4 valve Norton Manx

Three computers and still no photobucket success. I give up and will stick to origami !
Thanks again John for your kind assistance.

This is the best I can do, hopefully is is enough to show the basic arrangement in sufficient detail.
In a previous post I incorrectly said the injectors were located via a boss on top of the intake runner. In fact they are located below the runner, the threaded holes just being visible. The fuel spray was directed against the back of the intake valve.
Just visible up inside the combustion chamber is a squish land on either side of the valves. The head sat on thick cast iron liners which were deeply spigotted into the crank case. The liners were surrounded by an aluminium jacket which was rubber sealed top and bottom. Valve sizes were huge, intake 53 mm, exhaust 45 mm, and both were sodium filled

A bit more info on Kuzmicki here, regarding how Norton came to find Leo Kusmicki in their midst.
http://thevintagent.blogspot.com.au/201 ... quish.html
one comment at the end of the article states.
“Charlie Edwards's recollections that you quote from Woolett are consistent with those of Geoff Duke from his autobiography (In Pursuit of Perfection, pg. 51). Duke says that Edwards discovered that Kusmicki the sweeper had some good ideas about internal-combustion engines and introduced him to Joe Craig, as you state. Given that Kusmicki was a very smart man and knew he knew things that others did not, and given that the Norton OHC racing single was world renowned for its output and dependability, it seems plausible that Kusmicki was smart enough to plant himself inside the race shop with a broom in his hand as a means to bypass the regular hiring channels. Sure it's speculation, but it makes more sense (to me anyway) than the argument that the meeting was random chance. including some follow up commentary on his hire at Norton”
ando

In 'The Manx Norton' by Mick Walker, the true story of Leo Kuzmicki is told. The factory floor sweeper story is a load of rubbish, Kuzmicki was a trained engineer who got caught up in WW2, captured and suffered at the hands of the Russians, escaped and eventually made it to England where he enlisted and fought on the side of the Allies. After the war he obtained a position with AJW, a would be motor cycle manufacturer, and from there to Nortons, answering an advert for an engineer. His widow told the story of Kuzmicki's background to Mick Walker when he was researching material for his book. It is generally acknowledged that Kuzmicki was the brains behind the post war Manx engine development. Apart from containing further details on the above, the book is a good read.

johnm said:

The photo from underneath for Snotzo

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Thanks for the pic, and the international cooperation to show it.
Quite good, for pre digital era - when you didn't know what you had captured, if anything...
Big valves indeed.

Be quite a fearsome beast, with its full quota of hairpins fitted.

Snotzo said:

The 4 valve norton back in the 60's/70's was built by Sid Mullarney, with guidance from Bill Lacey, who made certain Cosworth parts available for examination in the design stage. Drawings were done by Tony Monk, but the engine was eventually completed and raced with great success by Bob Newby. The Mullarney original was a 350, but subsequently a 500 engine was built and was permitted under the then existing rules.

Some interest has been expressed in building replicas of the Mullarney 500, but all representations have been turned down, citing the rule that if only one machine of its type was made, then only that machine may be used. While this rule is still enforced in Classic racing, the Isle of Man run under their own rules, and machines such as the MV3, Paton and Molnar4v are apparently welcomed.

While Andy Molnar's 4 valver has an incredibly good external likeness to an original 2v Manx, the Mullarney engine top end looked very different.

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Well personally I'm disappointed that the Mullarney 500 4 valve Manx is generally illegal - just because I'd like to see it (and more of them) racing. Does anyone have any photos or more info on it?

If the 2 valve manxs are faster though,
maybe a question needs to be asked around why we would want to see more of them,
when they are not remotely authentic to the period ??
And not going to give better racing. Yet.

Now, if they were in some other class where they wouldn't detract from the 'real thing',
I couldn't agree more....

Well personally I'm disappointed that the Mularney 500 4 valve Manx is generally illegal - just because I'd like to see it (and more of them) racing. Does anyone have any photos or more info on it?
jseng1

The Mularney machine is eligible in CRMC events, Classic 2 , for machines raced in GP, TT and certain short circuit racing, 1964 to 1972. Being the only one, it's up to the machines owner, Bob Newby to decide if it will ever race again.
I knew the builder, Sid Mularney quite well, and the draftsman, Tony Monk, very well. Sid at the time had MGP winner Dave Williams working with him, and it was Dave who did most of the machining. I have quite a lot of the details of the engine build which I will endeavor to find. A rather interesting side note to this - Dave Williams worked as an engineer at the OCTEL Company Ltd, a company for whom Leo Kuzmicki also was working for in 1975.

