Fuel Smell in Garage?

[Jack Houpe]

I just took the gasket off each of the caps.

With EFI fuel is continually being circulated which heats up the fuel and also creates vapor and fumes, I think our cars originally designed for carburetors are dealing with a number of modern problems which they were not intended for. The solution is a vacuum line to a charcoal canister going to tanks which would be sealed. I discovered that I can not run my EFI system with a sealed tank as it build pressure in one tank not permitting the fuel to cross over from one to another so I have put up with the smell of fuel in my garage when it gets warm. I really don't want to add all the extra lines and tanks as its pretty tight as you all know.

 

[Tim Kay]

Someday my house will blow up! I have two cars in a one car garage (with lift rack) so the gas oder from the 40 is a bit stonger for that reason alone. I contribute the oder to two small rollover type breathers adjacent to both filler caps that are normally open. They only close if there is a surge of fuel against their internal ball.

What really helps in my situation is to reduce the level of fuel in my tanks to lower the vapor smell. If I have full tanks and walk into the closed garage it practically makes my eyes water. Therefore it gives me good reason to take the long way home to reduce the fuel level if I know i won't be driving the car for a while.

Good to know I'm in good company on this one, seems a common issue.

 

[Chet Schwer]

I tried a regular Stant gas cap on both my GT40 and Cobra. It helped with the odor but I got kind of worried about the pressure in the tank when the cars were sitting for longer periods of time. The cobra tank would "pop" loud when I would remove the cap after the car had been sitting in a temperature controlled garage.
Chet

 

[Jack Houpe]

Chet there have been reports of SPF owners removing the cap and fuel coming out due to the pressure.

Tim I guess its a part of life if you own one unless you put all the charcoal tank stuff in.

 

[Tim Kay]

Tim I guess its a part of life if you own one unless...

Jack, the smell of gas is not my least favorite and believe me there are worse vapors that come out my house. I have two teenage methane cloud sons.

 

[Seymour Snerd]

It turns out that on the upper side of that skip-welded flange, at least on my car P2160, the entire periphery of that joint is continuously welded. Thus interruptions in the weld underneath are not necessarily evidence of a leakage path.

I'm sorry to say I need to correct the above misinformation (in post 12; see post 11 for picture and context). I just discovered that even though the rim on top with which the locking cap mates is continuously welded around it's circumference, there is still leakage below if the welding underneath is not continuous. Apparently this assembly is actuall three pieces welded together and joining in the same plane: the pipe, the flat collar, and the sheet metal rim with notches for the gas cap. I chose to repair mine by simply laying down a fillet of JB Weld in the area that was not welded.

You can test for leaks here by duct taping the top and bottom pipe openings shut, and corking or taping one of the vent fittings shut. Then you can blow or suck on the other vent fitting and any leakage will be obvious.

 

[Seymour Snerd]

Chet there have been reports of SPF owners removing the cap and fuel coming out due to the pressure.

I don't know if the above problem was the intended target, but later cars have a check valve in the form of a trap door in the filler neck assembly. I got a couple of these from Dennis Olthoff and installed them at the bottom of the lower section of pipe; it's an easy install because they have three ears with 1/8" holes just right for pop riveting to the sides of the pipe. With a little encouragement the hose then slides over those ears and on up over the bead and into the clamping area.

I've been trying to understand how that might happen; my best theory is that with the tanks pressurised (due to lack of venting for whatever reason), opening one cap allows the opposite tank to unload its excess air volume into the one that's open. If we assume the tanks are equally full, and the resulting expansion in the closed tank is more than about a factor of 2, then it pushes gasoline out of the opened tank because the volume being pushed into the open tank exceeds the air volume already there. Does anybody buy that explanation?

If that's the explanation, then there is an amusingly theatrical workaround: have your passenger open the opposite cap exactly when you do (like waiters at a fine French restaurant serving the main course; Voila!)

Or do you then both end up with gasoline all over you?

 

[Jim Cowden]

This model of 40 seems to have an ongoing issue with tanks.
I don't know why SPF haven't sorted out the issue by know,or maybe they don't see it as an issue.

Charcoal canisters are the go,SPF must be living in the dark ages if they are not fitting them to their cars,I don't know how they would pass most laws and standards even for low volume manufacture.
Obviously the laws they build to allows them this but that does not make it OK for it to smell like a lawn mower.

If you run a canister you run a solenoid vent valve,when the cars ign is turned on the the valve opens and allows the flow of vapour to the air filter.
This also drops the pressure in the tank.

The system needs to be completely sealed when not in use.
All modern cars are this way and it works, To me it sounds like the system in the SPF is still back in the 60's and needs to be modernised.

