Inlet balance pipe question

Thomas aus LAU said:
For over 40 years I have trusted the same woman and always a good mineral oil. Both work fine.
The price including freight is a fair 7.43 EUR per liter.

Only with a high tuned modern engine, I would switch to modern oils like Motul 300 V.
Here the price is significantly higher at 13.30 - 14.00 EUR / liter.

Switching neither woman nor type of oil seems to save money. 😁

Thomas aus LAU

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300V has been around decades Thomas. I've used it on and off since the 70s.
It is very expensive in small quantities, something like € 20 a litre but it's € 8 a litre if you buy 200 litres at a time, which our club does.
All my racing friends on British bikes use it. You can space out your oil changes, and stick it in your old car after draining it from the bike.
Not expensive at all.

The cheapest kind of woman is those you see in magazines.

Paul
 
Paul Marx said:
We're not talking taste, we're talking money.
Paul
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Paul, with that argument you only have to virtually ride a motorcycle in a computer game.
It's cheaper than a real motorcycle and doesn't give a real driving experience.

With my wife and my Laverdas, I prefer to have optimization potential in a few places, but on the other side a real live feeling. :giggle:

Thomas aus LAU
 
Hi Thomas, interesting comment about closing off the oil feed to the primary drive. I would suspect it would improve flow to the top end? Tell me more. How did you do it, brass plug, or self tapper in the hole?
 
Marty it is a tiny hole, and can be blocked with a scrap of silicone/anything pushed in there when the pump is off. Personally I don't think it will make any difference and not worth even thinking about. If all the oil ways are open through to the rocker arms and the pump is in good nick, that hole is insignificant. Andy Wagner recommended blocking the hole into the tacho drive (LH cam end cover) if using high volume oil pump to avoid oil pushing up into the cable and leaking.
 
martymoose said:
Hi Thomas, interesting comment about closing off the oil feed to the primary drive. I would suspect it would improve flow to the top end? Tell me more. How did you do it, brass plug, or self tapper in the hole?
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Well, if the hole on my S is anything to go by, it's 4cm long by 1.5 cm high.
I'm more than dubious about blocking it since at the best there are 3 thimbles of oil kicking around in the primary.
If you're worried about oiling the top end, don't let the machine tick over for any lengthy period.
I'm more than dubious as well about a high volume oil pump on a bike used for touring rather than long stints on the track.

Paul
 
martymoose said:
Hi Thomas, interesting comment about closing off the oil feed to the primary drive. I would suspect it would improve flow to the top end? Tell me more. How did you do it, brass plug, or self tapper in the hole?
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From my point of view it makes sense to close the small hole.

I wouldn't use silicone or glue to do this.

It is easier to close the small opening with a hammer + punch (d = 1.5 - 2.0 mm). 1 - 2 blows are enough to press the aluminum and close the opening.

And never forget to check the oil level regularly (at least every 1000 km) and top up oil if necessary. The dipstick is only put on and not screwed in.

Too often I see strange Laverdas with too low an oil level.

Thomas aus LAU



Thomas aus LAU
 
Paul Marx said:
Well, if the hole on my S is anything to go by, it's 4cm long by 1.5 cm high.
.....
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You have to mean something else.

I spoke of the very small bypass hole (> 1mm) on the right side of the oil pump from which oil should also spray onto the Triplex-primarychain.
The primary chain runs permanently in the oil sump. From my point of view, it doesn't need to be - when I'm diving in the pool I don't need a shower to get wet.
If you block the oil hole, more oil comes into the head to the camshaft = (y)

Thomas aus LAU
 
Thomas aus LAU said:
You have to mean something else.

I spoke of the very small bypass hole (> 1mm) on the right side of the oil pump from which oil should also spray onto the Triplex-primarychain.
The primary chain runs permanently in the oil sump. From my point of view, it doesn't need to be - when I'm diving in the pool I don't need a shower to get wet.
If you block the oil hole, more oil comes into the head to the camshaft = (y)

Thomas aus LAU
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Oh, that hole. Do you really believe that it would deprive the top end of oil? The rev counter drive is a much bigger oil passage.
Paul
 
Found this explanation on another site,

"The balance tube on most 4 stroke engines is only there for idle and off idle regions. It does not affect anything at higher RPM. It really does not have anything to do with pulsing or ram effects.
The main thing it does is it allows a higher RPM for the same slide position because each cylinder can draw a little extra air [mixture] from the opposite cylinder during it's intake stroke.
When you are tuning a single cylinder engine you will often find that the transition from the idle circuit to the needle circuit is the hardest to get right. On a single the transition happens at a low RPM as you first apply the throttle and unless it is just right a single will often cough or be rough right off idle.
When you have a twin with a balance tube then the engine will be able to run faster for the same throttle setting because of the extra air supplied by the balance tube. That means the transition from the idle circuit to the needle circuit is going to happen at a higher RPM where it is going to be less noticeable and easier to tune.
The transition is also going to be less noticeable at a higher RPM when the ambient conditions change enough to throw the mixture off a bit.
If you pinch the balance tube on an idling engine you will find the RPM will drop. When you raise the slides to get the RPM back to where it was you also pull the needle farther from the jet and change the air pressure under the slide. Then to get the mixture correct again you will usually need to adjust the idle mixture screws or jet and change the slide cutaway and sometimes a different needle or jet will be needed.
Getting the transition from the idle to the needle just right is critical when the engine speed is only 1500 rpm. It is a lot easier if the transition does not happen until 2000 or higher."
 
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