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Peter Williams cam.

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Hi all,

I have not been able to get a much info on the PW cam other than it makes the bike go better.

How so, I wonder ?

Is it a race type cam ?

Is it useable for every day road riding ?

Do you have to make changes to carbs, ignition etc ?

I haven't seen any test that actually describes living day to day with that cam.

I don't want a kick in the arse ride but rather a smooth and flexable ride in most conditions.

So, how is it on start up ?

Once under way how different from stock is it ?

Where and how does it benifit the motor in every day riding ?

I'm looking for a realistic subjective answer please.

I once had a 'race' cam in a Commando that made the bike hopeless to ride under 4000 R'sPM.

As I'm almost an OAP I don't want to have a scary ride that may ruin the experence.

Thanx. D

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These might give a fraction of info:

http://atlanticgreen.com/camsurvey.htm

http://atlanticgreen.com/images/cam940.gif

But for some subjective information perhaps have a chat with Mick Hemmings (the main seller of the cam) himself. I found him a very helpful person and willing to chat at quite some length. He can advise you on the best way to get the type of performance you desire:

http://www.mickhemmings.co.uk/

Les

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I have a PW 3 cam supplied by Norman White. One main reason for fitting was that at the time a lot of cams were said to have been of dubious quality. I believe this may be a thing of the past. I said to Norman I did not want a race cam but wanted usable performance for the Road. he recommended the PW 3 with no other mods.

It works for me. I have pee shooter silencers and a K&N filter and the bike is 850 cc. It pulls like a train The exhaust is a bit blatty and a bit noisy .It was noisy before fitting the PW 3.

It is said to get the best out of it it needs top end work done to the bike but I am quite happy with it.

I would Talk to Andover Norton, Norman white and Mick

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They give good low down power and keep pulling hard. A well set up bike with a PW3 is quite a bit quicker than standard but in my opinion they are horrendously noisy to ride behind even when fitted with standard reverse cones.

Whereas the standard cam will let you float through villages on a whiff of throttle almost unheard apart from the occasional over-run twitter, a PW3-equipped bike will wake the dead in the churchyard.

When I had mine fitted, the Mk1 RITA was re-jigged by Mistral engineering to take account of the cam profile. I believe that this is something that they did back in the day with the 4S as well.

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Previously richard_payne wrote:

They give good low down power and keep pulling hard. A well set up bike with a PW3 is quite a bit quicker than standard but in my opinion they are horrendously noisy to ride behind even when fitted with standard reverse cones.

Whereas the standard cam will let you float through villages on a whiff of throttle almost unheard apart from the occasional over-run twitter, a PW3-equipped bike will wake the dead in the churchyard.

When I had mine fitted, the Mk1 RITA was re-jigged by Mistral engineering to take account of the cam profile. I believe that this is something that they did back in the day with the 4S as well.

Agree with all that. I used one for 7,000 miles (2 yrs) and it needed retarding 5 degrees to achieve the timing figures. Mine was a 750 with 9.3:1 (Combat head + 030" baseplate, no base gaskets) and enlarged (by a PO) inlets. Yes it did give a bit more mid and upper range 'Go' but it was the reason I started using earplugs! I think if you're talking a standard bike then it might work better on an 850. Its not scary, no kick like the 2S and 4S at 4500 rpm, just underwhelming really, probably great over 6000!!

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Hi David

Just as an addendum to the other replies above, I attach a small treatise by Peter Williams himself on the design of cams which perhaps offers some more information?

Peter

Attachments pw3cam-pdf
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I run a PW3 on an 850 and am unaware of any exceptional noise levels. I have not received complaints although aniother user with a PW3 on a 750 said he thought that was noisy.

My article on fitting a PW3, published in Rh262, Nov/Dec 2008 goes into the subject in some detail. So much detail in fact that Mick Hemmings and Norman White wrote to Roadholder, suggesting that I had made it all look too complicated. The intention was to produce a detailed text based on the instructions provided with the camshaft to enable an inexperienced user to fit one. I leave it to any readers to judge.

As the Roadholder archive does not go back that far, I have extracted the article as a .PDF but it is too large to add here as an attachment. I will try to send a copy directly.

