8 valve head conversion

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rotorwrinch said:
I don't think Mr Canaga would mind my posting a link to the scanned 8 valve article that he posted a while back. Ken would you have the rest of the article?

8 valve head conversion



Rj
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Torque is from how much mixture and pressure is in chamber to com-bust to heat nitrogen to pressurize above piston. It takes some rpm to draw in mixture fast enough on un-boosted applications so the bigger the bore the more torque at lower rpm and therefore the motto of There is no replacement for displacement. This also is why small ports with high velocity make more low rpm torque than big ports that can flow more at hi rpm. Also the 2 valve heads tend to out low torque 4 valve head d/t more swirl than tumble turbulence, unless the 4 valve has 2 size valves &/or staggered opening valves,then can out grunt the 2 valve. If Norton had only gone into business with TC and Drouin we might still have 2 valve torque monsters to beat today.
 
comnoz said:
However I do recall reading of someone who has tried it on a Norton. It would be a difficult task given the poor access to the inside half of the chamber. Jim
Click to expand...

You're probably thinking of MEZ in England, who used to do this twin plug conversion, using a smaller plug size for the second plug.

8 valve head conversion


Ken
 
What I heard from Pete Lovell is that when they had the 8 valve working well it put out 90 HP with a stock cam and pulled the spokes out of the rear wheel. The bike crashed at speed and was totaled.

As for HP a very well tuned 750 long stroke racer can put out over 70 hp and a short stroke can put out 80+. Of course you have to have the right pipes, ports, valves, cam and intake manifolds. Most Norton racers today are not that highly tuned.

If you want all the HP you can get from a Norton. Take a close look at a Harley 750 XR flat tracker and copy everything - the exhaust , inlet track , valves, cam action, ports , bore/stroke etc etc as close as you can. They were using the D shaped port way back. All the developement has already been done and its the best breathing 750 pushrod twin on the planet. I'm not promoting Harleys here - just want to see the Norts pull away. I took it as far as I could but there is plenty of room for improvement.
 
rotorwrinch said:
I don't think Mr Canaga would mind my posting a link to the scanned 8 valve article that he posted a while back. Ken would you have the rest of the article?

http://media.photobucket.com/image/nort ... 2.jpg?o=72


Rj
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No problem RJ (and Dave). I have the other two pages of the article, but only in .pdf format, which photobucket doesn't take. I'll see if I can convert them and post them later. In the meantime, this is another short article on the head.

8 valve head conversion


As far as I know, Andy Molnar still has the patterns and rights to the head that he acquired from Les. RJ, Do you have any updates since you talked to him a whle back about selling them?

Ken
 
jseng1 said:
What I heard from Pete Lovell is that when they had the 8 valve working well it put out 90 HP with a stock cam and pulled the spokes out of the rear wheel. The bike crashed at speed and was totaled.

As for HP a very well tuned 750 long stroke racer can put out over 70 hp and a short stroke can put out 80+. Of course you have to have the right pipes, ports, valves, cam and intake manifolds. Most Norton racers today are not that highly tuned.

If you want all the HP you can get from a Norton. Take a close look at a Harley 750 XR flat tracker and copy everything - the exhaust , inlet track , valves, cam action, ports , bore/stroke etc etc as close as you can. They were using the D shaped port way back. All the developement has already been done and its the best breathing 750 pushrod twin on the planet. I'm not promoting Harleys here - just want to see the Norts pull away. I took it as far as I could but there is plenty of room for improvement.
Click to expand...

There seems to be some question about that 90 hp number. Piper claimed 90 hp, but Norton claims the 750 only made 74 hp with the 8-valve head. Maybe we're mixing up shaft hp and rear wheel hp again. Or the 90 hp Pete mentions might be from a 920. I used to drop in at Fair Spares, now Norvil, back in the '80s when I had business trips to England, and I remember them running the 8-valve head in a race bike with a 920 engine. On the other hand, my memory isn't all that reliable now.

Ken
 
lcrken said:
I have the other two pages of the article, but only in .pdf format, which photobucket doesn't take.
Ken
Click to expand...

