British Anzani A & B Stock & Alky Racing Engines

John (Taylor) Gabrowski · 10-10-2007

British Anzanis came from the UK with some variations of heads for their A and B displacement engines. One style of head's combustion chamber was the classic "bell" capped hemi style head with the combustion chamber centered equally around the diameter of the bore size tapering upward to the spark plug hole making it a classic 8 to 1 compression ratio for gasoline oil use as a stock racing motor. This style of cylinder head is common place with most loop scavenged 2 stroke gasoline engines today but Anzanis came out with them priort to 1960 with the loop scavenging. This cylinder head was seated on top of a composite multi layered type head gasket well suited for gasoline use but was found to be unsuitable for higher compressions where Methanol and Nitro were used.

The cylinder head for Alky racing used a combustion chamber with an offset squish feature to it that would raise the air fuel charge accross the lower part of the head to where it would squish the air fuel off to one side into the combustion chamber proper. Compression with these heads depending on machined thickness could be varied from 12 - 14 to 1. Composite head gaskets proved to immediately to leak badly. Bill Tenney's standard adice was to custom make sheet copper and in cases alminum single layer head gaskets that would then be head gasket glue coated and torqued down with the standard BSW head bolts. Leakage was pretty much eliminated where nitro percentages in fuel did not exceed 15%.

On the North West Jim Hallum and his associates pretty much used a whole lot more Nitro than down east so their approach to Anzani cylinder heads turned out quite different. They were using upward from 25% to over 30% nitro'd methanol based racing fuels. They too initially started out with using the revised sheet copper head gaskets to stop compression leakage associated with Alky/Nitro fuels. They soon found that using more nitro exceeding 15% produced head gasket leakage on both sides of the copper head gasket. To remove the source of the leakage from one side or both sides of the copper head gasket they dispensed with the head gasket itself altogether by careful machining of head surfaces and also using a specialized heat proof proprietary alumina joint cement that when the head was placed on the block it seemed that it could have run without headbolts because the glue set so tight. But, in reality head bolts were necessary and installed and the head to block joint did not leak.

Still not completely satisfied with the distance between the headbolts having adequate torque evenly spead over the head and block matting surfaces, Jim Hallum removed the casting plugs that closed off the water jacket openings to the head, threaded in a steel insert into each casting plug and installed a pressurizing capbolt that forced the inside of the heads water jacket side of the casting downward to the engine head. Process one became torquing the head down glued at the mating surfaces with its 6 main head bolts and process 2 was to torque down 4 capbolts through the casting plug adapters that served to spread the torque more evenly on the cylinder head to block joint surfaces more evenly ensuring no leakage ever occurred as a possibility and none did.

The engine had a kind of not installed bolts look to it, but it worked well. These head bolt and joint cement improvements did not find their way East to Bill Tenney no different than the Tenney modified to 6 intake port loop engine blocks then too untilizing 25%+ nitro'e methanol fuels never found their way to the Nort West, but they are another story that involves the North West's evolution of the "T" type exhaust ports.

John (Taylor) Gabrowski · 10-15-2007

One thing that was well noticed back in the early days 1950s into the early 1960s were the 2 approaches to racers exhausts. There was one course of practice were all the exhausts as many megaphones as there were, including exhaust plate and even the filler block where used were to be hosed down with water to cool off any heat they gave off. Similarly engine blocks that normally cooled from the base of the block upward saw more cooling water entry points installed between cylinders as well as deep cooling tubes installed through the rear water jackets at the head down to where the pipe inlet inside the engine block was right adjacent to the exhaust port to get the hotest water there out of the block first to achieve cooling to the maximum.

In spite of all this cooling water spraying like some proverbial hotel shower off the surfaces and innards of these engines, the deflector engines in particular with their 30% larger piston crown areas still melted down with great frequency. An engine that was running number one in one heat melted crowns completely on the second heat and so on. With the appearance of the British Anzani cast iron loop charged class A and B Alkies there was the changes that had racers scratching their heads. One real question was just how was a cast iron block on those things supposed to cool in relation to anything aluminum? IT used a single water inlet at the base of the cast iron block and then 2 outlets in total (one at the top of the cast iron block and one at the top of the cylinder head). Unknown to most then was that the cast iron or "gutter iron" Anzanis blocks were cast of remarkably has extremely good heat transfer properties. Also being understood morso then was the flat top or near flat top pistons involved in the loop scavenged operating system of the engine lost the heat soak characteristics retained by the deflector engines because the surface area was 30% smaller and without the intake deflector on the piston crown all deflector engines retain as their cross flow scavenging system required, so they, the Anzani loop engines ran basically cooler to begin with. Where deflector engines lost breathing in intake and exhaust efficiency as the rpm went up it was the direct opposite to the Anzani loop engines that got more efficient in transfer and exhaust as the rpm kept climbing gaining in efficiency as it climbed.