For what it's worth, I would fit a PW3 to any 850 I had apart but I cannot comment for the 750.

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Would it be possible to split the file into several PDF's Chris? I'm always interested in reading any such article as I am sure other members are too....Thanks....Les

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Previously les_howard wrote:

These might give a fraction of info:

http://atlanticgreen.com/camsurvey.htm

http://atlanticgreen.com/images/cam940.gif

But for some subjective information perhaps have a chat with Mick Hemmings (the main seller of the cam) himself. I found him a very helpful person and willing to chat at quite some length. He can advise you on the best way to get the type of performance you desire:

http://www.mickhemmings.co.uk/

Les

Thanx Les.

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Previously Chris Grimmett wrote:

I run a PW3 on an 850 and am unaware of any exceptional noise levels. I have not received complaints although aniother user with a PW3 on a 750 said he thought that was noisy.

My article on fitting a PW3, published in Rh262, Nov/Dec 2008 goes into the subject in some detail. So much detail in fact that Mick Hemmings and Norman White wrote to Roadholder, suggesting that I had made it all look too complicated. The intention was to produce a detailed text based on the instructions provided with the camshaft to enable an inexperienced user to fit one. I leave it to any readers to judge.

As the Roadholder archive does not go back that far, I have extracted the article as a .PDF but it is too large to add here as an attachment. I will try to send a copy directly.

For what it's worth, I would fit a PW3 to any 850 I had apart but I cannot comment for the 750.

Thanx Chris.

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Previously Peter White wrote:

Hi David

Just as an addendum to the other replies above, I attach a small treatise by Peter Williams himself on the design of cams which perhaps offers some more information?

Peter

Thanx Peter.

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Previously K Glassborow wrote:

Previously richard_payne wrote:

They give good low down power and keep pulling hard. A well set up bike with a PW3 is quite a bit quicker than standard but in my opinion they are horrendously noisy to ride behind even when fitted with standard reverse cones.

Whereas the standard cam will let you float through villages on a whiff of throttle almost unheard apart from the occasional over-run twitter, a PW3-equipped bike will wake the dead in the churchyard.

When I had mine fitted, the Mk1 RITA was re-jigged by Mistral engineering to take account of the cam profile. I believe that this is something that they did back in the day with the 4S as well.

Agree with all that. I used one for 7,000 miles (2 yrs) and it needed retarding 5 degrees to achieve the timing figures. Mine was a 750 with 9.3:1 (Combat head + 030" baseplate, no base gaskets) and enlarged (by a PO) inlets. Yes it did give a bit more mid and upper range 'Go' but it was the reason I started using earplugs! I think if you're talking a standard bike then it might work better on an 850. Its not scary, no kick like the 2S and 4S at 4500 rpm, just underwhelming really, probably great over 6000!!

Thanx mate.

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Previously richard_payne wrote:

They give good low down power and keep pulling hard. A well set up bike with a PW3 is quite a bit quicker than standard but in my opinion they are horrendously noisy to ride behind even when fitted with standard reverse cones.

Whereas the standard cam will let you float through villages on a whiff of throttle almost unheard apart from the occasional over-run twitter, a PW3-equipped bike will wake the dead in the churchyard.

When I had mine fitted, the Mk1 RITA was re-jigged by Mistral engineering to take account of the cam profile. I believe that this is something that they did back in the day with the 4S as well.

Thanx Richard.

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Previously les_howard wrote:

The PW3 cam....it makes me wonder what the PW1 and PW2 were like ....maybe they didn't work too well?....Les

Nice try. There were no PW1s or 2s.

I have rode to work this morning on my Commando 750 with a PW3 cam, my son is running one in his 750 Commando, and our "family racer", propperly set up, gives the same performance the best works engines gave but with an all-round rideability like a road bike.

The PW3 is my choice for a road bike, an improvement on the original designs.

Peter tells me he is puzzled why owners still insist on the original camshafts as he knows- and so do Norman White, Mick Hemmings and humble me- that his camshaft is a definite improvement on the originals.

The fact my bike is rather loud has little to do with the PW3 cam but more with the fact it is a high-compression shortstroke.....

