Dommy rods

Years ago I asked Les Emery if it could be done. Apparently it can with some machining. Later 99 cases have a bulge at the back to make room for the longer throw crank. Funnily enough I discovered that my spare crakcases have that very bulge. I got round the fragility of 99 engines by putting an Atlas engine in mine. Having the option to fit new AN650/Atlas rods is very appealing, particularly in view of my small but expensive collection of broken 99 rods.

Gordon you must be very unlucky or doing something wrong. I have ridden and raced various 99 engines for 40 years and never had a rod let go. Pistons, main bearings, camshaft followers and pushrods...yes!!! But no conrods.

Robert might want to consider a set of Carillo conrods for his special. These are a bit pricey but will allow him to use his 650 crankshaft inside the older 99 crankcases. They don't have the high shoulder that the standard 650/750 Norton conrods have that catch on the cases.

The word of warning .........if using old 99 barrels for the job then make certain that are bored/honed along the whole depth otherwise you will find a nasty wear ridge near the bottom just waiting to snap off a piston skirt.

I suspect it was a matter of fatigue life - I have raced the 99 and I was in the habit of cruising for hours on end above 6,000 rpm. The RAF had a habit of posting you hundreds of miles away from your family and only giving you very short weekends - 12:00 on Sat until 22:00 on Sun and 700 miles to cover. The rod failures were usually when I was being sensible - trundling along at 75, minding my own business and bang. I did lose two through cracked pistons which holed and allowed the combustion flame to cut through the small end eye. Not really the rods' fault in those cases. It did put me off Hepolites though! I think I am a bit more sympathetic to the engine these days...

Previously Phil Hannam wrote:

Gordon you must be very unlucky or doing something wrong. I have ridden and raced various 99 engines for 40 years and never had a rod let go. Pistons, main bearings, camshaft followers and pushrods...yes!!! But no conrods.

Robert might want to consider a set of Carillo conrods for his special. These are a bit pricey but will allow him to use his 650 crankshaft inside the older 99 crankcases. They don't have the high shoulder that the standard 650/750 Norton conrods have that catch on the cases.

The word of warning .........if using old 99 barrels for the job then make certain that are bored/honed along the whole depth otherwise you will find a nasty wear ridge near the bottom just waiting to snap off a piston skirt.

phil if you use a 650 crank and corrillo rods in standard 99 cases would you still need the cutouts at the base of the barrel spigots? i ve always wondered if the cutouts were for 650 s only?

phil if you use a 650 crank and corrillo rods in standard 99 cases would you still need the cutouts at the base of the barrel spigots? i ve always wondered if the cutouts were for 650 s only?

Hello now you cannot use 99 barrel for 650 there not the same and you end up splitting the barrel if you do standard 99 case have to be numbered after 14-96600 has there the 650 manxman cases fitted to 88 standard and 88ss and 99SS and standard , the 88/99 SS has the 650 Manxman valve train and camshaft , The 650 Manxman came out well before any 650SS they where built from November 7th 1960 the 88/99SS these were built from April 1961. so anything after April 1961 will have the Manxman Cases and it was the 650 manxman that had the very first down draft cylinder head with parallel twin ports the 650 as shorter rods but has a longer stroke 89mm so the spigots are a we bit longer , you need a 650 barrel and these are near impossible to get in our days , origianal pistons were BHB as fitted by Rolls Royce Norton only used the best. its was the AMC cost cutting that did for Norton And before anyone gets on there high horse , about the Norton Manxman 650 let me remind you all with out this machine there would be NO 650SS or 88/99SS OR Atlas Or Commando and any thing in-between . so it played a significant roll in Norton History like it or not, its set in steel

yours anna j

Previously eddie_simpson wrote:

phil if you use a 650 crank and corrillo rods in standard 99 cases would you still need the cutouts at the base of the barrel spigots? i ve always wondered if the cutouts were for 650 s only?

Eddie....you are totally correct. You must have the cut-outs in either barrel if using a 650 crankshaft. Otherwise the rods will make contact. Of interest here...if you check 99 barrels they also have a chamfer at the base of each cylinder to help with rod clearance. The later 750/850 barrels also had slots for the conrods.

Anyone converting a 99 for 650 use must remember to add these slots/cutaways. Also very important is to file a round profile in each of the slot corners to stress relieve and prevent cracking.

Previously Phil Hannam wrote:

Previously eddie_simpson wrote:

phil if you use a 650 crank and corrillo rods in standard 99 cases would you still need the cutouts at the base of the barrel spigots? i ve always wondered if the cutouts were for 650 s only?

