Laysons Early-A Modified Filler neck?

[66Dvert]

I bought one of those Sentry flapper doors a while ago and it did nothing to stop the back flushing when filling up. I drive 40 miles each way to/from work and would really like to fix this problem so I wouldn't have to get gas all the time.

hmm I did my friends valiant and it works perfectly. I did have a problem getting all those teeth to dig in to the tube so it worked like an unleaded flap, but it sealed up the tube quite nicely. before the mod he couldn't fill the tank up all the way cause it just overflowed. after the fix it would kick the nozzle off right before it filled up. it did not do anything for his sharp turn leaks but a new cap from Damraider or ssdan would fix that problem. I also have it in mine but I'm going to cut mine and weld in a washer about 3-5 inches down the tube(I'll be measuring the standard nozzle length so it just sticks through the washer.) to create back pressure once the nozzle is in so it trips easier.

 

[My*65*Dart]

hmm I did my friends valiant and it works perfectly. I did have a problem getting all those teeth to dig in to the tube so it worked like an unleaded flap, but it sealed up the tube quite nicely. before the mod he couldn't fill the tank up all the way cause it just overflowed. after the fix it would kick the nozzle off right before it filled up. it did not do anything for his sharp turn leaks but a new cap from Damraider or ssdan would fix that problem. I also have it in mine but I'm going to cut mine and weld in a washer about 3-5 inches down the tube(I'll be measuring the standard nozzle length so it just sticks through the washer.) to create back pressure once the nozzle is in so it trips easier.

I have no leaks from the cap when driving but overflows when filling up even with the "no lead" flapper door installed?????? I'm going to try a few things, maybe the washer like your talking about. my '65 filler tube has a vent line that runs from the tank to the filler tube but it still overflows when filling up???

 

[DonC1965]

Are gas pump un-leaded fuel nozzles a smaller diameter than leaded nozzles? Maybe this is the problem since we all have to use un-leaded fuel nozzles on our cars.

 

[66Dvert]

Are gas pump un-leaded fuel nozzles a smaller diameter than leaded nozzles? Maybe this is the problem since we all have to use un-leaded fuel nozzles on our cars.

I think (yeah I know) that if you still have enough back pressure to trip the nozzle you should be ok. I know some models work better with nozzles that have that rubber bellows on the nozzle to trap air coming out , but my friends works even with it on full (handle squeezed all the way)pressure and no bellows. Ive got mine done (flapper) but not drivable yet and have a backup filler tube I'm going to modify a different way (washer) and see if that works better.