Terry's Valve Springs

wilkey113

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Anyone have any experience with Terry's brand valve springs? I'm looking to buy a set, and wondering if they're good, bad or basically the same as stock Norton springs.
Thanks
Jeff
 
So, Ariel, BSA, Norton, triumph etc. don’t fit terry’s valve springs as standard then :?:
 
Everyone used them in my young days but as to whether they are now made to the same standards as they were then.......
I personally employed standard NVT sold Commando springs and still have a few new sets around that came out of NVT after they closed. Used them in our short stroke Dommy decades ago and that would rev to 8,000 with no problems..... APART from the vibes that is !!
 
Youll Get Valve Foat at 8500 ( on a Triumph 650 ) if you do . And theyll be shot at 20.000 miles if you regullarly use 8.000 sometimes . :wink:

Originals in 70s were DRAWN Wire , so had DRAW MARKS , as in along the lentgh youd think they were cellary stems & wouldnt wok , But they DO .

W&S / Norvil , are JoMoCo & better . Being Centerless Ground yankee marvels . With the big ugly Norton Followers , Norvil are probly Preferable .
If they still exist . Being Progressive rate you get more horsepower and it all tuns and osscilates smoother . Thus should give reduced wear .

Terrys are good of the lights , tho . :D

Terry's Valve Springs
 
I was looking at an NOS set o Terry's on eBay, but ended up missing out and someone snatched them up.
I'm looking for a set, or two sets, for a couple of 650 Dominators that I'm building.
 
Matt Spencer said:
Youll Get Valve Foat at 8500 ( on a Triumph 650 ) if you do . And theyll be shot at 20.000 miles if you regullarly use 8.000 sometimes . :wink:
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Or even valve float.

Terrys used to recommend that their valve springs be changed every 2 race meets, I think it was.
Nortons are known to have changed them for every race meeting...

There was a discussion someplace here about I mentioned I obtained a set of S&W valve springs for a Commando, a good while back. And apparently they were seriously long life springs.
They went out of business, but someone bought them up and are still going ?

Wonder if springs can age if they are not used.
One for the matallurgists or spring makers ?
(Can they age if they sit compressed in a bike ?)
 
Rohan said:
Wonder if springs can age if they are not used.
One for the matallurgists or spring makers ?
(Can they age if they sit compressed in a bike ?)
Click to expand...


I've asked that regarding springs sitting in compression in firearms. Conventional wisdom is to unload magazines and detension internal springs when not in active use, but when I asked an engineer friend of mine, his answer was that a spring does not know how much time it has been sitting while compressed, only how many cycles it has undergone, making the unloading of magazines very slightly counter-productive.

His metaphor..."Do you put your car up on blocks every night to keep the suspension fresh?" Now, I'm sure there are fine details that matter in each case regarding the exact spring in the exact application which could bear on the situation, but still, that made sense to me in general. Would love to hear a second opinion.
 
AgentX said:
I've asked that regarding springs sitting in compression in firearms. Conventional wisdom is to unload magazines and detension internal springs when not in active use, but when I asked an engineer friend of mine, his answer was that a spring does not know how much time it has been sitting while compressed, only how many cycles it has undergone, making the unloading of magazines very slightly counter-productive.
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Torque wrench manufacturers usually recommend backing off spring tension to the minimum setting when the tool isn't in use.

http://www.mountztorque.com/learning-ce ... que-wrench

It is thought (and has been proven) that leaving a calibrated wrench at one setting impacts spring linearity, disallowing accurate use at other settings. It does not happen every time, but over time linearity can be impacted causing error. This is the reason for the recommendation to turn a wrench back to its minimum setting when not in use
Click to expand...

http://www.norbar.com/en-gb/News-Events ... que-wrench

1. Storing your torque wrench


When a torque wrench is in regular use it does not need to be wound back. However, when storing a torque wrench for an extended period of time, users should always wind it down to the minimum scale setting and never to zero.

