British Anzani A & B Stock & Alky Racing Engines

[John (Taylor) Gabrowski]

The following pictures show this high load smooth disk test wheel Gene Strain introduced to me for the Anzani back in 1978 that was developed by the Hallum and Anderson influences from the North Western USA. Smitty's story about how Ron Anderson showed them how they work at OMC is so vivid a description of how impressive these test wheels are and work, I never again used a Mercury test wheel ( I had worn out 3 Mercs at that point) for any engine after that, be they stock racing Mercurys, my other Anzanis, Modified Mercurys of all displacements from 30, 40, 44, 49 and 60 cubic inch. After rebuilding 2 Quincy Flatheads a D and a 44 inch F, the same test wheels were applied giving those same hold down the revs, load and tune effects that really set up the engines well. From these pictures it is quite easy to develop your own sets of this flat disk testwheels.

[John (Taylor) Gabrowski]

My error is - Ron Anderson worked on OPCs not OMCs and not at OMC but at Mercury. One gets kind of wound up generating these things to read and you get writer's blindness!

[John (Taylor) Gabrowski]

Trying to give more perspective to the 2 stage pipes Bill Tenney developed and I understand midwestern racer Dick Hopenrath even used to use thes 2 stage pipe sets in races during these early days. I could not just leave readers with the idea that the pipe looked like some kind of wild turkey buss you charged up with shot, nails, glass and black gun powder and went Thanks Giving hunting with. I found a trusty leftover no good expansion chamber from testing on Merc deflectors and shoved it on. It gives some perspective to length of the systems being supported and tested in the early 1960s and the adding to the overhanging weight added to an already heavy Anzani cast iron loop block being run.

They faced the same weight and lengths problems with these concept pipes in the North West according to Jim Hallum. They too tried 2 stage pipes using a megaphone and an expansion chamber. Because of the great added weight the next thing to go and was taken off were the uper and lower megaphones so the engine still used a gated 2 stage system was essentially dumping right out of the exhaust ports and then once the raceboat planned off switched to the expansion chambers to go for the sustained high racing speeds. The next thing they ran into in the North West was where they used high loads of nitromethane with straight megaphone systems the Anzani was able to do so without developing abnormal crankshaft problems. With expansion chambers and no nitormethane, the high pressures involved in good working pipes found the earlier generation tapered big end pinned cranksahfts could not take the power without severe consequences. It would be the next generation of improved heavy duty crankshafts and connecting rods with improved bearing systems developed by Harrison (HRP) Racing Products) that allowed further Anzani expansion chamber exhausts development that saw eventually the "rams horn" stinger type expansion chamber pipes developed and used by Ron Anderson pictured here some frames earlier on this BRF thread. Bill Tenney too developed a type of "rams horn" expansion chambered pipes but their development stopped without further improvement long before Ron Anderson made his work quite well.

The following series of pictures mocked up of what a 2 stage Bill Tenney developed megaphone switch to expansion chamber racing exhausts could have bascially looked like. Long? Yes! and very very heavy.

[John (Taylor) Gabrowski]

One of the most unique features of the British Anzani outboard racing engnes was its unique combination of combining piston porting with a crankshaft rotary valve running right through the midsection of the crank. This combination though ported on the smaller side and not to any very narrow powerband because the were originally designed as stock racing engines on gasoline/oil. This allowed a situation when the engine was running where there was a port opening (rotary valve or piston port) or closing within any part of the crankshafts rotation which served to smooth out air/fuel transfer pulsing producing a very powerful motor. At this time in the 1950s there was no other engine that combined loop scavenging with piston porting with a crankshaft rotary valve system. It was revolutionary and every other manufacturer took notice especially when Anzani started to capture records that seemed incapable to such small displacement engines.

In the hands of the North West's, Jim Hallum there was extensive enlarging of carburator and piston port openings where the piston port coupled with piston skirt trimming effectively doubled the active port sizes thinning the castings port walls to the limit of thinness. Being stuck with the mild timing and restrictive sizing within the crankshaft midsection which was also a type of sleeve main bearing he could not take the rotary valve further. What he did go to next was to add 1 Tillorson HL right accross from the rotary valve opening face by locating the carb opposite it right on the crankcase wall. The result was speed and power increases. Then he added to that 2 Tillotson HL series carbs on top of McCulloch chainsaw reed blocks where each carb sitting on its reedblock penetrated one crankcase half of the engine. The performance result was immediate and found to be better than the carb opposite the rotary valve and Vacturi alone and was even noticeably better when he dammed the rotary valve off making it inoperative using blocking methods that effectively turned the Anzani into a reed valve combination piston port engine with 3 carbs though you see pictured the record setting engine with 3 HL carbs with the single Vacturi. The engine would be started off lean on the 2 or in case 3 small HL crankcase side mounted carbs which through the use of a cam brought the Vacturi carb on line last to get to the highest racing speeds possible after it had planned off.

