MHKflyer52 Posted May 9, 2010 Share Posted May 9, 2010 Well here is something that has never happened to me or to any car I have owned. A little background information: I store my 7 in my car trailer when I am not driving it or keeping it at my home and it is secure on our family property and I am the only one that has keys to the trailer. 7 secured to floor of trailer with four cargo straps to keep it in place during transportation. Trailer locked and secured with car inside trailer. Fuel tank 3/4 full (approx 3 gallons of gas in tank when parked in trailer two weeks ago) after auto-x that I participated in. Battery disconnected with an electrical master switch plus another master switch. All switches in the off position. Electrical master switch key removed from car. Opened trailer to Friday night May 7 to check straps before moving the trailer to my home so I could use my car over the weekend. Smelled fuel but did not see any signs of a fuel leak while checking cargo straps. Move trailer to my home and parked it in front of the house (Friday evening). Saturday morning (May 8) went out to open trailer and get the 7 out to go for a ride as the weather was just about as perfect for driving a 7 for the shear enjoyment. Un-hooked the cargo straps and put the ramp down (enclosed trailer). Noticed the smell of fuel so I looked to see if I had a fuel leak or signs of one and did not see any sign of a leak. Connected electrical master and climbed into the car to start it. Turned master switch on, turned fuel pump on, fuel pump sprang to life and pressurized and stopped as it should. Pushed starter button. Engine turned over very slowly and tried to start but would not start, acted as if the battery was down and did not have the power to turn it over so I climbed out and just pushed the car out of the trailer. Went back into the trailer to get my battery jumper box and did not see any signs of a leak on the floor of the trailer as I walked into it. Returned to the car and removed the hood and to my supersize it looked as if the carb (Weber Down Draft two barrel) was seeping fuel out the filter. Removed air filter cover to find the carb full of fuel and a puddle of fuel and oil now under the car due to the angle of the street where the car was parked behind the trailer. Turned the Battery Master OFF immediately. Pulled the dip stick to see the oil and saw that fuel and oil were seeping from the dip stick holder. Now I am shocked as I have never seen anything like this with an engine, especially with the fuel tank located low in the chassis (carb is approx 20 inches higher than the tank and the fuel pump [faucet type] is located on the frame rail that the floor is attached to and is level with the bottom of the tank). Put dip stick back into holder to stop leak. Push car into garage and put up on jack stands. Checked the fuel tank to find it almost totally empty (approx 1 qt of fuel left in tank). Drained oil from oil pan to find that I now have 3-1/2 gallons of oil and fuel in four oil drain collection containers and less than a quart of fuel in the gas tank. I now have the valve cover off, plugs pulled so I can check that I did not damage a valve when I tried to start the car when it was in the trailer and it was full of fuel and oil. Did not find any damage to the valves so I think I lucked out and did not hydraulic lock the engine when I tried to start the car. Talked to a friend and he thinks that the cars gas tank vent might be plugged and that the tank became pressurized due to the heat inside the trailer while it was being stored causing the fuel to be pushed through the fuel pump and up into the carb float bowl and then into the intake manifold and then into the engine. My plan is to fill the engine with oil to coat all the internal parts then hand crank the engine to get the oil and fuel flushed out of all the passages and then drain the oil and replace the oil filter and then fill the oil again and then crank with the starter to get oil pressure and then drain and replace the oil and filter again then start the engine and bring it up to temp and the repeat the oil change again. Any ideas or suggestions will be considered and are much appreciated. Side note my engine is now as clean inside as the day I finished building it up as far as I could see with a bore scope that I have access to. Looked into each cylinder and into the oil pan through the drain plug and cut the filter in half to see if there was any metal in it from when I tried to start the engine while it was full of fuel and oil, NO METAL SHAVINGS I think I might have not toasted my engine but will not know until I start it and run it. Link to comment Share on other sites More sharing options...
slngsht Posted May 9, 2010 Share Posted May 9, 2010 pretty wierd. the gas vabor pressure theory totally makes sense. how is your tank vented? Link to comment Share on other sites More sharing options...
drew... Posted May 9, 2010 Share Posted May 9, 2010 Martin, Add 1/2 teaspoon of 30W oil into each cylinder before handcranking to protect the rings and cylinder walls. Link to comment Share on other sites More sharing options...
MHKflyer52 Posted May 9, 2010 Author Share Posted May 9, 2010 Martin, Add 1/2 teaspoon of 30W oil into each cylinder before handcranking to protect the rings and cylinder walls. Thanks Drew. That was one of the first things I did after draining the engine and pulling the plugs before sticking the bore scope into each cylinder to look at the valves. Link to comment Share on other sites More sharing options...
