Where are the Domiracers now???

I have been told, but never seen, that Sonny Angel of Sonny Angel Motorcycles in National City California has one of the original Daytona 88 units.

Domiracers interested me since I heard about the Thalhammer Domiracer years ago, and was offered the rolling chassis of that bike, but with a Manx engine in it. I met Rudi Thalhammer last summer and he confirms he got a Domiracer engine off Doug Hele and installed it in the chassis of his Manx. He rode it for a while but he had component failure in the engine- I can't remember now what it was- tried to repair it but it blew up again.

The Thalhammer engine was sold later, I believe with the bike, but since got lost. The buyer did probably not understand its importance and rarity.

Thalhammer and Paul Dunstall confirm not a single part of the works engine was identical to standart production, all castings different, valve gear different, head different, ditto crankcase and crank, slipper pistons running in a special alloy barrel which had Elnisil coated bores (done by Mahle in Germany for Norton at the time).

I also had an exchange of e-mails with Paul Dunstall recently, when we were seeking his authorisation for Andover Norton to reprint his book "Norton Tuning". Paul got all the ex-factory Domiracer leftovers out of the race department in Bracebridge Street. He was bit lost, he admits, having gotten a mass of material without knowing anything about the background. Were some of the components tested? Were they rejected for some reason? What was the idea behind some of them?

He seems to have had no means to contact Doug Hele- or perhaps Doug Hele wasn't interested at the time, having moved on to Triumph- so Paul probably did not do as much with the material as he could have done, being without access to the background information.

Paul also says he binned all his motorcycle stuff when he retired from the motorcycle business, so asked me to mail him a drawing of the Domiracer engine which I found on the net.

Somewhere near Salzburg in Austria some collector may have a peculiar Dominator engine and no idea what it is.............

Previously wrote:

Here is a link to the photo of Heinz Kegler's 1962 Works "Daytona" Domiracer twin:

http://img208.imageshack.us/img208/3721/keglerdomiright.jpg

This bike had the 1.6" rod journals, the needle bearing cam and timing gears, bucket cam followers etc. but it used an iron cylinder. This is a recent photo of it, it is race-ready. Heinz tuned it and preserved it for the last 48 years!

The 1.6" crank was broke, but Heinz found that the standard 1.5" crank was just as good or better if it was used with steel Carrillo rods. I would like to see a real Domiracer turn up someday, but the Kegler bike may be the last bucket-follower works twin left intact.....

Here is it's spare valvetrain:

http://img213.imageshack.us/img213/7809/valvetrain1.jpg

And a close up of one of the special bucket cam followers:

http://img94.imageshack.us/img94/1010/valvetrain2.jpg

Benjamin,

I have a Kegler clutch in my Manxman, I expect you are familiar with his clutch modifcation. was that developed for the racer?

Regards

Steven Phelps

Previously wrote:

In the clutches that Kegler modified for customers he put an angle on the part of the clutch basket which the clutch plates would bear on under torque. This angle screwed the plates together giving the clutch a servo action so that less spring pressure was needed for the clutch to do it's job, and in turn much less pressure was needed on the clutch lever.

The clutches that the Norton factory tested had the angle in the clutch hub though, which was much more expensive to do than modifying the clutch basket. Kegler told me that he had three of these servo clutches that the factory tested and decided against implementing in production, thinking they were too much expense!

When the factory did not want the special clutch hubs anymore, Kegler "liberated" them and used them in his Daytona 88 racer. In Kegler's personal notebook, he writes that if the experimental DOHC 750 Norton twin would have made it to production, then it was supposed to have the servo clutch. Kegler was the one who tested the DOHC twin for Berliner. Since Berliner was the largest distributor for Nortons in the world, if he did not buy any, none would be built. Kegler tested the DOHC twin, deemed it a piece of junk as it broke down on every single test ride it was ever taken on, so Berliner told the Norton company it was a no-go. So if anyone is wondering why that neat looking DOHC Norton twin never made it into production, it was because it was tested and found not to be a good design at all.....

Thank you for answering that. I spoke briefly to Heinz when he wasmodifying my clutch, the swingarm brackets he made and some questions i had about the Laycock overdrive in my triumph. we 've lost a lot of information with his passing and a great individual to know.

The clutchis a very nice and thorough modification. he also sent me sketches and notes as to how it was accomplished

Regards,

Steven Phelps

Previously wrote:

In the clutches that Kegler modified for customers he put an angle on the part of the clutch basket which the clutch plates would bear on under torque. This angle screwed the plates together giving the clutch a servo action so that less spring pressure was needed for the clutch to do it's job, and in turn much less pressure was needed on the clutch lever.

