SAAC Forum

The Cars => 1967 Shelby GT350/500 => Topic started by: tonys_shelby on March 31, 2021, 12:48:09 PM

Title: Non venting gas cap for storage
Post by: tonys_shelby on March 31, 2021, 12:48:09 PM
It seems like I have so much fuel evaporation because I don't drive the car especially over the cold months, I'm wondering if I just install a non evap. Gas cap for storage. Does anyone else do it?  I use Sunoco Optima.
Title: Re: Non venting gas cap for storage
Post by: jk66gt350 on March 31, 2021, 04:18:36 PM
I also don't drive my car that much.  I typically only go through 2-3 tanks of gas a season and store my car for 5-6 months of the year like most others in the northeast.  I have never experienced or heard of any significant evaporation while a car is not used.  How much fuel is going unaccounted for?  Anybody else experienced this?
Title: Re: Non venting gas cap for storage
Post by: Bob Gaines on March 31, 2021, 04:20:26 PM
Quote from: tonys_shelby on March 31, 2021, 12:48:09 PM
It seems like I have so much fuel evaporation because I don't drive the car especially over the cold months, I'm wondering if I just install a non evap. Gas cap for storage. Does anyone else do it?  I use Sunoco Optima.
Do you realize what is involved with switching out a pop open gas cap on a 67 Shelby? You may want to find out before trying to switch caps because it is a lot of work.
Title: Re: Non venting gas cap for storage
Post by: 67 GT350 on March 31, 2021, 05:53:32 PM
Can't you just pop it open and get a small gas cap and install it with the flip open, open? It is just for storage, thus your not driving it.
Also, interesting topic, my 70 Boss can loose up to a 1/2 tank in no time.
Title: Re: Non venting gas cap for storage
Post by: Bob Gaines on March 31, 2021, 06:19:05 PM
Quote from: 67 GT350 on March 31, 2021, 05:53:32 PM
Can't you just pop it open and get a small gas cap and install it with the flip open, open? It is just for storage, thus your not driving it.
Also, interesting topic, my 70 Boss can loose up to a 1/2 tank in no time.
Nope. That is because the pop open ring sets on top of the filler neck eliminating clearance needed for a typical cap to twist,lock and seat. I am sure you could rig up something like a big cork or the like to close off the neck. Taking off the ring is what is so labor intensive.
Title: Re: Non venting gas cap for storage
Post by: Side-Oilers on March 31, 2021, 06:23:23 PM
I have never heard of, nor considered, fuel evap during storage with a vented cap.

Has anyone else here experienced similar?

I live in SoCal, near the beach, so temps and humidity levels are relatively constant throughout the year.
Title: Re: Non venting gas cap for storage
Post by: tonys_shelby on March 31, 2021, 08:36:51 PM
I think part of it is the Sunoco fuel but in 2 months 3-4 gallons loss.  I've figured out a twist on cap that I can get to go flush to the pipe and have the pop cap open. Yes just for storage. No don't want to remove the tail lights etc to remove original cap.
Title: Re: Non venting gas cap for storage
Post by: 67 GT350 on March 31, 2021, 10:13:18 PM
Can you show us in pictures?
Title: Re: Non venting gas cap for storage
Post by: Side-Oilers on March 31, 2021, 11:12:06 PM
Maybe your kid/nephew/friend/neighbor is taking it out without you knowing?  8)
Title: Re: Non venting gas cap for storage
Post by: 557 on March 31, 2021, 11:27:00 PM
"Sleepdriving"?Better check the odometer to be sure. :D
Title: Re: Non venting gas cap for storage
Post by: tonys_shelby on April 01, 2021, 06:16:56 AM
Pictures...what do you want a picture of?  The gas cap? 
Title: Re: Non venting gas cap for storage
Post by: tonys_shelby on April 01, 2021, 06:33:49 AM
Hey I think it's weird too that's why I bring it up. First time using this fuel in a storage type situation. And wondering if anyone else runs into it. I put a piece of rubber ( thin ) between the cap and Filler neck and the vapor built up enough pressure when I opened it later that day it popped opened and it the vapor rushed out. Have heated garage so temp is consistent for most part.
Title: Re: Non venting gas cap for storage
Post by: shelbymann1970 on April 01, 2021, 09:05:36 AM
So I had a half of tank of gas in my 69 Mach1 since Spring of 2015. I used stabil but will drain the gas out before I fire up the car in the next month(5-6 year engine bay detailing). So under the evaporation are you saying of the 10 or less gallons that was in my car in 2015 I should be about empty on what is in the tank? Yes, I have the same vented system with the pop open gas cap. Gary
Title: Re: Non venting gas cap for storage
Post by: 67 GT350 on April 01, 2021, 09:31:24 AM
Quote from: tonys_shelby on April 01, 2021, 06:16:56 AM
Pictures...what do you want a picture of?  The gas cap?

If you find an answer.
Has anyone seen the repro pop down gas cap that gives the option to conceal a screw on cap? I wonder if that would work on a Shelby? It would be completely wrong though. but it would allow you to leave it on year round where you flip the cover down and take the cap off. I got one of these for my 67 GT and I did not use that option.
Title: Re: Non venting gas cap for storage
Post by: tonys_shelby on April 01, 2021, 07:48:18 PM
Shelby man, it's hard to say I've never ran into this before which makes me think it's the type of fuel. 67 Gt350, I have seen those before not real interested in something to use all the time just will put on a regular type for storage and leave it popped open.
Title: Re: Non venting gas cap for storage
Post by: 98SVT - was 06GT on April 01, 2021, 09:58:41 PM
Try to fill up before storage with real gas - no alcohol. Use Stabil. If you want to eliminate the vented cap just lay a piece of plastic bag across the opening and snap the cap shut.
Title: Re: Non venting gas cap for storage
Post by: shelbyluva on April 02, 2021, 02:44:44 PM
I did something similar to what is mentioned above, Saranwrap over filler and shut cap over it so I didn't get a whiff of fumes when walking past over the winter.
Title: Re: Non venting gas cap for storage
Post by: oldcanuck on April 02, 2021, 03:06:00 PM
Quote from: 67 GT350 on April 01, 2021, 09:31:24 AM

Has anyone seen the repro pop down gas cap that gives the option to conceal a screw on cap? I wonder if that would work on a Shelby? It would be completely wrong though. but it would allow you to leave it on year round where you flip the cover down and take the cap off. I got one of these for my 67 GT and I did not use that option.

Fran,

I have one on my GT-350.... didn't you notice !  I'll take you on a tour next time over.......

Bob