British Anzani A & B Stock & Alky Racing Engines

[Jerry Combs]

John,

At that time I was only 21 and trust me dad did not like any "helpful" information from someone who he felt was wet behind the ears. I don't know if Tenny had told my dad what percentage of nitro to use but I suspect not. Prior to the porting change dad's Anzani had been a very strong runner winning most of it's races. I ran it a couple of times on my boat and liked it but dad wouldn't let me borrow his motor after that. Dad prefered smaller hulls than I did, he liked the 9' 9" size and I prefered the 11' 6" size.

Until I got my Koenig and big Bellcraft I was probably not really a very good driver and dad could usually beat me. Once I got a rig that I was comfortable with things fell into place for me and I started winning a few races.

Jerry

[John (Taylor) Gabrowski]

The smallest hydro I have ever seen an Anzani parked on and run was a Swift Atomic A hydro from the mid 1960s. The Anzani engine parked on that little boat with the standard size transom made the motor look half the length of the raceboat. Put a skinny 140-150 driver into it and it, the Swift looked overwhelmed entirely by both the engine and the occupant. The little boat just flew! The bottom really carried it as the tops aerodynamics where compromised by the driver and then the engine anyway at that point. After seening a few more Atomic As tripping around turns a plywood right side sponson deflector anti-trip plate was screwed and glued on that overlapped the top by a couple inches and trailed rear of the sponson by another couple that threw one hosing spray off to the right drowning anyone trying to turn on your rightside outside. There is one of those little Swift Atomic As still here in storage with its owner from way back then. It seems that racing retired the Alky Swift Atomic As to B stock hydro later and they ran real great in their time powered by Popper Merc 20Hs. Its still hard to get used to that DSHs, like my Swift Big D then were only 10 ft 6 or a little longer and Alky As generally were at 11+ ft. already at that point.

[John (Taylor) Gabrowski]

Everywhere else but the North West USA Anzanis generally if not all relied on the Vacturi A0 500 carburator used commonly on Johnson, Evinrude, Elto and other related engines with custom machined varied throat sizes sleeved in for class A or B Alky mounted on the side of the Anzani's cast iron block facing the opening to the piston ports. A tortuous S turning chamber leading to the crankcase rotary valve started in the ast iron block to the pistons ports started 90 degrees off the direct directional flow of the Vacturi's carb barrel was carved diagonally through the center of the crankshaft using a floating bushing surrounding the center of the crankshaft to support it (not unlike a floating turbocharger shaft sleeve bearing of today in principle) with a window in one side providing timing to the rotary valve's opening window going through the crankshaft itself.

Unlike a disk rotary seen on Konigs where the timing of the disk could be custom cut that would result in engine performance programming differences, the Anzanis crankshaft rotary timing was very fixed and only aimed overall that the engine would get its air/fuel charge in block and in the crankcase through the pistons ports and rotary valve supposedly at the same time filling the pumping chamber to the maximum to transfer it all to the appropriate cylinder.

The theory more or less worked. But the engine's breathing was far from perfection. Early on it was found that cutting back the piston skirts by varying amounts at the piston ports significantly increased power by dealing with the piston ports ability to bring down the pulsations at the piston ports making air/fuel smooth out through creating actual piston port overlap. In short when one piston port was on its way to close the other one was opening making the air/fuel stream more continuous.

In the North West in the hands of racers Hallum and Anderson, they took one extra step by parking a self pumping Tillotson HL carb directly on an adapter right on the crankcase directly opposite the crankshaft rotary valve to enhance the air/fuel flow this way directly into its opening face at the rotary valve. There was no attempt to cut out the tortuous S bend between the crankcase and block, just to add that direct opening and HL carb directly opposite it smoothing out and quickening the air/fuel flow velocities to the crankcase area significantly with the result that the engines power went up significantly from the small added carb and passage change.

Anzanis in the North Western USA and far Western Canada (Alberta) were soon seen sporting this 2 carb combination being fed their fuel streams by the OMC fuel pump and spill over return to tank fuel feed systems.

There were more additions and refinements yet to come involving reed valves, pistons, crankshaft modifications ignitions and pipes taking several more years in the making in the North West but down east (the USA midwest to the eastern seaboard further development had slowed with Anzani winding down parts production overseas and the introduction of the HRP (Birmingham Metal Products) product lines to support Anzani in aftermarket parts and services, the development of the Harrison loop engines parrallel to that period.

[John (Taylor) Gabrowski]

Pictures following. The first three are of (Montana's) Roger Wendt's 350 hybrid Anzani's engine block as it was disassembled for museum restoration.

The engine was a Hallum and Anderson type hybrid. Anzani crankcase with machining to fit the smaller Tillotson HL carb, cast iron main block, later generation crankshaft with Konig connecting rods, Harrison ignition, Harrison aluminum flywheel & rope plate, Vacturi primary carb with on the fly adjustable high speed needle rack and pinion, Tillotson HL secondary carb, OMC fuel pump, typical west coast style supported Anzani stacks, Mercury clamps and saddle, steel tower and Konig gearcase.