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I have to say I'm surprised that David is considering the PW3 cam. Without doubt this is a high performance cam with massive lift. He says he does not want performance so in his case I would just use the standard Norton cam. My 72 Norton Commando made absolutely ample power for the road and I was pretty satisfied with it at the age of 21 and I often wheelied it away from traffic lights with ease. Nowadays I wouldn't be riding it half as fast and it would be difficult too on the congested speed limited British roads so why would I need more performance? It is also true that sportier cams can make engine exhaust notes much louder as they open earlier, longer and are more open at any given point of the cycle. I currently ride a Model 7 with original low lift cams and just 29 BHP but I rarely open it up to the max. I suppose it's human nature to want to make something "better" than original, perhaps it is in the male ego not to settle for something STANDARD.... like: "It has got to be better or the bike will seem boring when I show it to friends... it has to have something EXTRA...you know, faster than standard" but one should really weigh up what IS BETTER and give any negatives the same importance as to all the "exciting" things you THINK might be coming your way.

Les

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Have to agree with Les. The standard cam does a very good job. With a national speed limit of 70 mph, just how often are we going to need or use a bit more top end? I see so many motorcyclists on the road with 100+ bhp under them just bumbling along. Absolutely fine, but I suspect that people with very fast superbikes are just engaged with a bit of one-upmanship. Not that we feel superior to all the rest by riding Nortons. Oh no. Certainly not.

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I asked Peter Williams about the noise aspect earlier this year having returned half-deaf from a touring trip with three other Commandos, two of which were fitted with PW3s.

He said that he had fairly recently become aware of the increased noise aspect, with more PW3-equipped road Commandos now in use and it had not been noted during development.

This is perhaps not surprising as it was not designed for and not homologated as a road cam. I very much doubt if Norton Villiers could have got the Commando through noise testing fitted with it.

Peter did confirm that increased overlap was the cause of this characteristic.

For me nowadays, the increased noise is a trade-off too far and I no longer enjoy seeing high-street shoppers cover their ears.

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The noise and performance can be controlled with the right wrist. It can be ridden quietly by changing up early and slower use of the throttle for passing horses and nice people. For cars that pull out in front and pedestrians that do not look except at their phones just let the Norton shout at them like Mr Angry its all in the wrist action. Works better that having the headlight on or high viz jacket.

Now I am straying off topic, so must put mister Angry back in his box.

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I have a 4S cam fitted to my 750 fastback and it is definitely noisier than my 850 which has a standard cam, however I do love the crack it adds to the 750's exhaust note. I don't think it has yet offended any high street shoppers.

I originally fitted the cam to the 750 when I was racing it in the CRMC production bike classand really I can't see any other reason to fit go faster parts to a classic. My belief being that if you want to go faster the best way is to buy one of the wonderful modern machines that will give stunningly more performance than any commando and it'llhave brakes toslow you fromthe extra performance.

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I hope Gordon won't take this as sarcasm, but I can't help wondering if he has been on a motorway recently. Unless you mingle with the trucks in the slow lane, 70+ mph is not really keeping up with the traffic, and in the fast lane much less than 90 will bring you a Mercedes sitting on your rear number plate.

Going to the Banbury run the other week my '72 Combat-engined Fastback didn't experience any problems in cruising with the rest of the M40 traffic, but I'm exercising my 5th Amendments rights about the exact speeds involved.

Previously Gordon Johnston wrote:

Have to agree with Les. The standard cam does a very good job. With a national speed limit of 70 mph, just how often are we going to need or use a bit more top end? I see so many motorcyclists on the road with 100+ bhp under them just bumbling along. Absolutely fine, but I suspect that people with very fast superbikes are just engaged with a bit of one-upmanship. Not that we feel superior to all the rest by riding Nortons. Oh no. Certainly not.

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On the noise issue, is it the actual physical volume (i.e. extra dB) or is it a change in the quality of sound that the PW3 produces?

A desmo Ducati of almost any vintage, from 750SS through Pantahs (and my own ST2) to Multistradas and Panigales has a distinctive sound quality that, according to my understanding, is a product of the much faster valve opening and closing, and longer overlap, that desmo operation makes possible.

