Honda Twins banner
1 - 9 of 9 Posts

·
Registered
Joined
·
315 Posts
Discussion Starter · #1 ·
Is anyone on this forum running the Cappellini paper filter conversion on their CB350? If so, what change interval are you using?

I am still replacing the filter + oil, every 2500km. But I guess the interval could be raised a bit due to the paper filter that does a better job filtering out contaminants. By the way: I am not trying to cut costs on oil but I'd like to know what everybody else is doing. One other option is to keep changing the oil at 2500km but change the filter every 5000km.
 

·
Premium Member
Joined
·
2,154 Posts
Duh, actually the centrifugal filter is the best as long as your using high rpm. It 'throws' anything 'heavy' to outside of cup (after-market oil additives, etc)
The paper filter only gets stuff around 30 micron plus doesn't filter at all when oil is cold and pressure relief valve opens (Itink most are only rated between 6 to 15psi?)
I would stick with 2500Km or 1500mile oil change unless you upgrade clutch springs and use synthetic oil (clutch will slip with stock springs and synthetic oil)
 

·
Registered
Joined
·
3,538 Posts
Filtration has little to do with oil change intervals. Multi grade petroleum oils get their multi grade properties from long molecular chain polymers in the oil. These polymers do not last in transmissions. They get chopped up in the gears, think food processors. The longer the oil is in the bike the thinner it gets. Synthetc oils do not have these polymers and can last longer. My 450 got its first oil change at 400 miles and the second 900 miles later. Oil is critical in these bikes.
 

·
Premium Member
Joined
·
2,154 Posts
I'd kinda forgotten about that, I remember bikes getting pretty rough around 1200 miles before I started using synthetics XS650 didn't like to go more than 1000 miles on conventional multi-grade, you could feel the difference
 

·
Registered
Joined
·
2,837 Posts
Filtration has little to do with oil change intervals. Multi grade petroleum oils get their multi grade properties from long molecular chain polymers in the oil. These polymers do not last in transmissions. They get chopped up in the gears, think food processors. The longer the oil is in the bike the thinner it gets. Synthetc oils do not have these polymers and can last longer. My 450 got its first oil change at 400 miles and the second 900 miles later. Oil is critical in these bikes.
Exactly! I have an ongoing argument with a guy at work telling me oil never wears out. It just gets dirty. Heck a search on the internet says the same garbage. I wonder if that's why Jensen uses such thick oil that he cleans and reuses. I should reread his thread.
 

·
Premium Member
Joined
·
3,008 Posts
Oil does go bad.

The by-products of internal combustion motors get into the oil and will cause it overtime to become corrosive.

Internal combustion motors burning hydrocarbon fuels produce; H2O (water), CO2 (Carbon Dioxide) as the PRIMARY by-products.
However, there is also a Sulfur Content present in Hydrocarbon Fuels.
When burned that produces a SO2 (Sulfur Dioxide), which with the presence of the H2O component mixes and becomes H2SO4 (Sulfuric Acid)

The Sulfuric Acid in the exhaust gases is what rots out the mufflers and pipes in exhaust systems.

Some portion of the Exhaust Gases by-passes the rings and mixes with the oil in the crankcase.

Overtime the Sulfuric Acid component in the exhaust gas WILL turn the oil into a corrosive substance.

Moral of the story: - CHANGE - YOUR OIL !
 

·
Registered
Joined
·
3,538 Posts
Oil does go bad.

The by-products of internal combustion motors get into the oil and will cause it overtime to become corrosive.

Internal combustion motors burning hydrocarbon fuels produce; H2O (water), CO2 (Carbon Dioxide) as the PRIMARY by-products.
However, there is also a Sulfur Content present in Hydrocarbon Fuels.
When burned that produces a SO2 (Sulfur Dioxide), which with the presence of the H2O component mixes and becomes H2SO4 (Sulfuric Acid)

The Sulfuric Acid in the exhaust gases is what rots out the mufflers and pipes in exhaust systems.

Some portion of the Exhaust Gases by-passes the rings and mixes with the oil in the crankcase.

Overtime the Sulfuric Acid component in the exhaust gas WILL turn the oil into a corrosive substance.

Moral of the story: - CHANGE - YOUR OIL !
There it this too, but multi grade oils will become their lowest viscoity over time. 5W30 becomes 5W, 15W40 becomes 15W and on. Our high performance Hondas will blow up a long time before the dirty oil gets to them. Single viscosity oil such as 30W and synthetics do not have the polymers.
 

·
Registered
Joined
·
315 Posts
Discussion Starter · #8 ·
A while ago I read a very long and in depth topic about paper filters, oil slingers and sythetic oil. I think it was written by Jens Akkerman. Not sure on what website it was, possibly this one. From that article I deduced that modern synthetic oils will make your oil slinger work less efficient because of the cleaning detergents in the oil. This undermines the basic working of the oil slinger. At least to some extent. This detergents will make the particles less likely to stick together in the oilslinger. Anyway.. that was my main motivation of converting to paper filter. I completely rebuilt the engine 3 years ago with brand new cam, new followers, new seals, new everything so after the run in periond I wanted to move towards full synth oil. It has been running flawless for the last three years so I am guessing the filter is not very restrictive because the cam and followers are still very quiet.

As for the oil change interval: Good point about the combustion contaminants. I'll guess I'll keep changing the oil every 2500km. In my case that would boil down to roughly once every year so that would be ideal anyway.
 

·
Premium Member
Joined
·
2,154 Posts
Almost all paper filters have a bypass built in to prevent excess pressure rupturing them so they pass totally unfiltered oil some of the time. I think te Cappelini kit uses Suzuki GS/DR 125 filter? (and various scooters using similar engine) I forget the bypass pressure on it but know if it's fitted backwards top end seizes as there is no oil flow (worked at Suzuki dealers for years) I still think the stock centrifugal filter is most efficient as it relies on weight of contaminants and not fibers to trap particles. The reason majority of CB350's seize top end is excess rpm for extended periods (or racing) the transfer piece in clutch cover shouldn't act as a pressure relief valve but it does. If the Capellini kit has a more positive supply, it's removed the major problem. There are other 'fixes', I invented because Honda screwed up making pump too good when 360 motor was designed so top end has more issues than 350 ever had. One thing I found, anyone who ad a top end destroy itself generally was of the opinion the oil was at fault and started using 20W/50 which compounded the problem. The actual answer was to go 'thinner (wasn't possible in 1970's 15W/40 was lightest easily available - except for 'Genuine Honda' oil) All of the late 60's Honda's with similar set up (CB160,175, 250,350) have thhe same problem at sustained high rpm, I even managed to seize a cam bearing on my 1968 CD175 (I was 'chasing' A Suzuki GT500 at the time though )
You will see various posts where people have found what looks like layers of 'cardboard' inside centrifugal filter, it's actually the very fine particles packed down almost solid
 
1 - 9 of 9 Posts
Top