LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently October 19, 2021, 1:47 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 8 posts ] 
Author Message
PostPosted: September 14, 2021, 12:27 pm 
Offline
User avatar

Joined: December 4, 2010, 1:53 pm
Posts: 83
Location: Edmonton, Alberta, Canada
Hello everyone.
I have a 10 gallon jaz fuel cell. I have a Miata fuel pump, pickup, and return mounted on one side. There is aviation foam inside to prevent some sloshing. On the other side, an 8AN fitting for venting, attached to a hose which is coiled a few times before going to the bottom of the body, per Jaz instructions. I found out last night at a racetrack lapping event, that fuel is pouring out of the vent hose under hard right hand corners.
Can I install a valve in there? An suggestions?
thanks
Doug


Attachments:
20181205_111636-small.jpg
20181205_111636-small.jpg [ 72.99 KiB | Viewed 1158 times ]

_________________
book 4AGE build, W58 transmission, Corolla GTS live axle
Top
 Profile  
Reply with quote  
PostPosted: September 14, 2021, 1:14 pm 
Offline
Mid-Engined Maniac

Joined: April 23, 2006, 8:26 pm
Posts: 6170
Location: SoCal
First, is the vent line being run to as high as possible in the chassis before turning downward? Another solution is to run the vent to the other side of the car, using cornering force to keep the fuel in the hose trapped.

Yes, a one-way valve can be placed in the vent line, since its primary purpose is to let air into the tank as gas is consumed. During filling, air exits the tank up out the filler pipe. Where a one-way valve may mess up things though, is as the fuel heats up, it expands and has to go somewhere.

A compromise is to place a bit of brass in your existing vent hose with a very tiny hole in it (like 0.063" maybe). That lets air go both ways as required, without letting a lot of fuel escape. That, coupled with it looping as high as possible, should fix this issue.

[edit] Rereading your post, a -3 is all that's needed unless you plan F1/stockcar fuel stops.

_________________
Midlana book: Build this mid-engine Locost!, http://www.midlana.com/
Kimini book: Designing mid-engine cars using FWD drivetrains, http://www.kimini.com/book_info/


Top
 Profile  
Reply with quote  
PostPosted: September 14, 2021, 8:05 pm 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 7093
Location: "Banana Republic"
Loops should be 6 to 12 inches above the vent fitting.
The loops should be horizontal, not vertical so the loops can drain back and a turn in one direction will only go so far in the looped hose. Big loops work better than small loops.
You can also vent a "roll over valve" that has a floating ball.
Many oems have valves in the vent since the charcoal canister should not receive liquid fuel, only vapor.

It is also a good idea to pretend you have a proper stand pipe in the filler neck and never completely fill the tank to leave 10 percent expansion space.

_________________
My posts are my own opinion and do not represent an official public position by any other person, place, thing, animal, vegetable, mineral, etc.
https://www.azsenaterepublicans.com/audit
https://www.oann.com/india-govt-declares-most-populated-state-officially-covid-free-after-widespread-use-of-ivermectin/
https://www.oann.com/fauci-hhs-officials-discuss-using-new-virus-from-china-to-enforce-universal-vaccines-in-footage-from-oct-2019/
https://www.oann.com/the-story-of-iverm ... -the-drug/


Top
 Profile  
Reply with quote  
PostPosted: September 14, 2021, 9:17 pm 
Offline
Always Moore!
User avatar

Joined: November 9, 2007, 3:40 pm
Posts: 4051
Location: Pittsburgh, PA
I had a similar issue with an ATL cell and did something like what Kurt suggested. The height of the vent line loop was limited by the trunk lid. I filled a 6AN coupler fitting with JB Weld, drilled a 1/16" hole in the cured JB Weld, and installed it just above the cell's vent fitting in the vertical position. Any fuel that makes its way through the small hole will drain back and it seems to limit flow enough that it doesn't overflow even when the tank is full.