The basic details of the Mularney 4 valve engine are as follows.
The engine was based on the 76.7 mm stroke (and flywheel assembly) of the 350 Manx married up to a 90 mm bore using a Cosworth piston. Mularney had developed his own crank, using an interference press fit crankpin, in conjunction with a Titanium con rod.
The total swept capacity was 488 cc. Tony Monk drew up the cambox, which used only three gears, each camshaft carrying two cam lobes which actuated the valves via Cosworth buckets. The cams were copies of Cosworth DFV items, giving a valve lift of 10.4 mm for both valves, and set to the standard Cosworth timing figures initially, of max. lift at 102 degrees before and after TDC, exhaust and intake respectively, although Sid later preferred the exhaust cam to be advanced by 2 degrees. The valves were to Cosworth specs, but both were increased in size to 30.5 mm exhaust and 36 mm intake.
Compression ratio was initially set at 10.8 to 1.
Early dyno tests carried out on Bill Lacey's dynamometer, showed 58.5 bhp at 7000 rpm, power taken from the gearbox output shaft.
At first the race results were somewhat disappointing, but Bob Newby spent considerable time in fine tuning the carburetion, finally sorting the problem by lengthening the induction tract.
What other changes Bob made he has not disclosed. The engine eventually was said to produce peak power at 8000 rpm, and be safe if run up to 9000.
I have asked Tony Monk to look through his notes of the work he did to see if any photo's exist of the early engine. He unfortunately did not keep copies of the drawings he made, but they have been preserved and are in the possession of Michael Mularney, Sid's son.
For those who have copies of Classic Bike, August 1982, you will find therein an article on the complete machine, together with a rider test by Alan Cathcart.

I'll take a dozen please.
Can they deliver by Tuesday ?


Looks like Panthers and Vinnies get top billing.

Thanks for posting.

If I was involved in historic racing using either a genuine or Molnar manx, I'd be annoyed if somebody fronted with a 4 valve manx engine in their bike. However if the class was intended to promote development and the organisers were up front about it, I'd be happy to compete. I think a Seeley frame, TTI 6 speed box with a late model Jawa speedway engine would be a delight to race. I'm amazed some event organiser has not already gone down this path. If it had happened in the 60s with two strokes and multi cyl.bikes excluded and a 500cc capacity limit, the manx and G50 might be now be very interesting.

With historic racing there is always somebody looking for a way to cheat. One guy suggested that because the Wal Phillips fuel injector existed in the 50s, he could run one with an appropriate modern EMS.

I had a bike fitted with a Wal Phillips fuel injector way back when. It was the only way to make it rich enough to stop the thing seizing. Yes it was a 2t.

A they weren't really a fuel injector at all, more like a floatless drip feed. A tube and a hollow spindle with fuel delivery holes in, linked to the throttle. Rubbish really.
Any attempt to make it an injector in the modern sense would be no different from adding an nozzle and electronic gubbins to an AMAL.

Wal Philips designed his 'injector' for use on JAP engined speedway machines, where the fuel was methanol.
Some folks, nickguzzi included, tried them on engines that were road raced. One instance that I personally knew about was the injector that Sid Lawton fitted to one of his AerMacchi's for the I.O.M. Rider was Tom Phillips. Sid mounted an SU float bowl alongside the injector, and found that not only did it make for much easier starting, but returned incredibly good fuel economy - and the bike was quick. Unfortunately Tom crashed in the race in the Greeba section and ended up in an intensive care unit. I never heard of Sid using the injector again.

This is some way off the manx 4v original post, but some may find the injector info of interest.

The suggestion was not about using a Wal Phillips injector in it's original form. It was simply mentioned as an excuse for fitting a full fuel injection system with EMS to an early bike to be used in historic racing. For myself I don't have a problem with that unless the class is intended to only include bikes representative of the era. One thing or the other - authenticity - or open slather. Cheating stuffs historic racing, and historic racing stifles development.

Presumably it would have to be some sort of silhouette class.
As the Wal Phillips device was much cruder than a carb and was an "injector" in name only, I would think it would be easier to convert a period carb to proper injection - you could at least try to hide the injector in the float bowl for instance.
Then the other difficulties arise - quite large electrical demand, where to hide everything else, getting it approved if it wasn't quite a true silhouette etc.

Back to the topic, I feel it is a shame not to allow the development of 4 valve engines. Some of us are more interested in the technological developments than who won (yes I recognise there are plenty of folk who have the opposite priorities).
Once machines like the Mularney are too fragile to be made competitive, they just become museum pieces. Just like the real Manx.
Once the Aermacchi appeared, the writing was on the wall, particularly for the 350's. A couple of years on the Japanese 2t's arrived and it really was all over. *
No one wanted to spend the money to properly fettle the Manx so they were usually thrashed n' trashed or retired. I stupidly refused a knackered 350 for £200.
Similarly I turned down a Post war Vincent twin - can't remember which model, asking price £90. I found out later it had been pushed into a cellar of a house which was bulldozed for a new road. Real archaeology to unearth that one.