So too it became well noticed that Anzanis did not hose their exhausts down as cooling water was deliberately hosed away from the engines block and exhaust pipes surfaces leaving them dry and presumably hot as the engine twisted many necks watching them go by time after time without the catastrophic piston melt down failures so many others engines were plagued by. This emerged as the second approach to 2 stroke exhausts that persists today in modern day expansion chambered racing exhausts systems.

Well known to the mechanical and aeronaughtical engineers of that early period like Bill Tenney, Jim Hallum and followed closely by their contemporaries was that any pressure or vacumn sonic wave passing on a surface does so faster and more efficiently when the surface they are following is smooth, even temperatured, hot in temperature and resonant with the material being followed. You could see it all at work with just 2 jets of water streaming 5-6 feet out the sides of the Anzani engine clearing all its megaphone exhaust components leaving them dry. Nearly every other engine of that period was being soaked down to cool to the extreme. It was not understood by the general community of the day that even persists in more modern times that a dry hot pipe was the most sonically efficient pipe. Indeed pipes that were even water water hosed down on the outside also became water injected on the inside too, not cool the pipe but to fool the engine into reacting as if the pipe was a longer pipe than it actually was, was achieved giving some added success to water soaked exhausts systems of the day from another operating angle.

Today's offshoot of the even temperatured hot exhaust pipe principle is mirrored in modern day expansion chambered exhausts that are generally kept out and away from the water spray and in cases expansion chambered exhausts are ceramic coated to retain even heating and even insulation wrapped to retain therir heating to produce best power through fast and efficient sonic waving pluses back and forth producing a supercharging effect. If you were to ask today's pipe formula developers and makers if they make pipe formulas specific to boat racing, their answer would be no, they don't make 2 stroke pipes that are exposed to water though they are seen on raceboats because they would not work properly when wet, which all goes back to the days when the Anzanis showed up on the scene in the late 1950s with their loop scavenged engines using their hot and dry exhausts that eventually put the engines into the century marks setting records in the process.

It all goes back to say that British Anzani started a revolution in 2 strokes with its loop scavenged operation, what is so much not known was that Anzanis approach to 2 stroke exhausts was just as important but that was lost in the scramble of recognition of all the changes that came so fast in the game of follow the leader that developed 2 stroke engine wise, industries wide, over the entire globe that followed.

John (Taylor) Gabrowski · 10-21-2007

During discussions with some Anzani racers and engine preparers and born out by particular wear and failure areas seen one critical weak spot with all pre Harrison changes to later versions was the piston connecting rod.

For the high tech, leading edge and revolutionary aspects of the Anzani engine there were 2 weakspots on the rods themselves and at both ends, big and small ends. The small end was bushed with a bronze type bearing slotted at the top of the connecting rod and into the bronze bearing itself to allow in lubricating and cooling oil from the air/fuel spray circulating in the crankcase.

The principle of using a bronze bushing itself provides for a sleeve bearing surface which by itself makes for a reliable bearing where moverment at the small end is limited in swing to the up and down motion of the piston itself. Similarly the heat from the piston crown had little effect as the bearing and wristpin surfaces were well washed with lubricant preventing any abnormal wear. The critcal thing was that this same bushing in terms of tolences of machining as well as its careful centered installation also played a big part in how the rod was kept centered between the piston itself and the big end of the crankshaft and the bearings at that big which at speeds of 9,000 rpm came to be very critical too. A sloppy wrist pin bushing bit to piston pin and piston pin piston bosses meant a sloopy big end piston rod action that meant on rotation the sides of the big end of the piston rod could and did create blue heat stress spots between the crankshaft and the sides of the big end of the rod creating friction and failure points.

The big end of the Anzani rod, the rod being one piece used an alloy roller cage and narrow and tall high speed roller bearings separated by a one bearing to one cage section for a one to one aspect ration between each next bearing. When there was side to side bearing slop movement from a too loose a wrist pin to wristpin boss to wristpin bushing fit and the sloppiness was carried all the way down to the big end of the rod and crankshaft creating contact points between the big end of the crank and the big end of the connecting rods the heat created was enough to cook (created coking of the caster lubricant into hard carbon conditions) lubricant (caster) on to the alloy bearing cage sludging up the cage enough to slow the roller bearings down until they would themselves no keep rolling but would start to slide instead creating such friction that the alloy cage would crack, melt or both along with the sliding instead of rolling roller bearing would all as a mass try to weld itself as a ring of hot metal around the big end of the crank and inside of the connecting rod all creating a massive mechanical failure capable of throwing the rod if not stopped real quick that would necessitate engine repair and overhaul.

