Has anyone any experience with the Norton racing camfollowers marketed by Norvil Motorcycle company (Fairs Spares, Les Emery). In particular reliabilty, quality of workmanship, experience under race conditions.
The standard followers can fail (stellite pads breaking up) and should not be lightened and therefore a better system is attractive. My priority is 120% reliability not a performance gain. Another option is to fabricate roller followers but this is a lot of work and requires the camshaft to be reground.
My concern with just stumping up the 260 UK pounds is that a 4S camshaft I bought 5 years ago at Fairspares had poor quality workmanship and when measured (brand new) on a cam tester it had significant errors in the base circle, quietening ramps and one inlet lobe was advanced WRT the other. Dynodave reported similar problems. See his camshaft note. (The PW3 camshaft I replaced it with was perfect) I want to make sure these followers are good before I pay up.
I spoke to a supplier to Norvil years ago, the stories he told me have ensured I have never bought from Norvil. Your best bet is to speak to Mick Hemmings, he races Commandos and stars in the NOC DVD's on the Twin and Gearbox rebuilds. No email or website so you will have to dog and bone him, RGM have also given me excellent service over the years.
RGM, spares and service, +44 1946 841517 Mick Hemmings, spares and service, +44 1604 638505
Re: Norton Racing camfollowers#65856 07/19/069:14 pm07/19/069:14 pm
I can second that opinion, I stopped dealing with Norvil years ago after they ripped me off with rubbish parts and refused to even talk about it. Much better to go to Mick Hemmings for quality and good friendly service and advice!
Re: Norton Racing camfollowers#65857 07/24/063:53 am07/24/063:53 am
Thanks for the comments. These followers are a new item and doubt if many have been sold as yet.
Not to be too hard on Norvil they sell to a price and while I have had problems with three items from them I have had several standard type parts which have been fit for purpose. My experience has been that it is the "racing" or one off type stuff which has not been up to race quality. They are not alone in that by any means.
I have bought several items from Mike Hemmings and they have all been good. I dont think he sells any special followers however.
I want to try better followers because many old ones are cracked and some new ones throw the stellite pads off. A very experience Norton guy down here uses crack tested and refaced older followers in preference to new parts.
Re: Norton Racing camfollowers#65858 07/24/0610:29 am07/24/0610:29 am
Re: "they sell to a price". I'll accept that if the difference in quality is visible or called out, on a cosmetic part, an accessory &c. Never on a hard racing part. Think what a bad follower costs: 1. race 2. your time (and skin?) 3. new cam 4. strip entire engine, gaskets, seals, flush oil tank, cooler, lines What's that worth, $1,000? I'll eat week-old bread if needed to afford higher quality racing bits. If that's really 260 pounds for a set of 4, you can have them made cheaper than that. A friend of mine made his own titanium roller lifters (H-D), and is looking for marketable similar bits.
Re: Norton Racing camfollowers#65860 07/24/062:37 pm07/24/062:37 pm
Dont understand all these problems with cam followers . Never had ANY problems with them even when poodling round the Island at 8000 plus rpm on a short stroke(68 x 68) 500 Dommy when the G50 threw a small end in first practice and poor old brand new never even ben tested let alone having the carburation set up 500 Dommy was dragged out just to get a few laps in. Of course I run the cam and followers in a cam shaft oil bath as designed into the original Dominator crankcases By Mr Hopwood to ensure correct cam / follower lubrication which was then from about '60 on removed further and further by the idiots at Norton every time they introduced new editions of crank case till it no longer existed.......OR by us youthful know nothing idiots who read for example Paul Dunstalls book in which it shows a picture of an idiot removing even more of the oil bath so a higher lift usually go slower cam could be fitted. I wonder how many of you have ever considered that most if not 99% of the cam and follower problems are not the result of owners not following correct cam and follower break in procedure????? There wrere certainly a bath of bad followers wher the incorrect method of ataching the stellite to the followers had been used. It probably saved a penny per follower!!!!! Bet an acc'o'untant made the decision to sace that penny!!
Re: Norton Racing camfollowers#65861 07/24/064:08 pm07/24/064:08 pm
OOPS, CORRECTION. The reason for the bad batch of cam followers was simply that the brazing technique required to stick stellite on to cast iron is a tad difficult and the Company that had done them since time began had closed and a new company was used and they got it wrong and no one picked it up till they started to fail.....and even then not all failed......
