View Full Version : Cat Filter Installed Post OEM
Well I spent this morning installing a 2 micron Cat filter post OEM. The pictures are in the link below. It is setup where It can be easily switched back to stock configuration. The truck has 9500 miles on it so I went ahead and changed the OEM filter. I cut it open and it was pretty dark brown all the way around the bottem about 1/3 the way up with 2 dark streaks about 1.5 inches wide all the way to the top, no sign of water. Put about 60 miles on it this afternoon with no leaks or problems. tongue.gif
Barry
imported_
03-01-2003, 19:34
Down and Dirty, just the way I like it, angle iron, 1" tube and a beautiful fully adjustable brace :D
Thanks for posting the pics, I think this is what my truck is goin to get.
Oongawah
03-02-2003, 00:09
Wow, what fine job. Nice pics too. Thanks, Chuck.
Maverick
03-02-2003, 00:47
SWEET!!!!!!!!
Corndog
Is there any problem getting to it to change it?
Corndog,
Very nice!!
Could you also post the CAT part numbers you used?
smile.gif
BigO
You will have to remove the inner fender to get to it and the OEM filter
to change them now.
jbplock
Here's a list of Cat part numbers for the assembly.
You will need 2 bolts to attach the cover which are standard
1/4x1 1/2 and 5/16x1 1/2,you might have to grind the ends off a
little bit to keep them from bottoming out.
FILTER BASE.......1N-3789
FUEL FILTER.......1R-0750 SHORT
GASKET.....1P-0436 (GOES BETWEEN COVER PLATE WHEN REMOVING PRIME PUMP)
COVER...6N-4414 (REPLACES PRIME PUMP)
PLUG...9S-4182...(bleeber plug)
SEAL O RING...3J-7354...(GOES ON BLEEDER PLUG)
WASHER...5P-0537
WASHER...9M-1974
Barry
pepperidge
03-04-2003, 10:18
Corndog,
Ever thought about making a few extra brackets?
I would be very interested if you want to make some extra $$$.
Heck, you could even market it as a kit with all hose fittings and hoses pre cut.
To save on shipping weight we could just pick up the Cat parts ourselves.
Just thinking out loud again.
woundedbear
03-04-2003, 13:34
Corndog,
Thanks for sharing your istallation and P/N's. Needless to say, I really like what you did and am going to do the same with my truck.
I have a couple of questions, if you wouldn't mind answering:
1)The clearances look very tight for the CAT filter, and I am in the process of fabricating a bracket for myself. Do you have more specific dimensions so that I know my part will duplicate yours? More specifically, I want to know the overall length from firewall mounting surface to filter base mounting surface.
2)Did you have any trouble priming the system without the CAT prime pump on the filter base? I thought about using an additional prime pump instead of the cover plate, but at an additional $53 cost, if it is not necessary, I will not pursue it.
Again, I would like to thank you sharing this with us here. I have been sitting back trying to decide what to do and this alternative really met all of my criteria: 2 micron, post OEM, reversable, mounted under hood and economical (~$94 for all the P/N's that you stated above and $12 replacement filters).
pepperidge
I hadn't thought much about it, but if you have no other option
I recon I could cobble up another.
woundedbear
I got in late this evening, I will measure the bracket tomorrow night and let you know. As far as priming it was no problem at all to prime both filters with the OEM pump. The clearance ended up being about 3/16 to 1/4 inch all the way around, but the mount is very solid.
Hope this helps:Barry
CORNDOG,
Please post us a note on your results when you have done some heavy towing, now that you have your CAT filter setup installed. Would be especially interested in whether you experience any hesitation/stumbling, etc., towing 10 - 12k lbs. up a mountain/steep grade. Many thanks,
Ardmore
pepperidge
03-04-2003, 21:55
I hadn't thought much about it, but if you have no other option I recon I could cobble up another.
__________________________________________________
Corndog,
Shoot me an e-mail (pmbono@bellsouth.net) and Let me know what were looking at and I'll get back with you Monday afternoon. I'm leaving for a family vacation tommorrow an won't be back till late Sun, night
Thanks,
Barry,
Regarding the 3/16 to 1/4 inch clearance on your CAT installation, have you checked to see if there is any contact between the CAT and it's surroundings from engine vibration and movement? The picture of your filter taken from below shows the OEM fuel line close to the CAT. (http://www.oldmacksrus.com/Duramax%20Picts/DSCN0245.jpg)
Maybe a piece of split hose over the hard fuel line could add a little protection.
smile.gif
jbplock
I'm gonig to change my inlet to a 90 tonight
I'll check and see if anything is rubbing then and
let you know.
ardmore
I'll let you know as soon as I get a chance to
do some towing.
