Diesel fuel line installation

[Waltthesalt]

I'm repowering from gasoline to a 16HP Beta this includes a new fuel system. I'll be using dual RAYCORs. I read somewhere a suggestion to have one filter for the engine and the second using a small electrical pump to in effect be a continuous polishing system. That when the engine is running or when otherwise you decide the electrical pulls fuel thru the second filter and return it to the tank, like an installed polishing system. See any downside to this?

[PorFin]

Walt,

Are we talking about two separate Racors or one of the pre-assembled dual filter housing sets?

[Waltthesalt]

two separate RAYCORs

[PorFin]

OK, that opens your options.

The argument for two separate circuits (one for engine; one dedicated for polishing) is that they are independent. You also have the ability to use both simultaneously.

The argument against is that it may not be the most efficient use of your resources.

With a combined supply and polishing system, you add a great deal of flexibility and a reassuring level of redundancy. With a combined system you have the ability to use the second Racor as a back-up to the first -- if your primary clogs, you can restore engine fuel supply by redirecting the fuel flow. You also have the electric pump as a back-up to your engine mounted lift pump. The downside is that it will be a more complex system, which calls for more hose and three-way valves.

[klem]

In my opinion, many of the home polishing systems are really pointless. Your engine's fuel pump is pulling fuel through your primary filter which is "polishing" your fuel. If you add a second loop to polish the fuel using another lift pump, you will essentially double your flow rate but with added complexity. To properly polish fuel you need high flow and high pressure which a normal lift pump is totally incapable of supporting. The professional polishing rigs actually flow enough fuel to clean out the corners of the tank, something that almost no home built polishing rig can do. The pros can also move around the fuel return to help get flow in hidden parts of the tank which you can't do with a normal sending unit.

Having a second electric lift pump in parallel with your fuel system that can be isolated is very helpful. When you need to bleed the system, you can use this pump. It is best if installed as close to the fuel tank as possible. In addition, it acts as a backup in case your engine lift pump fails.

Having multiple filters is good too. Putting them inline allows you to have different size ratings and filter efficiently. Personally, I really like the filter manifolds with 2 filters that allow you to choose which one is active so that you can actually change the other without shutting down. If you ever get junk in your fuel tank, having this setup is hugely helpful.

[jrd22]

Cool Walt, let us know how the repower goes. Pics!

If you are going to install two filters I would design it so you could use the polishing filter as a back up in case the other one clogs up. It will involve more connections, valves, etc, but since you will have it anyway you might as well be able to use it in an emergency. As far as the polishing goes, I'm not sure if the volume you'll be able to pump will be very effective, but it can't hurt.

[Waltthesalt]

Thanks for the thoughtful advice, pros and cons.