For all who have not seen it before ....Part of a letter to me from Mr Hopwood dated 21-7-1981 .. 'The camshaft tunnel of the Dominator engine was designed to retain as much oil as possible and in fact collected oil from the flywheel rim......' Run an olde original crankcase Dommy, park it for a decade with the crankcase drain plug out and as soon as the cam is next rotated the lobes will come up coated in oil that has been retained in the camshaft oil bath. TRY THAT ON YOUR COMMANDO !! Another quote. This time from a Piper Cams Book.Page 36. ' Research indicates that most cams that wear out start to fail during the first few moments of operation. We have found that many cams are irrepairably damaged before the engine is started because the basic rules of camshaft break-in have not been followed The cause of premature cam and tappet failure is metal to metal contact between the tappet and cam lobe. Should this contact occur due to lack of proper lubrication or excessive high pressure due to valve train interference shearing the oil film, galling will take place. When galling takes place, metal is transferred from the cam to the tappet or from the tappet to the cam in a process comparable to welding. Small areas of microscopic high spots present on all machined surfaces become overheated due to friction and pressure and bond together tearing sections loose from the tappet or cam lobe. These pieces of metal remain atached to the face of the tappet or the cam lobe and creatr further local overheating during the following revolutions of the camshaft and lead to ultimate failure of the effected cam and tappet. There are a number of mistakes that can lead to ultimate failure. 1. Inadequate lubrication during the initial rotation of the camshaft with full spring load applied. 2. Interference in the valve train due to improper installation and failure to check for interference, spring boxing, and collar to valve guide or piston to valve contact are the main problems.(spring boxing..in our case most probably the use of a high lift cam without setting up the springs to allow for the greater lift resulting in the springs becoming coil bound or applying excessive load to the tappet and cam) 3. Installation of used tappets on a new camshaft. No matter how good tappets look new tappets must be used with a new cam.
The page gives lots of other causes and advice one of course being that when you strip an engine you MUST put the tappets back in the same position they were removed from so the origional tappet and cam lobe relationship is maintained I assume reground (CORRECTLY) followers = new .
NOW DO YOU SEE WHY MR HOPWOOD SO CAREFULLY DESIGNED INTO HIS NORTON TWIN AND BSA TWIN MOTORS CAMSHAFT OIL BATHS?????? Perhaps you will now be thinking that it was only around the time of the Atlas and early Commando introduction that the cam problem became prolific.... It amazes me how some cams last so long before they become round!! Guess todays oils must be more 'clingy'. Incidentally I think that if you were to dig deep in Triumph history you would find that at one time over 30% of all unit 650 motors had the exaust camshaft changed under warrenty.....the inlets were sort of OK because they got most of the oikl being flung off the crank Triumphs' EVENTIUAL solution , after years of being told by several employees, was to nitride them giving a surface hardness of approaching 1000 Vickers. Of course if you drop one and it hits something hard at the wrong point of contact bits can flake off.......I swear I once saw a very old set of 500Triumph twin cases with lumps inside where an oil bath would once of been...... Some Norton specialists replace customers camshaft oil bath.....well one I know does..hopefully he will remember to remove the stress raiser Norton left within the DS crank half of the crank he is sorting out for me sometime. He put the crank between centes. with both big ends at the top they were at the same height..at 90 dergrees ..12 thou difference. Hey ho yet another Norton crank to sort out as usual!!! Quality control at Norton???? Not a chance.!
Re: Norton Racing camfollowers#65862 07/24/065:50 pm07/24/065:50 pm
BDM , the overwhelming majority of cams in other engines than Norton are doing just fine without an oil bath . Surely there must be other , more important reasons for premature cam failure in a Commando ?
Why not check out www.stevemaney.com if you are after top quality race parts...........and he uses standard followers!! Some might say expensive, but then quality is never cheap, and I've never had any of his parts fail, been using them for about 15 years, and I abuse my motors, 8000 rpm on a standard 89mm stroke!
