OK--I believe in the centrifugal oil filter now!!

[jensey]

Having said that I will answer a few questions :


@ Snakeoil :

So you are saying that it is important to only run a specific type of dirt in your engine??

Looking at conclusion 2, the answer is YES, it is important to run a specific dirt in your bike ! ( and other specific circumstances).

I've been told that the dirt was better back when these bikes were new.

I wonder who was that, do you have a name for me so I could test his theory ?


@ Brewsky :

Jensen, what kind of dirt would you expect NOT to be filtered by the centrifugal filter?

The answer is for example glass, but it is just one of the many parameters in the filter functions, and I think it is explained in detail by me.




@ kirbb9 :

I just want to buy some of that dirt.
How many miles between changes?

I have a few dirty spinning filters around and I'm willing to scrape the dirt out and send it to you. After all, the dirt in the filter is filtered out. Please pm me for costs and shipping details. Bill silver is clear about the intervals, so I won't comment on that.


@ Bonjour :

The biggest reason why Honda probably got rid of the mechanical filters was
less power loss
Less weight
quicker gas respons
less breakdowns
less maintenance
smaller engine design
cheaper to produce

And thus overall more reliability.

Better filtering was likely not the first reason why it had to go.

Less power loss

Do you realize that a paper filter is a huge resistance in the oil flow, therefore absorbing energy thus leading to power loss ?

Less weight

If build on the crank, I wonder if this will be more heavy then a standard oil filter. When engineered correct, the weight of the filter is part of the needed weight of the crank to make it run smooth at low rpm's.

Quicker gas respons

Same reason as above.

Less breakdowns

: why ? can you give a good and known argument here ?

Less maintenance

: possible.

Smaller engine design

: Did you ever compare a standard oil filter with the spinner on a CB450 for example ? The spinner on a bomber is smaller than a standard oil filter.

Cheaper to produce

: Maybe, but not cheaper for you, see your own statement.

And thus overall more reliability

: Well, it depends how it is constructed, and in the case of a CB450 were the filter is integrated in the crank, I tend to say no.

Better filtering was likely not the first reason why it had to go

: Wrong, and I gave arguments it in detail why you are wrong.




And finally thanks to the TS (topic starter) : I hope you are a good believer, as stated in the TT (topic title), I guess you are enlightened now.

Steve, thanks for bringing your arguments in a such professional way, as I perceive a tendency in your postings as being changed in your opinion according to these kind of matters compared with a few years ago. It it the English weather perhaps ?

Hoping to having answered all questions,

Jensen

[Cheburashka]

And finally thanks to the TS (topic starter)

Uh. . .You're welcome?

I kind of feel like I've let the bad genie out of the bottle.

I probably shouldn't do this, but I'm interested. Where does engine dirt come from? I assume it's tiny particles of soot and dust that get by the holes in the air filter and small bits of metal and fiber (sorry--fibre) that are in the clutch, and perhaps remnants of parts that are breaking down. That means aluminum, steel and whatever is in that clutch.

Mine has the original clutch. I'm certain it's not kevlar. Possibly fiberglass. Possibly asbestos. Is fiberglass in the clutch discs the reason why the specific gravity of glass becomes an issue?

[G-Man]

Jensen

Well done! A good post indeed! Now for my questions....

a) Is this a sermon to the God of Oil Filtration or are you about to market the "Jensolator" high quality oil filtration system for classic Hondas? :-)

b) I understand the quality of your work and thinking but do you think that there is an economic benefit here for users of Honda 305s? i.e. have you costed the mods (not all your development, just the 'production' cost). Machining, pipework etc?

e) are the mods reversible? You know what the originality police will say ......

d) How many miles for payback?

e) Could you provide pictures and other details of your pump / filter / pipework mods so that I could have another look? I've tried searching but the original posts seem to have gone.

G

[jensey]

I kind of feel like I've let the bad genie out of the bottle.

No, I'm a physics engineer, and I do try to understand things by analysing, not by believing.

I probably shouldn't do this, but I'm interested. Where does engine dirt come from?

Interest is the seed of all knowledge. The dirt comes from different parts in the engine (wear), from blow-by (residue's of combustion) and from the oil it self (the oil cracks while used).

Mine has the original clutch. I'm certain it's not kevlar. Possibly fiberglass. Possibly asbestos. Is fiberglass in the clutch discs the reason why the specific gravity of glass becomes an issue?

No, not specific. A part of all debris will be filtered out, a part will not be filtered out. In the end particles which are not filtered out will accumulate at the bottom of the crankcase.

Jensen

[jensey]

Thanks G,

a) Is this a sermon to the God of Oil Filtration or are you about to market the "Jensolator" high quality oil filtration system for classic Hondas? :-)

Maybe....

b) I understand the quality of your work and thinking but do you think that there is an economic benefit here for users of Honda 305s? i.e. have you costed the mods (not all your development, just the 'production' cost). Machining, pipework etc?

No, since the amount of miles people put on these bikes are in most cases too low to make the difference. For the CB450 it's another story, a company in Italy is producing a paper filter conversion, and these are sold once in a while.

e) are the mods reversible? You know what the originality police will say ......

All changes are done to the oil pump body, and it's irreversible for the pump body that is..

d) How many miles for payback?

Never calculated, but every knows the costs of rebuilding these engines.

e) Could you provide pictures and other details of your pump / filter / pipework mods so that I could have another look? I've tried searching but the original posts seem to have gone.

No, I don't have any pictures of the mods yet. Within a few weeks when I get the bike out of the atic I will take pictures. I quoted the original post, so it's still there.

btw, if interest is big enough I can look into producing another batch,

Jensen

[Snakeoil]

Well done! All questions answered with clarity and backed up with empirical data. The only point I might argue with you Jensen (and I do so with great trepidation so maybe request further clarity is probably a better approach) is putting the medial filter on the suction side of the oil pump, if that is indeed what you did. Since, to your point this is not a positive displacement pump, it is my understanding that as a general rule theses pumps do not suck as well as they push. So, from that I would think (best I can do at this point) that there is potential for the pump to starve or partially starve as the filter does it job and becomes more restrictive. You said in one of your replies that the media filters provide a "huge resistance in the oil flow". So one can assume that as they do their job that restriction increases until the bypass valve, if there is one, opens.

When you were developing your media filter mod, did you find that the pump had the potential to be staved for oil?

General consensus amongst those who have spent careers working on vintage bikes, is that a media filter is best installed on the return side. This does require that the tank be squeakly clean and likewise the engine if maximum oil cleanliness is to be achieved and maintained. The basis for this is you are on the pressure side of the pump, be it the oil pump or the scavenge pump in the case of their being one, and this assures sufficient pressure to push the oil thru the filter and return it to the sump or tank as required.

What were your observations on this?

As a side note, I would do this for any filter, be it on the suction or pressure side of a pump, but much more important for one on the suction side, fill the filter with oil before installing it or the pump will suck air until the filter fills.

Thanks,
Rob

[G-Man]

Jensen

Thanks!

If your mods are confined to the oil pump casting. I would consider that a reversible mod!

I'll have another look for your original post.

G