Norvin Single race bike first run

[greg brillus]

Hi there All........well after 8 months of work, countless hours and loads of money.........here is my Norvin racer that started off with a Jawa (ESO) 500 single engine, now converted to a Vincent Comet engine..........This was it's first run today, and we ran it several times adjusting the ignition timing and the mixture on the Gardner carby........After this it ran very well with no major issues or hesitation when opening the throttle.........There are lots of nice features which I am happy to discuss, and my guess is that it should perform rather well........Hoping to take it to the track later this coming week and give it some shake down runs, bed the brakes in and perhaps set up the front and rear suspension which is all new and fully adjustable.........Must thank Neal Lowe for his help in setting up the ignition and my wife for videoing this without earmuffs on........... ......... Cheers for now.......... Greg.

 

[bmetcalf]

Can you change ignition timing with the laptop?

 

[greg brillus]

Hi there Bruce, Yes it's an Ignitech system and fully programmable........we started off with 5 degrees initial and 30 full advance, but upped it to 10 and 35.........played around with the carb mixture a bit and it ran much cleaner with almost nill hesitation or 8 stroking, which is how it was when first started. Twin plugs with a hall effect pick up and chopper disc mounted to the crank pulley.

 

[davidd]

Greg,

Congratulations! Very nicely done.

David

 

[Martyn Goodwin]

Hi there Bruce, Yes it's an Ignitech system and fully programmable........we started off with 5 degrees initial and 30 full advance, but upped it to 10 and 35.........played around with the carb mixture a bit and it ran much cleaner with almost nill hesitation or 8 stroking, which is how it was when first started. Twin plugs with a hall effect pick up and chopper disc mounted to the crank pulley.

is that with petrol or Methanol?

 

[greg brillus]

It runs on methanol, which is very common on classic race bikes here in Australia and NZ........The piston is a 12:1 comp ratio but we machined some material off the base of the muff to reduce the squish band down to 0.035" so I feel the piston is about 12.5:1 now........ I will get some pistons made to up the comp to around 14:1 to make better use of the fuel.......The piston in it is a CP and nothing really special, so there is more to be done there. The bike was away getting the exhaust done by a crowd who specialize in performance exhausts, this uses lengths of pipe that get larger in ID from section to section, and the muffler uses a perforated tube that acts as a mega with absorption material around it. The bike is far noisier than it was with the old engine, and this did not surprise me at all........ I feel it will be over the DB limit at some tracks so I will need to do something there. We had also been machining up a nice primary cover for it, and this is mostly finished.........Just the odd bit to finish off here and there now........It still tips the scales under 130 Kg's, this with oils but no fuel........ i was happy to get that figure as it weighed in at 130 with the old engine, and I know the Comet engine was a few kg's heavier than the ESO.........As usual I've gone overboard with it, but that's just what I like to do.

 

[Mike 40M]

Please, give us more pictures. How did you manage to get weight 10 kg less than a standard Manx?
I'd suggest that you move the kill switch. A good place is where the GP carb air lever is close to the clutch lever on a Manx. I can flip it with my left thumb, still gripping the handlebar. My Gardner came with a grub screw as a throttle stop. It dropped down blocking throttle slide partially open. In a situation where taking hand off the handle could have caused more problems. Now replaced with a hex head screw.

 

[Martyn Goodwin]

Methanol - here is a 'lift' from the next edition of OVR that has direct application.

 

[greg brillus]

Sorry for the delay, I'm going to a track day tomorrow, lets see if it and I hold together..........Been busy with getting it ready so will report on progress and so on after........Cheers.......Greg.

 

[greg brillus]

Minor update, so we did the track day.......All seemed to be ok it started up fine with no initial problems.........After about 4 or 5 laps I returned to the pits......the throttle was sticking pretty much every time, and there was an oil leak that appeared to come from between the head and cylinder barrel........cleaned it up with some help from Peter and Kevin who came along for support.......Gave it another quick run, but same thing over again.......Packed up and went home.......on inspection the carb has a tight spot with the feed tube and the long mixture screw, plus the return spring seems too weak.......The oil leak was definitely from the head/barrel joint but caused by oil passing up the threads on the right rear cylinder hold down stud.......I'm pretty sure i used some liquid thread sealant on all of these........But the oil feed from the auxiliary pump is forcing much higher pressure on this point.......... Anyway it is all fixed now and awaits another run......... I blanked off that spindle with a disc of brass sheet, and have opened up the timing cover jet holder so the excess pressure passes down to the lower gallery and will use the original relief valve to dump the extra pressure........the cam and followers is getting plenty of oil delivery now........The carb was a matter of some fine fettling and I added an extra piece of spring to boost the original one......... It would appear that it might pay me to add some oil or similar additive to the fuel to help lube the carby slide and the top end of the engine, as methanol runs very dry and is quite harsh on the bore as well......... I have seen plenty of racers at the tracks using methanol and having no end of trouble with the carb slides hanging up, so it is not uncommon.......... The noise from the exhaust wasn't so bad at the track........And I don't think the engine vibrates as bad as the last one.........It certainly has no shortage of power, given the extra capacity........92 x 100 bore and stroke. Let the fun begin.......