Barry
woundedbear& jbplock
The demensions on the bracket are 4 7/8 from firewall and 4 1/4 wide. As far as the clearances, I added the 90 fitting tonight and checked for rubbing and found everything to be ok, after driving it all week. I added the new pictures with the 90 degree fitting to the web site also. I'm thinking of changing the other one to a 90 also to dress things up a little more.
Barry
Barry,
Thanks for the feedback. Your installation looks very solid. Nice Job! smile.gif
woundedbear
03-07-2003, 08:25
Barry,
Really appreciate your efforts! I have purchased everything I need from CAT and Parker, now to just finish my bracket. I am going with two 90 bends, too.
Thanks again for you help! smile.gif
On edit: Once I verify my bracket fitment, I will post a CAD print for reference to anyone interested in this secondary filter alternative.
[ 03-07-2003: Message edited by: woundedbear ]</p>
george morrison
03-07-2003, 15:04
Barry,
Now for *the* question.. I have seen more than one instance where the additional filtration and resultant ultra clean diesel fuel has resulted in a significant increase in fuel mileage. I do not know if you have closely tracked your fuel consumption to this point but if you have it will be most interesting noting the affect. There are products being marketed which use rare earth metals to 'align ions' in diesel fuel and do indeed have affect on burn efficiencies. Correspondingly, removing actual physical particles goes far beyond the 'ion' alignment, greatly facilitating/optimizing the burn process...
The increased fuel mileage has been evident to some degree in just about every installation.
Will be interesting..
George Morrison, STLE CLS
GMC-2002-Dmax
03-07-2003, 15:18
Looks Good,
I am debating which path to go with.
The DP article has an under the truck RACOR 600 pre filter article.
Kennedy has the Mega Filter in the works.
Now a CAT Filter install.
What is the cost of the CAT parts, if you don't mind posting it.
Thanks,
GMC
George
I've tracked every drop of fuel thats been put in my truck since the day I bought it. As soon as I can get a full tank run through it I will let everyone know. Of course this time of the year it might be hard to tell, but my milage has been very consistant so far.
GMC-2002-DMAX
The parts from CAT was $95 + about $25 for hose and fittings.
Barry
GMC-2002-Dmax
03-08-2003, 07:49
THANKS!!!
GMC :D
For all those who have ever whined about having to pony up a few bucks to join this page, this and the ultra-long fuel filter thread ought to be enough evidence of the wisdom of their small investment. GM ought to join. It might learn something.
Thanks, guys,
TC
I decided that I would add my other post's reply to this thread as well since they're so closely related in the hopes of getting a response.
Dura-max3
You installed your filter pre-OEM, between the tank and the OEM filter, and corndog put his post OEM, between the OEM filter and the injection system. Am I clear on that?
When you have that 2 micron filter between the tank and the OEM filter does that not make the OEM filter redundant and clog up the 2 micron filter much more quickly? I just want to be clear on that because I intend to put one in my truck also. I believe it is the one mod that will give our trucks the most longevity. Stu
Tsckey:
You can edit your double post & delete one of them. Just go to the date line and click on the icon with the pencil...it will take you to edit, where if you look in the left top corner there is a box that says "delete" just check it off amd then click the box at the bottom marked "Edit Post" and your post will be delted.
smile.gif
[ 03-08-2003: Message edited by: ccds ]</p>
dmaxstu,
I believe the issue involves neither filter reaching 100% removal of 2 microns particles. Most filters talk of significantly less removal than 100%, so two in a row substantially increases the percent removal of 2 micron particles and larger.
You would have to change the first filter more often, but to get the most filtration all the time, you would change both at the same time.
However, I am no expert and these are my best guesses.
Don
woundedbear
03-10-2003, 10:41
Just a warning to others...over the weekend I was a victim of vehicle tolerance stackup. :(
For the first time since I bought all of the essentials for the post OEM CAT filter project, I opened the hood and measured for bracket dimesions. Unfortunately, unlike Corndog's truck, I don't have the clearances for the CAT filter that he does. I guess the truck to truck variance shouldn't suprise me. Many of the components that interfere are bent tubing and pipe that, due to process capabilities, are not held to the strictest of tolerances.