The carb inlet hole was immense by Anzani standards nearing the borders of the casting allowing the larger opening. Similarly were the interior piston ports, transfer ports, inlet and exhaust ports of standard number. Of interest is the cylinder in one case is brass metal from the block being repaired after some incident that broke off major pieces. Its a testament to the skill of the repairer that this engine went on with these brazed repairs to keep on competing successfully. It was run on 40% nitro Alky fuels and was very successful dealing with the Konigs and other contemporaries of its day.

The 4th picture is the typical North West style of fuel systems that pumped fuel to Vacturi primary and small Tillotson HL secondary carbs with its rack and pinion slider mounted on top the big Vacturi for driver facing forward adjusting the high speed needle jet for optimum richened performance.

The last picture of the 2 Anzani pistons is typical of the cut back/notched skirt at the piston ports allowing for intake overlap smoothing out intake pulsing resulting in more power.

There were some more profound changes to pistons later that made a difference for racers again later.

[John (Taylor) Gabrowski]

These are the first Anzani expansion chamber exhausts I ever seen on any Anzani. They are from the USA's North West Region 10 area and I understand a product of Ron Anerson's team. (courtesy of outboardracing.com)

Bill Tenney also got into the expansion chamber exhausts that were quite different both block mounted and fixed like the North West's but trailed farther behind a distance instead of curling back and forth like the North West's. Tenney seen to the development of 2 stage types where a little short fat megaphone per cylinder was switched between them and a pair of long and trailing expansion chambers. Tenney's had an extensive metal frame to hang the weight of these overhanging 2 pairs of 2 clustered pipes. The exhausts manifolds were a heavy steel cast product had an exhaust gate the driver switched back and forth on the go.

[smittythewelder]

Hallum had exhaust cut-outs, too; I'd bet on him having made the first ones. He made a pattern and had the housings cast in aluminum, then fabricated shafts, valves and linkages. The idea was to plane off and get going on standard megaphones, then pull a lever and switch to the bounce-pipes, which is what they called expansion chambers in those days. Pretty quickly it was decided that the megaphones were just excess weight, so they were omitted, and when the boat left the pits it was using what were basically open exhaust ports. I don't think Ron ever bothered with the valves. This was about the time that they had the mixture control working well, and it wasn't as hard to get on plane without fouling as previously. That could be a Ron engine in the photo, but I think it might be Hallum holding the flashlight.

I have a feeling I told this story earlier. This thread is a monster.

[John (Taylor) Gabrowski]

Its facinating how these exhaust systems were in development during similar periods of time hundreds of miles apart. For sure Jim Hallum's aluminum components system sounds like saving weight off the overhang of that cast iron block own weight was a priority. These Anzani engines were already notorius for breaking their aluminum tower midsections off at the neck separating the engine from the tower only to be held there by the steering bars and cables. Tenney's switchable systems were all cast steel and welded steel. I have the complete switchable elbos set for those pipes but I have only one section part of one Tenney's version of those early bounce pipes/expansion chambers. It is heavy so I can imagine what the rest of it weighed togethee assembled and then times 2 plus a long mounting frame supporting them too! Somewhere I have pictures of Tenney's version of a "ram's horn" type too that went to scrap back then?? He and his son were into Karts too and that stuff may have gone to karting enthusiasts I understand after he passed away. Where those pipes are now is unknown. There is a British Anzani Kart in the Smithsonian Museum/Institute on display. You can see that Kart on the internet, the Anzani engine was using the traditional albiet they chromed them, crescent shaped pipes. That was one loud Kart for sure.

That Vacturi carb high speed needle ajusting rack and pinion setup to lean the engine while it ran up and richening it for racing on the fly for racing speeds was one safer way of doing things than getting back into the transom are from where you were to reach and turn the high speed jet with your hand. Years passed I watched racers dump doing it as well as getting out of control real bad and recovering too. That is how I tuned my first KG9 Merc with its surface mounted high and low speed needles knobs that came through its cowls in the days before I scored and learned how and then used test wheels. That was suicidal in my 10 ft 6 D Stock hydro but pretty manageable in the Ashburn D runabout I campaigned then. Similarly so it was easy for A and B Anzani runabout drivers.

[John (Taylor) Gabrowski]

The following does not have to do with some new fangled shot gun they used to shoot wild turkeys in the bush but comes close in looks!

The following pictures is of the Bill Tenney built 2 stage exhaust system. It is one of his first of 2 forays into the world of the earliest expansion chambers in outboard racing. It still used a vestige of a megaphone system to start the engine off that was then "switched" to the expansion chambers once the raceboat had planed off and the Vacturi richened for racing speeds. The term "bounce pipes" are expansion chamber exhausts as they were referred to in the early 1960s.

The picture shows about 1/3rd of the expansion chamber they designed and built to hang on a frame rearward straight back from the Anzani engine. The other design is the "rams horn" type seen in the previous picture from the North Western region. These pipes were being developed were within similar time periods and the understanding is that there were cooperative efforts and information exchanges between the midWest and the North Western USA groups in terms of their development.