The clutches that the Norton factory tested had the angle in the clutch hub though, which was much more expensive to do than modifying the clutch basket. Kegler told me that he had three of these servo clutches that the factory tested and decided against implementing in production, thinking they were too much expense!

When the factory did not want the special clutch hubs anymore, Kegler "liberated" them and used them in his Daytona 88 racer. In Kegler's personal notebook, he writes that if the experimental DOHC 750 Norton twin would have made it to production, then it was supposed to have the servo clutch. Kegler was the one who tested the DOHC twin for Berliner. Since Berliner was the largest distributor for Nortons in the world, if he did not buy any, none would be built. Kegler tested the DOHC twin, deemed it a piece of junk as it broke down on every single test ride it was ever taken on, so Berliner told the Norton company it was a no-go. So if anyone is wondering why that neat looking DOHC Norton twin never made it into production, it was because it was tested and found not to be a good design at all.....

Hello Benjamin, Years ago I did hear of a Norton dohc 800 twin built in Germany. It had twobevel drive shafts going through the push-rod tunnels to a re-designed cylinder head. The bevel drives meshed with a shaft in the camshaft housing with a beveled gear and small counter weights on it. What became of the engine is mystery? I have a Early Norton Manxman 650 and I am looking for a piar of mufflers for it if you may know of someone who has some for sale Yours Anna J Dixonannajeannette@btinternet.com 01430 430831

THE BIKE

11.00 am Friday June 16th1961 Isle of Man senior TT rider number 8 Tom Phillis pushed off the DougHele experimental 500cc Norton DomiRacer.

At the completion of the 6 laps the DomiRacer came home in 3rdplace in doing so became the first twincylinder motorcycle to lap the TT circuit at over 100 mph.

My DomiRacer is not an original when Norton moved from Birmingham to London the DomiRacer project was scrapped Doug Hele moved on to achieve more glory with the BSA Rocket 3, allowing Paul Dunstall to purchased the DomiRacer bikes and spares. The 500 never took off as a serious challenger to the Manx and G50âs and faded into history.

In the late 60âs I decided to keep the legend alive. My DomiRacer is as close to the 1961 machine as you can get the only part I have been unable to find is the trick cylinder head.

Previously wrote:

That is cool George. Maybe if you get a chance you could throw up some links to photos of your bike.

Does your bike have the large-journal crankshaft, 2mtt magneto and bucket tappets in the engine?

I am corresponding now with a gentleman who claims to know the whereabouts of the original Phillis Domiracer and it's engine and is negotiating to get possession of it, we will see what happens with that!

Hi Benjamin, My engine is one of the short strokes with a one piece billet crank, with the special light weight con rods, and titanium push rods.

I will let you know more along with some photographs.

In my quest to find a complete works DomiRacer I have been on many adventures and have been shown many so called ex works machines but all turned out to be fakes. Iwastold a few years agothat there is a machine with a works engineand lowboy frame in a private collection in Japanit was on offer for £24000 + shipping costs the only way to confirm the providence was to go out there but there was not enough info forthcoming to justify traveling halfway round the world.

I wish your gentleman friend good hunting.

I have what i thinkmay be an ex works 650 bottom half that may have come from the Norton factory at Bracebridge Street. It came from Reg Dreadon as a friend of mine bought it back in the late 1970's, and then passed it on to me when he did not ride British bikes any more. It has no crankcase numbers, the drive side part of the crankshaft that would haveheld the alternator has been machined off. The camshaft bearings are fitted with needle roller bearingsand there is a screw hole, in the end of the crankcasefor an oil feed direct into the camshaft to oil the needle roller bearings. This is where a breather was fitted to the Norton Atlas motor. Ithas been in thebottom of one of my wardrobes for years. It may or may not be an ex factory engine, but is looks a bit trick.

The camshaft is still in my 650 engine's bottom half, and the cam that came with it looks just like the one in the picture. It also has oil holes in the same place as the picture that was posted. It has a number stamped just where the breather is,or i suspect the engine shop number. It only has three holes drilled on the drive side crankcaserather than the normal six. This may have been foran engine and clutch chain cover. The breather hole at the back of the crankcase that is used on the pre Atlas engines has been blocked off. The bottom half looks like it had a different breather arrangement, and it could have used the inlet or exhaust rocker covers to breath out of. It is different and i never gave it that much thought, but i suspected it may have been a Norton ex works 650 race engine.