If you need help converting just let me know.
 
Thanks,Dave, but I finally got around to downloading a conversion program. This is all three pages of the article.

8 valve head conversion


8 valve head conversion


8 valve head conversion


Ken
 
Ken,
It has been 4 or 5 years since I talked to Andy Molnar about the eight valve project. At that time , all the tooling and patterns could be had for a price. I remember talking to you about that situation. I respect your experience and opinion on these matters. You have been the lead man on several projects that have brought some great products for the rest of us. Unfortunately projects of that type do come at a price. You (and I) felt that Andy was not asking an unrealistic amount for the works.

I was not convinced that I would ever recover the cost of getting into the custom cylinder head business. Andy was not interested in producing any himself. A person could get into that business for the cost of a new automobile. All that would get you to the point of being able to start doing the re-engineering and tuning work.

Gary Robinson got into this cycle years ago with the Thunderheads for Harley Sportsters. He said that he lost an important part of his backside anatomy on that deal. Turned out to be a great product with the potential to sell to thousands of Sporty owners. He had the misfortune to have a product that exceeded the demand.
 
That was my recollection of our discussions. With the small number of owners willing and able to spend several thousand dollars for an 8-valve kit, you'd do well to break even on cost, and certainly never recover your initial investment. It would have to be a labor of love by someone who could afford to lose a lot of money and time. Now where did I put that lottery ticket?

I'm just grateful that Ken jumped in with the Fullauto head production. I'm quite sure he isn't getting rich off all us tightwad Norton owners.

Ken
 
One of the mates raced a triumph with the nourish weslake top end crank and pistons in the period four unlimited post classic class here in Melbourne, quite sucessfully I might add, The weslake designed top end owes little to the original triumph configuration with a pent roof combustion chamber and flat top pistons, in retrospect this design was the forerunner for all modern four valve designs.
heres one I found on craigslist.

8 valve head conversion


950 NRE Nourish Weslake race engine - £1600

950 NRE Nourish Weslake engine 80.5 x 93

Pistons and rods practically new.

Heavy duty 'Puma' cases. These will not fail!

Iron barrel for better heat disipation.

180 degree crank.

Engine studs spaced out to enable engines bigger than 1000cc to be achieved with bigger pistons, if you're brave enough.

This is one stonker of an engine @ 95HP. Bags of grunt. I loved riding it but unfortunately stripped it to have the crank lightened and then went and bought a triple instead.


sounds like a bargain to me! :)
 
lcrken said:
That was my recollection of our discussions. With the small number of owners willing and able to spend several thousand dollars for an 8-valve kit, you'd do well to break even on cost, and certainly never recover your initial investment. It would have to be a labor of love by someone who could afford to lose a lot of money and time. Now where did I put that lottery ticket?

I'm just grateful that Ken jumped in with the Fullauto head production. I'm quite sure he isn't getting rich off all us tightwad Norton owners.

Ken
Click to expand...

Correct. May have my not inconsiderable investment back in a few more years. Or not.
 
He who can read between the lines and is familiar with the niceties of British jounalism in conjunction with the customary unrealistic and over-positive "riding impressions" given, knows from that "test" the testbike performed like the proverbial dead bockwurst. Which it did when Nortons themselves first tested the Piper heads that, to cap it all, fell apart every two minutes- or so those involved with the project still recall. The telling "still in a relatively mild state of tune" phrase is in the test, a phrase that is the British journo's way of telling the more intelligent part of the readership the thing hesitated to move under its own steam. Where the 70+ bhp figure comes from that an engine with the piper head supposedly gave when tested by the factory I do not know. I heard figures 20bhp lower from those who tested the contraption.

Having had the misfortune to ride a bike that was the greatest heap of s**t I ever rode, disguised as the "Commando to end all Commandos", built by a character deservedly forgotten now, only to read a delirious writeup on that very heap only weeks later in Classic Bike, I can vouch for the rose-tinted glasses journalists put on. These are even more so when they are being confronted with the latest product from a regular and prominent advertizer.

