Having followed up on Olderdan's hint to check the U tube videos, it would appear that the taps were made from bolts with the existing thread form. While I had always understood the basics of making a simple "thread chaser," the one video goes into detail making a real tap from an existing bolt. This is a bit more involved and requires a substantial equipment outlay. I guess I will be needing to buy the taps. Thank you for sharing all the same.
olderdan (Sep 24, 2017)
You are right about them being a pig to adjust, I wish I had thought of your brilliant mod about 50 years ago, never seen one on a 2 stroke before.
I got shot of them after a while as for a road bike if you forgot to turn of the fuel as you stopped you ended up with a sump full, I don't think they were ever intended for road work so I switched to twin Amals which seemed to work almost as good except on full bore.
Actually they were advertised at the time for road use as well as Racing, although Wal was a speedway bloke so IIRC they were first made for speedway. That means using alcohol which needs much less accurate mixture control than petrol.Originally Posted by olderdan
I used them and my clones for only a few years, always on race bikes only. I later used various carbs of my own design and later still discovered the Gardner carbs which were superior in all aspects. In the early 70s I moved to England to race in the island. I started a business making cast wheels and race chassis and Ron Gardner came to me for a chassis to resurrect the Rudge marque for which he and a partner owned the rights. He had stopped making the carbs then due to other work, we had become friends and I approached him with the idea that I restart the manufacture of the carbs, but with a slight difference. I was getting a lot of magnesium castings done and I talked him into letting me make them in Magnesium. Since then the interest in classic racing has boomed and those carbs are being made again by the Gardner family but in aluminium again. i still use Gardners on my race bikes unless the regulations forbid them, some organisations do. Then I use a Dellorto SS1.
Click for full size view.
Initial fitting of a WP "injector" on a 2 stroke which was the first engine that I ever built. I did the casting in the backyard.
Last edited by tonyfoale; Sep 24, 2017 at 03:32 PM.
NortonDommi (Sep 25, 2017), Seedtick (Sep 24, 2017)
Hello Olderdan,
Last time I saw it in one piece was around 1980 but from memory that looks very similar, Had the chrome trim on tank and rims but will be painted factory maroon. Needs one rim replaced which is not bad.
I have a reasonable selection of taps but will look at Tracy Tools if any needed. I also find https://www.voelkel-shop.com/en/ not bad either and am in love with their serial taps.
tonyfoale,
Thanks for the observations on the Wal Phillips carb I've never seen one but always been fascinated with their simplicity. There was a popular carb based on similar concept used in USA car circle racing I believe.
To you and Olderdan thanks for the correction as to O.E.C. steering. I did use this idea on a trike front end that was built backwards with one wheel in front as it was set up to move the contact patch to outside of triangle, seemed to work well and a huge improvement over the girder front end it replaced.
it was simple in concept, that is an air valve connected to a fuel valve via an adjustable linkage. However, that simplicity hid some underlying complexity in matching those two valves which was beyond what the linkages could correct, unless the design was spot on for the engine under consideration.
The problem stems from the relationship between the flow area and angular opening of each valve. neither are linear due to the nature of air and fuel flow and geometric effects. As a quick example, imagine that the fuel valve is too large for the engine. A first thought would indicate that you only have to adjust the linkage to open the fuel valve less relative to the air valve. The problem with this is that then the fuel valve is operating in the range where the geometry dictates that the rate of area increase is high. In other words a small increase in the throttle valve opening will result in a disproportionately greater opening of the fuel valve compared to a carb with a smaller hole in the fuel valve. Therefore in order to be able to get good mixture ratio throughout the opening range you would have to size the fuel hole to each engine. Of course as this was sold as a general purpose device the hole sizing had to be a compromise.
On the other hand the Gardner was just as simple mechanically, but much more sophisticated in its mixture production.
Click for full size pix.
Pix of a Gardner.
LOL, as soon as I saw the header I knew it had to be Tony posting. Pretty sure the majority on here have never even heard of a Wal Phillips injector. Takes me back to the 'Pride and Clark ads in 1960's motorcycle magazines, my father was a subscriber, I couldn't wait to get hold of them day after delivery (dire consequences if I opened one before he had a chance to read it LOL)
Didn't Jaguar use a modified version of Gardener at one time? (6 bank with common slide?)
I was always told to use 127 t gear to cut metric threads on inch lathes (the only ones we had when I was training in 1970's)
For anyone who isn't 'keeping up' 25.4mm=1inch, first full multiple of 25.4 is 127. On a big lathe with a lot of torque it can be a big gear though, gear teet can only be made so small before they break up
Last edited by crazypj; Sep 27, 2017 at 10:54 AM.
Unfortunately my father never subscribed to anything like that but I was lucky to have been given about 20 years worth of the Blue'un and the Green'un 1940s through 1950. I read each one religiously and so I formed a good historical background prior to the 1960s when I started riding.
My father did have a bike before I came along but just for transport not for fun. My mother made him get rid of it when he dumped her off the back into mud.
Click to enlarge.
Dad and his bike.
LOL, pretty sure there are still about 20 yrs worth of 'Blue and Green' buried in front garden when my mother made dad 'get rid' of them I remember him digging holes about 4 ft + deep and placing stacks in them.He had them from mid-early 50's until late 60's. Mother couldn't get him to drive so we only had motorcycle/sidecar growing up. I still think outfits are the most fun you can have with your clothes on. He never did get a car licence.
Oh, just remembered , this was about Cycle threads. I learned precision machining so I could fit BSA wheels into my Royal Enfield 'Continental's' (had 5 at one time, could only keep one running though ;o) ) It's come in handy over the years to be able to 'make' stuff fit'
Last edited by crazypj; Sep 27, 2017 at 11:05 AM.
Although I built two championship winning sidecars, my own attempts at riding asymmetric three wheelers always ended with Desperate Dan style holes in hedges. diabolical invention. Actually it was my inexperience with sidecars that allowed me the freedom of thought to design something a bit different which worked well. Today's racing rules have outlawed most of what I did. Here are a couple of pix.
olderdan (Sep 28, 2017)
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