The big end of the rod had another shortcoming. To lubricate the big end of the rod it was designed that lubricant would get in from the sides of the rod between the big end sides and the crankshaft. This seen as not enough the big end was bored as well with a oiling gallery from the outside of the big end of the rod through to the middle of the bearing surface so each bearing in turn could be set awash with libricant as the roller went over the oiling gallery hole centered on the rid right in the middle of each bearings rolling surface. This was fine in terms of design but so much rested on machining results any error there could result in desasters and did.

When the big end oil gallery was installed hindsight with what today's engineers have examined and since found was that the gallery hole penetrating the rod was too big increasing the chance that the rolling bearing could develop a wearing flatspot that did happen causing the roller bearing to skid instead of rolling damaging the bid end bearing surface of the rod, the roller bearing itself and the crankshaft big end pin necessitating their complete changout and renewal. The boring of the oil gallery in the big end of the connecting rod also presented a problem where the installed hole left a weakened surface on the inside of the rods surface where a fragment of the bore hole at the bearing surface would pit throwing metal into the big end bearings causing their failure much like putting a door stop wedge under a door in this case the bearing stopped, skidded and wore a pit into the bearing surface of the rod causing massive bearing, rod to big end pin failures.

The small end of the connecting rod similarly was not perfect as nitro methane loads in the Alky fuel mix could eventually create a pounding and bearing wear condition where the bronze wrist pin bearing would fracture on the crankcase side of the bearing necessitating its replacement though total failure was rarely the experience causing massive engine damage or failure.

Harrison (HRP) Harrison Racing Products seeing the big end and small end problems over a time history scotched the problems on both sides of the connecting rod and crankshaft moved to eventually resolve all the problems by going to a second generation more heavy duty crankshaft. It was without tapered big end pins, they were straight. he crankshaft by mass was 15% heavier and complete full circled. Harrison changed to Konig connecting rods that like Mercury used no bored in big end oil gallery holes that proved to be early potential and real failures on earlier Anzanis. Harrison designed and used modified big end roller bearings based on OMC and Mercury outboard designs principles and at the small end they used Torrington needle roller bearings at the small end with small end shims (like Mercury Outboards) to keep the rod centered from the piston small end to the crankshaft and connecting rod big end completely resolving the problem of big end crankshaft components coming into big end connecting rod outsides friction creating contacts allowing for a jump in power and rpm not previously possible with pre Harrison Anzanis. At that time it meant more nitromethane in the fuel could be used in the engine safely so it could go up to the 40% ranges. Such an engine was the Ron Anderson prepared class B Alky 2 carbed engine Roger Wendt (Montana, USA) campaigned successfully into the 1970s. None of this went un-noticed by Jim Hallum (Washington state, USA) who never got to obtain or use this new Harrison (HRP) revised crankshaft. Hallum however went on to the development of the "T" type exhaust port facilitated by refinements possible through the use of single Dykes "L" rings but that is another story in the amazing British Anzani development that spawned a revolution outboard motor marine industy world wide that is still going on today.

**Bill Van Steenwyk** · 10-21-2007

John:

Even though we have never met, I have been following this thread with great interest. I have always been very interested in the technical side of 2-cycle engines (never had the machinery/equipment to do any work on them myself which was probably just as well) but due to my long friendship/customer relationship with Harry Pasturczak was at least exposed to a lot of theory during visits with him, rides to boat races, and many, many late nite phone calls.
He was on close terms with Bill Tenney and spoke with him on a regular basis in the 70's/80's regards modifications to all kinds of PRO outboards and also kart engines, snowmobiles, etc., the whole gamut he worked on for various people around the country. I feel confident some of the modifications he made to my Yamato 80 which was used as an RB class engine came from discussions he had with Tenney.