Previously wrote:

I would be interested to know what the numbers are on the cases, and it would also be nice to see some photos of it. I have a lot of sets of early 650 cases, including a bike with engine shop #2 in it. I would like to compare yours to these.

The Hele works racing twins had the cams like you are talking about, but Dunstall sold them also. Often Dunstall's were marked with the model number he used for the cam grind. I wonder if he got hold of the vendor that supplied Doug Hele and had them make them for him too. Turning out a cam like that with holes drilled in hardened lobes was pretty unique.

The Bracebridge Street 650 Nortons from 1962 and earlier had a special breather on the intake rocker cover that was quickly discontinued after those works were shut down at the end of 1962. This breather is listed for some of the other Norton twins, but I have not seen any old original 500 or 600cc bikes with the feature. Of course it was a lot of small bits that were easily lost over time.

I have seen first hand three old 500cc racing twins here in the USA with the pressure oil feed to the cam end, I am pretty sure one had it added later. I have some old drawings that show how to machine cases for this feature.

My personal email is sportspecial@hotmail.com if you want to correspond and trade information on the early 650 Nortons etc..

Hello Ben I know a very nice man is Sweden that as two Domiracers one a 500cc the other is a Manxman rebuilt for the Swedish GP witch it won . The engine number is 18-95058 .so its only 11 machine earlier than the one I own and it as the inlet breather system and now the correct silencers to and this was down the the Very Nice man in Sweden .And He as his Own little Museum of Norton Motorcycles 15 in all two of the Manxmans and a late 62 Polychromatic blue 650ss and it as a two tone tank been blue and dove grey just like his ES2 in Red and dove grey . there very nice colours that knock your eyes out . But back too the Domiracers The Manxman is In Black and alloy tank and oil tank short race seat .GP carbs 9" 4 LSB wheel hub .its fitted in a low boy frame two but with the top tubes at the back of the tank pressed in like the slim line frame but look much like a low boy frame with modification to it . yours AJD

The barrell studs that are left in the crankcases that i have, are of the small thinlongtype nut that are standard at the front of all Norton twins, that hold the barrell to the crankcase. They are all of them this size, so this engine may have had a different barrel to the standard Norton type, or even an alloy barrel. The camshaft dores not have any numbers on it, and it is just a plain camshaft. There are some numbers stamped inside the crankcases, inside the timing chest. The oil feed holes in the crankcases are also of the later largerdimensions.

Previously wrote:

The barrell studs that are left in the crankcases that i have, are of the small thinlongtype nut that are standard at the front of all Norton twins, that hold the barrell to the crankcase. They are all of them this size, so this engine may have had a different barrel to the standard Norton type, or even an alloy barrel. The camshaft dores not have any numbers on it, and it is just a plain camshaft. There are some numbers stamped inside the crankcases, inside the timing chest. The oil feed holes in the crankcases are also of the later largerdimensions.

Anthony, that 650 sounds as if it might be the bottom half of my 650 "domiracer" that I used late 60's early 70's before I took over the Corbett/Dunstall. It had come to me from Roger Corbett who was associated with Paul Dunstall.However ithad a needle roller Dunstall cam, the breather you describe and the crank and rods were mirror polished. It ran on a Lucas/Wader racing magneto. Top end has special valves (Dunstall?) and titanium valve springs caps.

On another interesting note for all you who have been following the Norton Domiracer storey above, I have somewhere one of the original 1.6" factory 500 cranks, that came to me from Roger Corbett,via Dunstall, presumablyfrom the Norton factory. I always intended to use it in a 500 motor for the IOM but had no rods, and in those days that was a major stumbling block. Also I had no other parts for the engine except some elliptical rocker adjusters to allow for external tappit adjustment and presumably lighter rocker arms. I do have some original experimental Dunstall cams, but have no idea for which engine they were produced.

Ginger Blayney

Previously wrote:

The camshaft is still in my 650 engine's bottom half, and the cam that came with it looks just like the one in the picture. It also has oil holes in the same place as the picture that was posted. It has a number stamped just where the breather is,or i suspect the engine shop number. It only has three holes drilled on the drive side crankcaserather than the normal six. This may have been foran engine and clutch chain cover. The breather hole at the back of the crankcase that is used on the pre Atlas engines has been blocked off. The bottom half looks like it had a different breather arrangement, and it could have used the inlet or exhaust rocker covers to breath out of. It is different and i never gave it that much thought, but i suspected it may have been a Norton ex works 650 race engine.

