British Anzani A & B Stock & Alky Racing Engines

[John (Taylor) Gabrowski]

Where the Pacific North West concentrated on the biggest of existing ports in intake, intake transfer, piston ports and exhaust ports, Bill Tenney was working hard at increasing the loop characteristics by adding 2 extra cylinder transfer ports by having 2 on each side to loop charge the engine then adding 2 more below the exhaust port also connected to the intake transfer tunnels to have fresh air / fuel give one final push sweep to get the last vestage of any residual burn't air / fuel out of that cylinder with that final push out of those 2 added below exhaust port transfer windows.

Tenney started with a concept engine, a 250cc class A Alky engine by using just one cylinder out of 2 to prove the concept. Once he was satisfied he was on the right track he then proceeded to do one complete 250cc block and similarly the same to a 322cc block retaining one carburettor as the basis for air / fuel induction to the engine. According to a Tenney engineer, these engines with increased breathing and added nitro belched serious additions in horsepower. Of the 3 blocks 2 were heavily damaged in the garage fire of 1967 in that all their alluminum components melted in and around the engines Their full development stopped though several racers already had such conversions out there from Tenney they were getting used to.

It has been decided that one of these two pre-assembly engines will be sporting the gated twin exhaust switchable systems that was the precurser to these engines trying expansion chamber exhaust systems. It is fitting that one of these sport this pipe set as Dick Hoppenrath campaigned such an exhaust equipped engine and successful so at times in the USA Mid-West.

Pictures were be soon forthcoming of such an exhaust equipped 6 intake port loop Anzani engine.

Can anyone come up with pictures of Dick Hoppenrath running out there in the early 1960s having such an exhaust system pictured while he was using while running?

[John (Taylor) Gabrowski]

It turns out that these brass welded Anzani stacks are brass alright but they are not plated as such with chrome, in fact there is no chrome on them or in the brass alloy they are made of. A metalurgist indicated they are made of a brass alloy called "Nickel Silver" which has no elemental silver nor nickel in it but with 56% copper, 27% zinc plus added trace elements as part of the alloy mix render a brass alloy that is very silvery in appearance that can be buffed to a high sheen that is chrome like in appearance. It seems the pipe maker wanted to build a nice set of Anzani pipes that could be polished at any time to make them bright and chrome like even after heat discoloration from racing. These pipes were clearly designed and built with some other results in mind not found using iron or steel.

[John (Taylor) Gabrowski]

Whille cleaning up the Tenney 322cc 6 intake port loop block for restoration reassembly reminders of the intense garage fire are all over it. The block instead of grey color cast is, is no longer grey like most cast irons is but now is blue black in color thoughougly. The fire was so hot around that engine that it melted the engine where everything on it alluminumm melted and puddled away including the pistons inside, the cylinder head, the crankcase, the tower, clamps and gearcase it was sitting on until other than the flywheel, rods and anything steel, like its pipes or cast ended up as a pile of twisted melt, ash and clinkers on the foor from the heat of the fire.

While reading steel making specs and how its made most steels are basically all iron with added trace elements added in the molten mix to make the various steels. One has to ask what if any metalurgical change has occurred to this cast iron loop block from the intense heat and smoke of the garage fire? From all this heat and being subjected to contaminated carbonized smoke, and the intense heat, could the properties of that cast iron block been turned into some form of steel now with different properties than the grey cast iron it was originally?

[John (Taylor) Gabrowski]

According to some readers email, I was asked to check the straightness and flatness of the cylinder head and cylinder base decks for heat distortion? That done and none found, in spite of the blocks color change it is doubtful that there was any change to the cast iron other than some minor heat treating of dubious value is the given opinion.

Thanks readers.

[John (Taylor) Gabrowski]

In doing some initial Anzani world wide distributions examinations of engines, records just are not there. There were the 2 interesting engines Anzani built of which one was the Dual Unitwin of which one was winning C Alky Runabout races in the USA in the early 1960s as featured restored in some pictures and posts on another thread in this historical area on BRF. They were originally gasoline fueled engines. Where else they might turn up is yet to be seen.

Another engine was the "Sport Twin" which was 2 single cylinder engines linked to one common transmition and fuel supply to run both engines on a common tower using a single gearcase and propellor. Did any of these turn up in North America?

Anyone have something to surprise the community?

[John (Taylor) Gabrowski]

Courtesy of UK's Twister is an Anzani twin cylinder powered classic stock racing runabout, on the trailer and at speed. Immaculate workmanship! Enjoy the pictures.

[John (Taylor) Gabrowski]

This little picture courtesy of our UK member, Twister is of the Anzani Sportwin which was based on coupling 2 single cylinder Anzani engines together with common use elements to make an operational engine. This engine is of the pre-Loop engine days. How much Anzani engineer Charles Harrison had to do with this engine is being researched. Did any of these engines make it to the North American continent is unknown.

[John (Taylor) Gabrowski]

The force of a Anzani B Alky 2 carb model engine explosion ripping the engine apart as it rev'd up in 1976 broke its Tillotson HL Alky carb base off one side along with its crankcase side adapter. When it comes to a blown up engine nothing in the short block survived. On the exterior this carb was the only peripheral casualty.

Enjoy the pictures.

[John (Taylor) Gabrowski]

Pictured here is the completed restoration by Rod Champkin (aka BRF's -Twister) of a British Anzani 250cc - class A stock gas, cast iron blocked and loop charged racing engine for the owner of the newly resurected British Anzani Company now back in business. In terms of this restoration, to finish the job it took some parts from different parts of the world to do it. The owner has some plans to make up a hydro this engine was last run on as an A stock gasser with some speculation that a second hydro to run a class B stock (350cc) Anzani will also evolve from the same effort. With good hard work and good fortune we can see these engines in the future run side by side on their respective boats to be seen here on BRF for their historical representation in the stock outboard racing world, overseas of yesteryear.

Enjoy the pictures, Twister's restoration is immaculate.

[Tomtall]

With good hard work and good fortune we can see these engines in the future run side by side on their respective boats to be seen here on BRF for their historical representation in the stock outboard racing world, overseas of yesteryear.