Motorcycle vs Car Oil Filters

Originally Posted By: MrCPU
Harley parts must be coated in nicotine, or cocaine or something. Especially the ones that get changed a lot.


If you are inferring they are expensive. You are right. But there are few replacements in the market that meet the same specs that are less expensive. Harley Davidson engines are unique in their design compared to other brands and designs (especially automotive designs) they are considered very loose tolerance. They shed lots of metal especially during break-in that automotive toleranced engines do not and therefore require better lubricant filtration to protect them. Every twin cam engine has a pair of cam chain tensioner shoes that are plastic and shed debris throughout the life of the engine. Most require replacement at about 40,000 miles. Believe me you do not want this debris floating around the oil passages in your engine. Therefore, HD specs 5 micron filtration to protect against these types of issues. Like I said before 19 micron might work. But you can buy a 5 micron filter for about $5 more than a 19. Not worth the risk to me.
 
I'm sorry if somehow I cannot seem to convey my point. I'll try to clarify.

It's a matter of what is "required" and what is an "upgrade".

I highly suspect that a 5um or 10um filter is not "required" for the proper operation of any of the HD products. I suspect that they are designed to run quite well in a (guesstimate) 20um nominal arena.

I whole heartedly agree that the Wix 51348 filter does not filter to the same nominal rating of the 63798-99a HD filter. WHAT I AM TRYING TO POINT OUT IS THAT THERE IS PROBABLY NO NEED FOR SUCH TIGHT FILTRAION IN THE FIRST PLACE. Wix has a suggested application, as does Baldwin and Purolator, that meets the OEM filtration spec for the engine environment. Just because HD chooses to offer a "better" filter as an "upgrade", does not mean the engine necessitates such filtration.

The filter you named (63798-99a) is clearly considered an upgrade by Harley-Davidson. They clearly call it out as such on their official website. That is not me picking something out of thin air, but a direct reference to the HD information. If they call it an "upgrade", it is fair to draw the conclusion that there is some subordinate filter that meets a lower required spec. That lower spec is the requirement for proper operation; the "upgrade" is not. I don't know how you could aruge with that logic.

And speaking of logic, I have to continue this nit-picking a bit further. You seem adamant that two things necessitate the use of the 63798-99a filter, with a bypass function that is supposedly very capable at low pressue/low rpm, AND a 5um nominal rating. Here's my thoughts on that ...

You have described a mutually exclusive situation. The two characteristics can exist in the same filter, but they are counter-intuitive. If a lubrication system is so dependent upon such fine filtration, then why does it employ a bypass that opens so easily and so frenquently??????? Would that not offer extended opportunities for "dirty" unfiltered oil to pass around the filter, thereby contaminating the downstream components, and negating the 5um rating? Or, on the other side of the equation, if such bypass operation is critical to supply a minimum amount of oil at all times, especially at low rpm/low flow times, and you KNOW the bypass is going to open frequently, then why is there a need for such fine filtraion (5um), when you KNOW the oil is going to bypass the filter media frequently? See - it just cannot be resolved with common sense.

Regarding the concept of "proof" - I'll say this. I believe the onus is on you to "prove" that HD engines "require" such a fine, super-premium filter. The reason I say this is that HD admits this filter is a upgrade, and not a requirement. I at least provided links that show my side of the debate to be supported by other parties. The links to the HD enthusiast pages were not meant to convey "proof", but were to show that even the HD faithful are confused and contradict themselves in information sharing. The link to the official HD website is self-evident; it supports my position.

BTW - I realize that PT1 won't probably believe me, but I do have a degree in Mechanical Engineering from Purdue, I worked at Ford Motor Company for 16 years, and I'm now a statistical quality engineer for UTC. That's probably not good enough for him, but perhaps the others following along might see the creedence in my thoughts.
 
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Originally Posted By: dnewton3
I'm sorry if somehow I cannot seem to convey my point. I'll try to clarify.

It's a matter of what is "required" and what is an "upgrade".

I highly suspect that a 5um or 10um filter is not "required" for the proper operation of any of the HD products. I suspect that they are designed to run quite well in a (guesstimate) 20um nominal arena.

I whole heartedly agree that the Wix 51348 filter does not filter to the same nominal rating of the 63798-99a HD filter. WHAT I AM TRYING TO POINT OUT IS THAT THERE IS PROBABLY NO NEED FOR SUCH TIGHT FILTRAION IN THE FIRST PLACE. Wix has a suggested application, as does Baldwin and Purolator, that meets the OEM filtration spec for the engine environment. Just because HD chooses to offer a "better" filter as an "upgrade", does not mean the engine necessitates such filtration.

The filter you named (63798-99a) is clearly considered an upgrade by Harley-Davidson. They clearly call it out as such on their official website. That is not me picking something out of thin air, but a direct reference to the HD information. If they call it an "upgrade", it is fair to draw the conclusion that there is some subordinate filter that meets a lower required spec. That lower spec is the requirement for proper operation; the "upgrade" is not. I don't know how you could aruge with that logic.