The breather arrangement we used when there was a cam end feed to needle race camshafts was a one that I believe came off G50 Matchless racer. It was a spring loaded plastic disc inside a hex body with a threaded stem. The drive side end of the crankshaft taking the engine sprocket was drilled through and threaded. This breather was then used as a large "bolt" for want of a better word to retain the engine sprocket. It was a very efficient system. The spring loaded disc worked only in one direction, letting out any and all crancase pressure. The hole being at the very centrifugal centre of the crankshaft meant the there was no possibility of oil coming out of the breather.

I still have one on my 750 Dunstall Spine Frame which I can photograph some time if people are interested.

Reading some of the other messages above, I realise I also have a set of the bucket cam followers, with an alloy 750 Dunstall barrel that Roger Corbett blew up in practice on the spine frame bike in the IOM. I guess they also came from the Norton factory via Dunstall. I didn't realise that they fitted them to the works Domi's, though I guess they are the same size 500cc through to 750cc. I hope to try and repair the barrels this year and refit it to the bike and may include the bucket followers as well.

Well a sort of gosh moment that some one on the forum may have actually raced that engine. There arenumbers stamped inside the crankcase and inside the timing chest. The numbers stamped inside the crankcase is 11T, and this number is also stamped inside the timing side inner near the top with a 6.0 also stamped but the stampings are different. On the back of the case where the breather has been blocked off is stamped 1853, and that is it. I have had this motor for over 30 years, and never really knew what it was, so it is nice to hear from some who may have actually raced it. The crankshaft that came with it is not polished, but is of 650 configuration, but with the alternator part machined off. The camshaft asi explained earlier does not have any numbers stamped on it, but it does seem as it has been run, as it has some wear marks on it.

Yes, but you will have to give me a chance to go through a couple of garages of spares and parts to put my hands on them.

Unfortunately in the old days when I raced, they were just "old parts" and at the time of no great use, though I always knew that they were interesting, so they will have been on one of the back shelves for over 30 years. I can readily find the bucket followers so will start there.

Benjamin,

I apologise I only took your stated dimension for the crank journals. I can only remember them as being noticeably oversized for a 500. I seem to remember thinking at the time that they would probably have used the journal and big end shellsof the 600, though I had no evidence for this and my memory is pretty hazy after 40 years. I just hope I can put my hands on it. I know I had it, and I know I never got rid of it and have mentioned it to people over the years. Unfortunately I have built up quite a collection of cranks over the years. It came with a pile of Norton bits from Roger Corbett, when I bought the damaged spine frame Dunstall from him. Some of these parts had also definitely come from Dunstall, but Roger also may had some connection with the Norton factory. He told me that the spine frame he used was an unused spare one from Dunstall, although the forks and front wheel were from one of the racers, I believe the one in the Roy Bacon book. However he told me that the manx rear wheel he used was from the last batch of 25 made by the factory. Now, did he get that from the factory or from Dunstall? You are right in saying that the man to solve a lot of these riddles is Paul Dunstall himself!

Previously wrote:

An engine shop number of 1853 would be right in the ballpark for a Norton 650 engine built in the summer of 1962. I have a bit earlier 650ss with a shop number of 13xx and have seen a guy in Australia mention an engine shop number in the low 2000s for his 650ss dispatched in September.

Dunstall does show that G50 breather mod in his tuning manual. How very nice that someone has possibly been reunited with some of their old racing parts.

I'm probably the guy in Australia that Mr Gradler is referring to. My 650SS has shop number 2001. Build date, according to NOC records, was 19 September 1962.

Cheers

Previously wrote:

Well Nigel, Heinz Kegler did specifically state 1.6", but after 1963 all those special parts were either used up or blown sky-high so it has been a long time since anyone has seen any around here. Kegler said the rods that came with the race bikes were special to fit the big crank journal, but they were still aluminum and did not hold up well to the abuse of the American riders and tracks.

Kegler then used the strong 88ss style cranks(small sludge trap) along with steel Carrillo rods, which he helped develop by sending Carrillo some factory drawings to work with, and also they had Mahle make forged copies of Hepolite pistons. This combination worked very well as despite running in some long fast races such as Daytona different years and 6th in the 67'Canadian GP, they never broke another crank in the classic era. It was only much later, during a vintage event in the early 80's that Kegler finally had a rod journal crack all the way through, but the steel Carrillo rod held the crank together until he shut the engine down and caused no other damage!

