180 vs 120 oil pumps

Piet,

OK if I understand this correctly, triple oil pumps are.

1972 through 1976 have 7mm pumps. (1000cc 180 motors)

1977 through 1982 have 9mm pumps. (1000cc and 1200cc 180 motors including series II)

1982 through 1989 have 10mm pumps. (1000cc 120 motors)

Andy Wagner only sells the 10mm pump and it is shown as being suitable for all 180 and 120 bikes. So I am assuming what he is making is the last version 120 pump and it will fit any 180 or 120 triple?

Bruce
 
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Most probably Wagner uses the 10mm gears as also used in his 750 pumps, so no, it's most likely not the same as the 120° pump. Width means nothing without also stating diametre and tooth count.

The 180° gears have a different pitch to the later 120° pump gears, see my post that Rob kindly dug out. Wider is not necessarily better, nor is the same width the same in volume numbers.

Displacement volume of the pump is determined by the volume of the tooth gap, which in turn is a product of gear module, width and tooth count.

Basically, any triple pump will fit any triple engine. Basic design and drive train remained the same from beginning to end.

piet
 
3crider said:
Just a note on oil pressure. Let’s not try to compare a Laverda engine with a plain bearing car type engine. Plain bearings generate and need oil pressure to keep the crank and other plain bearings such as the camshafts from touching. The oil pressure is generated by the oil pump delivery exceeding the oil leakage past the bearing shells and the rotating elements. A loss of oil pressure is almost always catastrophic for such engines. Such engines also need an oil pressure relief valve.

Laverda engines have rolling element bearings on the crank and elsewhere. Rolling element bearings only need about 1% oil to lubricate with the other 99% generally for cooling.

The Laverda engine needs and will happily run with very little oil back pressure and any pressure generated is from restrictions due to the oil galleries, camshaft plain bearings, oil cooler, oil pipes and oil filter, (if fitted).

The biggest weakness, IMHO, is the gearbox output stub shaft plain bush that receives no oil pressure and is dynamically loaded in 1st to 4th gears. Top gear is a 1:1 is a straight drive through so no differential motion. (Note: Some of the racers used needle (rolling element) bearings for this very reason but on a machine running in top gear for long periods, such needle bearings could brinel. The design is just poor.

The freewheeling gears in the gearbox also have plain bushes but spin under no load and are stationary (so no differential motion) once in their gear, so generally get enough oil.

So, Laverda engines do not rely on oil pressure but do benefit from oil flow. That oil flow also helps with cooling. So, a larger pump would not be a bad addition as long as the back pressure generated from such a positive displacement pump does not rise so high that the crankcases and pipes etc get hydraulically overstressed as there is no oil pressure relief valve.
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How do the cam bearings fair in this? Would they benefit from a restrictor orifice to increase pressure to them only?
 
Paul Marx said:
Why modify something that's satisfactory?
Paul
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The standard bike is satisfactory but we all mod and tweek for reliability, performance, handling, comfort or whatever.
In this case, I'm not seeking to modify, just exploring possibilities around oiling with ref to 3crider's knowledge.
 
Oil supply to the cams is one of the least worrying issues within these motors. In fact, it is restricted in 120° engines, the exit bores in the cam bearings being only 1.5mm as opposed to 2mm for the 180s. This in turn increases flow elsewhere.

No need to re-invent the wheel.

piet
 
RobinCov said:
The standard bike is satisfactory but we all mod and tweek for reliability, performance, handling, comfort or whatever.
In this case, I'm not seeking to modify, just exploring possibilities around oiling with ref to 3crider's knowledge.
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Yes, but moding for reliability something which is satisfactory at best is a waste of time and mostly ends up wrecking a perfectly good engine.
Paul
 
sfcpiet said:
Oil supply to the cams is one of the least worrying issues within these motors. In fact, it is restricted in 120° engines, the exit bores in the cam bearings being only 1.5mm as opposed to 2mm for the 180s. This in turn increases flow elsewhere.

No need to re-invent the wheel.

piet
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I didn't realise there was already a restrictor built in... Every days a school day.
Thanks
 
MVma said:
3C/3CL 7mm : 7,8 liters/minute
1000 Jota/1200 9mm : 10 liters/minute
RGS 10mm : 15,6 Liters/minute
"New" production 10 mm: about 10,8 litres/minute (actually quite variable depending on the manufacture).
Click to expand...

Looking back in this quote, it cannot be right.
The oil pump is a gear type and deliverers a positive displacement. Therefore, for any given revolution of the engine, a given amount of oil will be delivered. Yes, there will be a tiny amount of back pressure leakage across the pump but ignoring this, as the revs build, more oil is delivered per unit of time, to the engine. So the above quote in liters per minute must be wrong unless is is quoted at an exact engine rpm, which it is not.
The units should be quoted as volume per rotation of the oil pump or per revolution of the engine, probably in cc's.
If the pitch circle diameter of the gears, the numbers of teeth and the effective circumference of the working section of the pump were known, together with the drive gear ratio, the oil delivery figures can be calculated either in cc per revolution or liters per minute for a given rpm of the engine.

Nick
 
3crider said:
Looking back in this quote, it cannot be right.
The oil pump is a gear type and deliverers a positive displacement. Therefore, for any given revolution of the engine, a given amount of oil will be delivered. Yes, there will be a tiny amount of back pressure leakage across the pump but ignoring this, as the revs build, more oil is delivered per unit of time, to the engine. So the above quote in liters per minute must be wrong unless is is quoted at an exact engine rpm, which it is not.
The units should be quoted as volume per rotation of the oil pump or per revolution of the engine, probably in cc's.
If the pitch circle diameter of the gears, the numbers of teeth and the effective circumference of the working section of the pump were known, together with the drive gear ratio, the oil delivery figures can be calculated either in cc per revolution or liters per minute for a given rpm of the engine.

Nick
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That quote was lifted from Piet's post back in 2015, see excerpt below....
Triple pumps @8000rpm engine speed (5400 pump rpm)
early triples 7mm/16T/23mm dia. gears, 7.84 litres/minute
Jota/1200 9mm/16T/23mm dia. gears, 10.09 litres/minute
Aftermarket 10mm/15T/22mm dia. gears, 10.84 litres/minute
RGS 10mm/12T/23.5mm dia. gears, 15.61 Litres/minute
 
RobinCov said:
Have you got the same graph for 180?
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I can do graphs as well. What would you like to see on one?

Seriously, throwing "data" around without citing the source is worthless.
Does hydroxychloroquine improve compression of Laverda triples? I can produce data proving that it does.

Paul
 
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