Not hard when you are building it,harder when it is built.

Jim

 

[Seymour Snerd]

the system in the SPF is still back in the 60's... I don't know how they would pass most laws and standards even for low volume manufacture. ...that does not make it OK for it to smell like a lawn mower.

I think SPF might argue that being back in the 60's is precisely their intention. I know that' s largely why I chose their product.

Philosphy aside, the requirement for a sealed fuel system came only from the later stages of smog control, and if we were to apply those standards to the SPF the gasoline tanks would be the least of our worries.

Regarding "laws and standards"... what laws and standards?

As for smelling like a lawn mower, first of all, they probably did in the '60s. It's a replica of a race car.

Secondly, if you read through this thread and the others on this subject there are relativley easy solutions for each of these problems most of which are associated only with earlier production. The shear volume of discourse on this subject may lead one to the perception that the issues are many and serious, but they a really aren't. The volume is partly my fault because I had the tanks out and decided to take a run at every single issue I could think of, and then to document it. Here's a summary, with solution(s):

1. Leak at filler neck due to incomplete welds. Fixed in production and updated part provided for free. Easy to repair with epoxy.
2. Leak between steel filler neck and aluminum collar due to my sloppy disassembly: reseal and add a bolt and nut just outside of drain spigot. Or just be more careful taking it apart.
3. Fuel surge out of filler neck. Fixed in production. Easy to retrofit.
4. Starvation driving down hill with low fuel: drive uphill only. Actually I think I've fixed this but it wasn't easy or cheap.
5. Inaccurate fuel gauge: easy to repair by lengthening/bending sender arm or replacing sender for $25-$70
6. Lack of venting through cap: easy modification to fuel cap.
7. Fuel filler passage way and sponsons not isolated from passenger compartment: fixed in production. No easy retrofit that I am aware of, but mitigated if all other issues addressed.
8. Vulnerability of fuel tanks in crash: drive an Escalade or a Chevy Volt, wear Nomex, or put in fuel cells at ~$5,000.
9. Evaporation from carburetor float bowl: inject, don't carburate.
10. Seepage through synth. rubber hoses: use Teflon.
11. Residual gallon or two in tanks: get a life. (although I believe I've fixed this as well. It's not easy)

 

[Jack Houpe]

The fuel smell is not that bad unless you have a serious leak someplace, you are right Alan its a race car not a new GT made for the everyday driver.

 

[Jim Cowden]

Alan
My comments are general comments, reading your post you appear to think they were directed at you.

The original post was about fuel smells, that was what my comments were about.
I know Randy and Jack had made comment about canisters

The majority are still venting to the air,maybe they think it is a crime to make it a sealed system.


AWATKINS QUOTE
I think SPF might argue that being back in the 60's is precisely their intention. I know that' s largely why I chose their product.

Philosphy aside, the requirement for a sealed fuel system came only from the later stages of smog control, and if we were to apply those standards to the SPF the gasoline tanks would be the least of our worries.


I agree making these cars road legal is no easy task.
Always room to make things better,its not a 60's car it is a reproduction and in most not all countries this car would need to comply to some of the 2011 pollution laws .
Canisters electric solinoids are all good things and will help towards fixing a problem regardless of laws,we are over 40 years on you can make improvements.
I dont understand why they would have an open fuel tank.

Sealed systems are not new I would guess 30 years at least.

Looking at the list you posted that is a lot of problems too deal with.
Looking at some of them they should never have got past the manufacturing stage without someone thinking this is going to leak fuel, lucky you have delt with them.

The original cars had bladders,from what I am gathering these cars dont.
So its not the original set up anyway, I would modify till I was satisfied it was fixed as it will not be sacrilige to change it anyway.


Jim

 

[Seymour Snerd]

Alan
The original post was about fuel smells, that was what my comments were about.
....
I agree making these cars road legal is no easy task.
...this car would need to comply to some of the 2011 pollution laws .

Looking at the list you posted that is a lot of problems too deal with.
...
The original cars had bladders,from what I am gathering these cars dont.

Some clarification:

• You said "ongoing issues with the tanks" so I listed every "tank" issue I could think of.
• Only three (1, 3 and 6) are even arguably design or production defects related to fuel smell.
• They are road legal in the US as manufactured, so it is "easy".
• They do not need to comply with any pollution laws in the US.
• Bladders are not suitable for road cars; they chafe, wear out, and have to be replaced. SPF made some specific deliberate decisions to deviate from the original andI have yet to find one I disagree with.
• You said the system "needs to be sealed" and "needs to be modernised". I don't see why.
• Also, if that were true, it would apply to all kits and replicas, not just SPF. I am unaware of any that supply sealed fuel systems, charcoal canisters, solenoid operated valves etc.

