Airstream345
Guru
- Joined
- Jul 3, 2017
- Messages
- 1,016
- Location
- United States
- Vessel Name
- FORTITUDE
- Vessel Make
- Kadey Krogen 54-8
If a multi-tank fuel system feeds into a single line before heading to each engine...then why do most twin engine boats have separate primary filters for each engine?
Couldn't you just run a single dual primary for all "inbound" fuel and then head off to each engine's secondary filter(s)?
I could see why an entire fuel system is completely separated (port only to port, starboard, etc using with a "polishing" transfer circuit, etc) but for many coastal, multi-tank, twin-engine boats - all tanks lead to a common "manifold" then off to each engine.
Is this just good marketing from the fuel filter companies to get you to buy two of everything?
Here is why I ask:
I've been contemplating some fuel system improvements. Currently I have what I described above: a common copper "manifold" (of sorts) in that all three tanks (port, starboard and belly) combine into a single line on the forward bulkhead of the ER. Individual tanks can be shut off from this line using a valve at each tank.
From this common fuel line two lines then feed into respective primary systems (port and starboard systems).
In my case the primaries include the original dual spin-on filters along with a newer, single Racor 500 water separating primary installed by the PO for each engine - presumably as a work around to filter changes/priming with the older duel filter system.
I can flip ball valves to route fuel through either the Racor or the dual spin-ons independently for each engine. The on-engine secondaries take it from there (typical Ford Lehman setup) and then each returns back to that engine's respective port or starboard tank.
It all works and I don't seem to have fuel delivery issues.
But the lines are as old as the boat, the PO install is...ahem "interesting". I also started looking at adding proper supply and return manifolds to make transfers easier and yes even polishing possible.
So as I'm looking at modern, just flip to the other filter, dual filter primaries, I started wondering....do I really need complete duplication if all of the fuel comes together before the primaries? Yes, I'll go through more filters, but given the cost of dual primary setups...and what I perceive to be no significant benefit...is it worth it to buy two of everything?
OK, school me (or fire at will)!
Couldn't you just run a single dual primary for all "inbound" fuel and then head off to each engine's secondary filter(s)?
I could see why an entire fuel system is completely separated (port only to port, starboard, etc using with a "polishing" transfer circuit, etc) but for many coastal, multi-tank, twin-engine boats - all tanks lead to a common "manifold" then off to each engine.
Is this just good marketing from the fuel filter companies to get you to buy two of everything?
Here is why I ask:
I've been contemplating some fuel system improvements. Currently I have what I described above: a common copper "manifold" (of sorts) in that all three tanks (port, starboard and belly) combine into a single line on the forward bulkhead of the ER. Individual tanks can be shut off from this line using a valve at each tank.
From this common fuel line two lines then feed into respective primary systems (port and starboard systems).
In my case the primaries include the original dual spin-on filters along with a newer, single Racor 500 water separating primary installed by the PO for each engine - presumably as a work around to filter changes/priming with the older duel filter system.
I can flip ball valves to route fuel through either the Racor or the dual spin-ons independently for each engine. The on-engine secondaries take it from there (typical Ford Lehman setup) and then each returns back to that engine's respective port or starboard tank.
It all works and I don't seem to have fuel delivery issues.
But the lines are as old as the boat, the PO install is...ahem "interesting". I also started looking at adding proper supply and return manifolds to make transfers easier and yes even polishing possible.
So as I'm looking at modern, just flip to the other filter, dual filter primaries, I started wondering....do I really need complete duplication if all of the fuel comes together before the primaries? Yes, I'll go through more filters, but given the cost of dual primary setups...and what I perceive to be no significant benefit...is it worth it to buy two of everything?
OK, school me (or fire at will)!
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