Engine/Transmission (1998.5 - 2002) Fuel flow rate required??

[lsenus]

What is the GPH rating of the LP's on the Jan. '99 CTD? I ask because I'm looking to put a Racor filter setup on my truck pre lift pump to protect the pump. Also, what would be a recomended filter micron size? 2? 10? 30?

 

[Ncostello]

45 GPH is a good figure to use as a minimum. I believe thats what the stock filters are capable of. I wouldn't go below that. I used to use a 80 GPH Stanadyne filter setup.



Go for the 2 micron filter. 10 is the standard ISB (and ISC) filter rating... but if you can do better go for it. It will be better for everything.

 

[rweis]

I've got the RACOR 690 with a R690T (10 micron) filter pre lp. I think with the R690T and the OEM 10 micron I am really getting 10 micron clean at the VP.



I change the R690T every 25k miles or about once per year for my driving. I change the OEM ff once a year as well (just because it makes me feel good to do it once a year or so).



I LOVE the 690! I get several drops of water every month, and last month I got what looks like plastic curly shavings (3 of them). The curly shavings would have screwed the lp for sure. I also get some fine particulate each month.



I put a ball shutoff valve on the 690 bracket so when I change the filter or work on the fuel sys I can shut the tank completely off.



I put my lp on the frame and so far 45k and running fine.



I did a fopah though when I did the last R690T change. I only had 1/8 tank of fuel and the lp would not draw the fuel up the fuel tank plumbing and into the 690. Already had the filter off, so could not go fill the tank. I thought I could start the engine and it might draw the fuel through. It drew the fuel into the 690 but then I had a ton of air in the fuel system and of course the engine died after about 10 seconds of running.



But I now had fuel in the lines up to the lp and I just loosened the post filter fp gauge just prior to the VP and let the lp pump the lines clear of any air, tightened the fp gauge fitting when the flow was good and bubble free, and she cranked right up.



I think the RACOR 690 and moving the lp to the frame (and the fuel pressure regulator bypass set to 12 psi) is the answer to the fuel system woes. You still have to carry a spare lp because the lp will crap out eventually, but for the $$ of the RASP etc so far I should be at about 300k miles for breakeven cost.



If you live in a cold climate you can also put a heater in the 690 and have nice warm fuel through out the entire fuel system (lp and all) on cold days. That should keep the lp happy.



Bob Weis

 

[MDale]

I was just wondering where you got your filter setup at? Any link to websites, and what sis it cost? I would that to do this setup on my truck.



Thanks matt

 

[rweis]

I built mine. I got the RACOR 690 (R90T 10 micron filter element) from SouthEast Power Systems ( I know the 645 would have been enough, but I only wanted to change the filter 1 time per year (25k miles, 1600 gallons) so I got the 690). The brass ball valve from a good plumbing supply. I the SS fuel lines from Summit.



I mounted the 690 on a 1/4" steel plate that is attached at the top by bolts through the bed stiffeners and at the bottom on angle iron brackets for the running boards. The whole thing is in the under side bed pocket at the front of the bed on the drivers side.



I get into the fuel system right where the OEM tank line comes over the left frame rail (under the truck back by the tank) + about 2 ". Earl has a fitting 3/8 compression to AN-6 that I used to get it into the AN-6 sizes. Then I go to the RACOR 690, then I go to the lp on the frame rail, then I put a Mallory 4307M bypass regulator, set at 12 psi, to keep the OEM lp check valve CLOSED (because the OEM lp check valve seems to be a major cause of lp failure). The bypass regulator is plumbed back to the tank vent line. The fuel line goes on to the OEM ff and on the the VP-44 with all Aeroquip fittings (including the inlet / outlet of the OEM filter and VP) and AN-6 lines (I took out all the banjos and stock fuel supply lines). I left in the stock fuel return line from the VP and engine T. I monitor the fp post lp just before the OEM ff, and post OEM ff just before the VP-44 inlet.



I am testing a workaround to keep the VP-44 from hammering the fp gauge just before the VP-44. I have lost 2 high quality solid state Westach sensors on an 18" snubber line in 2 years. I think I MAY have a better mousetrap by puting the pre VP fp sensor on 120" of fuel line that snakes around the air intake horn in circles and figure 8 patterns to buffer any VP pulses.



The 120" line also makes it EASY to bleed air in the fuel line if necessary. Unwrap enough of the 120" fp sensor line so it can hang over the front grill into a bucket, loosen the fp sensor, and bump the starter, run it until there are no air bubbles (maybe 2 bumps of the starter), tighten the fp sensor fitting while the lp is pumping, re snake the long fp sensor line, and crank her up.



Hummmmm, I got carried away I guess, oh well, now you know,



Bob Weis



The filter is on the tailgate side of the 1/4" slab for protection from road debris.



The cost: Filter is $25, filter head is about $50, ball valve about $25, SS lines and fittings $probably more than the entire filter and valve. Peace of mind PRICELESS (but DO carry a spare lp, it WILL fail eventually, but it will be super easy to change with it on the frame rail).