aware
of conditions under which rated horsepower was determined.
The .7 hp spread in itself probably did not lead to significant
performance differences. However, carburetor linked to ignition
advance made for easier starting and operation which did
matter a great deal.
Louis
1941 KB1 2.9 hp rated @ 4000 rpm poppet valve
1941 KB1 A 3.1 hp rated @ 4000 rpm carburetor MS type
1941 KB2 3.2 hp rated @ 4000 rpm carburetor
1941 KB3 3.2hp rated @ 4000 rpm carburetor AJ3A possibly AJ8A
edit #2
It may be that K1 and 8820 in actuality had same output and the chart
is in error…they have identical powerheads that should produce same power… transposing numbers seems plausible as
to why the the power and rated rpm differ.