Previously wrote:

Well Nigel, Heinz Kegler did specifically state 1.6", but after 1963 all those special parts were either used up or blown sky-high so it has been a long time since anyone has seen any around here. Kegler said the rods that came with the race bikes were special to fit the big crank journal, but they were still aluminum and did not hold up well to the abuse of the American riders and tracks.

Kegler then used the strong 88ss style cranks(small sludge trap) along with steel Carrillo rods, which he helped develop by sending Carrillo some factory drawings to work with, and also they had Mahle make forged copies of Hepolite pistons. This combination worked very well as despite running in some long fast races such as Daytona different years and 6th in the 67'Canadian GP, they never broke another crank in the classic era. It was only much later, during a vintage event in the early 80's that Kegler finally had a rod journal crack all the way through, but the steel Carrillo rod held the crank together until he shut the engine down and caused no other damage!

Hi Benjamin,

I used to use an 88ss crank(stamped SS if I remember right)in my 500 "Domiracer" but broke it across the drive side journal at a race at Thruxton. Unfortunately on standard ally conrods. Again I still have the bits somewhere including the downdraught 500 head. I know that the other (works?) crank was bigger because I couldn't use it (no rods)and so went to the 650 motor I mentioned earlier. I even contemplated machining the 500 crank down to take standard rods, but even in those days I realised it was special enough for that to be an act of vandalism.

I'm sure it's in there somewhere, though I dread to think what state it is in.

We used to use Italian GPM pistons, because they did an amazingly light 500 pair. However I did manage to burn a hole through the crown of one of them!

Norton sold all the race shop Domiracer bits to Reg Dearden and Paul Dunstall. Dunstall has written describing how he turned up at Bracebridge Street in a van to be given so many parts the van could barely move. I have a MCN advert placed by Paul Dunstall in late 1971 or early 1972 advertising and itemising the parts he had for sale. I will dig it out and scan when I can.

Previously wrote:

Mr. Blayney, what are the chances of viewing some photographs of the 1.6" journal 88 crankshaft and the elliptical rocker adjusters?

Hi Benjamin

I have now dug out the factory 500 crank with the oversize 1.6mm (i've miked it at 1.599) journals. I knew it was in there somewhere.

Sorry but it is a bit rusty, but I will take some photo's if you are still interested and post them on here for you.

At least you now know that one has survived!

Haven't come across the elliptical rocker adjusters, they are there somewhere, but also have a very interesting 500 barrels that have needle roller mounted "fingers" that ride on the cam instead of cam followers.

This also came from either the factory, Paul Dunstall or Roger Corbett or possibly all 3!

I'll photograph it as well.

Ginger Blayney

Previously wrote:

Well thanks for the trouble Nigel. Of course it would be interesting to see photographs of the parts. This website and it's features do not always work for me, so I would not mind a copy of whatever photos you come up with being sent to my regular email address, sportspecial@hotmail.com.

It would be interesting to compare them to a late 88ss crank, and see if all they did to make the cranks for the production racers was to not machine it down so far. Norton being such a small company it seems they always did things as cheaply as possible, especially after AMC had hold of their purse-strings.

Dunstall talked about the works-style Domiracer cranks having 1.75" rod journals, and until one pops up out of someone's stash for us to inspect I guess we will not know how those were made, machined from an existing forging or custom machined.

Kegler said the 1.6" cranks had matching special rods, but they were all alloy just like the street Dominator and he said they did not last, from what I can gather after two years they were all used up and Kegler being the practical man did not save any old blown engine parts for us to look at 50 years later. Again keeping Norton's very limited budget in mind, I wonder what was made from various production parts and what was completely custom, we may never know.

Previously wrote:

Sonny Angel has/had one of the Norton model 88s that were built by Paul Dunstall and Francis Beart for the 1964 Daytona race. In that race Frank Scurria, Ronnie Rall and Ken Hayes rode these three bikes.

I closely examined one of these bikes and talked at length with Frank Scurria and Kenny Hayes about the bikes. They were NOT Domiracers. First they were put together two years after the original Norton works and race department was closed, and again they were mostly the work of Dunstall . Norton had Dunstall put them together at the request of the American Norton distributor Berliner Corporation. The engines had Dunstall needle bearing cam conversions but none of the Domiracer parts and the gearboxes were standard wide-ratio units. For the Daytona race Kenny Hayes had to install his own personal close-ratio gearset so his rear wheel would not lock up going into slow turns!

