i have been trying to organise my return line, and was looking at going to use the vw fuel filter(as vw calls it)
that was basically a swirl pot (at this page below)
http://www.shoptalkforums.com/viewtopic ... e&start=75
but they are no longer available .
so i started looking else where for a similar type of filter/swirl pot .
i have found this but not sure if it will work, as it only has 3 hoses.
it has no breather or return to the tank.
so would this be useable as a return, or would it fill with air (being not able to breath properly)
and cause a vapor lock. would any of these 2 be able to be used
[/img]
[/img]
re return line the easy way ?
-
- Posts: 335
- Joined: Thu Dec 03, 2009 3:04 pm
Re: re return line the easy way ?
You might want to look at the c5 corvette filter. It even has a built-in regulator.
1971 Truckaru (WRX eng/trans powered Domus flatbed bug-truck) - build thread
- raygreenwood
- Posts: 11895
- Joined: Wed Jan 22, 2003 12:01 am
Re: re return line the easy way ?
The corvette filter is identical internally to the picture above it. All VW Audi products use the same type of filter which incorporates a regulator into it. This is also nothing whatsoever to do wit ha swirl pot.
Its very smart design to put the regulator...in the filter...and as far from the fuel rail as possible because all regulators create a harmonic in rhythm with the rotating cycle of the roller cells in the pump. You get much more stable fuel pressure with this set up.
As far as a "swirl pot" goes...its not just a pot with three inlets. Also volume is critical. What you need is a chamber with an inlet mounted at mid-height, the inlet to the system down ,low and a much smaller....like about .010"...bleed in the very top going back to the tank as return line. When installed upright, fuel flows into the chamber filling it. Air flows upward and vents through the small orifice. The inlet to the ring main is down below where no air will ever get to it.
The object is to have enough pump that you can have roughly the equivalent of a fifth injector bleeding out of the pressurized swirl pot at all times without causing fuel pressure drop. But the orifice also needs to be large enough that what air does get in...vents almost instantaneously so it does not for a bubble that acts as a hydro-static cushion to the fuel... effectively dropping pressure.
This system is not to be confused wit ha fuel pressure accumulator like CIS injection had that uses a rubber bladder.
You can make a more effective swirl pot than money can buy...anywhere....by taking a piece of 3-4" stainless pipe and putting threaded and sealed caps on each end and putting the lines in with bulkhead fittings and barbs. The orifices you can buy at McMaster Carr supply on page 499. Ray
Its very smart design to put the regulator...in the filter...and as far from the fuel rail as possible because all regulators create a harmonic in rhythm with the rotating cycle of the roller cells in the pump. You get much more stable fuel pressure with this set up.
As far as a "swirl pot" goes...its not just a pot with three inlets. Also volume is critical. What you need is a chamber with an inlet mounted at mid-height, the inlet to the system down ,low and a much smaller....like about .010"...bleed in the very top going back to the tank as return line. When installed upright, fuel flows into the chamber filling it. Air flows upward and vents through the small orifice. The inlet to the ring main is down below where no air will ever get to it.
The object is to have enough pump that you can have roughly the equivalent of a fifth injector bleeding out of the pressurized swirl pot at all times without causing fuel pressure drop. But the orifice also needs to be large enough that what air does get in...vents almost instantaneously so it does not for a bubble that acts as a hydro-static cushion to the fuel... effectively dropping pressure.
This system is not to be confused wit ha fuel pressure accumulator like CIS injection had that uses a rubber bladder.
You can make a more effective swirl pot than money can buy...anywhere....by taking a piece of 3-4" stainless pipe and putting threaded and sealed caps on each end and putting the lines in with bulkhead fittings and barbs. The orifices you can buy at McMaster Carr supply on page 499. Ray