Norvin Single race bike first run

bmetcalf

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" oil feed from the auxiliary pump " Do you have a gear pump like Marcus/French Section? Apologies if you already described it; if so, can you post the link?
 

greg brillus

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Hi there Bruce, yes a small Mikuni oil pump off a DRZ 250 Suzuki dirt bike.........Similar set up to Marcus's one but spun much slower........ I think Marcus one spins at the same speed as the crank, whereas mine spins at the same speed as the large idler gear.......I will post some pics of it in the next day or so.........Cheers.
 

Marcus Bowden

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Greg my handsome,
Why so much oil pressure going to the cylinder liners, I've had mine blanked off for thirty years.
The pump is a Honda 90 step threw and only supplies the cams at about 15psi (1Bar)
The next Comet will have the same pump but fed directly into the oil filter chamber so all oil is filtered then get as much pressure as possible to B/E bearing with 5 to 10 psi to cam, again no oil to cylinder liner.
About the 1950 Grey Flashes were tried with a plain bearing (RR77) but failed but no one mentioned any change in pumping arrangments, but PCV did wish he kept his gear pumps from the "A's". presently doing an "A" Comet with a plain bronze B/E with a 3/16" wide supply pump .
bananaman.
Yes there is a storie of a Two CV in the tropics requiring lubricating oil so they squeezed in ripe bananas and kept the engine going much more quietly than beore.

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greg brillus

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I did not drill the liner and figured that this might have been enough, but the extra oil pressure made its way up the stud threads........now blanked off at the cover. I am not sure that running high oil pressure to the big end is a good idea, and this was why I wanted to keep the 2 pumps separate via the restriction in the timing cover........I feel the aux pump needs some kind of relief valve so it now shares the one down the bottom with the original pump set up.
 

greg brillus

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has anyone got any idea what the stock relief valve limits pressure to......?.......My thoughts about the aux pump was to simply drown the cam lobes and followers in oil.......Thus by running it at the same speed as the large idler, and with the engine running at race revolutions........maxed at say 7000, it should not deliver insane amounts of oil.......So it takes 3 1/3 turns of the crank for one turn of the large idler......At 7000 rpm the pump would be turning at just over 2100 rpm........I was able to spin it up to about 1500 with my drill and the delivery was not excessive..........
 

greg brillus

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Thanks Mike, I was a bit suspect of a weak spring, so I added another short length of a stronger spring to help.........The lower feed tube and the upper tapper needle seem to be offset in the housing slightly to the rear of the carb........this seems to add to the "Jamming affect" of the slide as it closes........I have added a thin brass shim to the upper housing joint to help here. I forgot to reply to your query about the weight of the bike verses your Manx........ Well that is a difficult one..........I know the Slimline frame is heavier than a genuine Manx frame........have you ever had your bike on the scales to see what it is........Mine is almost exactly 65 Kg's on the front and same on the rear........this is with oils but no fuel. I have gone to a lot of trouble to save weight in many area's over the whole bike........at significant cost too.......But I did not machine any material from the main engine casings or covers. Lots of small weight savings, including all new suspension........the rear coilovers are very light weight, as are the Ceriani fork yolks. Do you know what the Manx engine weighs........They are a large engine with massive fins and cambox............ Cheers.
 

Mike 40M

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Weight lifting is not my favourite sport. A 350 Manx engine I have laying around weights approx 41 kg with magneto, without carburettor. The one I raced last weekend is 70 kg front and 79 kg rear. Quite a standard one with flyscreen. 2 litres of oil. approx 1 litre petrol. HEAVY duty TTI 5-speeder. Homemade silencer at 800 grams. Gardner carb and float bowl, lighter than a GP.
Edit: According to bathroom scales, which I think is relatively accurate. Wife doesn't think so.
 
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