Mercury 20H exhaust prototype

[Mike 41P]

From AOMCI July 2013 this is the prototype built by Edgar Rose in 1954
Shown by Albert and John Snell
I had wondered 'how did they develop this' and now here is this picture that explains it
See the article for more detail

[Guest]

Back in the 70's my Mercury dealership sold Quincy parts. Some time ago I ran a check on the dimensions of the conversion tube, ie. length and exit area and was surprised that the dimensions are nearly exactly the same as a Quincy "B" long pipe, although they aim straight back. Quincy pipes were well known for there performance improvement and one can only guess that Mercury ran a Quincy pipe on their dyno and played with the length. When all is said and done the Quincy design was proven best so they reformatted it to make the conversion. The prototype unit that the Snell brothers have was run on a boat and proved the performance gain required to pass the Champion Hot Rod. The flow of the prototype conversion performed as good as the Quincy pipe so the next step was to cast it in aluminum. When the conversion came out my brother and I had the first kit delivered to the east coast and it was sold through Edgewater Marine in Islip N.Y. My brother even drove over to N.J. to pick it at the Mercury branch so we could use it in a marathon.

Alan

[dwhitford]

I think Quincy (O.F. Christner) might have had some input into the design of the "Conversion" 20H exhaust. I'll defer to Paul Christner (Old Looper1) for corroboration.

During JAN 1966-DEC 1968, I worked with a guy known to me as Cookie Fernandez in Bud Wiget's Lakeland Marine Supply in Lakeland, FL. Cookie was a great mechanic and an astronomical BS artist, as corrborated by his son,Tom, whom I've had the great pleasure of meeting at boat races during the past 6 months.

Cookie once told me that he worked for Chris during the winter of 1966-'67, and his main job was then boxing up the conversion units for shipment, ostensibly from Fond du Lac. You need to take whatever Cookie said with a grain of salt, even according to son Tom..

Doug Reed and I never saw a conversion unit until summer 1960, at least not me, maybe Doug knew of them before. We promptly bought the 1st one and converted his big brother's ol' Green Hornet in time for a race in Aug at Alexandria Bay in an ocean of rough water.

My point is that Merc & OF Christner worked hand-in-glove on stuff for quite awhile, and the Conversion Merc exhaust is but one example.

[Fast Freddie]

I think Edgar Rose could give a very accurate history of the 20H conversion development, too.

[charlieblackwoodt47]

I have seen the 20h conversion run when I was racing back in Texas ( in the 90's) How well would they compete today?

[dwhitford]

Charlie, they probably make enough horsepower in Stock nowadays, but boat handling would probably be the problem. Champion Hot Rods were advertised in the 1950s as weighing only 47 pounds. Add maybe almost 10 pounds for a current Champion or Sidewinder.

The Conversion Merc Mark 20H weighs at least 75. Pat Davids once commented to me that the Foo-Ling runabouts of the late 1950s were competitive with the Champions but not with the 20H Conversion engines because of the extra weight and atendant handling problems.

A current B (20-cubic-inch) Sidewinder has a 30mm DelOrto carb on it, also far bigger than the 1" or less (probably 15/16") Carter model N on the original Champion. The later (Swanson) champions had a different (bigger ?) Lectron slidevalve carb, don't know the size.

My point is that the Champions have evolved since 1953 or so, you need to be a student of their history, and the Sidewinders are the latest best evolution.

[Mike 41P]

The 20H today can be run in AMH/250MH. A good one can break into the top 5 in a field of good 15HR's. AMH is the best way to run your 20H's today. I ran my 20H until 2005 when I was 5th in ModNat. I've been running 15HR since then

[charlieblackwoodt47]

sounds like a runabout would be doable to then... I remember Rusty Siten ran one on a runabout no bigger the the A/b sorensen I have now.

[A/B Speedliner]

About three years ago we ran a brand new, I mean everything was new, built from parts we had at Hillsdale in AMH. In every heat of a total of six heats we ran third every time. Our driver had never run this class before and we ran against hot rods with pipes.

David

[charlieblackwoodt47]

About three years ago we ran a brand new, I mean everything was new, built from parts we had at Hillsdale in AMH. In every heat of a total of six heats we ran third every time. Our driver had never run this class before and we ran against hot rods with pipes.

David

Thanks David.

[Guest]

Here is a link to one heat of A MOD. Might also state that we were running about 30 pounds overweight. The 20-H is heavy when compared to an A Hot Rod.
http://www.youtube.com/watch?v=51e4VbG-nZQ


Alan

[jsilvestri]

It would take a special combination for a 20-H to out run a good A-Mod Hot Rod. If nothing else, the Hot Rod will out accelerate the 20-H every time and that really adds up after three laps. I've experienced it myself when I ran my 20-H Hydro against several really fast A-Mod hydros and have seen it happen many, many times to others.

[Mike 41P]

exactly how I experienced it, so now I run the HR, but you know what, I still can't beat Tom, but I can get a lot closer and give him some trouble if he makes a mistake and gives me an opening

[53-W]

Just so you all know we will be running 20H B classes at Wakefield 2015 on Saturday Aug1st.
Along with KG4 A and 30H C and 55H D hydro and runabout.

[Mike 41P]

Just back from a good weekend at Crystal Lake with my 20H, so I thought I would bring this back to surface