( They're also louder as well, if you consider a 750SS on Contis ! )

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Previously christopher_winsby wrote:

Make sure your followers are good or fit new, use lube provided on cam.

Thanx Christopher,

I will mate, it's standard practice. I'm going to use those new hydraulic lifters. ;)

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Please don't get arguing over this topic you lot.

I have been looking at Jim Schmit's products. I like the cam, cam followers, rod's and pistons. I want the bike to look standard factory but to run better.

I live in New Zealand, our roads are good in some areas and rough in the rest. We have lots of steep mountainous roads and some long flat bits with not too many cops.

I guess I want a better made cam than the factory one which is poorly made. It has 'chatter' marks on the on ramps that shouldn't be there.

The previous owner was a big fat bastard, he told me he had problems kicking it into life a few times. He said that once he had been kicking for 40 mins before it started. Not good for the cam. The problem was, as I discovered, the electronic ignition was shorting on the frame. Long story.

I guess I want the bike to ride in suburbia nicely but have some honk when the loging trucks come belting along.

I don't mind a bit o noise as I'm rather deaf, the result of playing drums in Rock bands for 45 years.

Don't be supprised by anything I may do, or not, Les. I like to gather tons of info before I commit to anything. PW cam seems like a good option. But then I may change my mind, or not.

Thanx for all you kind advice and opinions. It is appreciated.

p.s. I'm dyslexic so please excuse the spelling.

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Hi Julian, yes I do ride on Motorways when I have to. The difference is that here in the wilds of rural Scotland they are nowhere near as frenetic as down south. Having said that, my 745cc Dominator will sit at rather in excess of the limit but these days I tend to take it a bit easier than I once did. I get as much pleasure in riding one of my slower machines as I do from the Norton.

Am I not right in thinking that in New Zealand the speed limit is rather lower than here? So no pressing need for a go-faster option. That said, it's each to their own.

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Hello David

On a recent thread on the accessnorton forum One of the regular posters (who is a noted commando authorotiy) He quoted that just swapping a standard cam for a PW3 robbed the bottom end of a 2-3 HP and put 2-3 HP up at the top end.

To get the most benefit out of a PW3 cam the head has to have some work done on it. Large valves, gasflowing etc etc

If you want a regular rider that is not excessively loud, dosen't wear the valve gear out earlier than expected and is quite capable of keeping up with modern motorway traffic stick with the standard cam.

If on the other hand you ride around at WOT all the time go for it.

Its your money. spend it how you want!

regards

Peter

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Previously Gordon Johnston wrote:

Hi Julian, yes I do ride on Motorways when I have to. The difference is that here in the wilds of rural Scotland they are nowhere near as frenetic as down south. Having said that, my 745cc Dominator will sit at rather in excess of the limit but these days I tend to take it a bit easier than I once did. I get as much pleasure in riding one of my slower machines as I do from the Norton.

Am I not right in thinking that in New Zealand the speed limit is rather lower than here? So no pressing need for a go-faster option. That said, it's each to their own.

Thanx Gordo,

What's a 'speed limit' ? ;) ;)

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Previously Gordon Johnston wrote:

Hi Julian, yes I do ride on Motorways when I have to. The difference is that here in the wilds of rural Scotland they are nowhere near as frenetic as down south. Having said that, my 745cc Dominator will sit at rather in excess of the limit but these days I tend to take it a bit easier than I once did. I get as much pleasure in riding one of my slower machines as I do from the Norton.

Am I not right in thinking that in New Zealand the speed limit is rather lower than here? So no pressing need for a go-faster option. That said, it's each to their own.

Thanx Gordo,

What's a 'speed limit' ? ;) ;)

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Previously Gordon Johnston wrote:

Hi Julian, yes I do ride on Motorways when I have to. The difference is that here in the wilds of rural Scotland they are nowhere near as frenetic as down south. Having said that, my 745cc Dominator will sit at rather in excess of the limit but these days I tend to take it a bit easier than I once did. I get as much pleasure in riding one of my slower machines as I do from the Norton.

