You can buy (2) OE-type fuel pumps and FPR's for what the FASS costs. Besides, the FASS has a limited lifespan and will cost 3x another OE-type pump to rebuild and leave you w/o a fuel pump for at least a week while they rebuild it. I spent several $100 on diesel when my last FASS failure happened because I was on the road.
$40 OE-type fuel pump: (lifetime warranty)
New Fuel Pump Installation Kit Ford Pickup Van 7 3L Diesel E2236 | eBay
I've run an OE-type fuel pump and the Magnafuel FPR for the majority of the 170k veggin' miles I have on my F350. I'm no longer a fan of the FASS...
Worst case scenario, every autoparts store in the country can get a PSD pump the next morning - if its not already on the shelf! It takes just minutes to swap it out and be greasin' again!
You can use something like a WIX 33972 filter before the fuel pumps. Available from O'Riellys or NAPA.
Wix 33972 & Napa 3972 Fuel Filter: FleetFilter Secure Online Store
Water-separating filters can not/do not/will not remove water from WVO - skip this unnecessary addition to your design.
You only need to measure fuel pressure in one place. You wanna see the pressure the heads/injectors are getting. This is enough to tell you a filter is getting plugged up. You could measure vacuum between the pumps and pre-pump filter, but thats still superfluous IMHO.
3/8" fuel lines are adequate up to the tee to the heads. I suppose you can use the existing tee to the heads - can you post a pic of this and the OE FPR for me?
30R9 'fuel injection hose' is adequate, but I know somebody who's using this:
3384 | Black Push-Lock Hose
I recommend the ptfe-lined SS braided hose on the engine. Since 'rubber' hose has a limited lifespan with all the heat, oil and degreaser, etc its exposed to up there. The aluminum tubing (TIH) is fine elsewhere.
This is what my engine fuel lines look like now:
You can DIY these hoses from discounthydraulichose or get them made at a local hose shop. Note - if you use this hose you MUST protect everything from it. It will wear a hole in anything it touches!! I just sliced cheap hose and put on mine, but you can slip vinyl tubing or similar over it before assembly for a cleaner look.
If you are gonna use (2) fuel pumps, I would switch to a deadheaded design and use CV's. This will make the simplest and most reliable system. You can use a manifold block like I posted above (mcmaster.com) and put your CV's, fuel pressure and temp senders in it. Then plumb the other side of the heads to a normally-closed 12v valve for purge.
YES, I highly recommend the coolant pump. We were getting these for about $60 - but somebody recently said they've gone up...
I didn't understand what yer doing with the 'wavy steel freon channel I pulled off an old refridgerator'?? Heating the whole tank is not the best design and carbon steel (or especially copper) in contact with VO is baaaaaaad. I suggest using something like the Hot Fox or building your own 'heated pick-up' that focuses the heat in the area where the fuel is being drawn from the tank. If you do put a HE in the tank, make sure your design includes protection from movement as a result of sloshing fuel - but specifically, something akin to a root beer float. Picture a semi-solid chunk of cold VO banging around in the tank like a wrecking ball when you take off, slow down and negotiate corners.
Speaking of HEAT. If ya put the VO pump, FPR, etc under the cab - then you can run the return from FPR in TIH and instead of dumping it back in the VO tank, tee it into the suction line where it leaves the tank. This creates a 'looped return' which will add copious amounts of heat to your VO and greatly reduces the strain on the fuel pump. Also, do a 'coolant wrap' on your VO filter like you can see in the pic I posted above. If your TIH 'loop' is at least 12-15ft and you have an adequate heated pick-up - you should see more than adequate VO temps before the heads without the need for a FPHE.
So, you're veggie plumbing will go like this - VO tank, heated pick-up, tee, TIH to pre-pump filter, VO pump, FPR ('return' from FPR will go in TIH back to the tee at heated pick-up), VO filter and on up to CV and manifold block.
Diesel will go from D2 tank to pre-filter, pump, FPR (return to tank), to D2 filter (use a water-separating filter here!
) and up to CV and manifold block.
The purge will go to 12v valve under cab and return to VO tank. Run this hose/tubing parallel to the VO lines in HOH fashion, so ya don't end up with gelled fuel and inability to purge in cooooooold weather.
For coolant, tee into the heater core hoses. The 'return' line goes to top of water pump. You want the hottest coolant to hit the TIH between VO tank and pump first, then in-tank HE, then TIH for return from VO FPR, then coolant pump and finally coolant wrap on VO filter. I also recommend putting a valve on the supply to heater core for colder AC in the summer
, but also on the supply to the VO loop so you can turn OFF the heat to veggie-system in the event ya won't be burning VO or wanna put D2 in this tank. You don't wanna 'cook' VO returning 500mi home after ya used all yer high cholesterol fuel and you never wanna heat D2.
Also, consider adding a valve before and after the VO filter. Before the filter allows you to change filter w/o draining the tank while you are changing it and after the filter allows you to isolate VO system in the event you had a CV failure or perhaps ran over a Prius and ripped part of your system out.