[torqhead]

Used to have a sump on my tank, but really didn't like the looks of it. Now I'm running the RobbMc 1/2 pickup in a new tank on the GTO but my problem is I have to have at least a 1/2 tank if not more to prevent from running out of fuel in second gear on launch. Anyone have any suggestions on how I could improve this besides using a sump?

[sleepy]

Install gates in the tank to prevent the gas from running to the back of the tank. Like a racing oil pan.
Or you could instal these. http://www.atlltd.com/aircraft/prodd...AD-004&cat=146

[Pontirag]

take some time to look at the baffleing used it sport plane design, also dont discout the aircraft remote sump oiling systems examples.

[Bill Meyer]

I had that same issue when I was running "pure stock" many years ago. I took the stock tank out, had it opened up and cleaned. Then they welded in a partition just to the left of the fill tube. Tank now was about 5/8 the regular size, looked like stock,filled like stock,fuel guage worked, but with 10 gallons, it was full and all the gas was on the passenger side. Too bad I sold it!! - Bill -

[First Bird]

I'm with you Torqhead. Been looking for a solution for a while now. So far this is my leading design:
A "Y" off our 1/2" pickup, going to 3/8" fuel line to Walbro pickups.

3/8" is the largest permanently submersible fuel line I've found so far. I believe the right stuff is rated SAE 30R10. Gates makes a product:
http://www.gates.com/brochure.cfm?br...ocation_id=541
that is spendy at $30/ft and hard to find. It looks to be available in 5/16" and 3/8" which won't work for us since we have the RobbMc 1/2" pickup.

I thought a "Clunk" might work. Something like this, which is too small obviously but a possible design solution:
http://www.jetskisolutions.com/p61_f...kup_clunk.html

http://www.out2win.com/catalog/img/RC016.jpg

Originally I thought a clunk would be the answer. One clunk attached to 3/8" fuel line would be great at moving around in the bottom of the tank, following the fuel, but it would be restrictive. Using two clunks to increase flow capacity might help but you introduce the possibility of one clunk being uncovered while the other is still in fuel. In that case air will be picked up instead of fuel. That's where these Walbro pickups come in:
http://www.autoperformanceengineerin...l/pickups.html

If they are uncovered, instead of flowing air, they shutoff and force the other pickup to continue flowing fuel.

This is what I've come up with so far. I don't have an answer yet. I'm just regurgitating info I've found online. I'm planning to drive my car on track days so my fuel will be going right and left, and to the back of the tank so I'd like to find a better fuel pickup too.

[screamingchief]

A small one gallon (or so) "surge tank" would probably be the best option,though it certainly will not be the easiest one to fab up and package (especially if you dont want it to stick out like a sore thumb or pose any major safety risks or such).

You would likely set up the surge tank so it was constantly re-circulating the fuel in the surge tank via a submersible low pressure electric fuel pump,and the surge tank would likely employ some sort of return to the main tank to allow for said re-circulation.

Then you would instead draw the main fuel supply for the engine from that surge tank via your normal fuel system instead of drawing it from the main tank.

Even if the low pressure pump temporarily loses the fuel supply due to slosh or such,the smaller surge tank should still have more than enough fuel left in it at any given time to keep the engine well supplied till that low pressure pump can find the fuel again to refill the surge tank.

Also the smaller surge tank would be far less susceptible to slosh and launch forces than the larger main tank would be,especially when it incorporates things like baffles and a pick-up design to avoid those sorta problems.

FWIW

Bret P.

[lust4speed]

It would seem like baffles only slow down the transition of the fuel, and might not keep the pickup covered. Baffles impede flow both ways - wouldn't a trap door flap work much better for drag racing? Either one is going to require the tank to be dissected, so why not get a little more elaborate? It would not only trap the fuel, but would also allow fuel to easily flow forward when the G force subsides.

[torqhead]

Right now my car is in paint (completely stripped now) and so I thought a good time to attack this situation. So I spent some time drawing up this idea, thought I would go to a radiator shop and see if they're willing to do it for me. It would keep the car looking stock and I think solve my problem. Give me your feedback guys, any appreciated.

