Why the left?

marshg246 said:

I wish I would remember to say "stock bike" a lot more often in my posts. I haven't raced since the early 70s and that was Motocross and Hill Climbs. I don't build/work on race bikes or heavily modified bikes, so I don't think about them. Every bike I build/own, idles as soon as started including Combats, plain 750/850 Commandos, Bonnevilles, Tridents, etc.

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I respect a guy building stock bikes that work. I know you have things under control. I'm generally on the edge of being out of control 24/7 365.

I purposely tune for a fully warmed up motor and just enough fuel at idle to prevent the dreaded first stop sign stall. As it warms up it richens up. My Norton is sort of a mild race motor build with a license plate on it.

I can't remember the 70's in the correct chronological order without putting all my energy into it. All that partying eventually catches up.

What? er, what were the 70s? Where was it? Was it stock or modified? Is it still on offer on ebay?
geez I don't remember either...

Onder said:

What? er, what were the 70s? Where was it? Was it stock or modified? Is it still on offer on ebay?
geez I don't remember either...

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You young'uns should allow your age to be displayed so us old guys know not to confuse you with ancient history

The 70s were a follow-on to the later 60s (starting with the summer of love, 1967: a time when you could still dip your wick without worry of death as a result.)

marshg246 said:

You young'uns should allow your age to be displayed so us old guys know not to confuse you with ancient history

The 70s were a follow-on to the later 60s (starting with the summer of love, 1967: a time when you could still dip your wick without worry of death as a result.)

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Until her husband found out.

They had some good drugs back in the 70s the drugs today just sends people crazy, maybe stop parking the bike on the left side of the sun, hang on where's that Billy, in the old days I did some of my best thinking when stoned but today's drugs are what the doc gives you or the made stuff thats made in the backyard and sends people crazy, you just don't know what's in it or cut with.

ashman said:

They had some good drugs back in the 70s the drugs today just sends people crazy, maybe stop parking the bike on the left side of the sun, hang on where's that Billy, in the old days I did some of my best thinking when stoned but today's drugs are what the doc gives you or the made stuff thats made in the backyard and sends people crazy, you just don't know what's in it or cut with.

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The best drug ( Marijuana ) , is now totally legal all across of my country . New York state and other ones too .
Surprisingly since it's been legalized , I see less people using it every day . It was more fun to break the older laws ?

Since we are talking about drain routes in the head and R. side barrel drain route into timing chest and inequalities in this / pooling left side , how about creating an oil drain channel in the head to equalize ?

I had the bright idea (for a few minutes) to drill the head, cylinders, and crankcase for a left-side drain. Sounded easy until I realized the cylinders have a thicker area on the right for the drain

A groove along the mating surface of the head over to the drain might work, but I would be concerned about leaking and I don't have a mill to try such a thing.

I think I saw somewhere where a drain had been added to the head and then piped to the crankcase.

Torontonian said:

The best drug ( Marijuana ) , is now totally legal all across of my country .

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IMO the legalization of mind altering drugs such as you have mentioned compromises the mind development of our young and believe it eventually dumbs down the younger population that use it...who I believe end up with a lack of ambition and critical/ logical thought.
A attribute alot of the younger generation seem to have these days.
No wonder they call Marijuana "Dope"

marshg246 said:

I had the bright idea (for a few minutes) to drill the head, cylinders, and crankcase for a left-side drain. Sounded easy until I realized the cylinders have a thicker area on the right for the drain

A groove along the mating surface of the head over to the drain might work, but I would be concerned about leaking and I don't have a mill to try such a thing.

I think I saw somewhere where a drain had been added to the head and then piped to the crankcase.

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This is how Steve Maney does it... might interfere with the Magneto installation though

kommando said:

The pressure is reduced by the frictional losses within the galleries, but these are not a lot between the 2 big ends which are close together, especially on a Norton with the large diameter central sludge trap which is less restrictive than a drilled gallery. The problem is they had the exit holes in both big ends the same size. The right hand one gets fed first and with the good flow and pressure the amount of oil that comes out is more than 50% of the oil which then reduces the amount of oil fed to the left side to under 50%. So the left side suffers from a lower flow more than the slight reduction in pressure. The fix would have been to make the hole in the right side big end smaller than the left side so as to equalise the flow out of the two big ends. They would have had to experiment to find the best performing hole sizes, today it would be modelled on a PC.

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And there was me thinking the pressure reduced because the oil was escaping through the oil feeds & big end bearings....

B+Bogus said:

And there was me thinking the pressure reduced because the oil was escaping through the oil feeds & big end bearings....

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And it does, if there were no big end holes and no rockers to feed the pump would still want to feed oil and the pressure would increase until the pump was leaking oil out of the body via the joints, shaft etc until the crank end seal reversed and then the pressure would drop. The pressure is determined by the total flow and the combined orifice sizes, hence why the pressure drops at the big ends when the rocker feed pipe splits. But in an engine the fictional loses over the short distances between the different holes mean the pressure seems constant at all points you could measure for a given RPM ie a fixed flow. This ignores the centrifugal forces at the big ends and the pressure release valve doing its thing.

I am just trying out some effects of a 10M head over a length of pipe 160M long using on line calcs and the pressure will be affected by the frictional losses but only once the fluid starts to flow. The static pressure is unaffected and will be the highest pressure measured, as soon as the bottom valve is opened the pressure will drop as the friction starts to have an effect. The effect is enough for some redesign to be needed, eg more head or shorter pipe run or the project is dead.

marshg246 said:

Especially when the crankcase mods are done that are recommended with some sump breathers, the timing chest only gets its oil supply from the intake rocker drain on the right side. On the side stand, a lot of oil must be in the drive side intake rocker area for any to get to the timing side drain when on the side stand.

