TYTILIDIE
METH HEAD
Ever notice we have some of the most knowledgeable people here? We have engine geniuses, transmission experts, rear end gurus, turbo nuts, tuning gods.................But we don't have any one on here who KNOWS about gas tanks. I searched the internet today for some answers to my questions and I am finding out fast that the average car crowd knows little about gas tanks.
Whats the first thing most of us do when we start modding our trucks? We toss our ABS, get EGR delete kits and throw out that stinky old evap canister. I don't know about you guys but my truck reeks of fuel sometimes and sometimes the fuel will actually push out of the gas cap. I tried initially (years ago) to run the line that went to the evap unit to open air. The smell was unbearable. So the next time I had the tank out, I capped it off at the sending unit. Well guess what, I STILL had fuel pushing out of the gas cap.
Now that I have a sumped tank and external pump, I for some reason thought these issues would go away, they didn't. I had a leak in my tank last week and got it fixed this weekend. I put some fuel in the tank, sealed it all up and pressurized it. No leaks. After a few minutes, I grabbed some windex and sprayed around me plugs to see if they were leaking. Only thing leaking air was the sending unit o-ring.
Well I went ahead and put the tank back in. I am still buying a new tank and sump and am going to have it put together right so I never a leak again. It struck my curiosity to what other people do with their tanks in these situations. So I ventured on the interwebz and did some searching. Turns out, there is very little information on this, especially from people that actually KNOW about gas tank "science". After doing some good reading, I am finding some people claim that when you ditch the evap system, it is to be replaced with vent. These guys were using what they called roll-over vents or check valves. From what I could read, it was being used mainly as a way to get the vent out of the tank so to speak. They would then run a hose to a breather/filter to the inside of the gas tank door.
I read some other stuff saying that basically, your "vent" has to be the same diameter as your fuel line to your pump. Return line was not mentioned though. The thought behind this was that as your pump is pumping, you are consuming XX amount of fuel. For every XX amount of fuel you consume, it is replaced with the amount of air via the GAS CAP. This I thought was interesting. I always thought the gas cap was the vent? I mean after all, I always get fuel all over the side of my truck from it. So basically, these guys were saying if your vent is too small, the nature of your pump, line set up is moving more than the vent can disperse.
So for your experience, what do you guys think about these theories? I am going to order my new tank this week and am not sure if I should order one of these vents. It involves drilling a hole and installing it as a bulkhead fitting. That's a lot to swallow, drilling a hole in a new tank for something that might not even work or leave with the same problem I already have. So is there anyone here who KNOWS fact for fact what needs to be done?
Sorry for the long post, I thought it might spark some good interest and good a good thread going and maybe attract a gas tank scientist:lol:
Whats the first thing most of us do when we start modding our trucks? We toss our ABS, get EGR delete kits and throw out that stinky old evap canister. I don't know about you guys but my truck reeks of fuel sometimes and sometimes the fuel will actually push out of the gas cap. I tried initially (years ago) to run the line that went to the evap unit to open air. The smell was unbearable. So the next time I had the tank out, I capped it off at the sending unit. Well guess what, I STILL had fuel pushing out of the gas cap.
Now that I have a sumped tank and external pump, I for some reason thought these issues would go away, they didn't. I had a leak in my tank last week and got it fixed this weekend. I put some fuel in the tank, sealed it all up and pressurized it. No leaks. After a few minutes, I grabbed some windex and sprayed around me plugs to see if they were leaking. Only thing leaking air was the sending unit o-ring.
Well I went ahead and put the tank back in. I am still buying a new tank and sump and am going to have it put together right so I never a leak again. It struck my curiosity to what other people do with their tanks in these situations. So I ventured on the interwebz and did some searching. Turns out, there is very little information on this, especially from people that actually KNOW about gas tank "science". After doing some good reading, I am finding some people claim that when you ditch the evap system, it is to be replaced with vent. These guys were using what they called roll-over vents or check valves. From what I could read, it was being used mainly as a way to get the vent out of the tank so to speak. They would then run a hose to a breather/filter to the inside of the gas tank door.
I read some other stuff saying that basically, your "vent" has to be the same diameter as your fuel line to your pump. Return line was not mentioned though. The thought behind this was that as your pump is pumping, you are consuming XX amount of fuel. For every XX amount of fuel you consume, it is replaced with the amount of air via the GAS CAP. This I thought was interesting. I always thought the gas cap was the vent? I mean after all, I always get fuel all over the side of my truck from it. So basically, these guys were saying if your vent is too small, the nature of your pump, line set up is moving more than the vent can disperse.
So for your experience, what do you guys think about these theories? I am going to order my new tank this week and am not sure if I should order one of these vents. It involves drilling a hole and installing it as a bulkhead fitting. That's a lot to swallow, drilling a hole in a new tank for something that might not even work or leave with the same problem I already have. So is there anyone here who KNOWS fact for fact what needs to be done?
Sorry for the long post, I thought it might spark some good interest and good a good thread going and maybe attract a gas tank scientist:lol:
