British Anzani A & B Stock & Alky Racing Engines

[John (Taylor) Gabrowski]

From a previous posting, something I thought was some kind of saw horse queen joke are a couple of samples of open bearings with an inside bushing to support the top of a class A-B crankshaft at the top of the crankcase. If those bearings were supposed to run open in the air, did some leakage through the bronze bushing below it leak enough to lubricate the open bearing? Or did the driver turn around with a squirt can of oil to give it a periodic shot while underway, racing?

Featured also are what most would expect. A bearing housing that housed 2 ball bearing sets and a top seal yet here are these open bearings and they are both snap ringed to keep the bearing against the housing and stop them from moving up or out too. There is no evidence that there was ever any oil / grease seal on one or both sides of the inserted now open to air ball bearings either. Something weird here I can't explain. Anyone have any light to shed on this weird way of running top of crankshaft bearings?

[John (Taylor) Gabrowski]

Having cleaned up and dismantled the open bearing end caps and wanting to not leave the bearings open even on a show engine I am wondering if a grease / oil sealed ball bearing could be fitted and even used once in a while with startup without burn up? That would retain the installed bronze bushing and seal the system further without loosing the ball bearing system on top which is not seen once the flywheel is installed.

[John (Taylor) Gabrowski]

To go to the 3 and 4 carb Anzanis and Harrisons one pretty much had to find a dealer repair depot McCulloch chainsaw graveyard to get a stock of Tillotson HL carbs but more important, the base with reed valves underneath the carb. Two such graveyards have been found mainly because scrap recyclers dislike other metals in aluminum scrap and none one is going to have some of their dealership service staff clean the stuff of steel parts on hourly keeping in mind the price per pound of scrap aluminum. Still, finding these dusty derelict caches was just plain lucky. It is amazing how rain water destroys aluminum exposed to the elements over time.

[John (Taylor) Gabrowski]

These open bearing end caps for British Anzanis pictured here came up in discussion with Jim Hallum. He had never seen what I described and pictured here as being something an Anzani would run of any vintage they had being running in the North West. Still he referred to other outboards that had such bearings where the bottom crankcase pressure with its residual oil would be piped to the open bearing and sprayed on it as the motor ran. Jim was also familiar with the use of an inner bushing some babbit, some oilite bronze and others of hot dipped silver where leakage past the bearing would prove lubrication to a bearing above that one but never did he see this on the top of an Anzani. I mentioned to him that I had sen a Qunicy Flathead 4 cylinder engine with all half of each rod silvered from the bottom to midway up the rod to the small end. This he said were racers/engine builders using silver as a bearing type of separation surface on the rod's surface so the rod's steel would not touch the sides of the crank cheeks where steel to steel contact would otherwise make a considerable amount of friction. Asking me if I had ever seen frictioned colored big ends on connecting rods on their sides next to the crankshaft cheeks was the rod being pushed sideways real hard and that friction resulting. It was more prominent on Alkys than gasoline/oil engines because of the inherent dryness of the alky caster mix versus gas/oil. Jim stressed when assembling any racing engine that the rods should not be sloppy in their centering within the small end wrist pin to piston side as well as on the crankshaft cheeks to sides of the connecting rods next to the crankshaft cheeks. To the small end it is paying close attention to the wrist pin washer fit (Mercs) and in the big end, plating the sides of the big end with silver which is a very good bearing material. Keep the connecting rods centered real well at its power unemcumbered with any side thrust friction.

Jim also gave out some good pointers and how to construct jigs for tearing down and putting together multi-piece crankshafts with both taper pin and straight big end pins. That is a subject to make a good article of all by itself for the future.

[John (Taylor) Gabrowski]

If there was any effort to lighten Anzani flywheels it was sure evident where these open beairng end caps were used. The Anzani's center main section of the crankshaft in pictures already posted weighs as much as all the rest of the crankshaft components combined attached above and below its rotating mass. The stock Anzani racing flywheel weighed in at nearly the same weight as the whole crankshaft itself and even in the stock gasoline state or the Alky racing state the engine would rev up so fast it was a race to drop/throw the engine and boat into the water to race nearly as soon as the engine started or you risked engine explosion and they from time to time did explode just that way. That demonstrated that the engine could accellerate even quicker if much of the flywheel was done away with having all the weight of the crankshaft deliver engine torque at racing rpms. They were not wrong in their assumptions so there is a history of the flywheel being cut down from 4 pounds to where they were used at 1/2 a pound in weight for racing with no ill affects to the engine. Shortly I will picture the flywheels for posting in this thread in their evolution from stock racing weight to extremely light flywheels for Alky racing.