And speaking of logic, I have to continue this nit-picking a bit further. You seem adamant that two things necessitate the use of the 63798-99a filter, with a bypass function that is supposedly very capable at low pressue/low rpm, AND a 5um nominal rating. Here's my thoughts on that ...

You have described a mutually exclusive situation. The two characteristics can exist in the same filter, but they are counter-intuitive. If a lubrication system is so dependent upon such fine filtration, then why does it employ a bypass that opens so easily and so frenquently??????? Would that not offer extended opportunities for "dirty" unfiltered oil to pass around the filter, thereby contaminating the downstream components, and negating the 5um rating? Or, on the other side of the equation, if such bypass operation is critical to supply a minimum amount of oil at all times, especially at low rpm/low flow times, and you KNOW the bypass is going to open frequently, then why is there a need for such fine filtraion (5um), when you KNOW the oil is going to bypass the filter media frequently? See - it just cannot be resolved with common sense.

Regarding the concept of "proof" - I'll say this. I believe the onus is on you to "prove" that HD engines "require" such a fine, super-premium filter. The reason I say this is that HD admits this filter is a upgrade, and not a requirement. I at least provided links that show my side of the debate to be supported by other parties. The links to the HD enthusiast pages were not meant to convey "proof", but were to show that even the HD faithful are confused and contradict themselves in information sharing. The link to the official HD website is self-evident; it supports my position.

BTW - I realize that PT1 won't probably believe me, but I do have a degree in Mechanical Engineering from Purdue, I worked at Ford Motor Company for 16 years, and I'm now a statistical quality engineer for UTC. That's probably not good enough for him, but perhaps the others following along might see the creedence in my thoughts.


Well you admit you are making a "guesstimate" about the filtration level on the new Twin Cam engines. If this is true then why would the manufacturer fit all the new TC engines with a 5 micron filter from the factory and specify this part number specifically as a replacement? yes this is an upgraded filter designed to provide what the engine design people at HD deem necessary for engine longevity. There is your "proof". All you need do is read the owners manual. If you don't believe me call a HD dealer and ask what the MoCo recommends. This whole idea of some kind of profit conspiracy theory is ridiculous. If not then find a 5 micron oil filter that fits the bike for less money. Saying you "guess" that the engine will operate at 20 micron filtration is misleading and just your opinion. You are free to operate your motorcycle with no oil filter if you so choose but to infer that going against the manufacturers spec for a new generation of engines is a good idea based on some non-technical opinion is definitely misleading. That is my point. The burden of proof is on you to prove why the HD spec is no worthy.
 
One interesting note: Purolator Pure One oil filter ( one of the very best automotive oil filters on the market) #PL10241 which is a 20 micron rated filter that will fit the Harley TC 88 & 96 engine is $5.88 at AAP. However, the one recommended by Purolator for the HD TC88/96 engine is part # ML16822 which has the HD spec. it is $10.99 at AAP. SO apparently those greedlings at Purolator are in bed with the thieves in Milwaukee at Harley Davidson.
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If not then why does purolator have a seperate application chart for motorcycles on their website? If you call and ask them they will tell you that the filtration requirements set by the engine manufacturers are different and require a different filter.
 
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BTW do you really want to run a 20 micron filter that will allow some particles larger than 20 microns to float around in your oil when the oil film thickness is about 25 microns? Which means if a Pure One Filter is 98% efficient at 20 microns there are 2% of the particles larger than 20 microns getting through and not trapped in the filter. Any of these that are 25 microns or larger are larger than the oil fluid film thickness and will scratch internal surfaces. This is a true bearing surface killer for sure. Not worth $6 IMO.
 
Ok, made a few calls to those "in the know" they said you definitely want 5 micron filtration in a HD TC engine mainly because of the cam tensioner shoes that shed plastic which can easily clog the smaller passages & jets. They also went on to say a 20 micron filter ( in a TC and NOT an EVO) is asking for trouble. The guy did mention that many people now cut open the used oil filters at about 25,000 miles to look for the orange plastic pieces parts from the shoes to give an indicator if they are coming apart. He also mentioned only 2 or 3 manufacturers even make a 5 micron synthetic media filter for the application. The purolator ML one would be fine.
 
"If not then why does purolator have a seperate application chart for motorcycles on their website? "

The same reason that oil companies list motorcycle oil,
and small engine oil, and three kinds of 2 cycle oil.
The average joe doesn't realize that, for the most part, there is little, if any, difference in the verious versions, and will
pay more for 'special' products.

To be specific, and it's just an opinion, 20 um is pretty small, and I doubt there are any orifice or jet in the lubrication system that is anywhere near that small.
If there are concerns about plastic bits floating around the internals, why would the filter be designed to go into bypass so often or so long?

Using logic with a Harley-Davidson devotee is an oxymoron.
 
If there are concerns about plastic bits floating around the internals, why would the filter be designed to go into bypass so often or so long?