A fully loaded torque wrench, left in storage for a long period, can cause a ‘set’ in the spring, causing it to weaken over time. On the other end of the scale, by completely off-loading the spring, other components within the wrench may move fractionally relative to each other. When you reapply spring compression the orientation of these components can change, therefore affecting accuracy. All in all, it is better to leave a bit of compression in the spring while in storage.
Click to expand...

https://www1.snapon.com/display/231/Too ... ench08.pdf

9. If using a click-type torque wrench, always store it at the lowest level on the scale.
Click to expand...
 
AgentX said:
His metaphor..."Do you put your car up on blocks every night to keep the suspension fresh?"
Click to expand...

There was a spring maker near me (until recently) where you could take your car/truck springs (and probably bike springs too) where he would bake them in a red hot oven then suitably cool them out to make them like new again. He was doing a thriving business when I took down a pattern to get made....

Owners of single cylinder motorcycles were advised to put the piston on tdc so the springs weren't compressed when parked. Not in the owners handbook, but in accessory magazines.
Not possible if you have more than one cylinder
 
Did not Helmut Fath when designing and building his 4 cylinder engine on which I believe he won a World sidecar championship have a Sweedish friend who did his Masters degree or doctorate looking into valve spring performance and ended up manufacturing single coil springs for British motor cycles?
 
So today I picked up my phone and had a chat with a spring maker in Redditch. They have all the patterns for the Terry VS raqnge of valve springs and manufacture some occasionally and have at times manufactured springs for Andover Norton...... TROU*BLE IS......The wire suitable for valve springs they have to buy from a company in northern europe and it does NOT come in lengths of a couple of yards at a time but long rolls which cost a lot of money. Thus unless they have the correct wire in stock on the shelf it requires a large expensive order to be placed if springs are to be manufactured CORRECTLY and thus to give RELIABLE service. They have to be shot peened and sometines they have to sub this process out which costrs money, all the Laycock Engineering produced diaphragm springs fitted to the Villiers Starmaker / Commando and rotary Norton clutches were shot peened to increase their fatigue resistance...spent hours talking to the Laycock Engineering ChiefCclutch Designer picking hois brains on such subjects over many years.
As I understood the long converation I had with a certain Gentleman (who for his sins and great sence of humour) is now in my address book the original Terry company no longer exists making valve springs.
A great many years ago when a Gentleman was scouring all Vandervell stockists in the UK and buying for me every set of 40 thou undersize Norton big end shells he could find (at the time people in their ignorance would junk their cranks thinking 30 thou undersize was the max regrind size) we discussed the cost of setting up 'the line' to produce a batch of new Norton big end shells and the cost was so great that every Norton owner in the World would of had to buy a set every year for the rest of their lives to make it financially viable. OK so I jest but you get the idea. The demand is simply not there and the company was so big and probably run by poxy accountants by then etc etc and Heath and Maggie along with The Chamber of British Incompetence (CBI) were busy closing down as much of British industry as possible (helped by the incompetent unions who in my experience were even more incompetent than British mismanagement and that takes some doing....... Now we reap the benifits as our deficiet increases and the pound devalues.........remind me how long ago it was that there were 4 Dollars to the Pound...........
Hope I have not upset anyone....AGAIN.

TOOTHED BELTS ARE THE MOST EFFICIENT FORM OF POWER TRANSMISSION FOR MOTOR CYCLE PRIMARY DRIVE USE. ( I should add THOSE toothed belts with modern tooth forms........) For proof try reading SuperCycle Magazine Sept 1977 (or 78?) in which they dyno tested a Harley employing chain and belt primary drive systems.......The belt was found to be 5.5 hp more efficient at the higher linear chain speeds employed.......
 
It had long been recognised that swedish steel was amongst the best - they don't make much of it, but it was good.

There is a famous story that during WW2, the RN and RAAF did blockade running to sweden, to pick up roller bearings for some critical uses in things like spitfires and tanks. Heavily loaded, they NEEDED really good steel to last.

Also, I read someplace that all the 531 tubing that Reynolds used since the war was all sourced from Sweden.

The steel used in S&W valves springs, from the USA was supposed to be pretty good - lasted for life.
Apparently it all has to do with how little impurities are in it... (?)
 
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