Re: Norton Racing camfollowers#65864 07/24/0611:19 pm07/24/0611:19 pm
I guess it depends upon whether you want a camshaft and followers to last for 100,000 miles use or 10000 miles use if you are lucky. Without the oil bath every time you start your motor you risk damage occuring. With it there is no chance of damage occuring due to incorrect lubrication' Now I personally dont care what people do but they never had the cam failures on pre Commando engines that they did on Commando models and examination of the various crankcases shows the oil bath had ben virtually removed on the first Commandos only being slightly present by the tilting forward of the motor and TOTALLY removed by the time of those crap Combat cases.On the last 820 lumps there was merely a lump of alloy where the oil bath had once been.Mr Hopwood designed motors for reliability. On the Works Domiracer the cams were pressure fed as they were on Geoff Monty and Dudley Wards Monard race bikes etc etc etc And I think you would find that Mr Hele spent a lot of time at Triumph simply trying to sort out cam oil supply via the followers.It changed on an amazing regular basis..... Of course Mr Dunstall who bought up the Norton Domirace bits and pieces including a pile or so of development cams also used needle rollers and positive oil supply for his race bikes. Personally IF the 500 short stroke ex Gus Kuhn/Dave Potter raced crank ever gets built up again and has a tad of development thrown at it the followers will be much lighter BSA ones.If memory serves correctlt the Domiracer ones were bucket ones...std ones with the top bit cut off and longer push rods working in the bottom of the follower Hang on I will check that...Yep the pretty picture shows bucket followers , linger push rods and holes in the cam for lubtication. I nelieve we are going back to chilled iron cams now......Wow full circle.
Re: Norton Racing camfollowers#65865 07/24/0611:29 pm07/24/0611:29 pm
I agree with Panic on race parts . Im prepared to pay what it takes to get reliabilty for race parts. My own skills are only up to roughing out followers which could then be finished by a real engineer but I had hoped to spent my limited time on other things.
Steve Maney is a very good suggestion I had forgotten about him.
BDM. Do you have a specific time period for these bad followers ? My reluctance to use them was based on exactly that - stelite pads coming off but if that is fixed then maybe Im worrying too much. I just rang the local shop and they tell me they have sold more than 50 pairs of followers made by Andover in the past few years with out any problems so it looks like they are Ok now.
Most of the oil bath has gone on my cases to allow the cam to clear the cases but in this race bike circumstance it is less of a problem because I pour oil down the push rod tunnel before starting at each meeting. I use Castrol R 30 castor oil. The PW3 camshaft is cast iron. The valve springs are set up to avoid coil bind and to keep seat presure at full lift to around 220 max. This controls the valves to at least 7500.
Its a long walk to Ohio from here - New Zealand. but it would be interesting. There would be no purpose in reving my bike to 10 k. It would run out of breath. In fact on the dyno it flattens after 6000 rpm. Our rules are hard on what can be changed. Standard bore and stroke for a start. - Ours is a points series of around 14 races over 5 meetings so keeping the bike in one piece and finishing every time is critical. Fail to finish one race and your toast !
Re: Norton Racing camfollowers#65867 07/25/066:29 am07/25/066:29 am
Excellent thread gents an special thanks to Beltdriveman, I wonder how many cams were ruined by an engine ex the UK being dry started after an ocean voyage ? The above assumes that the oil bath feature was absent, otherwise no problem. I built a "new" Triumph engine a while back, re-faced cam followers and new Harris cams, have been watching valve clearances like a hawk on a titmouse, about 7K miles now and relaxing. I wonder how many "unleaded conversions" occured because people either did not use moly on new assembly or mismatched cam follower to cam lobe [including direction of cam rotation] during a top end rebuild. I look at valve trains generally and wonder that they work at all, that attitude makes me very carefull.
1969 TR6R 7.62 x 51 is not a maths puzzle.
Re: Norton Racing camfollowers#65868 07/25/061:48 pm07/25/061:48 pm
Harley guessed wrong on bath design in 1937. They made a new engine (sidevalve 4 cam big twin) with the first of a train of cam gears with its teeth just barely dipping into a small shelf that held an oil pool, intending that the oil would be carried over from gear to gear like a water wheel. Good theory, except the pool was just that tiny bit too shallow - many, many failed cam gears. New right crankcase half with deeper pool (1/8"?) cured it, used on all later models with no other changes. I have a gut feeling that many brit motors could benefit from more oil to the lobe/tappet interface, easily done with an external line to the area taken off rocker oil, return, pressure switch etc. Downside is: has to be bullet-proof or its one more thing to leak, snag the wrench, break, over-tighten, vibrate-fracture and cause DNF.
Re: Norton Racing camfollowers#65869 07/25/065:49 pm07/25/065:49 pm
Norton could hve just put the cylinder head oil drain in front of their forward canted commando so that it would drain into the shallow oil shelf below the cam. Hot oil maybe yes, but oil none the less.
Re: Norton Racing camfollowers#65870 07/25/066:12 pm07/25/066:12 pm
Originally posted by 78AMIgrad: Norton could hve just put the cylinder head oil drain in front of their forward canted commando so that it would drain into the shallow oil shelf below the cam. Hot oil maybe yes, but oil none the less.