_________________
-Andrew
Build Log
Youtube


Top
 Profile  
Reply with quote  
PostPosted: September 14, 2021, 10:13 pm 
Offline
User avatar

Joined: December 4, 2010, 1:53 pm
Posts: 83
Location: Edmonton, Alberta, Canada
Thanks both of you for your great input.
I only have about 4 inches from the top of the tank to the underside of the deck. So, not much room for loops higher than the top of the tank.
How about this for a plan:
-add an -8AN male/female between the tank and the 90 degree fitting to the hose, fill the new fitting with JB Weld, and drill a small hole in it. Also, add an -8AN rollover valve that installs below the top of the tank, to replace the fitting there. The extra fitting should add an extra inch or so to the height of the loops.

I'll cut a hole in the foam below the filler, so that I can stop filling a couple of inches from the top.

Question: what do you guys think about moving the vent to as close to the centre as I can, to reduce the height of the slosh?

Also, what are your thought about the direction of the loops, front to back, or side to side?

thanks again
Doug


Attachments:
10-gal-street-rod.jpg
10-gal-street-rod.jpg [ 126.06 KiB | Viewed 1083 times ]

_________________
book 4AGE build, W58 transmission, Corolla GTS live axle
Top
 Profile  
Reply with quote  
PostPosted: September 14, 2021, 11:24 pm 
Offline
User avatar

Joined: July 17, 2008, 9:11 am
Posts: 5941
Location: West Chicago,IL
I used a 70's CJ Jeep anti-rollover check valve. I never had a problem with leaking fuel. That is the white canister in the upper RH corner of the pic. Getting enough height for a loop is difficult in a Locost. This was located a few inches above the tank top. I ran an output hose down to the ground just to know where any gas would be going.


Attachments:
JEEP ROLLOVER VALVE.jpg
JEEP ROLLOVER VALVE.jpg [ 84.17 KiB | Viewed 1078 times ]

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE
Top
 Profile  
Reply with quote  
PostPosted: September 15, 2021, 4:34 am 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 7093
Location: "Banana Republic"
I’d install a Jeep YJ valve for a plastic tank at about $20 then clip a metal tube to the rear firewall to serve as the vent hose, with a couple loops from side to side before dropping so fumes don’t collect. Window screen and a zip tie will prevent dirt dobbers from nesting.

https://www.ebay.com/itm/Jeep-CJ-20-gal ... 2274520624
The valve should be very tight in the grommet so undersize the hole in the tank. Pull the filler to reach in to support the tank top when installing the valve. Use soapy water.

Moving the vent opening in the tank only changes the driving condition when the tank will splash the valve.
The jeep cj has a nice liquid valve that mounts above the tank, then vents into the rollover valve (like Chuck’s) before venting to the charcoal canister. Nobody makes them anymore.
My 96’ tracker has a small plastic can above the tank that vents to a single loop and check valve before venting to the canister, all within three inches of the top of the tank.

_________________
My posts are my own opinion and do not represent an official public position by any other person, place, thing, animal, vegetable, mineral, etc.
https://www.azsenaterepublicans.com/audit
https://www.oann.com/india-govt-declares-most-populated-state-officially-covid-free-after-widespread-use-of-ivermectin/
https://www.oann.com/fauci-hhs-officials-discuss-using-new-virus-from-china-to-enforce-universal-vaccines-in-footage-from-oct-2019/
https://www.oann.com/the-story-of-iverm ... -the-drug/


Top
 Profile  
Reply with quote  
PostPosted: September 15, 2021, 8:05 am 
Offline

Joined: April 1, 2010, 10:26 am
Posts: 476
I run twin Jaz tanks, I have the two vents run into a T. The outlet does a loop de do and ends up on a vent cap with a check ball, works perfectly. I made to loop as large as practical and got the vent as igh as i counld, I think I got the vent from Pegasus Racing.

Graham


Attachments:
PXL_20210915_115711033.jpg
PXL_20210915_115711033.jpg [ 329.35 KiB | Viewed 1021 times ]
PXL_20210915_115702668.jpg
PXL_20210915_115702668.jpg [ 321.55 KiB | Viewed 1021 times ]
Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY