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Oil filter: Motorcraft FL-500S or FL-820S?

zzyzx

Steve
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0
Could somebody explain which filter you prefer/use, and why?

FL-500S

FL-820S

AFAIK, the FL-500S is the filter that comes on the Boss.

I've read the specs on both and both are high quality filters, but their specs are not identical, nor are their external dimensions.
 

steveespo

Lord knows I'm a Voodoo Child
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Both fit. I have been running the Ford Racing 820HP filter since my 2nd oil change (3500 miles) and have no issue with fitment or performance. Larger size cannister means more filter media. Supposedly higher pressure rating and better silicones for the gasket and anti drainback valve. FL 500 is fine if street driving and light track duty (drag or auto X) is all you use the car for
Steve
 
I use the FL-500S simply because that's what Ford recommends, but have been thinking about trying the Ford Racing filter CM-6731-FL820.

George
 
Justin said:
I got three K&N filters left over that were for my 06GT will those fit?

I would guess if it a aftermarket 820S it will fit but I have been told to use the newer FL 500S. I have not found out the technical differences between them but I guess there is a reason why Ford engineered a totally new filter for the new engines.

I questioned someone from Ford Racing about the possibility of a FR 500HP filter and was told the 820HP is the correct part for the 302S and R and there are no plans to make a 500HP filter. Right now that is the filter I use but if I switch back to the Motorcraft filter I will use the 500S even if I do not know the what the difference is.
 
384
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Maui
just picked up a fl-500s filter yesterday. that's was what I was told was recommended when buying the filter and only using it for street use mainly...
 

zzyzx

Steve
299
0
Oddly enough when I went to the Ford dealer to buy the oil and filter, he gave me the FL-820S - even after looking it up in the computer. I don't have any good explanation for that, but am happy that he did.

I've read the specs on both and bottom line, they are considered interchangeable, the FL-820S is FAR larger than the 500, and the FRP race filter is based on the 820, not the 500. That pretty much sealed the deal for me.

Some additional info:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2508115
 
This is interesting. I had my free oil change done at my selling dealer and he used the 820s filter, it leaked badly and was down 1 1/2 quarts in 300 miles, much of it on my garage floor and the underside of the car.

I took my Boss to my local dealer to see what was happening, they removed the 820s filter and compared it to the stock filter and said the sealent rings don't align correctly with the Boss motor. Replaced the filter with the stock filter, No leaks now or with the origional filter.

Dave
 
80
0
must of had the old o-ring stuck on and they didnt bother to check and put the new filter over it. The 820 filters are listed by ford to fit and recommended by ford racing however like everything the human factor doesn`t mean it will work everytime if not installed correctly.
 

zzyzx

Steve
299
0
I verified myself before installing the 820S on my Boss that the sealant rings are in fact identical - identical might be a strong word, but damn near close enough. I'll see if I still have my old filter and put the calipers to them both.
 
The gasket is pretty close to the same but I had a leak also with the 820s the first time I put it on and my lesson learned is that it needs to be slightly tighter than my experience with the 500S as it says plus 1-1/4 turn right on the filter.
 

ace72ace

Zaino, I put that $hit on everything
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zzyzx said:
Oddly enough when I went to the Ford dealer to buy the oil and filter, he gave me the FL-820S - even after looking it up in the computer. I don't have any good explanation for that, but am happy that he did.

I've read the specs on both and bottom line, they are considered interchangeable, the FL-820S is FAR larger than the 500, and the FRP race filter is based on the 820, not the 500. That pretty much sealed the deal for me.

Some additional info:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2508115

From that forum link here's the most interesting tidbit to me;

"The bypass valve setting and flow rate are the critical differences, aside from basic dimensions. The 500 has a lower bypass pressure and a lower flow rate than the 820."

It seems to me the most critical factors you have to weigh if straying from the OEM filter is if you have any 'cold weather' concerns (which nobody should have on the stock summer only tires) or heavy duty use at the track running 'flat out' :)

For street use I'm sure OEM is fine.
 

PeteInCT

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If you swap oil/filer as regularly as we do due to track driving I am hard pressed to see the need for anything other than the 500.
 

zzyzx

Steve
299
0
[quote author=ace72ace]
"The bypass valve setting and flow rate are the critical differences, aside from basic dimensions. The 500 has a lower bypass pressure and a lower flow rate than the 820."[/quote]

From the same thread, here are the numbers:

FL 500S:

By-Pass Valve Setting-PSI: 8
Anti-Drain Back Valve: Yes
Max Flow Rate: 10-12 GPM

FL 820S:

By-Pass Valve Setting-PSI: 16
Anti-Drain Back Valve: Yes
Max Flow Rate: 11-13 GPM
 
The 500 is the stock Boss oil filter and is fine for what you want to do with your GT.
 
VTBoss302 said:
I use the FL-500S simply because that's what Ford recommends, but have been thinking about trying the Ford Racing filter CM-6731-FL820.

Update: I have switched over using to the Ford Racing 820 filter

Worth the extra cost, IMHO

Appears more more robust than the Motorcraft 500
 

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