Hubbell External Air / Reed Valves

There has been a lot made these days of increasing race engines breathing capacities to make more of them in particular it seems for Mercury outboards in the FE catagory with racer seeing the Merc 44s near completely open to innovations. The whole thing settles around the idea of a working 3rd port to a deflector engine.

Quincy approached the idea of doing that third port that delivers an air/fuel charge to a piston port controlled by the skirt in the cylinder wall of a Merc where velocities of oncoming high velocity air fuel no longer accesses the reed valves which may very well be shut at that point streams right through the back of the reed block, enters the 3rd port machined into the crankcase and then the third port to ram charge the crankcase. This was a feature Quincy did with the deflectors as an added cost option but it was a full feature incorporated into all the Quincy Flathead Looper engines.

Randolph Hubbell had a different a novel idea for adding a "third port" that ran even earlier than Quincy's version. It was long recognized that the Mercury KG-7s (20 cubic inches 2 cylinder) and the Mercury KG9(H) and Merc 40Hs with their AJ carbs (like KG-7s) with their 4 cylinder, 40 cubic inch displacements just did not breath well enough anymore to compete against newer Merc technologies coming on stream, so Hubbell developed for some of his wildcat engines (and other modified Merc delfectors) the Hubbell external air reed valve. These external reed valves took a little flat landing and cut out machining on the air/fuel transfer tunnel side of the old Merc engines and were basically bolted in place where the inspection cover/air/fuel deflector sat taking its place and its job with an extra reed valve and hole to allow more air to come into the crankcase from the transfer tunnel side to increase the volume of air into the crankcase coupled to that of the air/fuel mix coming in on the AJ carb and reedblocks to give a boost to engine performance by increasing all transfer volumes to the next stroke for use. Along with this valve came the change where you had to richen the high speed needle to jet to make it all work. For many including me which was all I could afford at the time being a student with my 2 - Merc KG9s and later 2 - Merc 40Hs, it gave me as it gave others that bit of extra power to compete against the newest Mercs, the 20Hs and 55Hs which never the less still had more anyway than what you could put into these older engines.

Later evolutions of the Hubbell external air reed valves as well as the Quincy third ports saw some versions that carried their own little carb to make the whole system work better so seeing, though not common, a Merc carrying 4 carbs for a 4 cylinder where it had the Quincy installed 3rd port occurred. The Hubbel version allowed for 4 more carbs, so there was a Merc 4 cylinder with 6 carbs and so on.

Pictured with this thread are the Hubbell external air reed valves.

Pictured shortly after this post shortly will be some Quincy 3rd port pictures.

More Hubbell external air / reed valves.

Final Hubbell External Air / Reed Valves

What did the cylinder block look like? It appears that Hubbell must have hogged the block out for the air to come in (since the inspection cover slot is small andd rectangular).

Jeff

The only thing done was to take the "T" being the deflector and reed valve shape and made sure they fit the same shape they were to clear the transfer tunnel and where the previous insection port cover combo deflector sat by a small bit of cutting mainly for the reed valve and opening plus the two front narrow screwholes to hold down the front of the Hubbell while the previous two 1/4 in threaded inspection/transfer cover bolts did what they always did at the back. So its a small matter of cutting the top of the transfer tunnel a bit for the flapping reed petal and its opening to the outside plus installing two threaded holes to match the front holes of the Hubbell reed valve exterior cover at the front. Its easier than it looks. :)

Soon as I get a freakin' Scitilla magneto to work!

One massive challenge at a time.

Jeff