I'm not sure what I'll end up doing, but I hope to figure something out. I looked around the engine compartment and, as you all are well aware, it's pretty tight.
Two quick, but possibly dumb questions:
Wouldn't it be possible to frame mount the filter, but still be post OEM? Is the additional length of hose the issue here?
Is it okay if the filter is mounted on an angle? My thought is yes, but wanted to comfirm with others here. The design of the filters parallels oil filters and those are often mounted at an angle or even horizontal.
Be forewarned....
The OEM filter is mounted to the engine.
If you mount a large filter close to the OEM filter, engine movement during harsh acceleration/decelleration should be considered.
The space available next to the OEM filter puts a large filter rigidly mounted to the truck body/chassis very close to the OEM "floating" filter.
I have not done any study on this, it just came to me after reading these last few posts.
[ 03-10-2003: Message edited by: hoot ]</p>
I would not mount a spin on fuel filter any way but vertical with the head on top. If you mount it horizontal, the inlet and outlet is on the side and any accumulating water is much closer to them.
The WIF sensor on the oem should alert you before the water level reaches the media allowing 100% of the media to continue to filter fuel. I think it is important that water not surround the media below the fuel. This creates media that is no longer filtering fuel, it's just acting as a water barrier and this effectively reduces your media surface.
I don't like the CAT filter as a primary in-line because of the lack of a drain cock but it should work fine post-oem, just don't lay it on it's side.
MaxDiesel
03-11-2003, 02:56
Trace,
"I don't like the CAT filter as a primary in-line because of the lack of a drain cock but it should work fine post-oem, just don't lay it on it's side."
Am I wrong? I was looking at your pics and thought you had your filter installed pre-OEM.
Jim
MaxDiesel- Hi Jim-
You are correct. It has a drain though. A 2-mic filter like the CAT (or mine) will knock down the water pretty fast so I feel it needs a drain at least if it's pre-oem. When water encroaches on the media, the media no longer filters fuel, it just acts as a water block and fule is filtered in the remaining media above the water line. If the oem is getting a shot at the water first, the CAT without a drain probably won't see much water unless you just get a big slug all at once.
One reason I like the Stan was the optional bowl that goes from filter to filter and I can lean over from the passenger side and visually inspect for water. The Racor has the same option but it threads on and the Stanadyne has the integral seal and I don't think the Racor does. Kennedy is right, this is important. GM addressed it- their filter is nylon threaded.
The oem filter is designed to set off the WIF light/warning when the water is at an estimated 2 or 3 ounces. At this point it is still below the media. I have a cut open oem in my pics and you can see the funnel shape on the bottom of the oem below the media where the water sensor is.
I might be missing your point or question. Sorry.
[ 03-11-2003: Message edited by: TraceF ]</p>
Bulldogger
03-11-2003, 07:28
Woundedbear, go to John Kennedy's site and he has picture of a post OEM secondary filter mounted under the air box assembly this should address you situation. I'm gonna mount his kit there on my truck also, he wasn't joking about the MEGA size either.Dave
corndog,
I noticed some guys have used one brass fitting at the filter mount but you used a male/male fitting then a female pushlock. Any particular reason?
Does a male pushlock have a smaller through hole?
What inside dia. is the hose?
MaxDiesel
03-11-2003, 09:43
Trace,
Thanks, You did answer it. Probably in a way I didn't consider. I was going to do the CAT filter, but now want to find how avalable the Racor or Stan is in my area (Stockton) that has the bowl in the bottom.
Jim
Actually, GM/Racor did not address the issue with plastic, but with the center post seal. This ensures that fuel cannot transfer from dirty to clean side w/o flowing through the element. By going to a perimeter thread, there is no threading action at the clean side of the filter...
John,
Your setup looks pretty nice. You found that hidden pocket of space under there we all were looking for. Now we need a better way to remove and replace the wheel well without messing with the cheap plastic fasteners.
Idle_Chatter
03-11-2003, 11:30
You've got that one right, Hoot. I've been noodling that particular problem for a while now. Considered D-zus fasteners, but they are too costly. I'm just about to experiment with a nut-rivet and 1/4-20 panhead screw application.
WD-40 or my personal favorite dielectric grease!