Sonny Angel has Scurria's old bike, or what is left of it. He or his offspring recently tried to get rid of it on ebay and as far as I know there were no takers as it's reserve was too high and it was rusty and missing parts.

Dunstall also came over to Daytona in 64' with two of his own Dunstall Dominators to race at Daytona that were in addition to the three shipped to Berliner Corporation.

The Daytona Domiracers for the spring 1962 Daytona race WERE genuine works builds though, they had the 1.6" rod journal crank, hollow needle bearing cam with holes in it to feed oil to the shortened and hollow bucket tappets, also close ratio gearboxes and a chassis that was all Manx style parts except for the use of a slimline roadster style frame to suit AMA rules which demanded a "road bike".

Kenny Hayes also had rides on one of the works 1962 Daytona Domiracers and he said that it was faster and better all around for racing than the 1964 bike of Dunstall.

The first Domiracers had the lowboy frame, but later ones used a standard Manx chassis, and besides the slimline ones for Daytona, a couple of Manx-framed bikes were built with tuned 650cc roadster engines also.

Hello Dunstall story in the Classic bike this month says that when Paul Dunstall went the Bracebridge street Experimental work shop He found a number of Short stroke twins in airspace alloys and Not one nut bolt or screw would fit a production machine , there were crankshafts with 1.75 journals for short stroke 500cc twins and 600twin a 650 twin short stroke motors and he found 600cc Nomad motor with 1.75 journals , and two BRM DOHC liquid cooled 4 cylinder experimental motors along with 2 single cylinder 125cc Dohc motors and there wooden patents, He filled two Ford Thames vans with the experimental part and three race bikes in bits and he had a tailer for the frames etc what happen to this lot we will never know , Paul said there was stuff all over the place it was heart breaking too see ,

OK Finally as promised, pictures of the works Norton 1.6 crank and what looks like an experimental works barrel.

The crank has small internal oilway and has been left oversize at 1.6" on the external of the journal. The drive web has been machined back for drive sprocket.

It looks to me that they have adapted castings, to build a stronger crank, rather than build a completely new crank, which is exactly what I would have expected, given the state of Norton's finances, and that the race dept. was being run down.

The barrel equally looks like an original item that has been modified. The aluminium mounting block with needle rollers for the "flippers" may be an idea borrowed from AMC and would just have needed longer push rods. The whole tappet tunnel has been machined away into the barrel, possibly for pushrod clearance.The whole flipper designtakes some of it's heritage from overhead cam design, again quite likely from a factory that had concentrated on overhead cam engines.

The barrel top also gives a hint of the valve size/angle of the associated cylinder headas you can see where the barrel lip itself has been recessed to allow clearance for both inlet and exhaust valves. I thank Benjamin Cradler for his confirmation of these cutaways on the works barrels.

Sorry about the state of the barrel. It's as is, when unearthed from the depths of my spares garage.

Not pretty, or earth shattering, but at least there is now one 1.6 factory crank known to be in existence, and also an interesting factory barrel.

My next job is to try and unearth the eccentric rocker spindles and the bucket cams that I know are in there somewhere.

I hope the attached pics work.

Ginger Blayney

More photos

more photos

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more...are too large. Will resize.

Does anyone know how to get on more than one pic at a time?

Tony

Ken White has a collection of Domiracer 500cc engine parts and may be worth chatting to, as he was a first-hand spectator, in the Norton pits, during the 1961 Isle of Man Races.

He hasa crankshaft with 1.6" journals and says that big-end shells from an AMC engine (G45?) will fit them. He is having a set of conrods specially made as, apparently, originals are imitating 'hen's teeth'. He showed me thetiming gears for his engine. They are seriously lightened by drilling and slimming. See attachment for sample.

Paul Dunstall sold alloy barrel conversion kits for the 750cc engines either to make a 750cc or 810cc size motor. These included sets of slimmer crankcase studs to take smaller nuts. These were needed because the barrel castings were wider than the standard steelbarrels.

In the very early 70sI attended several Norton bike gatherings where owners had used similar alloy barrel conversions on their 650 engines. Some being stamped with 810 on the crankcases. (possibly doneby theDunstall workshop?) To fit the alloy barrels to the 650 engines the tops of the crankcase mouths needed to be opened a little in order to allow the sleeves to fit inside. I can not recall what happened to the breather arrangment but this must have been affected.