The unique problem with the Model 80 or any other engine being used in the RB (restricted B) class was you could do most anything you wanted to the engine but there was one restriction, hence the class name "Restricted B". That restriction was the Model 80 could not use more than one 25.4MM carb.
The most common carb being used (at least the first few years) was the Bing carb used on the four carb Konigs and perhaps other engines at the time also. If you are at all familiar with the Model 80, you are also probably aware that the reed induction used (2 four petal reed cages fairly small in total inlet area) was also a point of restriction, so that even if you tried a larger carb which we did several times for test purposes, not a lot was gained. I am sure you also are aware along with most anyone else fooling with 2-strokes at the time, was the attempt to tighten up crankcase volume so as to pump all the fuel that came into the crankcase into the cylinders so as to get all the fuel transfered to where it burned and generated power. But because you were limited as to the amount you could get into the crankcase of the model 80 to begin with because of the carb venturi restricted dimension, crankcase volume did not seem to be the big factor with that engine that it was with others that had no carb restriction, either on size or number of carbs. About this time we were reaching an RPM figure with the Model 80 that it was never designed to turn in stock form(10 to 10.5 thousand RPM) and were starting to have severe vibration problems in the powerhead, leading to pipe and pipe bracket breakage, ignition components shaking off the motor, and even breaking the cast aluminum Yamato Racing tower housings that we were then using in conjunction with the Yamato racing lower units. To that point we had not attempted any crankshaft balancing but because of so many vibration problems Harry balanced the crank in one of the engines by removing several pie shaped segments from the original full circle crankshaft that came in the stock engine. He would have preferred to add weight but for a reason I don't remember chose to do it by weight removal instead. We went testing very soon after he completed the job and in addition to finding the engine ran much smoother in the RPM range that had previously been such a problem vibration wise, we also picked up 2-3 hundred RPM and a mile an hour or two. At first we (at least I) thought the balance job on the crank had allowed the engine to go higher in RPM by the virtue of that modification alone, but in his typical inquiring mind way, Harry thought a litte further and determined that possibly the INCREASED crankcase volume gained might be allowing more fuel to be drawn into the crankcase through the already restricted carb/reed opening and be acting after the first couple of revolutions to fill it more completely with a fuel air mixture, as a storage medium of sorts that allowed a greater volume of fuel/air mix to be in the crankcase and then transfered to the cylinders through his highly modified porting arrangement present in the motor versus what was original. He had done away with the factory sleeves very early in the process and had blank sleeves made by LA sleeve and them ported them to his own spec. At this point the reason for the increase in power was purely supposition, so he proceded to make a further modification that would increase crankcase volume futher and see if we saw a futher increase. To do this he machined a pair of spacers that would move the two reed valve cages out from the original mounting boss on the crankcase approximately 3/8 of an inch. He had calculated this would increase the total volume of the crankcase for each cylinder by about a cubic inch I believe (this was in mid 80's so my memory may not be exact) and we went testing again and picked up another 1-2 hundred RPM, so to our mind that proved without a doubt that he was on to something. Next he dissasembled the crankcase and by hand work with a dremel tool he got enough metal out of the inside of the case to equal another almost cubic inch for each cylinder. This again increased the performance of the motor, not so much top end this time although I seem to remember about another 1 MPH or so, but really broadened the powerband and made it more responsive up thru the RPM range and also eliminated the use of water injection in the pipes which was a real pain in the butt and had caused many problems that were fully explained in another thread on BRF.

This same time frame, he passed on the information to Kay Harrison and Kay brought several Yamato's over to his shop just prior to the DePue Nationals. Harry and Kay dissasembled the engines and removed the aluminum plugs that were filling holes in the full circle crank discs in the engines. I never heard how that worked for Kay, or if I did, I don't remember the results, but it certainly worked for me. That engine, with one 25.4 MM Bing carb. and a 13-15 lower unit (not 1-1) set a Kilo record in 1985 at Moorehaven Fl. two way average of almost 91 MPH. We had to run in the canal on the north side of Moorehaven that year for some reason, and the acceleration area to the measured kilo was QUITE a bit shorter than is usual for a Kilo run. The boat was accelerating all the way thru the Kilo and nothing was in the water but the lower half of a three blade prop with the boat gently walking back and forth from sponson to sponson and daylight being seen all the way under and thru the bottom. Since the boat was still accelerating when exiting the Kilo, and the speed attained is calculated from the elapsed time you enter until you leave the kilo, I have no idea what the actual terminal speed reached was, but if I had to guess I would say between 95-100. This in no way takes away from Gary Walin's accomplishment with his B Hydro straightaway record in excess of 100 MPH but I think it stands as quite an accomplishment with only one, 1 inch diameter carb. It is probably the record I am most proud of, as it was set with a purely competition boat/motor setup.