I use CRC spray dielectric on my pins...
:confused:
Ok, I've got to ask this. Why could someone not make a "replacement" fliter system? By removing the exsiting hub and replacing it with a perimeter "case" style housing. The houseing would hold a replacemnet filter of desired micron filtration as well as having the "nipple" on the bottom for the OEM sensor. ;) The "drop-in" filter would be cheaper and much more easy to repalce than the OEM and back-up filters. :rolleyes:
--- John, I would really like your thoughts on this.--- Tell me why it would not work or what problems could be expected? I will say this, if you were trapped on the road due to a plugged filter, you could (shortly) do without it. The can would hold pressure with or without a filter. Dangerious yes.....but it would get you to a safety spot.
Burner
Once again, I believe that it will take 2 filters to get the job done. Look at the posts of guys adding dinky aux. filters and finding premature plugging. The finer the filtration, the more restriction, so a larger element is needed. I have yet to see anybody actually measure their restriction when adding an aux filter. The packaging of the Dmax will not allow a sufficently sized single 2 micron filter to be added in the factory location IMHO...
FWIW, even that "monster" of a filter that I use will add a MEASURED 1" hg. (approx) of restriction to the 2"hg already existing in the system with a NEW OE filter.
When I hit 10k OR 5-7"hg on my filters (both installed about 4k ago) I will change the OE unit first and check the drop in restriction. If it normalizes, I will continue use of the same element on the Mega kit and push on. If it still shows significant restriction, I will change the element. I am hoping we can go 15-20k on the Mega element...
John,
Are you using the GM Vacuum gauge (J44638, $200) to measure restriction? I have been searching high and low for a mating quick-connect fitting for the Schrader valve test port but haven't found one yet. I'd also like to be able to monitor filter restriction on my (coming soon) Mega Filter as you suggested. But, I would prefer to find an adapter (to NPT) for the quick connect coupling and use the vacuum gauge I already have. Any suggestions?
smile.gif
I'm working on it, but all I've found is a fitting that is SUPPOSED to be the one for about 1/2 the price of the gauge.
Installing a NPT Tee at the outlet of the Mega filter (assuming you are using as a secondary) will allow a gauge to be plumbed...
Idle_Chatter
The rivet nuts are my intention also. I plan on using alum or SS Deep threads for the nut and the pan head or wing bolts for the bolt. Depends on how the wing nuts look. I'm sure changing the filters on the road will be quick and easy W/O having to get under the truck. smile.gif
John,
Checking the "Hg vag after changing the OEM first was my exact intention also. I also want to establish a change interval base line for the MEGA filt but will continue to change the OEM as recommended.
I also have a 2 mic. silica gel packed tank vent that I ordered from G. Morrison. A little larger than 2-1/2"x 2-1/2". Was going to use this w/ a non-vented tank cap. Do you think any benefit can be realized from this. It may be a little overkill but we do have high humidity conditions down here and I sometimes drive in a lot of dust.
a bear,
"...Checking the "Hg vag after changing the OEM first was my exact intention also...."
I measured the Dmax fuel filter restriction at normal factory idle/high idle (rev limiter) after the truck was up to operating temps. Results are inches Hg vacuum:
OEM Racor with 1.6K miles 3.0"/3.5"
OEM Racor NEW filter 2.5"/2.75"
OEM Racor/KD Megafilter(both NEW) 3.5"/3.75"
I installed the KD system AFTER the OEM. It will be interesting to see what happens to these numbers with frequent monitoring.
[ 03-11-2003: Message edited by: mdrag ]</p>
mdrag
Thanks for posting the numbers. They will give me something to compare to. I will run the same series of checks and will post the results also.
Will be flying home in the AM and should have the MEGA filter when I arrive. :D
Bill,
Good idea about hooking up the vac gauge for monitoring at a glance. Sure beats the portable manometer I'm using. I am running post OEM so I think I'll run a tee like JK mentioned. I will try to find a glycerin filled gauge. Better for vibration. Unless one of you know of another type. :D
[ 03-11-2003: Message edited by: a bear ]</p>
MaxDiesel- At this point I am not making a recommendation to use the Stanadyne. This is an experiment on my part and although I think the fuel is quite clean I haven't tested. I think it's clean because the filter began to clog enough to cause a noticeable performance loss at about 2300 miles and my personal conclusion is that the media on my filter is inadequate for 400+ cubic inches. There is a longer Stan element I may try.
