British Anzani A & B Stock & Alky Racing Engines

[John (Taylor) Gabrowski]

The following picture is a late Model British Anzani with late model expansion chamber racing exhausts. The engine just can't get away from the classic crescent shaped exhausts systems even with expansion chambers. The shape remains. Anzanis so equipped also had a departure from the fuel they used which meant when you went with the supercharging aspects of modern expansion chambered exhausts you also dispensed with using nitromethane in the methanol fuels anymore. It was just too much power the earlier versions of the crankshaft to take.

[John (Taylor) Gabrowski]

The following 2 pictures are of a classic British Anzani MkII (1960s) Alky racing engine on display that came in either 250cc (Class A) or 322cc (Class B) displacements with a single large Vacturi carb to feed the engine a methanol / caster / nitromethane fuel mix.

[John (Taylor) Gabrowski]

I had to go out and measure the Anzani B Stock racing block (closer to 348cc?) I have stored. The B Stock Anzani has a full 30 millimeter carb inlet hole on the side of that cast iron loop block.

When the 322cc Anzani block was readied for Alky racing the inlet hole was not round as the stock one was but slightly enlarged and re-shaped from round to an odd shape to help direct air'fuel into the rotary valve some 90 degrees off the main piston ports.

On some engines Tenney as well as Hallum or Anderson prepared class B Alky Anzani blocks they went as far as 44 millimeter block to carb openings leaving some casting port passages paper thin. Generally though the 90 degree passage on the block to the crankcase for the crank rotary valve was left as is as was as. The crankshaft rotary valves to the crankcase halves through the crankcase center main was very mildly timed and even at times they tested with it the rotary valve eliminated and blocked by Jim Hallum when they fitted 2 Tillotson self pumping crankcase carbs sitting on top of reed valve bodies on some Anzanis having 3 carbs in total instead of 4 some versions used.

It was found that the Anzani could run better without the crankshaft rotary valve and crankcase carb mounted next to it. It is ironic that Bill Tenney must have taken that to heart and for future development as he made and I have here a NOS new Anzani crankshaft center section that has no rotary valve tunnels going to each crankcase half through the middle of this crankshaft main. By Jim Hallum's decriptions they were flirting with reed valve inductions on the crankcase side of the engine more and more as an alternative to an ineffective factory installed rotary valve of the original design.

[John (Taylor) Gabrowski]

It is quite usual from the North West Coast standpoint to plant at least a couple of carbs on Anzani B Alkys being the Vacturi primary on the cast iron loop block and a Tillotson HL self pumping carb as a secondary adjacent the crank rotary valve window being the most common. 2 Carb models east of the west coast were few and far between.

The picture of this class A Anzani is quite a departure from that North West norm and the development is unknown at this point. In this case the rotary valve window was sealed in the cast iron block as well as on the original side of the crankcase. The developer then swung the center bearing with its rotary valve opening window virtually 180 degrees over to the other side of the crankcase and carefully reducted a tunnel that directly flowed air / fuel to the window and crank center main rotary valve openings as the crank turned. This is in steep contrast to the original layout that involved a tortuous kind of "S" shaped passage way that started in the cast iron block adjacent to the primary block piston ports that then ended inside the crankcase. Not only was the S shaped passage gone but the new direct passage made the whole path straight and some over 1 inch shorter in intake length.

Jim Hallum commented recently how he felt the crankshaft rotary valve as it was factory installed was mildly timed and found to be in-efficient when they improved the situation by cutting off the rotary valve circuit and adding 2 Tillotson HL pumper carbs on reed blocks on forward crankcase sides. Perhaps this re-routing, shortening the intake circuit and straightening that circuit did something positive with the rotary valve. What is quite clear from these pictures is that this class A Anzani was well run and worked with this combination of 2 carbs with one swung to the other side of the crankcase with better directed rotary valve charging.

Enjoy the pictures.

[John (Taylor) Gabrowski]

The following picture is a Konig 2 cylinder magneto adapted to fit right on to an Anzani A or B powerhead. There were a few of these around.