The main reason I wanted to post this story was to point out one of the things that made Harry ZAK the innovator he was. He was never afraid to buck the conventional wisdom and try something different, even if it went against the commonly held knowledge regards motors at that time.

I have really enjoyed your posts, as the Anzani was one of the engines that the boat racers of my generation grew up around. I never owned one, or was even privy to seeing one apart, but your posts have answered a lot of questions I have had for a long time.

Thanks Again and I look forward to more information of this kind from you.

John (Taylor) Gabrowski · 10-21-2007

Like many I only saw Yamato 80s running as 20SSs Stock Outboards back in the later 1970s. They were one of the cheapest engines of that era ever brought into racing and left quite an impression of reliability with people that raced them and people like me that saw them raced. I never saw one apart ever. What everyone seemed to know is that they were loop engines of near 30 cubic inches and some expressed some designs to make them go faster we were beginning to hear about back then being the RB class. Adding a pipe and a Yamato nose cone gearcase like the Yamato 250, 350 and 500 alky engines and a racing pipe was the last I heard they eventually did. I was unaware of the carb restriction that was not really unlike the 26 millemeter carb bores found on stock gasoline burning Anzani engines set up from the factory stock racing until Tenney, Hallum, Anderson and others bored the tar out of those carb holes putting them in cases to 40+ millimeters making internal casting walls paper thing doing so stretching the limit in the size of carb sleeve you could macine and fit the Vacturi carb to make it go.

It is amazing that the Yamato 80 RB went as fast as it did but clearly the engineering was already part of it and had to be fine tuned to go the rest of the way you did. The 10,000 plus rpm the RB Yamato is something Anzanis and Harrisons were hard pressed to keep up to until that new generation of heavy duty Harrison developed crankshaft came around to give the reliablilty the earlier generations of Anzani cranks could not.

I too see little in terms of attempts to balance Anzani crankshafts, rods and even pistons nor the later Harrison crankshaft themselves but look under a flywheel of both Anzani or Harrison and its all there as that is what they went after to get it all to spin smoother. Numerous and assorted bore holes strategically put to achieve balance through that flywheel.

When it came to crankcase plugging to reduce crankcase volumes it was done to Anzani crankshafts with a lite weight solid material glued into place in 4 holes on each side of the cranshaft per crankcase half. There were 8 such pluggingings on Anzani plus the rotary valve surroud tunnel that that was not in and had no effect on ecah side of the 2 crankcase volumes. With the Harrison later generation of crankshaft there was no plugging but the crankshaft became full circle in every respect where with the Anzani it was just the center section that was full circle with the outside crankarms very much like a Merc or OMC. There was a lot of debate, trial and error as to what ideal crankcase volume came to be. With the advent of bouce pipes as early expansion chambers were called crankcase volumes were again very much the question because the change was so profound it became a whole new ball game in comparisons to engines still using megaphone open pipes. They were different like night and day by all accounts with movement to expansion chamber exhausts they looked at increasing crankcase volumes not unlike what you did with the Yamato 80 RB getting excellent results.

Anzani never got into reed valves the way Yamato 80 RBs did. When Hallum and Anderson added Tillotson HL carbs to each crankcase half section they mounted them on McCulloch chainsaw reed valve bodies and used progressive cam throttle connections that led to the Tillotsons opening first to where the piston port and rotary valve feeding Vacturi carb came on stream last to provide the breathing that brought the Anzanis into the 100+ miles per hour bracket setting the records back them. I asked Jim Hallum recently why with all the problems that the Vacturi was capable off on that kind of setup why was the Vacturi not subjected to sitting on top of some kind of surface reed valve box to change the nature of the engine's breathing and tunning to get there. Apparently it was because they had not developed to that point and it worked fine in progression with as many was 3 more Tillotson HL carbs coming on stream first before the Vacturi. It the Vacturi was like putting icing on the cake of that engine breathing to full potential. So it remains amazing that it took massive carburation (up to 4 carbs (3-HLs and 1 Vacturi) to get the 322cc Anzani to set their records and more amazing still that you almost the same speeds with a larger displacement Yamato 80 RB engine and such a tiny single carb all by its lonesome self. It would have been interesting to see what putting some 36 to 40 millmeter carb on your Yamato 80 RB could have done coupled to having the restrictions taken off the reed valve induction too to go with that all out unrestricted racing effort? Had anyone gone that far since your effort and if so what was the result?

It is interesting how 2 different engines engineered for gasoline racing went so far to setting records when set to methanol and modified accordingly to use it in Alky racing.