Media size is going to be important if one chooses to go pre-oem 2-mic. This is becoming evident. The Racor 660 may last longer and the 690 longer still because of the larger media surface area.
Kennedy's experience took him to the MEGA filter size and my own experimentation supports that media size is relevant to longevity.
I have an idea for a pre-oem install that will be simple and straight forward but I need to work with it a little before I say it may be feasible for our applications.
Hoot / Idle_Chatter
Just installed the 1/4 " aluminum rivet nuts to mount the wheel well liner. Used SS 1/4"x 5/8" pan head bolts and 5/8" OD SS stove washers. Had to bore the mounting holes 1 size over to set the nuts. Works like a charm and looks like new money.
Only did the front Five. Just fold the liner back and the OEM and MEGA filter are looking right at you for a speedy change. :D :D And you wont have to get under the truck. :(
mdrag / JK
These are the vac readings I got on the filters.
Post OEM 2.55 "Hg
Post OEM and MEGA 3.50
Looks like all are close.
Will now be monitoring post both filters for the trend / baseline test. Will post the results.
Where are you guys taking your vacuum readings? A company I work with makes a gauge adaptor that fits on a schrader valve. Once I see where the reading comes from I can determine if this gizmo will work.
Jelisfc,
When standing in the front of the engine the schrader valve is about 2" to the left of the alternator. Brass with a black cap.
a Bear,
How do you install a rivet nut?
Hoot,
You need a rivet nut setting tool. I got one at JC Whitney a couple years ago but it may be available from hardware stores. I have the cheaper one and it works just fine. Very usefull tool.
Try this link http://www.jcwhitney.com/productnoitem.jhtml?CATID=5396&BQ=jcw2
[ 03-14-2003: Message edited by: a bear ]</p>
Corndog,
Looking at your picture......
http://www.oldmacksrus.com/Duramax%20Picts/DSCN0245.jpg
Did you take this photo BEFORE you installed the
Parker hose to the OUT port of the OEM filter head?
It looks like the original hose still there and
I don't see a the blue Parker hose. Just
trying to figger the plumbing out :confused:
Very nice set up
[ 03-15-2003: Message edited by: 56Nomad ]</p>
FirstDiesel
03-15-2003, 07:56
Tommy
I love the idea of inserting threads in the fenderwell and doing away with those clips.
I'm not sure which tool it is to buy. There are som many choices there. Any help???
FirstDiesel
That page was confusing to me also. Try this link. Its a little more user friendly. It's the pdf version of the cat. After it opens go to page 61 then you can zoom in to read.
http://www.jcwhitney.com/pdf_index.html
[ 03-15-2003: Message edited by: a bear ]</p>
Here is what I have for installing rivet nuts. Its a handy tool to have...
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=1210
I asked my dealer about the plastic liner retainers and he just gave me a handful.
FirstDiesel
03-15-2003, 10:51
Thanks
We have a HarborFreight here in town. I'll stop by and check it out. I like the idea of being able to remove that fender liner without dealing with those clips. I've removed a few of them once to get to the fuel filter and have already broken 1. Think I'll do that as part of the MEGA filter project.
Trace,
The rivet nuts are a whole lot easier and sturdier. You don't have to mess with pulling and messing up that center core on the fasteners. The nut is permanently set behind the sheet metal.
56NOMAD
The picture in question was taken before I plumbed the CAT filter in.
Corndog
KompressorMan
03-15-2003, 18:05
FWIW, If you guys are installing a gauge to measure the delta P across the filter. It would be an excellent idea to use an electronic gauge with a memory. The flow across the filter is minute compared to what it's going to be under full acceleration/load. So, just idling the engine is not a good indicator of filter condition. Now if you had a gauge mounted in the cab, that's another ball game.
Herb
There is a 1" suction gauge for aircraft use that could be installed inside or in some hidden location if you want to monitor fuel system vacuum. You may not like the price, tho. It's $74.95 from Wag-aero. It reads from 0 to 7 inHG.
If you want a 2" in dash or pillar mount, you can go down to your local Pete, KW, or whatever dealer and get a fuel filter restriction gauge. I had one in my Pete. They are a common sight in O.O.'s trucks.
Steve
Kompressorman,
The idea of having a recall is a good one, but the restriction across from filter should not change with engine load.