The 8-valve head was deservedly burried, never to appear again.
 
Bewilderment was the thought at the time Id read it , one that I hit ' on the stands ' .

The Norton Head was RENOWNED for its Breathing ability , or ' Deep Breathing . A ' Paragon ' even .

It seemed there were other isues required further development before the limits of its Capabilities were reached .
notably , the current crowd regard say 30 mm dia as advatageous as regards gas speed , therefore , :D we would
assume another few thousand rpm's are redilly available without impediment with the 32 mm dia port ' Combat ' Head .

This possibly explains a reputation in regard to reliabiliy which is as much to do with disregarding the stated maximum revolutions . A study into the optioms to increase the durability of the ' bottom end ' to withstand operation at up to
10.000 rpm's or beyond ( for future top end enhancement :D ) would be a more practicable and PROFITABLE persuit .
 
ZFD said:
He who can read between the lines and is familiar with the niceties of British jounalism in conjunction with the customary unrealistic and over-positive "riding impressions" given, knows from that "test" the testbike performed like the proverbial dead bockwurst. Which it did when Nortons themselves first tested the Piper heads that, to cap it all, fell apart every two minutes- or so those involved with the project still recall. The telling "still in a relatively mild state of tune" phrase is in the test, a phrase that is the British journo's way of telling the more intelligent part of the readership the thing hesitated to move under its own steam. Where the 70+ bhp figure comes from that an engine with the piper head supposedly gave when tested by the factory I do not know. I heard figures 20bhp lower from those who tested the contraption.

Having had the misfortune to ride a bike that was the greatest heap of s**t I ever rode, disguised as the "Commando to end all Commandos", built by a character deservedly forgotten now, only to read a delirious writeup on that very heap only weeks later in Classic Bike, I can vouch for the rose-tinted glasses journalists put on. These are even more so when they are being confronted with the latest product from a regular and prominent advertizer.

The 8-valve head was deservedly burried, never to appear again.
Click to expand...

Well at least he had the balls to try it...in the words of the great Burt Munro " try and try again"! Better to try and fail .than never try at all...sounds like you have a real beef with the man :!:
 
John,
I don't think you got the point. Applause for trying, I'd most probably done the same, and my comments had nothing to do with my feelings towards Mr.Emery. It is about whether or not the whole project is appraised here in a realistic way. Which, according to information I got from people like Richard Negus, Bob Rowley, and Norman Hyde, it isn't. The whole Piper 4-valve head was a flop from the word go. Something to do with the basic design I was told by others who spent their lives improving 4-stroke engines and know far more about them than I ever will.
The Commando that I moaned about, just to give an idea on what to think of "tests" in Classic Bike, had nothing whatsoever to do with Emery, and I'd have freely given the name of the dipstick who built it, but the name escapes me now. That was in the early 1990s, and the glorious Norton tuner to end all tuners, who had his five minutes of fame in Classic Bike, is now deservedly forgotten.
 
This sounds an awful lot like sour grapes, Joe. Not like you....

Doug Hele mentioned 74 hp @ 7400 rpm there in that article.
Without seeing a torque curve or knowing the cam, thats about 50 % more than an 850 gave.?
Not to be sneezed at.

Some of the better 4 valvers around, after some development, output more low down torque than a well know brand of big twin. Not to be sneezed at at all.

But that Piper version would never do it, looks too much like a later econo CB250 !!!
 
No sour grapes here- I wasn't interested in that head or engine, ever. I wonder, though, whether Doug Hele really talked about 74bhp, or whether somebody told the journalist this was what Doug said. Certainly, at the time when I talked to Norman Hyde about it, he was nowhere near that figure but recalled it giving about as much as a production engine, though only for a short time.....

74bhp according to Peter Williams was what the best works 750 engine gave, ever, on the brake, and that is at the crank. He told me so at Salzburgring in July, 2009.

I should be more than surprised if that Piper engine gave anything near as much, and so would those involved in testing it at NVT no doubt.
 
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