Printable Version | Subscribe | Add to Favourites
New Topic New Poll New Reply
Author: Subject: it appears i need to vent my fuel tank then?
john_p_b

posted on 9/7/10 at 08:48 PM Reply With Quote
it appears i need to vent my fuel tank then?

in five years of having my car on the road i've come across this problem for the 1st time and i don't like it at all!

took my indy to work today, had it parked in the workshop nice and safe but then this afternoon was sure i could smell petrol, no one else could but i was sure of it! time to come home, jumped in and it refused to start, was obviously flooded but had no idea why, 1 flat battery and a jump start later it went but wasn't running very well, got it home and when i parked up on the drive and switched off i could hear fuel going into the carb! took the air filter off and the carbs were just about to overflow with fuel!

only reason i could think of was pressure in the tank, took the cap off and big woosh! now i'm guessing the cause of the pressure is the combination of me using the car a lot lately and thus the fuel tank is almost empty and the unusually hot summer.

so there is the story behind what's happened now what i need to do is figure out how to put it right to stop it happening again.

can i get a different cap that will allow the pressure to escape? or is there a specific valve i need to get and fit to the tank?

any help much appreciated as A. i find this quite worrying and B. the sump is full of petrol now so i can't even move the car until i've been for some oil!





built a car, built a home, had a family. lost the family, lost the home, still got the car.

View User's Profile View All Posts By User U2U Member
speedystew

posted on 9/7/10 at 08:55 PM Reply With Quote
this is what you want in the top of your tank

http://www.merlinmotorsport.co.uk/p3556/ROLL-OVER-VALVE-1/4-X--6JIC/product_info.html

View User's Profile View All Posts By User U2U Member
austin man

posted on 9/7/10 at 08:59 PM Reply With Quote
a one way valve will be needed that closes if the car rolls over obviously needs to be higher than the fuel filler





Life is like a bowl of fruit, funny how all the weird looking ones are left alone

View User's Profile View All Posts By User U2U Member
designer

posted on 9/7/10 at 09:07 PM Reply With Quote
The simplest way is to drill a small hole somewhere around the filler cap.

A small hole stops the tank pressurising, does not seep to much, even if the car does turn over, and does not cause any evaporation problems.

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
Antnicuk

posted on 9/7/10 at 09:32 PM Reply With Quote
you can get one from Car Builder solutions for about £8, which has 2 x 8mm tails so can just put in line in a hose from the tank. The small (2mm) hole in the filler cap works well also.





600 BHP per ton, Stylus Brought back from the dead! Turbo Rotary Powered!

View User's Profile E-Mail User View All Posts By User U2U Member
40inches

posted on 9/7/10 at 09:45 PM Reply With Quote
quote:
Originally posted by Antnicuk
you can get one from Car Builder solutions for about £8, which has 2 x 8mm tails so can just put in line in a hose from the tank. The small (2mm) hole in the filler cap works well also.

The CBS one only works one way i:e; it allows air in but not out, I know, I have got one

View User's Profile View All Posts By User U2U Member
Canada EH!

posted on 10/7/10 at 01:03 AM Reply With Quote
If you don't want to drill a hole in the tank you can mount a small fitting in the filler hose just above the tank and vent it to the outside.
This is the way US cars were built until environmental situations changed.
If you are nervous about rollover put a valve in, but this will not help in your present situation were pressure and not vacuum is building in the tank.

View User's Profile View All Posts By User U2U Member
dave

posted on 10/7/10 at 08:27 AM Reply With Quote
I have 1 of these and no problems.

poo






View User's Profile View All Posts By User U2U Member
40inches

posted on 10/7/10 at 08:33 AM Reply With Quote
quote:
Originally posted by dave
I have 1 of these and no problems.

poo

This is also a one way valve, air in, but not out for the OP's problem he needs a 2 way valve, I haven't found one for under £30

View User's Profile View All Posts By User U2U Member
dlatch

posted on 10/7/10 at 09:04 AM Reply With Quote
http://www.demon-tweeks.co.uk/Motorsport/Fuel_System/Fuel_Tank_Vent_Valves/Mocal_Fuel_Tank_Pressure_Relief_Valve/1546/0/23336

they do a cheaper one that fits to a weld in boss as well

either will do what you need and vent under pressure or vacuum

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
40inches

posted on 10/7/10 at 09:19 AM Reply With Quote
quote:
Originally posted by dlatch
http://www.demon-tweeks.co.uk/Motorsport/Fuel_System/Fuel_Tank_Vent_Valves/Mocal_Fuel_Tank_Pressure_Relief_Valve/1546/0/23336

they do a cheaper one that fits to a weld in boss as well

either will do what you need and vent under pressure or vacuum


£40 + postage

View User's Profile View All Posts By User U2U Member
Antnicuk

posted on 10/7/10 at 04:01 PM Reply With Quote
quote:
Originally posted by 40inches
quote:
Originally posted by dave
I have 1 of these and no problems.

poo

This is also a one way valve, air in, but not out for the OP's problem he needs a 2 way valve, I haven't found one for under £30



Thats strange, i spoke to CBS and they said that theirs shuts of when fuel hits it. They need to allow air both ways but no fuel and that is how it was sold to me???





600 BHP per ton, Stylus Brought back from the dead! Turbo Rotary Powered!

View User's Profile E-Mail User View All Posts By User U2U Member
David Jenkins

posted on 10/7/10 at 04:16 PM Reply With Quote
I got mine from ThinkAuto - not too expensive, IIRC.

LINKY






View User's Profile Visit User's Homepage View All Posts By User U2U Member
john_p_b

posted on 10/7/10 at 04:34 PM Reply With Quote
now that's slightly more locost! merlin want a tenner to deliver theirs!

i'm looking at the trv45 from think, does that look right?





built a car, built a home, had a family. lost the family, lost the home, still got the car.

View User's Profile View All Posts By User U2U Member
David Jenkins

posted on 10/7/10 at 06:08 PM Reply With Quote
It's worth ringing the people at Think - you can have an intelligent conversation with them, as they generally seem to know what they're talking about.

On-phone prices for P&P tend to be lower too - these valves weigh next to nothing, so you end up paying for whatever it costs (e.g. a padded envelope and stamps) rather than an arbitrary standard charge.

[Edited on 10/7/10 by David Jenkins]






View User's Profile Visit User's Homepage View All Posts By User U2U Member

New Topic New Poll New Reply


go to top






Website design and SEO by Studio Montage

All content © 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [© 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.