BritishV8 Forum

General Category => Triumph Sports Cars => Topic started by: RyanS on March 06, 2014, 09:25:44 PM

Title: Fuel tank venting TR6
Post by: RyanS on March 06, 2014, 09:25:44 PM
As I'm learning about the stock TR6 carbon canister, and the associated routing and anti- run on valve, I wonder if there is a better way to handle it for the Ford 302 carbed conversion.  I will need to run my fuel supply line on the outside of the inner drivers frame rail (similar to Calvins) as opposed to the inner side as it is run in the stock config.  If I can do away with the vent line running all the way up to the front, and somehow vent the tank in the rear it would be preferrable, but I don't want a smell issue, nor a fire hazzard.

What have some of you other guys done to vent the fuel tank?

Ryan
Title: Re: Fuel tank venting TR6
Post by: DiDueColpi on March 07, 2014, 02:57:49 AM
It's no secret that I'm a big fan of retaining the charcoal canister.
It costs nothing in horsepower.
It eliminates the fuel smell when the car is sitting.
And it's just better for the environment.
You can hide it out of the way in an inner fender or under the car.
Just never inside the passenger compartment or trunk.
Captured fuel fumes will wreck your whole day.
There are tons of different shapes and sizes available in the wrecking yards.
Run at least one anti siphon loop in the tank line and you're good to go.
Cheers
Fred
Title: Re: Fuel tank venting TR6
Post by: Jim Stabe on March 07, 2014, 09:32:04 AM
Fred

Could you draw up a simple diagram of how to hook one up using only what is necessary. The factory has a ton of tubes running everywhere.
Title: Re: Fuel tank venting TR6
Post by: RyanS on March 07, 2014, 11:35:31 AM
I'll second the simple diagram please.

Thank you

Ryan
Title: Re: Fuel tank venting TR6
Post by: BlownMGB-V8 on March 10, 2014, 05:38:25 PM
It's really pretty simple. A largish purge line feeds fumes to the rocker breather and through the engine and PCV to the intake. Smaller lines collect fumes from carb bowl and tank. Often the bottom is open as a vent for excess fumes and to allow fresh air in when it is being purged, and allow the PCV system to operate.

Jim
Title: Re: Fuel tank venting TR6
Post by: Addicted on March 10, 2014, 09:16:09 PM
The first diagram on this page looks pretty simple (early system).  
I've been contemplating evap vs an open vent myself.  
http://www.agcoauto.com/content/news/p2_articleid/294
Title: Re: Fuel tank venting TR6
Post by: DiDueColpi on March 11, 2014, 01:07:55 PM
Excellent diagram Mike,
I've been getting lots of requests to draw something up and have been a little tardy.
For lots of conversions there won't be a usable vent fitting on the carb float bowl.
If you are fuel injected you won't have that fitting as well.
So you will need to plug that port on the canister.
I like to use the early Gm canisters as all the fittings are marked on the top of the unit.
The correct ones will be from a carbed vehicle and have a vacuum operated diaphragm on top.
Some fuel injected units will work as well but most are electronically controlled and more difficult to fit.
The GM ones are generally large round canisters.
A better fit is often available from Ford as most of them were a more rectangular shape.
These canisters were used in just about everything from the 70s and 80s. From Alfa's to Z....somethings.
So a perusal of your local automobile re-purposing establishment will turn up lots of possibilities.
Canister sizing is important and this is one time that bigger is better.
The size is determined by the gas tank volume so pick one from a vehicle with a bigger tank than yours.
Most aftermarket carbs will have a vent port that you can use instead of tying into the PCV. system.
That gives you more options for hose routing and removes the possibility of fuel contaminating the crankcase.
Hope that helps someone

Cheers
Fred