**Bill Van Steenwyk** · 10-22-2007

John:

The model 80 which was the first yamato imported to my knowledge in the mid 70's for racing, was a 20cubic inch motor, so it was basically the same displacement as the Anzani's. The later versions of the Yamato, 102, 202, 302, were of slightly larger displacement, about 400CC or 24 cubic inches displacement. I believe the Model 80 was 326 or 327CC displacement in stock form, so not as large as you are thinking.

Again, your posts have been very interesting and informative. Thanks again for posting the pictures etc., that provide information I had never thought I would be privy to.

John (Taylor) Gabrowski · 10-22-2007

I was not aware the engine was only 20 cubic inches as somehow I was told it was more or near 30 and that stuck in my cranium until now. Then at Yamato 80 RB's 350CCs being about 20 cubic inches to the Anzanis 322cc being less going that fast with a Yamato Y80 RB with the carb size restriction was really hauling as a RB! I don't think you mentioned what the Yamato's compression was raised to for methanol fuels use or the method to raise the compression itself like a higher piston dome, revised combustion chambers or shaved heads or a combination of all those or some and some?

When I heard that the Yamato 102s, 202s and 302s were about 24 cubic inches I thought the Yamatos had dropped from the Y80s displacement that was locked in my head. I can remember Y80s were selling for some $400 to $500 USD$ back then and were considered a bullet proof heavy duty engine with a gearcase like a golf club. Most never thought them though some considered them a replacement for Merc's 20H Popper, but they were classed 20SS anyhow and slower than 20H at the time when they mixed them up at different races. I have never seen an RB run but heard they were quick.

**Bill Van Steenwyk** · 10-22-2007

John:

The stock bore and stroke model 80 as mentioned in the previous post was 326-327 CC short of even the 350 CC upper limit displacement for a "B" PRO motor. Right before ZAK passed away he built up a stroked model 80 crank using special crank pins he had made by a friend of his. He had two sets made so we would have a spare. I still have the spare crank pins. This gave one of the two RB engines I had a full 350CC of displacement and we hoped would allow us to compete better with the 350CC Quincy Z motor which at the time was becoming the dominant motor in the class, for several different reasons which I will not go into now. Along with the increase in stroke (we had to take this road to get to the 350CC displacement allowed because larger oversize pistons were not available) the stroker crank required a new set of sleeves be manufactured/ported and installed, because the porting in the sleeves in the engine at that time would not be proper with the longer stroke. Upon completion of this modification, the engine had gobs more low end torque but tended to stick pistons when the pipe was pulled up. Harry had a new pipe drawn up, but about that time was diagnosed with a brain tumor (early 90's) and he basically was not able to do any motor work for the last year of his life, so that project really never came to its full potential.

Regards the heads/compression ratio for methonal: I think it was in the neighborhood of 15-16 to one or at least that is what comes to mind. The head was completely remanufactured using a stock 14MM model 80 head that had the existing combustion chamber cut out, a new aluminum "plug" welded in, and then remachined for what Harry wanted. So a little old, a little new.

Regards the speed difference between a stock model 80 and a 20H: I owned a 20H in the mid 50's (merc remanufactured and sold by a merc dealer) but I only ran it once or twice stock, then it went on alky and a lot of quincy mods for NOA racing in Arkansas where I lived at the time. NOA called it Division 1 racing I believe, Could be wrong about that as it was a long time ago. The mercs were just coming on and we ran against a lot of Johnson KR's i believe the B motor was. Seems to me it ran stock in the 55-60MPH range, and a good Model 80 like they still run today in APBA stock is I believe faster than that. How much is due to more modern boat/propellor design I don't know. I would think the model 80 club foot would not be as hydrodynamically efficient as a quickie, although maybe the gear ratio in the model 80 unit would be easier to prop out.

John (Taylor) Gabrowski · 10-23-2007

Its pretty interesting how these Yamato 80s made their apprearance seemed like the westcoast first then spreading east in the USA. As far as I know there were only a couple ever sold in the Alberta (Calgary & Edmonton) area amd at the time they were about $500.00 as they mixed a lot with the Montana and Washington state racers and they turned up at races as the 20SS stocks. Here right dead center of North America on the Red River not a single Yamato 80 has ever been seen. Only in the 1990s did anyone see a Yamato of any sort being the 350cc and 500cc 4 cylinder Alkys. They were fast! Some thought them Konigs because of the close appearance until they got a close look and asked. Did Yamato try to copy the Konig design at first? The Japanese were always great at copying good things.