Similarly on the exhaust side Hallum kept widening the exhaust port as he went through ring advancement changes from rectangular stock cast iron rings to a combination of stock located rings plus a another ring grove added over them to allow for widening ports without adding ring shear due to port width but to also have the change where it was no longer the piston crown and ring lands areas were controlling exhaust port timing to the change where the top of the Dykes ring (L Ring) was controlling the exhaust port timing which was more precise leading to superior engine tunning at the highest power peaks without downward leakage. To deal with further ring shear and do away with more ring friction problems he eventually did away with the 2 other standard rings to where the Anzani used a single Dykes L ring. A drop from 3 to a single ring resulted in expanded and increased very precise exhaust timing/tuning capabilities.

With the use of the single Dykes L ring known as a pressure back ring where exhaust blow down pressures force the ring wall hard against the cylinder wall making it a pressure seal, it would also immediately spring back releasing ring to wall pressure the moment the exhaust port opening lessening ring shear even more. This allowed initially the widening of the exhaust ports to larger wide sizes and with the deletion of the stock type rectangular rings completely with their ring shear problems then allowed Jim to widen the exhaust port to be "T" configuration making the exhausts ports as widest as they could be in terms what the Dykes L ring would allow by itself. It was not long before other racing engines went down this route as well, following the leader.

The route taken from Bill Tenney's midwestern area went down some of the same ways. Multiple carbs were not followed, a single Vacturi was kept. Changes to pistons in terms of cutting away piston skirts to alter piston port timing was adopted. Similarly the types and kinds of piston rings used increased from 2 standard rings to retaining them and adding a 3rd top Dykes L ring. Using a single ring did not advance at that point. Where Hallum's engines kept and enlarged intake, exhaust and transfer ports, Tenney's developments did similar but never got into the use of "T" ' d maxiumum width exhaust ports using a single Dykes L ringed piston. Tenney did go another direction in development where 2 extra transfer ports were added right under the exhaust port 90 degrees opposite the existing 4 transfer ports for a total of 6 intake ports. In effect a bigger loop charging flow from another added angle to sweep the cylinder of exhaust gases more so than a 4 port version could do. Due to increased crankcase volumes more nitro was added to the fuel mix to offset the increases. All these changes increased the power of the Anzanis but it was the Hallum engines that produced the speed records pulling the Anzani over 100 miles per hour barrier to set records there in relation to other engines also pulling over 100* mph many times the Anzani's small size of 322cc B Alky displacement.

Other engines would follow Anzani's leads in time from ideas and concepts put to work pioneered by Jim Hallum but he got the Anzanis there first forcing everyone else to play catch up later. And all this from a non-racer who had an unbelievable understanding of engines, never raced an Anzani where others had a hard time grasping what had just screamed by them into the record books. He was, is and remains unique amongst his piers an engima.

[John (Taylor) Gabrowski]

Very early on in racing outboard two strokes it was a given that to attain racing speeds with power the engine had to breathe efficiently in terms of intake air/fuel transfers and exhaust blowdown. Many engines in the deflector or cross flow variety were desgined around recreational pleasure uses therefore crankcase volumes of up to 4 to 1 were very much a common place. To go racing it was realized that these crankcase volumes had to be reduced signiticantly where 2 to 1 or less had to be achieved for race engines whose powerbands were to the extreme high ranges of rpms they were expected to produce.

Anzani early on in the late 1950s already had a semi-full circle crankshaft in place to reduce the crankcase volumes down to where they were expected to be for racing outboards efforts. Jim Hallum and his contemporaries looked at these volumes critically too. The first things filled in to reduce the crankcase volumes were crankshaft assembly alignment holes in the crankshaft plates active within each crankcase half section. These were filled with a hard setting compound that would not vibrate out with crankshaft operation. Another crankcase section filled was the crankshaft center bearing encirclement tunnel that provided not only air/fuel cooling to the bearing outer, the passage also served to supply active pressure to be bled off to pressurize the engines remote fuel tank. It was found that the cooling aspects were not required as air/fuel passing through the rotary valve face and right through the center of the crankshaft with the crank rotary valve passages cooled sufficiently in any case. These measures brought better results dealing with crankcase volumes increasing transfer efficiency of air/fuel entering and leaving the crankcase.