Today, Jim Hallum gave discussions on the concepts involved here and what happened to the Anzani engines when these new exhaust technolgies were being applied and tested. It would be the earlier generation Anzani crankshafts (tapered big big end pins) that would prove to be the weakness with applying these new exhaust technologies that would keep Anzanis using megaphones and nitromethane until the Harrison developed heavy duty crankshafts that came along that would alieveate the problem of developing newer exhausts for the aging race engine.

[John (Taylor) Gabrowski]

Back around 1978, I was buying my first Anzani engine from Gene Strain in Calgary. It was a class B - 20 cubic inch Alky. Gene (Pappy) was hitting 80 years old and he wanted to make sure I knew everything he did about the engine. At that point I only had a history since the 1960s of a pitman helping in Alky and our local stock racing members and driving my own DSH, so it was important I listened, looked and watched everything and he made sure I did.

One very important point he made with the Anzani's gearcase was to show me that he used "whale oil" in it (the real thing) because he said if water got into the gearcase, the water turned the whale oil milky and but it kept lubricating. He proceeded to open the can and put his nose over it splashing a bit on himself and did the same thing to me when he urged me to smell it and indeed the stuff smelled real strong and sorta fishy to make his point as fowl smelling pee colored oil dripped from the tips of our noses.

The next thing came when he said you can tune the Anzani in a barrel of water to which he took me to his 45 gallon drum with a wooden transom bolted on to a slightly flattened side of the barrel where the backside of the barrel was suitably cut out to allow for the Anzani's bottom exhaust pipe to clear and fire out its sound and smoke. Filling it with water with a garden hose he proceeded to take out the engines "test" wheel that we were going to shear pin and bolt to the gearcase. It resembled a Merc's only that it was circular but it was hubbed and had a 1/8 inch disk screwed to the hub and that was supposed to provide loading to the engine as we were about to run it?? Ya, Gene grinned and he said these work best of all, they grab like no Merc ever could and he proceeded to tell me that these were designed by the guys from down south, the west coasters. He said that the fuel system using a fuel pump and a fuel return line back to the tank was also of their design and worked way better than the Vacturi carbs old cork float, needle and seat that used to stick.

With all that we set the engine in the barrel and clamped her down. Hooked the engine block's water hose to the garden hose, fueled her with some ALky mix he he shook vigorously and poured in the fuel tank out of a brown glass jug, primed her, put on our ear protection and I started her while Gene throttled her and showed me how responsive the engine was from its leaned out start to richening her up and running her wide open showing me how that test wheel disk held the rpm down really loading the engine down hard so nothing got too fast that could produce a parts failure. Gene explained though the test disk was smooth it was that feature, the smoothness that made the water stick to it making it a brake of sorts that no Merc B,C or D test wheel could duplicate. During this time the racket as astounding that caused a few people at the Chestemere Lake yacht and sailing club next door to stop what they were doing and look our direction and observe something they seen before being Gene fooling around with his old engines. We cut the engine not long after he demonstrated how easy and safe the Anzani was to be tuned in a test tank with a test wheel and those around came down to see and talk about what they had seen as they were clearly impressed with the show of one, even though it was in a barrel.

Years later, I was so impressed with this kind of test wheel and its reliability (no more breaking cast Mercury test wheels hubs and shear pin holes) that I encouraged making this new breed of test wheel locally and where ever else I was seen using it, it was explained to others for their benefit and duplications. Quite a few made that style of test wheel their own.

Just recently talking to Jim Hallum about that sort of test wheel, Jim talked about its origins and development there. He indicated that using different diameters of disks set screwed on this kind of test wheel hub, were good for testing, for any outboard racing engine. The smoothness of the disk really holds the revs down with stiff loading the engine to develop power and power curve information that have a mathematical basis to aid and add to engine development! Its neat what you can do with 1/8 inch harder grade aircraft aluminum disks of different diameters. Some of that math may just turn up here to help with your engine when you make and use your test wheel like these. There will be some pictures of this style/type of test wheel to follow this article shortly, so you can make this kind of test wheel your own.

[smittythewelder]

The old "Type C" gearcase lube from OMC was whale oil, prefered by the Anzani engineers out here and jocularly refered to as "whale sperms" (from sperm whales, you see . . .). Type C was superceeded by something more politically correct and easier on the whales somewhere around 1970, I think.

When Ron Anderson started work for Mercury in the early '70s, he walked into the racing development shop one day when they were trying to run the latest big OPC racemotor in a test tank. They told Ron about the impressive horsepower the engine was going to make at such-and-such rpm, but their test-wheel was ventilating and cavitating so badly that they couldn't get a reading. Ron went over to the machine shop and had them make one of those smooth test discs. He took it into the racing shop and talked them into hanging it on their super motor. Very skeptical about that plain disc letting their engine over-rev, the dyno operator advanced the throttle very slowly. But once the engine reached 4200rpm, straining mightily, the tachometer stopped climbing. Everybody looked at Ron, and he said, "Well, if your engine really made the horsepower you said, it would turn this disc at the rpm you wanted." Shortly thereafter, they transfered Ron to race engine development, and soon he was running the department.