Because the engine dry sump design is such (so old) that at start up the internals would be starved of lubrication. The real issue is why use plastic tensioner shoes which are an achilles heel for this engine. They should be using gear driven cams like S&S and others use and this issue would be moot. The 5 micron filter is probably a band-aid preventative fix to prevent a huge engine recall retrofit IMO. If you do a DFMEA the needs for quick start up lubrication trumps the plastic pieces "potentially" floating around in there that can be filtered out. So add a real tight filter spec that only involves changing an external part and you get a workable solution without having to add expensive cam drives. No doubt this was discovered as an after thought. Plus cam gear drives whine & buzz like crazy under load and there would be many customer complaints. Personally, I would have gone with a 10-20 micron filter and cam drives. Which on my RR of my tensioner shoes may happen since gears are bullet proof compared to the chain system.

Not a good choice on the part of HD but that is why they are stressing the 5 micron filter so heavily.

BTW, I have seen some of the tensioner shoes in the 06's come apart at 25,000 miles. Which really sucks because getting the internal one changed out is a PIA.
 
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Originally Posted By: PT1
One interesting note: Purolator Pure One oil filter ( one of the very best automotive oil filters on the market) #PL10241 which is a 20 micron rated filter that will fit the Harley TC 88 & 96 engine is $5.88 at AAP. However, the one recommended by Purolator for the HD TC88/96 engine is part # ML16822 which has the HD spec. it is $10.99 at AAP. ....


From Purolator's website:

PL10241:

Thread Pitch: UNF-2B
Relief Valve P.S.I.: 12-17
O.D.: 2.98
Height: 3.36
Threads: 3/4-16
Anti-Drain Back Valve: Yes

ML16822:

Thread Pitch: UNF-2B
Relief Valve P.S.I.: 12-15
O.D.: 2.98
Height: 3.36
Threads: 3/4-16
Height: 3.36
Anti-Drain Back Valve: Yes

My impression is that the two differences are a different paint job on ML16822 and a higher price tag.

Btw, Champion Labs makes the OEM Harley filters.
 
Well I don't have time to read through this whole thread but in a nut shell what PT1 said. dnewton read some information but it seems that he does not know the difference between a TC and an Evo and they are different in oiling systems and filtration requirements. The SP 5 micron is an "upgrade" for the P/Ns listed which are all Evo filters. Actual use of the SP5 on Evos has proven to be problematic so I wuld not consider it an upgrade at all. The SP5 is too restrictive for the Evos oil system it seems and there is plenty of real world emperical data on that.

If someone that does not own a TC says to use a 20 micron paper filter on that engine take it with a grain of salt. Better yet don't do it period. If some has a problem with anything that says HD on it fine. There are a handful of equal or better filters from K&N (Champion made), Amsoil (Wix made), Perf-Form and more. They are all expensive like the HD and they all use an advanced "synthetic" media. Hd went to to the higher filtration on the TC for the reasons PT1 noted, like or not.

Wix makes great filter but I would not use a 20 some micron paper filter on my TCs or even my Evo. There are too many better options out there for a price difference of a couple of buds spread over a 6 month period. It's a no brainer. And I'm an engineer (21 years aerospace) as well and that and plus $3.50 will buy you a Wix filter.
 
Originally Posted By: PT1
Ok, made a few calls to those "in the know" they said you definitely want 5 micron filtration in a HD TC engine mainly because of the cam tensioner shoes that shed plastic which can easily clog the smaller passages & jets. They also went on to say a 20 micron filter ( in a TC and NOT an EVO) is asking for trouble. The guy did mention that many people now cut open the used oil filters at about 25,000 miles to look for the orange plastic pieces parts from the shoes to give an indicator if they are coming apart. He also mentioned only 2 or 3 manufacturers even make a 5 micron synthetic media filter for the application. The purolator ML one would be fine.


Didn't you say the bypass valve will open at start up, thereby allowing all those big particles to circulate around the motor and clog passages?
 
dave - Probably more complicated than we'd need, with all the plumbing and such required. Plus, there's very little room between the headers and the engine to fit everything in there. We can get serviceable 20 x 1 filters for $5 - 6, with a little shopping.
 
For what it is worth, I use Purolator Pureone filters on all my bikes. You can't beat the filtration, plus with the recent sale on Amazon they were only $4.50 each.
 
Wasn't the 5 micron harley filter a bandaid to fix another problem hopefully till it got off warranty? a sharply machined chain that was scrubbing wear metals off it's tensioner
 
"Shedding debris" & "plastic bits" floating around in the engine kind'a scares me! I had an iron head kick-start 1000cc Sportster for my senior spring & summer quarters in college, cold blooded SOB that it was, it was a lot of fun and the only one I ever saw around campus (Oxford, Ohio) that didn't have some over-aged delinquent in "colors" riding it.

Just an over-aged delinquent in Frye boots, Levi's and a flannel shirt most of the time: me!

Cheers!
 
The Purolator Pure One is rated very highly for M/C's. I have done a lot of research, and have concluded that M/C specific oil and filters are just a marketing ploy to get us to spend more money. I've been using Mobil 1 15/50 and Pure Ones in my speed Triple for 33,000 miles without issue.
 
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