Hallum expalined that there were other efforts to reduce the crankcase volumes even lower by encircling the Anzani crankshaft lobe section on each half of the engine that was not full circle like the midsection of the crankshaft that was. In this case a kind of can was machined that could be welded or screwed onto the non-full circle sections of the crankshaft to drop the crankcase volume even lower. At this point it was explained that a type of threshold had been achieved where changes made to reduce crankcase volumes did nothing more to increase the performance of the engine. There was a plateau reached of engine breathing efficiency for an engine reving into the 9,000 rpm ranges.

The added metal can did increase other problems of reliability where if such an add crankcase stuffer added on, blew off, the result could be catastrophic engine failure. Such was demonstrated in the late 1970s when Calgarian, Gene Strain's 2 carb Anzani with such crankshaft machined fit and mechanically screwed on fastened add-ons blew up shredding these crankshaft stuffing cans, firing them through the crankcase as the engine grenaded showering bystanders with metal fragments gone in every direction as the engine destroyed itself upon being started and being rev'd up for raceboat drop on to the water. Speculation had it that there was enough nitro'd fuel in the crankcase as the engine reved up to cause an explosion tearing loose crankshaft components that would in fractions of seconds destroy the entire powerhead and that is what it did.

There would be improvements to later crankshafts in the later 1960s by Harrison (HRP) that would again reduce the crankcase volumetrics for Harrisons. HRP design changes would also deal with crankshaft and their components reliability which then also flowed out to the Anzanis of the North West. The HRP crankshaft was built completely full circle in all respects. The big end tapered pins of Anzani were gone with straight pins. These crankshafts were beefier, with improved bearing systems throughout top, bottom (both were caged wide type roller bearings) and with the use of Konig connecting rods and bearings technologies concepts from Mercury and OMC a much better crankshaft with reduced crankcase volumes was achieved differently. Crankshaft strength was greatly enhanced. Montana's / Roger Wendt's, Ron Anderson prepared engine is a fine example of the Harrison technoligied crankshafts put to work in a championship 322cc hybrid Anzani B Alky engine. It was remarkable in that it could easily compete with the new Konig Loop 4 cylinder 350cc engines and it took championships and ran some dead heats doing and proving just that.

[John (Taylor) Gabrowski]

Greetings to Lee Sutter of British Anzani engine fame.

I sure look forward to having Lee add to the history going on here from his unique perspecive being recreated hee for the Anzani outboard racing engines and their makers, users and drivers who also set records as well as those that just drove them.

[John (Taylor) Gabrowski]

"I raced alki boats for about 15 years, and was at “D” Lake in 1960 when Bill Tenney first showed up with the Anzani. I was involved with Hallum and Walin in the early days, and Ron Anderson in the 70’s. My last race with an Anzani was with a “Coil” pipe, progressive multi-carb, non-nitro engine in BRR at Nationals in Depue, IL in the early 70’s. Bill Seebold, Jerry Simison (sp) and had a great race. Every part was handmade, fragile, in short supply, and 100% development!!! Walin and I were racers, Hallum and Anderson were engineers. Jim and Ron had “ME” degrees from the UW."

This short, writer undisclosed, introductory historic recollection story is from a racer who is preparing to contribute historical pieces to these British Anzani threads. I would be great to have others too so involved to look at doing the same thing. Being part of that recounted history being developed here. Everyone who raced or prepared or helped with these engines being raced down to the pitman who helped with the raceboat the engine was on has a story to tell. If there is some difficulty in doing so there is help for the asking too, so don't be shy. We would love to hear from you if only to assist you with something that would be difficult otherwise.

[smittythewelder]

It's time for me to bow out of the Anzani threads here, since you now have access to the guys who have direct knowledge. I was merely a bystander, and have warned you my memory of these things is subject to correction. I'll still follow the discussion.

[Master Oil Racing Team]

Don't bow out Smitty. I have DIRECT knowledge of stuff that I have either forgotten or saw it from a different point of view. Joe is always reminding me of things I had forgotten or remember certain happenings different from the way he does. So chime in when you have heard or remember something of the story. There are always parts of a story that are missing. So Please keep adding your input.

[John (Taylor) Gabrowski]

I know that you will no doubt remain by and prime different writers at different times concerning different posts. Its part of you that we all enjoy.