Am I not right in thinking that in New Zealand the speed limit is rather lower than here? So no pressing need for a go-faster option. That said, it's each to their own.

Thanx Gordo,

What is a 'speed limit' ?

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Previously peter_shand wrote:

Hello David

On a recent thread on the accessnorton forum One of the regular posters (who is a noted commando authorotiy) He quoted that just swapping a standard cam for a PW3 robbed the bottom end of a 2-3 HP and put 2-3 HP up at the top end.

To get the most benefit out of a PW3 cam the head has to have some work done on it. Large valves, gasflowing etc etc

If you want a regular rider that is not excessively loud, dosen't wear the valve gear out earlier than expected and is quite capable of keeping up with modern motorway traffic stick with the standard cam.

If on the other hand you ride around at WOT all the time go for it.

Its your money. spend it how you want!

regards

Peter

Thanx Pete.

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Previously christopher_winsby wrote:

The noise and performance can be controlled with the right wrist. It can be ridden quietly by changing up early and slower use of the throttle for passing horses and nice people. For cars that pull out in front and pedestrians that do not look except at their phones just let the Norton shout at them like Mr Angry its all in the wrist action. Works better that having the headlight on or high viz jacket.

Now I am straying off topic, so must put mister Angry back in his box.

Crikey I hope I never get to the stage of wanting a quieter Commando, it is one of the big reasons I have always ridden one . PW3 sounds awesome just saying IMHO . Sorry have I gone off topic? If so yes put one in.

all best G

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I too fell for the PW3 cam in search of more performance. In hindsight it doesn't perform well enough to justify 170 quid. It does perform well enough when you have the revs above about 4500 and needs greater than 9:1 CR and some head work. If your old cam is in good nick I would stick with it and spend the money on a new pair of carbs or a decent ignition system. If you do decide to go with the PW3 just fitting it with the original timing marks is not good enough. As Keith says earlier, you will need to retard the cam timing by 5 degrees to get the figures recommended by Mick Hemmings

Getting up to 10:1 CR and valve clearances of 0.012" is not going to be good for that stealthy ride and easy starting. I've experienced the NZ feds first hand. They don't seem to have much of a sense of humour and work on a money raising fine system for the most trivial misdemeanour. The good thing about UK cops is, they are few and far between now.

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On the subject on exhaust noise. I tend to ride quieter bikes faster than noisy ones. Noisy ones are conspicuous and attract attention. Not always a good thing.

Should you hear an A10 with a hot cam and goldie silencers waking the dead through Glencoe in a couple of weeks it will be someone else officer, surely not me.

My Norton on standard cam and silencers is still faster.

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"Frenetic" is the word about motorways down here. Last Saturday on the M6 (on the way to the Norvil open day) I was in the fast lane overtaking when someone in a hot hatch on the on-ramp undertook everyone else -- fifth amendment applies, but given their apparent differential with me the driver must have been doing over 100 mph.

Previously Gordon Johnston wrote:

Hi Julian, yes I do ride on Motorways when I have to. The difference is that here in the wilds of rural Scotland they are nowhere near as frenetic as down south. Having said that, my 745cc Dominator will sit at rather in excess of the limit but these days I tend to take it a bit easier than I once did. I get as much pleasure in riding one of my slower machines as I do from the Norton.

Am I not right in thinking that in New Zealand the speed limit is rather lower than here? So no pressing need for a go-faster option. That said, it's each to their own.

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David Evans makes some good and important points regarding performance cams. To really get a good performance increase, other parts of the engine have to have comparable high performance potential, such as bigger carbs*, inlet ports and valve sizes, plus high compression pistons. I once fitted scrambler cams to an old matchless 500cc single with low 6.5:1 compression ratio. It made a glorious loud snarling exhaust noise and I just couldn't wait to try it. I was very disappointed, it felt much weaker at low revs and although it revved better it never made any real extra top end power simply because of the low CR and standard size carb. (it probably used more petrol too as the large valve overlap was likely to have lost petrol out of the exhaust ...it certainly run cooler surprisingly and I theorised it was due to the cooling flow of unburnt petrol)

Sports cams close the inlet valve much later than standard touring cams and it's only when the valve is shut can compression start, (lower BMEP) so you need a higher CR to compensate otherwise you get a woolier low end performance making the engine feel less punchy at low revs. However, when the engine tweaks are matched to the cam this early low rev loss is compensated for at the top end at higher revs.**

Then again as the bike will have the same gearing, say 110 MPH at max revs, this extra power is only available at this high speed and high engine revs (which perhaps will enable higher gearing), but at lower more likely speeds of 70 and 80 MPH the revs will be much lower and the extra power that the performance cam promises might not be there ....in fact it could still be lower as the max torque figure has been moved higher too.