Genuine period racing machines are mostly too fragile, and often dangerously so, to really race. The Molnars and Walmsleys and Summerfields etc provide the machinery for proper racing.
They may not be the real thing, but the racing is, and bring the delights and despairs to their riders and tuners as well as Joe Public like me who goes to watch.

* at least that was more or less what happen here in UK.

I have no problems with the 4 valve Manxes and special one offs, but they need to be run in their own class as Nickguzzi suggests.
I myself would love to develop such an engine but what would you do with it?
nickguzzi I brought my 1955 MANX (82x 88) for $375 Australian in 1971 and still have it and now, about to undergo a rebuild for Broadford 2015.
Best Regards
Burgs

Burgs said:

I have no problems with the 4 valve Manxes and special one offs, but they need to be run in their own class as Nickguzzi suggests.
I myself would love to develop such an engine but what would you do with it?
nickguzzi I brought my 1955 MANX (82x 88) for $375 Australian in 1971 and still have it and now, about to undergo a rebuild for Broadford 2015.
Best Regards
Burgs

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I absolutely love the Molnar and Walmsley bikes. I just wish I owned one. If I had a genuine Manx, I would never race it. I know of a guy in Sydney who owns two genuine factory bikes - the Artie Bell TT winner of about 1952, and the Eric Hinton bike from the fifties. When I look at those I recognise their intrinsic value. The claim that something is only worth what you can get for it when you sell it, is just bloody stupidity. If you see something like that being ridden by someone such as Surtees or Hailwood, you've had a life experience. However if you modify the bike in the process - what have you done ? They are a piece of history. Would you hang the Mona Lisa in your lavatory ? If we really want to race and have fun, we need a development class for 500cc air-cooled singles with no other rules. That way we can use up all the old Jawa speedway motors and other brands, and the racing would be much cheaper with no cheating. 'The best rules is no rules' ?
Probably the best fun way to go road racing ever. It's on 14 to I comp. methanol fuel, a race motor, cheap to build, reliable, and as fast as a molnar manx. :

This really does it for me. It is not eligible for any Australian road race class. Now why would that be the case ? You could build it for less that $5000 and it would be cheap to race and you would not be destroying a piece of history. I suggest we tend to put ourselves in a straight jacket when we race :

You can start with a new off-the-shelf engine :
http://www.speedwaybikes.com/cody/images/IMG_2375.JPG

acotrel said:

If we really want to race and have fun, we need a development class for 500cc air-cooled singles with no other rules. That way we can use up all the old Jawa speedway motors and other brands, and the racing would be much cheaper with no cheating. 'The best rules is no rules' ?

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You mean like these? These are two of our team bikes that we raced here in AHRMA Supermono/Sound of Singles classes, one with a Yamaha SRX-6 engine de-stroked to fit the 500 class, and the other with a Honda Ascot 500 cc engine, both air-cooled singles, but in our own chassis designs. We got a lot of class wins with them, but they were eventually outclassed by modern water-cooled bikes that run in the same class. My racing partner (the frame designer) got the bug to get back on the track after a 10 year break, so he rode the Yamaha in a few AHRMA races this year, just for old times sake. We'll probably do that again in 2015.





We also raced a Ron Wood SJ600 with a Rotax air-cooled single in the open singles classes. I eventually converted it to the water-cooled head twin cam version, but these pictures show it with the air-cooled engine. I raced it as an open singles bike, but with the 500 cc Rotax engine in place it would also fit your specifications for the class. The rider is of course me in my younger days (relatively younger, that is), with the bike still pretty much as Ron sold it. I later upgraded it a lot. The last picture shows it in it's current configuration.







You did say 500 cc air-cooled singles with no other rules. Or were you thinking of only vintage singles with modern updates, or some other sort of restrictions to keep modern bikes out?

Ken

When I race, I don't care what year the other bikes were manufactured. It is about the technology being similar. Obviously 4 valve motors give about 10% power advantage compared with a 2 valve motors, however I can live with that. Is your race class a normal AHRMA or AMA class ? I really love those photos you posted - made me feel the urge again and gave me hope that there is still sanity somewhere on the planet. It would be really interesting to race a Molar Manx against those bikes. And I cannot see why it should not be done. I've seen races here at Phillip Island with 60s two strokes racing against original manxes - seems obscene to me.
I don't know why, however I really dislike modern historic racing. Either you really race or you do demonstrations. There is no middle ground as far as I am concerned. The bikes in the photos you've posted are the real deal, and worth racing against.
I believe that there should also be development classes for aircooled four stroke twins up to 1000cc . We haven't seen a 750cc Paton yet. I'd love to race the Seeley Commando against a Paul Smart Replica Ducati.