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Burner,
A bypass doesn't apply to a fuel filter system since the fuel only takes a single pass through the filter before being consumed. A bypass works for oil because the oil is constantly being re-circulated through the filter(s).
John K,
If it turns out that there is not a practical way to add a better filter after the OEM primary filter, would it be acceptable (though not ideal) to put a "better" filter in front of the OEM filter?
[ 11-06-2002: Message edited by: jbplock ]</p>
George, JK
Is the efficiency rating of ~60% for the samples that were taken directly after the filter? From a previous post here George had said the following:
"Also, the sample point for the 'after filter' was the return line to the fuel tank. This then is after the fuel has made its complete trip through the filter, pump, injector circuit, and injectors. Thus, if we have a component producing wear particles, a failing component, carbon, etc. anywhere along the route, our particle count for this sample would reveal that debris also. This may be the source for the large particles and may well increase the particle counts.
We have additional 'before & after' samples that should be completed next week which are using a different sample point for the 'after', that being immediately after the filter, pump, but before the injector circuit. "
Have the results from the tests where the sample is taken directly after the filter come back yet? If the 60% efficiency rating is for fuel that's getting recirculated back to the tank, why is that so bad? If the efficiency for the fuel actually getting to the injectors is much higher (> 94%) then it should still be quite good, no?
Yes, the results for "after filter only" are complete and the results are consistent with our previous results, at 62% efficiency for greater than 5 micron particle size. The 2 to 5 micron size spectrum was only 44% efficient... More results this week but I think we have our answer at 60% to 64% efficient in the 5 micron component, the size most affecting our fuel system life.
George Morrison, STLE CLS
Comment on water separation
I changed my first filter at 12000 miles when I opened the filter drain cock for the first time only 2 drops of water came out (I assumed no water in the fuel I have been buying).
I cut the fuel canister in two and observed that only the bottom 1/2 was a discolored black and the top half was a discolored white, not what I had expected.
So I have to ask this question????? has my fuel filter been on BYPASS the whole time, but I just read there isnt a bypass so why is the filter so clean and no water?????????
Any response would be welcomed.
[ 11-06-2002: Message edited by: letsgo ]
[ 11-06-2002: Message edited by: letsgo ]</p>
George,
I add my thanks for all the work you are doing on this issue. If you need additional samples let me know and I'll forward one from my truck too.
Regards,
bob
letsgo,
What you saw is completely normal, as I have observed it in every fuel filter life test that I ever conducted. The fuel flow almost always starts at the bottom of the filter(depends on design) and works its way up as the media gets contaminated. The white was just the unused portion of the filter. If you noticed when you changed the filter there was a tube that went quite a ways into the center of the filter, its near the bottom of the media when installed and causes the suction pressure to be centered around there at the beginning of life. Had you ran the filter longer the media would have been used and coated entirely as you expected to find. Mine was around 3/4 used when I changed at 13k.
George,
Any ideas on what kind of filter set-up might fix our problem? The Stanadyne FM-100 is looking very promising to me.
I've got to add something else here before the lynch mob lights the torches and shows up on Racor's door.
The 95% efficiency numbers are obtained using fuel conforming to ISO/TR 13353, the ISO test for fuel filter particle retention and efficiency. This fuel is dosed with a much larger percentage of contaminant than you will ever see out of the pump, it looks black when totally mixed. This is done first to speed up the test so it doesn't take a month to perform, second it levels the playing field so everyones results can be compared at a predetermined contaminant level(George I assume will agree that initial contaminant level in fuels will vary widely depending on location), and third sets the contaminant at a level we should never see(makes the test harsher on filter).
With that said, as contaminant levels drop, your effective efficiency at removing them will fall accordingly.
Todd,
Did you find a spec on the Stanadyne FM-100's flow resistance (in inHg)? They quote a flow rate of 80 GPH but I didn't see a spec for flow resistance on their web site. Sent them an email request a few days ago but haven't heard back yet. It does look like a nice filter ( if the specs are as good as they claim).
jbplock
No I don't, but as George stated earlier tha our pump has a 60hg and the oem filter takes 8 of that. Therefore it will handle one more filter. Besides if it doesn't and it will, stanadyne makes one with a lift pump on it.
jbplock
Tech support at Stanadyne told it would be 2 inhg and 1psi on a new filter. Looking better all the time. The whole unit only cost $90 and that is with the head, element, hand primer and plastic bowl.