 

[Jim Cowden]

I agree bladders are a pain( maintenance)and life expectancy.
You guys are lucky that you don't have all the regulations that we have.
In OZ we have to comply with 2011 regs.
The emissions pass level has just been lowered to 95-96 spec to my knowledge.

You wont get a car passed without a sealed system or charcoal canister in OZ as you are omitting HC to the atmosphere.

I would think RF and DRB, Cateram,RCR export product does as well.

All the best

Jim

 

[Seymour Snerd]

You guys are lucky that you don't have all the regulations that we have.

In this particular area..... (let me show you our tax code).

Legally driving a 40'" tall 60's era race car on the street with side-mounted fuel tanks, 5 lbs/hp and 200 mph top speed is one case where America truly is "the land of the free and the home of the brave." :thumbsup:

 

[Chuck]

In this particular area..... (let me show you our tax code).

Legally driving a 40'" tall 60's era race car on the street with side-mounted fuel tanks, 5 lbs/hp and 200 mph top speed is one case where America truly is "the land of the free and the home of the brave." :thumbsup:

Well said!

 

[Seymour Snerd]

Thanks to Bill Musarra I have another entry, item 12 below, for the list of reported issues with the SPF GT40 fuel tank and related systems. Strictly speaking this is theoretical since I am unaware of an SPF owner observing the phenomenon.

1. Leak at filler neck due to incomplete welds. Fixed in production and updated part provided for free. Easy to repair with epoxy.
2. Leak between steel filler neck and aluminum collar due to my sloppy disassembly: reseal and add a bolt and nut just outside of drain spigot. Or just be more careful taking it apart.
3. Fuel surge out of filler neck. Fixed in production by addition of check valve (flapper or trap door valve) in filler neck. Easy to retrofit.
4. Starvation driving down hill with low fuel: drive uphill only. Actually I think I've fixed this by drawing fuel from the front of the RH tank, but it wasn't easy or cheap.
5. Inaccurate fuel gauge: easy to repair by lengthening/bending sender arm or replacing sender for $25-$70
6. Lack of venting through cap: easy modification to fuel cap.
7. Fuel filler passage way and sponsons not isolated from passenger compartment: fixed in production. No easy retrofit that I am aware of, but mitigated if all other issues addressed.
8. Vulnerability of fuel tanks in crash: drive an Escalade or a Chevy Volt, wear Nomex, or put in fuel cells at ~$5,000.
9. Evaporation from carburetor float bowl: inject, don't carburate.
10. Seepage through walls of synthetic rubber hoses: use Teflon.
11. Residual gallon or two in tanks: get a life. (although I believe I've fixed this as well. It's not easy)
12. Parking the car even slightly downhill with nearly full tank leaves trapped air at the rear, which with an increase in temperature can push liquid fuel out the vent system. This is an inherent property of any fuel tank that is long in one direction relative to height (that is, strays far from being a sphere). The obvious solution is additional vents at the rear. This could be accomplished on the LH tank via the return port, but the stock SPF RH tank has no such port. One could probably add one without removing the tank by drilling and adding a fitting, sealed either by epoxy or perhaps by some sheet-metal fitting technology I'm unaware of. The tanks are made of 22 ga stainless steel. Or with some nerve and agility you could fill the tank with water or argon and solder or braze from within the rear sponson cavity. Or of course disassemble the RHS front suspension enough to pull the tank out the front of the sponson.

 

[Steve C]

Alan,

To 4 and 12 above.

Fixed on P2125 by addittion of swirl tank. See pics in SPF section under "Upgrades to P2125)

Steve

 

[Seymour Snerd]

Alan,

To 4 and 12 above.

Fixed on P2125 by addittion of swirl tank. See pics in SPF section under "Upgrades to P2125)

Steve

I'll buy that for 4, but not for 12. How can adding a swirl tank keep an isolated bubble in the RH tank from expanding?

 

[Steve C]

Alan,

I was adressing the "trapped air in the rear" that could depending on ammount of fuel left in tank and the down angle of the car could starve the fuel pump but, with a fuel pot and seperate fuel pump for the swirl pot one wouldn't be vapor bound on start up.

Steve

 

[Seymour Snerd]

I was adressing the "trapped air in the rear" that could depending on ammount of fuel left in tank and the down angle of the car could starve the fuel pump but, with a fuel pot and seperate fuel pump for the swirl pot one wouldn't be vapor bound on start up

No, that's not what #12 is about. If anything the effect of this problem would be to assist the fuel pump (in a sort of perverse way).

By the way, since the factory recommended ride height specification is ~1/2" nose down, issue 12 occurs when parking on level or even slightly uphill ground.