Norton did that!........ The exhaust rockers drain in the front down the lifter/push rod tunnel. The hole is somewhat visibly obscured by the spring cup/seat. The intake rockers drain down the rear barrel drilling and into the the timing chest.
dynodave BSA 3 1961-1963 Ducati 3 1992-2002 Norton many 1951-1975 87 Serv-Equip 100HP MC brake dynamometer,
Re: Norton Racing camfollowers#65871 07/25/0610:13 pm07/25/0610:13 pm
I asked a few more questions locally about the followers, cam and oil bath.
Followers . The problem followers were more than 5 years ago. Local shop Xrayed them and found the material used to attach the stellite was poorly distributed. They threw out all their followers of this type. New ones from Andover Norton have been reliable but expensive. If you find cheap new followers they are probably old stock and no good.
Cam life. Running in is absoluely critical as detailed above by the other posters. A bike used for big miles and long trips will be fine. A bike used for "Bar hopping" and commuting will have problems.
Oil bath. Yes the oil bath went away with time which was not good. An aside - All Vincent owners in the know evidently park their bike on the left hand side stand. Before starting they move it to the right hand side stand for a short while. This ensures the oil trapped in the head flows over the cam. If this procedure is followed the cam lasts 100,000 kms. If not it lasts 5000 kms.
I think this is what called personality.
He also said I should use the BSA followers and get on with it!
Re: Norton Racing camfollowers#65872 07/27/068:06 pm07/27/068:06 pm
Just had to laugh a few minutes ago as the wind blew paper all over the place.....found a Classic Bike articla on a prototype 650 unit Norton (Sept 2004). The photos of the crankcases show that the cam has been placed at the rear of the motor (as Mr Hopwoods earlier BSA design)and as it runs within its own seperate oil bath that would of damn nigh covered the cam with oil that someone at AMC was fully aware of how cams and followers should be lubricated, especially cams and followers with small surface areas running at high speed with fierce accelerations etc if they are to last that is...... The Norton cam and followers being designed for a 500 twin plodding around at anything up to say 5000 rpm max. Clearly another example of how Mr Hopwood in including his camshaft oil bath into his Norton Twin design knew a damn sight more than a few so called Norton exspurts of these days!!!
Re: Norton Racing camfollowers#65873 07/28/069:31 am07/28/069:31 am
Dear Ludwig,Suggest you talk with Triumph service managers etc about their cam and follower problems. I believe you will find that at one time they were changing under warrenty 30% of exaust cams on the unit 650s.....Instead of correctly curing the problem with positive oil supply to the cams or running them in oil baths....(like every decent car motor produced these days and for the last 20 years-If they came from Japan!!!) they nitrided them giving a surface hardness of around 1000 vickers. If tou drop one on the floor or on the vice etc at the wrong angle bits flake off!!. The inlet cams gave less trouble because they got most of the oil flung off the crank....just like many olde british car engine designs where the oil was in the crankcase. I remember decades ago, in a friends garage,looking at two car engines both with the rocker/cam covers removed. One was a Ford the other a Jap. The Ford had a crappy bit of tube supplying oil to the cams, a tube that would block up causing cam and follower failure unless changed on a regular basis abd the Jap cam had more supporting bearings, larger diameter, wider cam faces and holes in the lobes for oil supply. The Jap motor was ENGINEERED, the Ford was engineered(?). With modern oils that cling in theory to everything it may be that Norton cam problems could be less and that 99.999999% that do occur are due to owner incompetence but it is really so simple to shove back the canshaft oil bath and probable casts less than 2 cams if done by a company. And a damn sight less if done by yourseld. Cams cost money. The metal that wears off them will probably be smaller than the holes in the filter paper and will circulate with engine oil unless caught by a magnet. I note some filter manufacturers are shoving magnets around the filters to catch these metal particles. Personally I would shove one of these new super magnets on the end of the oil tank filler caps oil level stick........It casts so much to rebuild a motor now if you can get one to outlast you.......