Performance tuning is all about MAXIMUM power at maximum revs so unless you are going to run the bike at maximum revs through the gears you may well find your normal method of riding of taking it to say 4000 RPM at gear changes results in SLOWER acceleration....Frown

Les

* What size carbs do you have David Watkins?

** Conversely it can be a mistake to fit High CR pistons to an engine fitted with a mild touring cam. The early closing of the inlet valve with this type of cam in effect traps too much gas at low revs and when the throttle is opened quickly results in too high a pressure being created if fitted with a high CR piston. The result is severe "pinking" so one has to open the throttle more slowly or retard the ignition which is not a good thing. More advanced ignition systems (car type) are designed to sense this pinking and automatically retards the timing or even changes the valve timing to suit different revs.

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Hi all.

I have got back onto this site, today being the first time since I had spinal fusion surgery.

I'm slowly getting into rebuilding the Norton which will be slow going as I feel 190 years old after an hour of stand up duties. Not to mention the fab meds they give me. Laughing

I am going to go with the PW3 cam and damn the noise.

Kiwi's tend to ride fast and dangerous. it's a national pass time. Screw the speed limit, I never was able to keep a look out for a speed limit sign. One has to keep ones eyes on the road after all.

Bung ho.

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One advantage of the PW3 cam is it is chilled cast iron so wear should not be a problem. do have your cam followers refaced before assembly and use some camshaft assembly paste. When you have the followers refaced make sure the machinist grinds them at 90 degrees to the axis. The muppet that did mine first time just tarted them up on a linisher and they were a mile out of square. Strange because the rebore he had done for me was spot on.

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I get the message that the PW3 cam is for tuned 750 and 850 machines.

At some point I am planning to build a sporty 500. Not a race motor, but accessible usable road power. Proposed engine is dynamo bottom end, 9:1 pistons and either a '50s alloy head or perhaps SS downdraft. I get the impression that a standard SS cam is the way to go. Advice? What sort of power can I expect?

As an aside, my 1955 Model 88 has the slightly higher compression 1956 pistons, and I think, the 21225 cam. What sort of power should it give?

Thanks

Paul

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Before you think about upping the power (and hence rpm) of your 88, consider the conrods. The 88 in standard or SS form is a sweet machine. However, it ain't new. The alloy (RR56 for the interested) rods do have a fatigue life. How far through their lives will your rods be? 10%, 99%? In the interests of reliability, you should seriously consider a relatively modest max rpm and think carefully about squeezing more power from it. If you know the full history of your con rods you can judge what is reasonable. Having experienced a catastrophic fatigue failure of a con rod it's something well worth avoiding.

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While I agree with Gordon that New rods would be a good investment, the 88 motor does not have a bad rep with the rods , most rod problems seem to follow piston failure or lubrication issues ,or just bad workmanship.I would certainly be happy to buzz an 88 ,but be a bit more reserved with a 99. If you do decide to proceed I have a new Hemmings 2s dommy cam for sale . Thunder Rods are availiable,

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My 850 Mk 3 rounded off itâs cams in Germany so l had new followers and a PW3 cam fitted by Norman White. The extra cost of the PW3 cam was negligible in the round. Initial impressions were that the bike was easier to ride in town and traffic - albeit less nippy. The bike seemed less enthusiastic about accelerating than it had done previously but when warm was happy cruising relatively easily at 85-90 mph two-up and heavily laden ( on the autobahn officer !) for sustained periods. Engine is otherwise totally standard. I have no idea what the top speed is. The bike is no noiser than it was previously.

I hope this helps.

Alan

 


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