Eddie....you are totally correct. You must have the cut-outs in either barrel if using a 650 crankshaft. Otherwise the rods will make contact. Of interest here...if you check 99 barrels they also have a chamfer at the base of each cylinder to help with rod clearance. The later 750/850 barrels also had slots for the conrods.

Anyone converting a 99 for 650 use must remember to add these slots/cutaways. Also very important is to file a round profile in each of the slot corners to stress relieve and prevent cracking.

thanks for reply anna and phil, how much longer are the base spigots on the 650 barrels? i dont have any to compare but i guess i could use longer liners in a 99 barrel.

phil, it sounds as if you have cut out the slots yourself. whats the prefered diy method, saw or grinder? what depth? cast iron is not an easy material to work with for obvious reasons.

regarding the manxman, i always felt the handlebars were a little too high for uk use and would attract too much interest from p.c. plod on his noddy bike.now of course we are more liberal and more open to radical ideas such as flamboyant paintwork , flares and apehangars , so if you want to sell anna?

regards eddie

Previously Phil Hannam wrote:

Previously eddie_simpson wrote:

phil if you use a 650 crank and corrillo rods in standard 99 cases would you still need the cutouts at the base of the barrel spigots? i ve always wondered if the cutouts were for 650 s only?

Eddie....you are totally correct. You must have the cut-outs in either barrel if using a 650 crankshaft. Otherwise the rods will make contact. Of interest here...if you check 99 barrels they also have a chamfer at the base of each cylinder to help with rod clearance. The later 750/850 barrels also had slots for the conrods.

Anyone converting a 99 for 650 use must remember to add these slots/cutaways. Also very important is to file a round profile in each of the slot corners to stress relieve and prevent cracking.

thanks for reply anna and phil, how much longer are the base spigots on the 650 barrels? i dont have any to compare but i guess i could use longer liners in a 99 barrel.

phil, it sounds as if you have cut out the slots yourself. whats the prefered diy method, saw or grinder? what depth? cast iron is not an easy material to work with for obvious reasons.

regarding the manxman, i always felt the handlebars were a little too high for uk use and would attract too much interest from p.c. plod on his noddy bike.now of course we are more liberal and more open to radical ideas such as flamboyant paintwork , flares and apehangars , so if you want to sell anna?

regards eddie

Hello Eddie just as I expected a british atituted on all things Norton , the Norton Manxman's bar's are Not too high for me there just right at 8" inch rise on them and thet give a nice ride and even better control than you think , the Norton Manxman was so designed for the USA a long roads speed limits are 60 mph in most places in US , but they very comfortable to ride in this country to even at 110 mph did not feel any wind or drag on me at all , has you may know I do ride this motorcycle in all weathers even snow, and the famboyant paint work was done so it brigthents up the bike for a selling point and it dose look a lot better then the drab black and silver , and is easy to maintain if you know what doing paint wise, I find this Machine to be one of the Best that Bracebidge street made, and as been very reliable, but just of late with this UK fuel that got some crap out of the petrol pumps that gotten in to the carburettor and block the fillter in the banjo and made the float needel valve not seat right any more , but this will be soon remended , the Norton Manxman was also built with ethaonl in mind , has in the USA they been using it for years , know has Ethol at the pumps, and other owners of the Manxman in the USA also say they love there motorcycle and enjoy riding them, and that my freinds is what it all about, So then I am a very proud owner of something a Bit special that came out of Bracebridge Street workshops , and there extra rare motorcycle and even more bispoke than the Norton Commando 961or the Norton Manx or Internation's And has for selling this machine . now its got my stamp mark on it, and runs like dream before the petrol bug , I would not sell for all gold in the hole world as you cannot buy these anymore there totally a one off motorcycle, So have lots of fun when the sun comes out to play, yours Anna J happy riding

was only pulling your chain regarding your manx man anna. i also experience more blocked jets from modern petrol than i remember with leaded fuel but i guess it could be that the petrol tank and pipes are getting old . however i would still like to know how much longer the 650 barrel spiggot basesare compared to a dommie?

was only pulling your chain regarding your manx man anna. i also experience more blocked jets from modern petrol than i remember with leaded fuel but i guess it could be that the petrol tank and pipes are getting old . however i would still like to know how much longer the 650 barrel spiggot basesare compared to a dommie?

Hello Eddie Well I am Not taking my top end off just to mesure It for you!

Yours Anna J