93 Prelude stock fuel fill alteration ideas?

[notbob]

Setting up a 93 prelude. Stock tank. The stock fuel filler is way small. We use hunsakers with an adapter on it.

Would like to replace the stock filler with an ATL style filler and run a hose down to an adapter to go into the stock tank or alter the stock filler to take the guts out and run a non vented cap. To do this, we need to come up with a vent solution since the cap/fill neck will no longer do the venting. Since the evap system is gone, my thought was to use the evap fitting and run a vent up and around the rear and down to a breather. Anyone have any experience with a prelude and altering the stock fuel setup and wouldn't mind sharing what you did to get better fuel flow into the tank?

Thanks!

[ross2004]

Basically all I did was cut out the flapper inside the stock neck. Yeah it sucks the stock opening is just barely too small for the Hunsaker without the adapter, but it's not terrible. I feel like we can fill  as fast as the adapter-equipped jug can dump. I took the line to the evap off at the base of the tank, ran a hose up along the filler neck, looped it, and back down exiting at the rear bumper.

[zack_280]

I don't have direct prelude experience, but do have general experience.

1. Use a proper rollover valve.
2. Use a proper fuel cap.
3. Use proper fuel lines.
4. Make sure your vent valve is above the fill inlet.  
5. Neck down the Hunsaker hose to whatever the minimum sized portion of the inlet to your fuel tank is.  Fuel will not go into the tank any faster than the inlet size of your tank allows.  This will get fuel in as fast as possible, but minimize overflow.
6. Try to have a route for any overflow fuel that avoids exhaust and brakes.  We ran the filler through a modified funnel to catch overflow and put a drain in the funnel with a hose that routes fuel through the trunk floor and pours directly into our catch pan.  We can refuel slightly quicker and with no spillage now.  

[notbob]

6 minutes ago, ross2004 said:

Basically all I did was cut out the flapper inside the stock neck. Yeah it sucks the stock opening is just barely too small for the Hunsaker without the adapter, but it's not terrible. I feel like we can fill  as fast as the adapter-equipped jug can dump. I took the line to the evap off at the base of the tank, ran a hose up along the filler neck, looped it, and back down exiting at the rear bumper.

Thanks! The cap is vented right? So did you just switch to a non vented cap then with the evap mod?

 

[ross2004]

No I'm still using the vented cap.

[notbob]

2 minutes ago, ross2004 said:

No I'm still using the vented cap.

You don't get fuel sloshing out the cap on turns when you completely fill the tank/neck

[ross2004]

Nope, and I watched very closely for it.

[Ron_e]

In a stock system all fuel caps are vented check/flapper valves to let air in the tank as fuel is removed.  Fuel liquid and vapour expansion are handled with the charcoal canister, there is a check valve on this line too.  If the cap is not vented your fuel pump would run dry shortly after leaving the gas station.

 

Old style caps, like 40+ years ago fuel caps both let air in and out, emissions regulations changed this I believe.  These caps would leak fuel in "spirited" driving.

[pintodave]

As a carry over from Huggy's vent thread, the more I think about our apparent leak after a pit stop at Daytona, I wonder if it was a bit of fuel in the neck getting past the OEM (vented) cap... our fill line is pretty flat, so we cannot take 'advantage' of packing the filler neck completely full like others, but we get a little extra in it. 

[Ron_e]

The rubber gaskets on the newer style caps get hard then they don't seal very well anymore, after that they crack for total failure.