Personally, I don't let any bike run while on the side stand for more than a few seconds and I don't let bikes "warm up" much before riding off gently.

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I don't even have a side stand!

I do warm the bike up thoroughly though because there is no option of riding away gently!

A comment on oil pressure and centrifuging.....

When the oil is hot enough and revs are high enough....the oil centrifuges out of the oil trap....potentially at a higher rate than the oil feed pump can pump it....when the rates of input and output are equal, the pressure is zero....but the flow is the really important issue....and this is why I would not race with an oil pressure gauge fitted....and only use one for start up testing after a rebuild.

B+Bogus said:

This is how Steve Maney does it... might interfere with the Magneto installation though

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Though, I think you will find the reasons Steve used this type of drain are not just oil flow away from the head.

He took a lot of metal out whilst porting, which can open into oil ways etc, high risk is the right side drain.

With this approach, he could close up that drain completely with weld and port away!

marshg246 said:

........

I think I saw somewhere where a drain had been added to the head and then piped to the crankcase.

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Specifically, to the timing chest, and replacing the right side feed to the timing chest.

kommando said:

The pressure is reduced by the frictional losses within the galleries, but these are not a lot between the 2 big ends which are close together, especially on a Norton with the large diameter central sludge trap which is less restrictive than a drilled gallery. The problem is they had the exit holes in both big ends the same size. The right hand one gets fed first and with the good flow and pressure the amount of oil that comes out is more than 50% of the oil which then reduces the amount of oil fed to the left side to under 50%. So the left side suffers from a lower flow more than the slight reduction in pressure. The fix would have been to make the hole in the right side big end smaller than the left side so as to equalise the flow out of the two big ends. They would have had to experiment to find the best performing hole sizes, today it would be modelled on a PC.

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Politely, I would call bullshit on this, mainly because Carrilo rods as an example don't have any oil holes and go into many high performance engines, JSM long rods and otherwise.

But also because such oil holes were added to various engines as an attempt to solve problems, but they did not.

Adding a hole to spray oil under the pistons seems logical, but as is often the case, simple logic can be sadly lacking when compared to what actually happens.

There is no clear proof anywhere that such holes are actually beneficial to oiling or cooling.

Or indeed, on the other hand, that they actually reduce pressure, particularly on engines like Nortons that run very low pressure at high rpm!

Trawl the threads, and you will find this has been discussed before.

SteveA said:

A comment on oil pressure and centrifuging.....

When the oil is hot enough and revs are high enough....the oil centrifuges out of the oil trap....potentially at a higher rate than the oil feed pump can pump it....when the rates of input and output are equal, the pressure is zero....but the flow is the really important issue....and this is why I would not race with an oil pressure gauge fitted....and only use one for start up testing after a rebuild.

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Maybe you should have an oil pressure gauge on, you would see that the pressure never drops to zero, if the oil system has proper oil feed and the pump is working correctly and nothing is plugged up. The oil in the sludge trap is thrown to the high side ( where the rod journals are) but the holes are horizontal and they line up very briefly mid stroke with the rod holes.

Norton oil pumps put out a lot more oil than you would think for a small pump.

To me is it folklore trying to explain why an engine blew up, when it was due to more workman ship, defective parts or a rider over reving it or simply running low on oil.

I've even run stock Combats without issues, my recent rebuilt Combat has an anti sump valve and an OP gauge and a catch can on the Oil Tank vent. I have yet to see any real amount of oil coming up the oil vent hose to the tank or oil in the catch can from the oil tank vent.

If I ever saw a street or race motor drop below 35-40 PSI at revs when hot, I would be checking to see what was wrong.

Carl H said:

Maybe you should have an oil pressure gauge on, you would see that the pressure never drops to zero, if the oil system has proper oil feed and the pump is working correctly and nothing is plugged up. The oil in the sludge trap is thrown to the high side ( where the rod journals are) but the holes are horizontal and they line up very briefly mid stroke with the rod holes.

Norton oil pumps put out a lot more oil than you would think for a small pump.

To me is it folklore trying to explain why an engine blew up, when it was due to more workman ship, defective parts or a rider over reving it or simply running low on oil.

I've even run stock Combats without issues, my recent rebuilt Combat has an anti sump valve and an OP gauge and a catch can on the Oil Tank vent. I have yet to see any real amount of oil coming up the oil vent hose to the tank or oil in the catch can from the oil tank vent.

If I ever saw a street or race motor drop below 35-40 PSI at revs when hot, I would be checking to see what was wrong.

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Check away, it was Peter Williams who calculated that on the mountain mile oil, pressure would drop to zero! (and shared that little gem with me in conversation in '78)

The pumps work...just....a crank spinning at over 7000rpm is a better centrifuge than you would think too!

I don't run a gauge, because at max rpm in top I really don't need the distraction of seeing a huge oil pressure drop, it would be hard to maintain concentration!! Just like you say....

.....and if yours never drops below 35psi, you should begin doubting it anyway, or just ride a bit harder!

Temp gauges are an experiment, I only used them so far on a track day, it's likely they won't be there on race day! Same logic...distraction!

SteveA said:

Politely, I would call bullshit on this, mainly because Carrilo rods as an example don't have any oil holes and go into many high performance engines, JSM long rods and otherwise.

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I was not talking holes in the con rods, I cover them up by fitting 2 bottom shells anyway as they add nothing, but the holes in the crank shaft that feed oil into the shell bearings so read again. It was answer to a statement that the lower oil flow out the timing side was due to frictional loses inside the crank as the oil moved between the 2 journals.