[Tom Vaught]

Originally Posted by torqhead

Used to have a sump on my tank, but really didn't like the looks of it. Now I'm running the RobbMc 1/2 pickup in a new tank on the GTO but my problem is I have to have at least a 1/2 tank if not more to prevent from running out of fuel in second gear on launch. Anyone have any suggestions on how I could improve this besides using a sump?

If this is a "Drag Race Occasionally" deal, (for primarily a street car), I would have a good fabricator make you a "Mezzanine Platform" that would mount in the normal Spare Tire location and be a few inches off the trunk floor. You can get 5 gallon fuel cells that have sumps already built into them. Mount the Fuel Cell securely to the "Mezzanine Platform"
and the Mezzanine Platform" to the trunk (like you would attach a battery in the trunk).

Run a steel/aluminum 1/2" fuel line from the fuel cell sump to a trunk floor plate.
The trunk floor plate will have a Bulkhead Gyro-lock 1/2" id fitting and the plate can be replaced after racing with a normal trunk plate.

Attach a line from the other side of the Bulkhead Gyro-lock fitting to you normal 1/2" fuel line when you race.

This keeps your car "stock looking", allows adding and removing the "proven" fuel cell/sump technology, and allows the serious launch times for minimal cost.

JMO

Tom Vaught

attached is what a "Mezzanine Platform" looks like.

[First Bird]

Looking pretty good. If it were me, I'd be incorporating some trap doors that swing toward the pickup, but stop vertically with force away from the pickup. That way, no matter which way the fuel is trying to move away from the pickup, it gets blocked.

[68lemans462]

Interesting topic. I have the EXACT same setup and the EXACT same problem on my '68 - stock tank with ROBBMC pickup. Keep the ideas coming!!

[torqhead]

Originally Posted by First Bird

Looking pretty good. If it were me, I'd be incorporating some trap doors that swing toward the pickup, but stop vertically with force away from the pickup. That way, no matter which way the fuel is trying to move away from the pickup, it gets blocked.

Hey Tom, My only thought on the trap door is moving part and potential failure. Effectively I was looking at incorporating this in the tank and it would be sealed again forever. Also, it's very rare that I go less than an 1/8 tank and hence why I'm thinking this would work.

[torqhead]

Originally Posted by 68lemans462

Interesting topic. I have the EXACT same setup and the EXACT same problem on my '68 - stock tank with ROBBMC pickup. Keep the ideas coming!!

Question for you, did you discover when you put the RobbMc pickup in your gauge doesn't read quite the same, I have about a good 1/4 tank or so and my gauge is on "E". Wonder how to fix this?

[torqhead]

Originally Posted by Tom Vaught

If this is a "Drag Race Occasionally" deal, (for primarily a street car), I would have a good fabricator make you a "Mezzanine Platform" that would mount in the normal Spare Tire location and be a few inches off the trunk floor. You can get 5 gallon fuel cells that have sumps already built into them. Mount the Fuel Cell securely to the "Mezzanine Platform"
and the Mezzanine Platform" to the trunk (like you would attach a battery in the trunk).

Run a steel/aluminum 1/2" fuel line from the fuel cell sump to a trunk floor plate.
The trunk floor plate will have a Bulkhead Gyro-lock 1/2" id fitting and the plate can be replaced after racing with a normal trunk plate.

Attach a line from the other side of the Bulkhead Gyro-lock fitting to you normal 1/2" fuel line when you race.

This keeps your car "stock looking", allows adding and removing the "proven" fuel cell/sump technology, and allows the serious launch times for minimal cost.

JMO

Tom Vaught

attached is what a "Mezzanine Platform" looks like.

Tom, Thanks for the idea, trying to avoid doing anything in the trunk and keeping the stock look hence going as far as doing something internally.

[68lemans462]

My fuel gauge works great - at least I think it does.. One thing for sure, if it's below 1/2 tank and I mash the gas, it'll stumble. When I go to the dragstrip, i top the tank off right before I pull in. No problems til I get to 1/2 tank...

I'd be also interested in possibly collaborating on this project, since we are in the same basic location and in the same boat. I know an excellent welder that would do this work for beer $$... Has anyone actually modified a tank? Any aftermarket tanks that would work without spending $1000's??