Thanks Todd.. Yes remember reading George's post on our pumps 60inHg rating and you're right that it should easily handle the load from the added filter. It just would be nice to know the Stanadyne spec. I just read one of the data sheets on the Standyne website and it states that the flow resistance spec is available upon request. If I get a response I'll post it. Being a chronic worrier, I 'm concerned that if I ever had a pump problem the dealer could claim that it was due to the added load of the extra filter... just be nice to have some back-up data in that case.
[ 11-06-2002: Message edited by: jbplock ]</p>
jbplock
Read my last post. I was posting the same time you were.
We have to assume that Bosch, Dmax, and GM designed these fuel systems to operate in the real world. Certainly, the cleaner the fuel the better, but there comes a point at which "good enough" is really good enough.
What I can't seem to locate in this thread is any data that equates a certain fuel cleanliness level to a certain number of miles or hours of operation, with comparisons between different levels of fuel quality.
What most people want to know is, what is the typical fuel system life with OEM filters, and what would it be with better filtration? Good data and proven results - in the real world...
MP
MorePower,
What I see is that there is proof that dirty fuel causes all kinds of problems in the new modern day high pressure injection systems. You can look around on the internet and see that. George quoted CAT's study of just that. I think if we wait till we have our own proof of this it will too late. I personnally don't have $5K or $6K laying around to buy injectors and/or a pump, when I can buy a $90 filter that will most likely eliminate the problem. As you can see adding another filter won't hurt. I went by my dealership today and ask the service manager if he would void my warrenty if I added another filter and he said most definately not. I have a great Service Manager, he's been a friend for at least 20 years.
I'm taking a middle ground here. The power of the internet is a great resource, BUT those poor filter guys must be really "dissing" it for all the calls/tech inquiries that they are getting from all of the people going off in ten different directions. :rolleyes:
As to data and proof, I am a simple man. I feel I am a pretty good judge of what works and what doesn't AND I know who to believe and not. Simply put if the post filter fuel is dirty enough (according to George) to harm hydraulic systems of a LESSER psi, with a better lubricating fluid, then it is obvious to me that this level of contamination is not good for our fuel systems. No need to beat me over the head get me to acknowledge this.
Sure GM and Bosch looked at what was required for filtration, spec'd it etc, but what happened when the bean counters said the price was too much? Did engineering have their sights set on 500,000 miles or 100,000.1 miles? These guys ARE in the parts business too!
It is obvious to me that we will benefit from improved filtration, but again, I'm not rushing into this...
John,
I respect your knowledge on all these subjects and I am not sure why you not "rushing into it".
If the answer to cleaner fuel is adding another filter , then why not go ahead and add one. Post OE or pre-OE? The fuel still gets filtered. Only thing is you might have to change one of the filters more often than the other one.
Hi everyone new to the Forum. I have been lurking for a long time but decided this was a good topic to start adding my $0.02.
Just a thought but if the Fuel/Water Seperator is not removing the water from the fuel then why not unhook the sensor go have an adapter machined to fit in place of the stock filter and have the other side made to match a CAT Spin on Filter or the Filter of your choice.
There is plenty of room for a larger diamter and longer filter. More filtering area. Not to mention the fact that if the filter was a little longer it would be much easier to get a strap wrench on the filter.
Any opinions good or bad are welcome.
Danny
Choreboy I agree,
I just don't know how to do that.
More Power I have to agree with you to a point about GM and Duramax doing their home work on filtration. But even as much as I love my GM vehilces I know that things always have room for improvment and what comes with them is not always the best solution. They are just wanting to get throught the warranty period so they gamble on what it will take to do that and hope for the best.
I worked at Navistar for over 10 years and I can tell you that what they know does not always get applied. I can see this even now with a large account that I have thats building generator sets. What is needed to do the job right is far from what they want to do because as JK mentioned it all comes down to the dollar.
I have had the Racor 2 micron on the 6.5TD for awhile now and it always gets fueled up at the same station. We have a known quality of fuel and we know what the filter did new. I will be doing another after filter sample soon. This might shed some light on how long the R45S element will last.
We were looking at a Dmax a couple of days ago to see just where to put the extra filter. There is plenty of room just ahead of the fuel cooler. We are going to try and come upp with a bracket that will clamp onto the frame so holes do not need to be drilled. Their is plenty of room to put on the 660 or 690.
Greg