The supply side of the Dmax injection pump is a simple pump much like an oil pump. The volume delivered will vary based on RPM. The FRP regulator controls duty cycle and varies how much fuel is fed to the rail to regulate the pressure. The balance of the fuel goes to the tank.
KompressorMan
03-15-2003, 22:32
JK
You are saying "there is no more fuel going through the filter at WOT than idle???? If that's true, the restriction/resistance/pressure/vaccuum would not change. But, if there is more fuel at WOT, then the delta P should increase. Bernoulli's Principle rules!!!
Herb smile.gif
What I am saying is that THEORETICALLY, the volume of fuel through the filter will be the same at any given RPM regardless of engine load...
kennedy-
Do you mean that the fuel system is always circulating fuel at the same rate and the filter is always filtering at the same rate? Just at idle a lot of fuel is returning to the tank and at WOT much less fuel is returning to the tank?
If so, what is the constant DMax fuel system filter flow rate expressed in GPH? It would have to be significant.
I am saying that it is my understanding, that the supply side of the pump delivers a flow rate based on RPM only. The faster the RPM, the higher the volume. What doesn't go to the rail goes back to the tank. Based on this, 3100 at "no load" should pull the same restriction across the filter as 3100 RPM at rated power...
Abear, does your gauge allow you to view while driving?
KompressorMan
03-16-2003, 10:46
Well that's what I thought. So, if based upon RPM's, there is more fuel flowing though the filter at WOT, and say the filter is partially blocked. Then the delta P across the filter will increase. Hence, a gauge with a memory, or in-cab, would make sense because you could see actual full flow performance and get a baseline accordingly. New filter, full throttle = X, then after a while, any significant difference would equal blockage, which is exponential. Once it starts, it's gonna get worse a lot faster.
In compressed air, one of the analogies I explain to customers is this. Say the filter has a 1000 holes when new. Then after a while, 150 holes get stopped up, you might have a little more differential across the filter. A hundred more get stopped up a little more delta P, but the filter gets half stopped up and you try to get the same amount of air through it and the pressure across the filter increases a lot more. Also, the more it gets blocked, the faster the remaining holes get blocked. This usually happens to the point that the filter actually ruptures then NO delta P and a pile of crap downstream.
Herb smile.gif
imported_
03-16-2003, 10:55
Correct me if I am wrong but if fuel is delivered based on RPM and not load, then idling up the engine under the hood should give you accurate readings on a temporary installed gauge. This would give you accurate readings for WOT. (or cruising RPMs) without driving the truck. A memory gauge or in cab gauge would be cool, but maybe not needed.
JK,
The gauge I used was loaned by a friend at the dealership.(under hood only) I think mdrag said he has one with a long hose.
Compressor man,
What is delta P. I assume it's diff. press.
Has anyone pulled the schrader valve to check the the threads where mounted. Looks like 1/4" NPT.
Big Blue.
No.
3000 rpm under load will require a lot more fuel than 3000 rpm absent load.
imported_
03-16-2003, 19:11
I wrote:
"if fuel is delivered based on RPM and not load"
This is how it works on my land cruiser and JK indicated that this may be how it works on the dmax. Then wouldn't my statement be true. The fuel that enters my injection pump is drawn at a constant rate across the filters based on RPM. The amount of fuel used (based on that constant)is dependent on load, and dictates what is bypassed and returned to the tank. Maybe I just don't understand what my fuel system is doing.
Lone Eagle
03-16-2003, 19:30
Correct me if I am wrong but I believe it was JK that said the fuel pump is positive dissplacement. If so it will pump a fixed amount of fuel at a fixed pressure for every revolution within design perimeters. One of these is suction head which can be measured in WG or HGs depending on the manufacture. Pump vacuum is an improper turm. We have a negative pressure on the inlet side but is not a vacuum. If we plug the fiters, the suction head increases and gives us a serious problem called cavitation. KompressorMan, I am a retired maintenance super and I can say with confidence that pneumatics and hydraulics have almost nothing in common. Later! Lone Eagle :cool:
KompressorMan
03-16-2003, 19:49
Lone Eagle,
I respect your experience, but fluid dynamics prevail. Air is a fluid. The main difference is air is compressable, hydralics, well no. Other than that based upon the laws I know about, it's pretty similar.