Re: Norton Racing camfollowers#65874 08/03/063:04 pm08/03/063:04 pm
Spoke to a gentleman who I would suggest knows more about the subject than most of us put togetyer. NO I cannot name him because IF \I do he will be somewhat upset with me AND I need to pick his memory banks, drawings, experience in the future. I asked about cam follower profiles. Apart from early Dommy cams which had radiused followers for the 650, 2S,3S and 4S he employs flat followers and for the 7s cam SIX INCH radiused followers. PERSONALLY I dont like the higher lift cams and have used the BSA A65 profile with flat followers and a proper exaust system. I would not mind beting that a proper tuned exaust system designed around the cam timin g etc gives most inprovement and that most people pLaying with cam timing are merely doing what hundreds have done before. Of course if you are totally mad and want to alter cam timing in approx half a degree increments all you do on a Commando is shove a couple of Tiger Cub 17 tooth sprockets on the timing gear along with a half link in the chain. (Which when I first played with it Renold did not make and the half link came from Germany..the gent at the Renold Ipswich office bought a few in for me). Yes it does fit... JUST. And the triplex chain wont wear as quick. Oh the silly things some of us play and waste out time with.
Re: Norton Racing camfollowers#65876 08/03/065:10 pm08/03/065:10 pm
I sent this previously so only the Gods know where it went or worse still to whome it went..... On the std idler there are 48 gear teeth each one giving a 7.5 degree change and there are 18 chain teeth each one giving a 20 degree change. Thus the smallest change you can get is by moving the chain sprocket one tooth (+20 deg) and moving the gear teeth in the opposite direction 2 teeth(15deg)giving a 5 degree change.
IF you were to increase the chain sprockets to 19 teeth you get a change per tooth of 18.95 ish degrees per tooth. If you line up theidler as one does normally and mark the slot betewen the gear teeth 0/49 and the chain sprocket tooth 0 then.... If you for example line things up on 43 on the gear and 18 on the sprocket then you move the cam by approx 0.79 deg one way and if you set up on 5 on the gear wheel and 3 on the sprocket you get a 0.79 degree change the other way .....38 and 16 or 10 and 5 = plus and minus 1.59 degrees 33 and 14 or 15 and 7 = plus or minus 2.37 degrees. I think there are 25 or 26 variations within the first 20 degrees as against 4 with the std set up unless you use an offset key in the keyway or a vernier cam sprocket. Unfortunately it was about 30 plus years ago that i played with a slide rule and log tables doing the calculations. I did actually fit a duples system to a mock up Comman
Re: Norton Racing camfollowers#65878 08/03/0610:37 pm08/03/0610:37 pm
I had that suspicion - "splitting the difference", just wanted to hear it directly, thanks! I use that to re-time the cam on H-D where the gear and lobe are integral - offset key on the pinion shaft either way + move 1 tooth either way, etc.
Re: Norton Racing camfollowers#65879 08/04/063:43 am08/04/063:43 am
Interested about your comment re the Axtel#3 grind being the source for the Peter William PW3 grind.
Do you have the figures for the Axtel#3 grind?
The reason I ask is that the PW3 is 50 82 inlet, 84 48 exhaust with a lift of 380. I know this is correct because I have measured it myself.
The NOC site http://www.nortonownersclub.org/ asserts that the Megacycle 560-NSS cam is the same as an Axtel#3 and gives the figures 38 66 inlet 66 38 exhaust, lift 359 which is clearly not the same. But I have no idea whether this statement on the NOC site is correct.
The NOC site also lists the Megacycle 560 N480 cam as 50 82 and 82 50 which is almost exactly the timing of a PW3 but the lift is higher at 436.
Earlier this year I talked with Peter Williams about how he designed the PW3 cam. He said he designed the 4S using a hand calculator but for the PW3 he used the computing department of a university in the UK to optimise the design minimising acceleration and cam dynamics. He was particularly concerned to minimise what he termed "stab torque" on the cam. I am looking at the diagram he drew for me as I write this.
He told me that he had become aware of these issues from his father Jack Williams who had been in charge of the AMC team 7R development for many years. In 1961 Mike Hailwood retired in the Junior TT on a 7R (That was the year he won the 125 , 250 and 500) History has it that a gudgeon pin broke. - but Peter said it was camshaft problems. (He should know - his father dismantled the motor after the race) He said that his father had not understood what was going on at the time but as computing power improved though the 1960s they were able to model the cam dynamics.
Peter never mention the Axtell cam and since the only figures I can find seem to be different Im wondering if you have any more information on this being the source of the PW3.
Peter also described the history of cam development in the UK factories both car and bike. He talked about sine cams and other developments, the people involved etc. He is a very straight guy, very polite and academic. Im sure he would have credited Axtell if that was where the cam grind cam from.
(You are right - Norman White does sell the PW3 cam. He was Peter's mechanic and was sitting beside Peter when he drew the diagrams.) This is the story of their trip down here to New Zealand. Norman will be back here next summer with the JP again. http://www.nortonracing.co.nz/index.html