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The Dutch 450

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K2-K6:
A curious question Jensen, is your view of filtering the oil so thoroughly influenced by that oil "debris" that collects in the crankshaft oil distribution channels?

I was just looking through the link to crank preparation that Ash has posted over on the cl450 rebuild thread and saw in much more detail what accumulates within there.

Another question,  if you smell the oil after it has run in your engine then compare that smell to new oil,  is there a noticeable difference between the two,  if so how would you describe the change?

jensen:
Hi Nigel,


--- Quote ---based on your compression measurements at around 7000 miles. I'd expect to see that level of completion at around 750/1500 Miles with the hone more conventionally completing it's work by that much shorter interval
--- End quote ---

Yes, but I wasn't surprised, and knew upfront that it would gonna take a long time to reach the maximum compression. When looking for example to the BMW flat 3 and 4 cylinders (K-series), one of the complains was that these bikes used a lot of oil from new. It took a long time before the rings were set, something around 4 to 5 K km. These BMW's used synthetics from the factory as I remember, and there where a lot of discussions going on. Nowadays, all engine are machined to perfection, with very low tolerances, and using synthetics from new.

The CB450 is an old bike, made in a time that precision wasn't that high, and breaking in was a process to correct a these mis-matches between parts in general. The process of breaking in was much more important than it is now, a lot has changed. This was also the reason for me to experiment with breaking in on synthetics.

Using synthetics in my classic bikes is a no-brainer for me since I've seen the effect of using this kind of oil in an engine. Many years ago (1997) I bough a new XRV750 Africa Twin, and before starting the bike I changed the oil to synthetics. Since then I always used synthetics in this bike, thus including the breaking in process.

I travelled many kilometres on this bike, and in 2017 I sold her with 360.000 km on the odo. Every year the bike was on the dyno, every year I tested the compression, and between 8.000 and 10.000 km it reached the maximum compression. In the beginning the bike used oil, but stopped using oil around 8000 to 10.000 km. The last compression test at 345.000 km on the odo showed that the compression was still very good (way within the specifications). The bike didn't use oil in an amount that I had to fill up between oil changes (8.000 to 10.000 km).

The only engine parts I had to replace were the clutch plates at 220.000 km's. The other thing I changed on the bike were the spark plugs, I went from normal spark plugs to Iridium ones. Since the XRV has two plugs per cylinder, the costs were very high in the 90's, but I didn't have to change those either every time (however I checked them every year).


--- Quote ---if you smell the oil after it has run in your engine then compare that smell to new oil,  is there a noticeable difference between the two,  if so how would you describe the change?
--- End quote ---

It smells good, but since that's an indirect measurement and depending on emotional and physical health, it doesn't say not much. I didn't smell gas / petrol, but it doesn't smell the same as new oil. The colour is much darker too.


--- Quote ---is your view of filtering the oil so thoroughly influenced by that oil "debris" that collects in the crankshaft oil distribution channels?
--- End quote ---

Since the high detergent power of modern synthetics, debris is not collected in the crank or in a spinner filter (the oil just cleans the spinner filter), it collects the debris in the paper filter itself.

A substantial part of debris in the oil are clutch plate particles, the other is waste of burned oil and fuel leaking through the oil rings. The larger particles of the clutch plates and the other debris are caught by the paper filter, the smaller parts are pumped trough the engine.

I use an external filter setup because the filter setup from Cappellini Moto uses a paper filter which is too small according to me (there is just not enough room to place a bigger filter). The used filter (from a Suzuki motor scoot) is just a single layer of paper, and not like many larger oil filters for cars, multi layers.

K2-K6:
I see what you mean about the BMW K engine situation Jensen, but feel that maybe an odd benchmark to base an engineering led evaluation on.

That engine series as far as I know used Nykasil plated bores which differ significantly from iron examples,  also using different piston ring specs to match the bore surface.
In addition, the layout gives particular problems with the bores laying flat which appear to gives poor oil evacuation from cylinder walls. It know they struggled with them in development terms ( I rode a 750  but not the 4 cylinder)  with the " sump" very close to the crank which doesn't appear to help clear oil from moving parts.
They also put the cylinder head on left of bike so when left on side stand any oil running out of the crank assembly, after switch off, collects in the cylinders next to the rings. Think they end up pinning some of the rings like a two stroke to prevent the ring gap being on the lower side of the piston.

I think if you run any bore with more oil than ideal in it,  then it would influence the rings bedding in rather than the oil type. It looks to me that to attribute any short comings to the use of synthetic oil in this engine gives the wrong impression.

It just looks like too many compromises in design to really evaluate oil type during run in and the affects it could impart.
Ultimately a dead end development wise for them,  too many compromises. I don't feel it should influence decisions for a move conventional layout and bore material.

Bryanj:
Cant comment on the oil in these bikes but can for commercials, The Merc v 6/8 commercial motor is run in with mineral oil then changes to synthetic but it is common to find zero oil consumption with mineral and measurable on synthetic, now as these take 39 litres on oil change and synthetic is a helluva lot more expensive careful maths has to be used to determine which works out cheaper especially taking in the oil change intervals of 100,000 Km on mineral and 180,000 Km on synthetic. the Dafs i now drive are doing 150-200 000 Kms a yesr. When looking at the change mileage do take into account that a lot of commercials use a centrifugal "Spinner" as well as paper filters and on the new stuff we can get 9 MPG at 44 Tonne

K2-K6:
I think thing's like that are relevant Bryan as it's something that can give a view of just how long the lubrication properties of oil can survive given the ideal conditions.

Also something that I was approaching there with my question to Jensen about oil smell, that was right in the assumption I was looking for fuel contamination that degrades the oil most on bikes I think.

Just listening to the newer big commercial diesels you can hear just how accurate the injection systems are nowadays. The very small amounts metered,  especially at low speeds makes them really quiet. Also significant is the mpg you stated,  that's pretty impressive to move that total load. Shows there's not much fuel going to waste.

I can see the conundrum Jensen faced regarding oil choice as wearing in of the bore and rings is a process that's diametrically opposed to trying to not cause wear to the cam. It seems that, for this 450 engine, those two areas could not be more distant in pure engineering terms. How you best achieve both at the same time is bound to bring up considered discussion.

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