Another way to think about load is, you turn about 2200 RPM's at 75 mph with 265 tires. Empty, you may get 17-18 mi/Gal. Hitch up that 36 foot fiver and see what happens. You still run 75/2200 but dang you can see the needle (fuel) falling.
Herb
Lone Eagle
03-16-2003, 20:01
I don't want to get in a pi**ing match. Compressed air is a gas. Later! Lone Eagle :rolleyes:
[ 03-16-2003: Message edited by: Lone Eagle ]</p>
Trace,
More fuel to the injectors but not through the filters. :eek:
imported_
03-16-2003, 21:01
a bear,
exactly
Lone Eagle,
Not to be taken the wrong way but anything that flows is considered to be a fluid, including air and gas. It's just not considered a liquid. As you mentioned though they have almost nothing in common. :D :D
PS: I thought the same thing at one time as I'm sure most others
[ 03-16-2003: Message edited by: a bear ]</p>
LanduytG
03-16-2003, 21:21
The pump has to be a positive displacement pump and yes it delivers X amount of fuel at a given rpm. But I bet you it has a bypass relief valve. The injection pump is a hydraulic pump and the hydraulic pumps I have worked with have a bypass relief valve. If it did not have a relief it would blow things apart if flow was ever block. Your oil pump in the engine works the same way.
Greg
Lone Eagle
03-16-2003, 23:19
Exactly Greg. Later! Lone Eagle
I'm with Big Blue- I am not clear on what the fuel system is doing. I asked this earlier but if it was answered I don't understand:
Do you mean that the fuel system is always circulating fuel at the same rate and the filter is always filtering at the same rate? Just at idle a lot of fuel is returning to the tank and at WOT much less fuel is returning to the tank?
KompressorMan
03-17-2003, 08:06
Trace
No, the fuel is not circulating at the same rate. The fuel pump takes in a given amount (X) and it's that amount times the engine speed (or pump drive speed) What the engine doesn't need due to speed and load factor gets sent back to the tank.
That's why I felt a need for a gauge with a memory or in cab display. The amount of fuel going through the filter is a lot less at idle than at WOT. Just noticed the last line of your sig. YOU RASCAL YOU!!
Herb :D ;)
KompressorMan
I've got it now. Thanks
LanduytG,Lone Eagle
The rail does not have a relief valve but instead utilizes a ECM controlled fuel press regulator. The ECM determines VARIABLE rail pressures for optimum performance at a given RPM/Load up to +-25000 PSI. Unused fuel is then sent to the tank VIA the regulator outlet. The LP pump delivers fuel to the system based on RPM only and at a rate just exceeding what is needed for that given RPM under load.
Lone Eagle
03-17-2003, 10:45
A Bear, I assumed the system had a pressure regulator to maintain a constant flow to the injectors. Somewhere in every pumping system is a relief valve to protect the system. I suspect it is in the pump housing. Later! Lone Eagle
Lone Eagle,
I didn't realize yall was talking about system protection. I stand corrected. And yes you are correct about needing a relief valve for protection. Sorry! :D :D
WOT isn't the issue, it is pump speed. The faster the engine turns, the more fuel it "pulls" through the filter. What the pump doesn't need it returns to the tank. ALL fuel passes through the EDU prior to flowing through the filter. The amount of fuel; delivered to the rail/injectors/engine should not affect the flow rate through the filter.
That said:
Check restriction at curb idle.
Check restriction at (3200rpm)high idle.
Done.
FWIW, high idle is a term interchangeable with max governed engine speed @ no load
So having said that JK- have we come to a conclusion as to the easiest, most practical way for all of us to do this?
Racor suggests at the bleeder port.
Lone Eagle
03-17-2003, 13:23
No problem a bear, You sound like a man that understands everything you know about hydraulics. Later! Lone Eagle
JK,
I agree and have agreed 100% Fuel rate through filter based on RPM only. Whats not sent to the rail goes back to the tank. Whew!! are we having fun yet.
The load I was refering to (unrelated to filter) is the load as seen by the ECM to know how much fuel/pressure will be distributed to the rail for optimal performance at that given RPM/Load. I'm gone drink a beer! :D :D
Anywhere between the pump and the filter that you want to check. Keep in mind that consistency is key here, and like a dyno test, you should do a baseline first and observe the progression.
Just like a dyno, the actual numbers often mean less than the progression, UNLESS there is a major deficiency...
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