Competition Fuel Systems

Waterman pump rebuild and anti-cavitation mod finished today.. picked up 3.6 gallons at the top 😲
I think that's a record for me.
The loss in flow from 8000 to 10,000 RPM went from 1.5 gallons to just .06 of a gallon !
A fuel system that's losing 1.5 gallons at high RPM has to be run too rich at low RPM for the engine to survive at high RPM, and that engine will never perform like it should.

Atomization: Fuel Atomization can be broadly grouped into 3 categories, listed from worst to best:
1. Spray
2. Mist
3. Fog

The quality is mainly determined by the nozzle body type, although fuel pressure plays a part as well.

#1 in the photo is a common Enderle deflector style that relies on a jet of fuel hitting an angled surface. These provide mainly a fuel Spray. Aerated bodies atomize a little better, especially at low pressure.

#2 Produces better atomization and a different spray pattern.. and tends more toward a Mist of fuel. Use where suitable, which for me is in the hat.

#3 Are impingement nozzles with a pin located very close to the exit of the fuel. These produce the best atomization and quite a lot of Fog. Commonly used in spray bar setups where they provide maximum cooling of the incoming air.

The earlier you introduce fuel into the intake air, the more time it has to affect temperature and density, and this is where you'll get the most benefit from better nozzles.
There's not much room, time or area to do much with fuel in the ports.. and remember it will accumulate on the back of the intake valve during overlap. I tend to use the Enderle deflector type here to direct the fuel in the port.

When the intake valve opens, air velocity, heat of compression, and combustion dynamics take care of fuel atomization.
Some droplets are too large to be burnt during the resident time in the cylinder, and these will exit the exhaust as unburnt fuel.

I've added video of the different types in the Comments.

Our new Adjustable Barrel Valve is finally ready to ship. Designed by Competition Fuel Systems in collaboration with Straightline Data Systems, it offers fully adjustable idle and stage circuit volume. No more modifying the spool to get the fuel you need at stage and this makes it easy to “try” different stage volume to see how the car responds.
Primarily designed for clutch equipped Alcohol engines that stage at high RPM, this metering valve has generous flow passages throughout, and offers:
Idle volumes from: 0.5 to 2.00 GPM.
Staging volumes from 5.00 to 11.00+ GPM.
It’s been extensively tested on the flow bench and the track.
This new barrel valve features:
• Lightweight billet construction
• High strength Stainless Steel spool and screws.
• Full AN10 inlet and outlet with higher thru-flow than a K style to minimise pressure loss to nozzles.
• High flow adjustable Idle and Stage circuits.
• Uses conventional Idle Check pressures.
• Fuel “ramps in” from idle.. no abrupt flow circuit changes or lean spots.
• Built in pump-saver – returns excess fuel to the distribution blocks.
• Takes conventional Enderle style screw in Main Jet.
It will ship complete and ready to run, with all fittings including inlet and outlet & spool arm. Every unit is individually flow tested with the pump saver set to your specs.

Thanks to Greg Gower @ Alky Pro for looking after us today - he is always so generous and looks after us well. We had the Beach Bomb fuel system on his flow bench today prepping for the new season. We can't wait to get racing again!