what psi pump

[rtw-1]

we just finished building our own articulating tractor and now comes the hard part. I can't seem to find anyone who know what the inline fuel pump pressure for a Kubota D-1402 engine. We bought a small Mr. Gasket with 6-7 psi but that won't keep it running at higher rpm's...any suggestions?

 

[Chilly807]

Typically you're going to want to see about 15 to 20 psi under full load. Any more isn't necessary for most machinery. Best bet is to get a pump that's capable of more pressure than that, then add a relief valve in the line between the boost pump and injection pump. That way you get a nice steady pressure at the injection pump.

Chilly

 

[Soundguy]

I think it's more of a flow rate, not a pressure issue.

4 psi should be fine.. as long as the flow can keep up.

soundguy

 

[Chilly807]

The problem with not enough pressure is that at higher rpm there isn't as much time for the fuel in the pump gallery to fill the individual elements, so you get an incomplete fuel charge delivered to the cylinder.

Detroit Diesel, for example, typically runs from 60 to 80 psi fuel pressure in their two stroke engines. Four stroke requirements aren't usually that high, and will function well with from 15 to 20 psi. You may get away with as low as 10 psi, but it's going to be iffy.

Flow rate is a factor as well, but these engines don't use enough fuel for most pumps to fall behind. The amount of return fuel plays a role as well, some engines need a restrictor on the return side of the fuel system to maintain adequate fuel pressure at the pump.

Chilly

 

[Soundguy]

Considering lots of older tractors have no pump before the injector pump at all, and only rely on the charge pump side of the injector pump.. I still think excessive high pressure out of the tank isn't a huge issue. pressurized fuel tot he cyl can be handled by the injector pump as long as it has a good fuel source with no air, and restrictions.

soundguy

The problem with not enough pressure is that at higher rpm there isn't as much time for the fuel in the pump gallery to fill the individual elements, so you get an incomplete fuel charge delivered to the cylinder.

Detroit Diesel, for example, typically runs from 60 to 80 psi fuel pressure in their two stroke engines. Four stroke requirements aren't usually that high, and will function well with from 15 to 20 psi. You may get away with as low as 10 psi, but it's going to be iffy.

Flow rate is a factor as well, but these engines don't use enough fuel for most pumps to fall behind. The amount of return fuel plays a role as well, some engines need a restrictor on the return side of the fuel system to maintain adequate fuel pressure at the pump.

Chilly