Anzani bakelite gears had a horrible reputation of shearing all the gears of the bakelite manufactured gear due to the pressure and vibration of he 180 degree swing of the geardrive to the corresponding top dead center activties of the engine firing causing the gears to loosen between the bakelite magneto gear and the steel gear under the flywheel it meshed too. Somewhere once worn and loosened in mass some time after a run that exceeded 4,000 rpm the bakelite gear teeth would just sheer off causing the engine to stop.

It was adapting the rubber mounted Konig geardrive to the Anzani's Lucas magneto that put a stop to all that shearing happening and from there on in most Lucase geardriven magnetos sported Konig fiber gears taking the rpms past the 9,000 range without difficulty.

Enjoy the pictures of the Konig magneto adapted fully for use on Anzani.

[John (Taylor) Gabrowski]

Most Anzani megaphone exhausts were generally rolled steel with a variation of pipe supports or struts to ensure the vibrating and harmonic pipe did not break off and stayed put when in competition. There was a distinct west coast variation where the struts were anchored to the top of the exhaust plave and on to the middle of the head giving the pipes a sort of PacMan look. The idea in that was to spread the load between 2 locations.

Bill Tenney on the other hand had the pipe supports welded only to the exhaust plate giving the exhausts a supported "Crescent" shaped look.

This pipe set in this picture was very much simplified. Instead of 2 aluminum cast shaping plugs installed in the overly rectangular stock Anzani exhaust port rendering it square and then easily adaptable to make it change from a square to round to go with exhaust pipes easily, the maker welded on 2 extended blocking tabs right on the exhaust pipes flange to do the shaping from the inner side of the exhaust port to the surface of the exhaust outlet on the block itself and then with that shape to a round exhaust pipe elbo.

Instead of external pipe supports most used the maker welded a buttress to each pipe following its inside curve to provide angular support. This is not inlike in principle to how Harrisons Racing Products cast their aluminum elbos for their aluminum tubed racing megaphones.

All three methods worked for Anzani albiet this is the lightest overall weight exhaust system ever put together to hang on an Anzani by almost half a pound a pipe making for a remarkably light setup especially with the Anzani's block being cast iron. These innovative pipes would have reduced the overhang weight and the stress it caused to the engine cracking blocks and aluminum engine mounting tubes considerably.

[John (Taylor) Gabrowski]

At a recent small 2 stroker (sled) parts sale and swap meet I purchased a NOS, what appears to be near complete 12 volt DC electronic powered up exhaust (twin pipe) water injection (European) kit that uses the pressure pumped pressurized bottle and solinoid regulated method of injecting 2 racing stacks, with every manner of controls, adjustable jetting, plumbing and all. It is highly compact in sizing and looks like it cost a fortune to make with heavy duty quality through out. Does anyone here have some experience to relate how this type of stack water injection system could be adapted to a 2 cylinder loop engine like an Anzani or Harrison etc. similar. This is unlike any Quincy Loop water injection setup I have restored. There is no dating on the kit but it appears to some to come from the 1970s to early 1980s. I am going to take pictures to post and may be trigger some information on this kind of system and its install.

[John (Taylor) Gabrowski]

The following sequences of pages depict one of the hottest British Anzani drivers of the early 1960s in the USA, Dave Berg. In 1962 Dave Berg lost his life in an even't first heat of A ALky Hydro. The Dave Berg Memorial Race and Trophy were launched in his honor to perpetuate the memory of more than just a good driver but an all around wonderful person that was lost to the sport.

Enjoy the pictures and words, source, World of Boat Racing Magazine.

[John (Taylor) Gabrowski]

Some more pages from 1962. You can sure tell the British Anzanis by their crescent shaped stacks in all cases!

[John (Taylor) Gabrowski]

Moving water injection for 2 stroke pipes back to the Technical Threads

I just acquired some technical information on water injection for 2 stroke engines. It is for that pictured system and it turns out that it is from 1995.

With that it is more appropriate and fitting to get this water injection for 2 stroke pipes subject out of Harrison and British Anzani engine threads which go back way further in history and return this subject to the Technical threads of BRF to be shared with readers there. That is where I will immediately post Electrical as well as Flow diagram aspects of the 1995 "TA" *tm system I acquired recently for readers to see there.