Visual or dimensional difference......
- Thread starter Robert E Naess
- Start date
Hello Trev, Can I take credit for making the plunger in my photo ? Cheers Bill.
Trev, Is the pump hole in the cases offset ?Cheers Bill.
That was a good read Roger, I must not thrash a cold engine !! A bit late after all these years !! Cheers Bill.
This all plays into my hands !! That I said from the start, Only use the single start pump !!Then you won't have to wipe the oil off your face, And you can put your old Bean can in the bin !!. Cheers Bill.
Just reread Kerry's bit from Roger, What he has left out is the fact that oil is already all over the working parts of the engine, Like when you start up, So although it's not pumping it's still there doing the job, I had a case years ago when sprinting, / Drag racing, My bike was going well, But at the end of the day I thought it was getting a bit noisey, Had a look in the tank, Nothing going round !! The pump had worn out But it was still going !!. Cheers Bill.
Bill: Thanks for the geography lesson about where Conways was located....I can still see that chopper Vin in that window to this day. At the time Shepard's Bush seemed a bit down its luck, but there were lots of ads on the telegraph poles offering spankings for a few quid!
The cycle shop where I bought the Vin was not on Goldhawk road, but some other place and was maybe called Goldhawk Motors, or? I can't remember, but they had a LOT of bikes and the fellows there who sold me the bike were quite struck dumb when I told them I was taking it on the "continent". They wanted to just ship I back to the US for me...... 8^)
timetraveller: thanks for your comments. it can measure the spline cuts and insure that the are correctly cut. Doubt that I will use the two start pump. Mostly sorting out stuff.
Much interesting info squeezed out however.......
Just had a thought, Just looked back at the Greg Brillus Threads, He used a 2 start on his new racer, What plunger did you use Greg ? Cheers Bill.
Hi there Bill, I think I bought a matched set from Maughan's.....being a two start pump and worm. It is quite novel seeing the faster delivery back to the tank, and I made a small baffle similar to what Norman described to stop the flow from coming "up" the spout. I also fitted a tank cap that has "No" oil hole in it at all.....the tank is breathing via the chain oiler at the rear which I have ran a line down into the top of the G50 plate and into the kickstart housing cavity, I drilled and taped a fitting immediately aft of the clutch cable abutment, this is also where I run the main engine breather to as well. But it connects at the bottom where the G98 kickstart spring sleeve screws in. I made the lines larger than standard......so far everything working well......no oil leaks, and very little oil/water collects in the kickstart housing area after an event, perhaps a tablespoon full, which I draw out with a piece of clear tubing.......Greg.
Hi Howard
Correct, essentially, there is little more than line contact between the worm and plunger teeth, and I wouldn’t think it is critical to use an angled tooth plunger with a two start worm. Desirable yes, but probably not mandatory.
However, and notwithstanding the fact your question has put me on the spot,
this is what I would do If I had a spare two start worm and a standard plunger.I would first check the tooth clearance in the standard setup.
So I’d start by removing the large hex nut and the plunger guide peg.
Screw an extractor screw (c/w nut) into the plunger and with draw it sufficient to lock the screw into the plunger.
Push the plunger back into its housing and install the guide peg.
Rotate the plunger back and forth (circular motion). This should give us a fair idea of the play/clearance between the teeth of the standard components. (If memory serves - and its almost 50 years since I last worked on a Vincent engine - there is quite a bit of play in the system)
Make a note of the clearance and then strip out the peg, plunger and worm.
Install the two start worm on to the shaft and insert the plunger and guide peg into the housing.
Again, waggle the plunger back and forth (circular motion) and make a note of the clearance/play and compare it with that of the standard setup.
If there is still a fair amount of clearance, and I think there would be, then in theory everything should be ok. However, we must go a step further and rotate the engine several revolutions until the plunger has revolved at least once, all the while checking for that all important clearance or play.
In the standard setup it appears the plunger rotates once per 15 engine revs or once per 7 ½ revs with a two start worm, so I would check the clearance every engine rev for at least 8 revs. Or twice per rev even.
If everything checks out clearance wise then again, in theory, we are home and dry.
But there are two caveats that I can think of.
The plunger turning twice as fast as standard would lead to increased wear in the plunger housing and more wear and stress on the plunger guide peg.
So on balance if I were a long distance cruiser ( in my dreams) I’d probably leave well alone and remain with the standard setup.
But if I were building a race engine or one used for occasional use, I’d use the two start worm and probably in conjunction with a lighter multigrade oil.
That is what I’d do on my Vincent (if I still owned one) under the circumstances outlined above.
So this is not advice, just a personal opinion.
Hope that helps
Regards
Roger
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