[torqhead]

Originally Posted by 68lemans462

My fuel gauge works great - at least I think it does.. One thing for sure, if it's below 1/2 tank and I mash the gas, it'll stumble. When I go to the dragstrip, i top the tank off right before I pull in. No problems til I get to 1/2 tank...

I'd be also interested in possibly collaborating on this project, since we are in the same basic location and in the same boat. I know an excellent welder that would do this work for beer $$... Has anyone actually modified a tank? Any aftermarket tanks that would work without spending $1000's??

sent you a pm

[Joel Koontz]

If you wait a few months Aeromotive will solve the problem for you. I have read (several places) that sometime next year they will be releasing stock appearing fuel tanks with built in baffles and high output in-tank fuel pumps. Designed for FI, but should work fine for a carb setup. I am currently using a high pressure in-tank pump with a McRobb regulator with a carb and it works great.

This is a link to what I installed http://forums.maxperformanceinc.com/...highlight=fuel

There is a similar one for sale on the forum http://forums.maxperformanceinc.com/...tank+fuel+pump that has 190 LPH pump(mine is 255 LPH)

[67 Lamnas]

Originally Posted by Joel Koontz

If you wait a few months Aeromotive will solve the problem for you. I have read (several places) that sometime next year they will be releasing stock appearing fuel tanks with built in baffles and high output in-tank fuel pumps. Designed for FI, but should work fine for a carb setup. I am currently using a high pressure in-tank pump with a McRobb regulator with a carb and it works great.

This is a link to what I installed http://forums.maxperformanceinc.com/...highlight=fuel

There is a similar one for sale on the forum http://forums.maxperformanceinc.com/...tank+fuel+pump that has 190 LPH pump(mine is 255 LPH)

Rick's Hot Rod shop already has a solution....not inexpensive, but a solution, none the less. You want a stealth tank. Talk to Victor. They have nice stuff, I put one in the Lamnas.

www.rickstanks.com

[TheSilverBuick]

I'm a fan of the simplicity of a surge tank. But as mentioned the tough part is making it and locating it in such a way it's not considered a hazard.

I use a 4" long by 2" diameter iron pipe for one on my EFI applications. It weighs a fair amount though but it's practically bullet proof! Dead nuts simple. I actually use my mechanical pump to pump into it and an EFI pump off the bottom feed. I've gotten the main tank down to less than 2 gallons with no noticable effects driving. I think my surge tank/pipe holds about 3 pints of fuel. Better fabricating skills can do better.

It doesn't really take much volume to work well, the down side is the added complexity of needing a second fuel pump.

[Tom Vaught]

I have posted this in the past but here goes again (concerning a surge tank):

Marty Palbykin, who some of you might remember campaigned the FIRST twin turbo
GTO to run in the 6s also owned a 69-71 Grand Prix that his daughter drove.

Marty wanted to put EFI on the car (after having my Prototype 3 bbl double pumper on the car for a while).

What he did was use a factory type High Perf mechanical fuel pump to fill a gallon sized fabricated "Surge Tank" located under the hood. The surge tank had a passive return system where extra fuel was gravity feed back to the fuel tank. This was easily done:

1) Mechanical Fuel pump feeds fuel to the surge tank
2) Return system maintains the fuel level in the Surge Tank by returning extra fuel once the fuel level in the Surge tank reached a certain height in the surge tank.
3) A Vent System to remove air bubbles/ pressure from the mechanical pump pumping fuel from the rear tank.
4) A FUEL INLET (for the EFI electric fuel pump) that supplied the EFI system on the engine.

Now if you just substitute a Pusher EFI type pump in the tank for the mechanical fuel pump and make the mechanical fuel pump the Primary fuel pump for the carburetor you can have the engine LOOK stock and still have plenty of fuel for acceleration runs.

Tom Vaught

ps The mechanical Fuel Pump WILL work a LOT BETTER when the fuel supplied to it is Gravity fed (Surge tank higher than the Mechanical Fuel Pump) vs being "sucked" by the Mechanical pump. In reality the fuel is pushed by atmospheric pressure forward to the mechanical fuel pump so you really need a proper diameter vent system to allow air/pressure INTO the fuel tank under acceleration.