[Mark75H]

That demonstrated that the engine could accellerate even quicker if much of the flywheel was done away with having all the weight of the crankshaft deliver engine torque at racing rpms. They were not wrong in their assumptions so there is a history of the flywheel being cut down from 4 pounds to where they were used at 1/2 a pound in weight for racing with no ill affects to the engine.

At racing speeds on a boat with a prop this disagrees with the laws of physics. The advantage is a more balanced motor, not pure acceleration by itself.

[John (Taylor) Gabrowski]

I am unsure whose physics you speak of Mark 75H but the age of cutting down flywheels for Alky engines was very much a Mercury / Quincy Merc alky deflector engines starting in the later 1950s and so to did this spread to British Anzani, Harrison, Quincy Flathead Loopers, Konigs, Crescents and so on as racing evolved in years. It was crankshaft designs in these engines that allowed the practices with some basis being race course length as well. A faster engine rpm spinup was obviously desirable with short and medium courses where flywheel weight would be less important on long courses with large pin curves. Flywheel size is pretty much seen pictorially in races as well as in engine parts pictures as years went by.

[John (Taylor) Gabrowski]

In order of flywheel evolutionary change:

British Anzani flywheel evolution from Stock B (UK) Gas and the beginnings of Alky here in North America were the same flywheel, machined steel, chromed over and no balancing other than what the machining afforded in its production. (35 & 36)

(39) Shows the first flywheel cut down where the flywheel remained the same thickness and the diameter became no wider than the outer rim of the rope plate. Balancing was done on its underside.

(38) Shows the typical second cut down where the flywheel diameter stayed at the width of the rope plate but its thickness went down 1/4 less than original stock thickness. Balancing again was carried out on the underside.

(37) Shows the third cut down where the diameter remains the same width as the rope plate but now remains only 1/4 as thick as the stock original. At this point the flywheel was getting so light balancing was not done.

(40 through 44) Shows the fourth and last possible cut down where the rope plate and flywheel were thinned down to 1/4 as thick as original and the diameter was changed to that of the flywheel side magneto timing gear. At this point flywheel weight had dropped from 4 pounds to 1/2 a pound rope plate, timing gear and flywheel as the single assembly. No balancing was evident on this the smallest flywheel assembly cut down.

(50 - 49) Shows extensive balancing of two cut down flywheels.

(51) Shows a typically unbalanced Stock and early Alky racing flywheel at 4 pounds in weight.

(45) Shows a late 1950s model Anzani rope plate of aluminum cast with machining.

(46) Shows the typical British Anzani embossed rope plate with inlaid red paint that was the typical unit used until Anzani stopped engine and parts production.

(52 - 53) Is the typical Anzani crankshaft center section that by itself weighs almost the same as the stock flywheel. As the flywheel was cut down this center section became the main rotating mass of the crankshaft accumulating most the torque for the racing engine. The top throw, bottom throw and big end pins together weighed the same amount as the singular crankshaft center section. Anzani did not go completely full circle crank where its later cousin the Harrison did with an entirely heavier crankshaft and a very light aluminum and steel cored flywheel.

It is unknown at this time if the smallest cut down flywheel was used on class A and B Anzanis but for sure it was used in class A Alky successfully. Stage 2 and 3 cutdowns were definitely used in Alky class B.

Enjoy all the pictures of flywheel evolution! They were spinning these Anzanis into the 10,000 rpm ranges in Alky racing in North America.

[John (Taylor) Gabrowski]

Final picture batch - Anzani flywheel evolution.

[John (Taylor) Gabrowski]

Readers asked - The center section of the crankshaft pictured has an egg shaped port that runs diagonally through the center of the crankshaft main that feeds either side of the crankcase half as the window rotates within the crankshaft Oillite bronze main bearing found there is the typical crankshaft rotary valve of the day. When it came to the gas burning A or B stock Anzani run in the UK during the period it worked rather well boosting engine performance but here in North America and running them in Alky A and B, . that became debatable. Builders like Jim Hallum and Ron Anderson found that deleting the very mildly timed crankshaft rotary valve entirely and going with reed valve at the base Tillotson HL carbs in a 3 carb configuration worked better. The 4 carb (2 Tillotoson HLl on each crankcase half & one HL above the crankshaft rotary valve crankcase opening in front of the Vacturi) and single Vacturi main carb configuration went best of all. There were also some 6 carb configurations (5 Tillotson HLs and 1 Vacturi).

The problem with the Anzani crank rotary valve was once it was machined into the crankshaft centre it was more or less fixed with the only timing change available by altering the Oillite bearing rotary valve opening. Some made the changes this way and still others went the root of adapting a Konig style belt driven disk rotary valve with 2 carbs however the most successful Anzani engines used the rotary valve in a 2 carb (1 - HL and 1 Vacturi) or the 4 carb version that set some straightaway records in the 100 mile per hour range in the early 1970s.