MHKflyer52 Posted May 9, 2010 Author Share Posted May 9, 2010 pretty wierd. the gas vabor pressure theory totally makes sense. how is your tank vented? Gas tank is vented through the cap. Replacing the cap with a new one as the one I have looks like the rubber that makes the seal to the tank neck is swollen so it is getting replaced just to be on the safe side. Link to comment Share on other sites More sharing options...
rnr Posted May 9, 2010 Share Posted May 9, 2010 Gas tank is vented through the cap. Replacing the cap with a new one as the one I have looks like the rubber that makes the seal to the tank neck is swollen so it is getting replaced just to be on the safe side. Is your gas cap a two way vent? I know that the one on mine is a one-way only (out -> in). If it is two-way would you mind posting a picture/part number because I have been looking to replace my current cap with a two way venting version. Link to comment Share on other sites More sharing options...
slomove Posted May 9, 2010 Share Posted May 9, 2010 Strange indeed. While the tank non-venting sounds like the only way to get the gas up there it also would require at least one float needle to leak? Link to comment Share on other sites More sharing options...
Boxologist Posted May 9, 2010 Share Posted May 9, 2010 residual electrical in the fuel pump and the pump failed continuing it to pressurize fuel into the carbs, overflowing, and spilling everywhere? Link to comment Share on other sites More sharing options...
slngsht Posted May 9, 2010 Share Posted May 9, 2010 residual electrical in the fuel pump and the pump failed continuing it to pressurize fuel into the carbs, overflowing, and spilling everywhere? pump can't fail and keep running to put 2 or 3 more gallons in when both master switches are off. Martin, Call BP. I hear they have a big container they can put over your car to suck all the gas out of it. At this point, they might sell it for $1, but you might have to move it yourself Link to comment Share on other sites More sharing options...
WestTexasS2K Posted May 9, 2010 Share Posted May 9, 2010 I agree with your friend tank was not venting and it over pressurized the carb needle in the carb filling the carb till it overflows runs down the intake into the cylinder and it leaks by the rings into the crank case. I had this happen on a previous project. Link to comment Share on other sites More sharing options...
WestTexasS2K Posted May 9, 2010 Share Posted May 9, 2010 Needle and seat will hold about 7 psi that is why carb fuel pumps are regulated to no more than 7 psi. Tank can pressurize to over 20 psi depending on how hot it gets. Depending on the fuel tank some have vents in the cap others are on the tank. Link to comment Share on other sites More sharing options...
slngsht Posted May 10, 2010 Share Posted May 10, 2010 Martin, why not run a little test to confirm this... unplug supply line to carb, and put a pressure gauge on it - on a day when you're home and have time to monitor it as pressure builds. Link to comment Share on other sites More sharing options...
erioshi Posted May 10, 2010 Share Posted May 10, 2010 The expansion theory sounds plausible, but I would think to pump that much fuel it would take quite a few heat/cool cycles and your vent would need to only allow outside air into the tank when cooling, how long was the car sitting closed up in the trailer? Is there any chance the trailer was left in a position where the front of your car (specifically the carb) may have been left sitting lower than the fuel tank? I'm thinking of something like the front end of the trailer on the ground instead of the trailer being level .. perhaps the tongue wheel sinking or being set really low. Testing the theory as suggest above sounds good, but you'd need to replicate the carb's needle & float in some way and place that assembly above the test collector where fuel couldn't be returned by air contracting when the tank cooled. Link to comment Share on other sites More sharing options...
jimrankin Posted May 10, 2010 Share Posted May 10, 2010 Good new is that there is just about no chance of damage from just cranking it a bit with a gas/oil mixture. Also no chance of valve damage from Hydro-lock as that is a connecting rod/piston dome issue and a starter motor usually can't come close to that much torque. My Harley used to flood when I parked it in the sun and the tank was near full, was the gas cap not venting "out" and a new cap solved the problem. Link to comment Share on other sites More sharing options...
BMW RACER Posted May 10, 2010 Share Posted May 10, 2010 The real good news is: The car didn't "fire up" That would have been a disaster!! Link to comment Share on other sites More sharing options...
MHKflyer52 Posted May 10, 2010 Author Share Posted May 10, 2010 (edited) The expansion theory sounds plausible, but I would think to pump that much fuel it would take quite a few heat/cool cycles and your vent would need to only allow outside air into the tank when cooling, how long was the car sitting closed up in the trailer? Well the car was in the trailer for 18 days and the average temperature during those 18 days in Ojai, CA. was 84 degrees which means that inside the enclosed trailer it was closer to 110 / 115 degrees. Your most likely wondering how I came up with what the temp inside of the trailer was. Well yesterday May 9, 2010 it was 78 degrees in Ventura, CA. were the trailer is now and I put a thermometer inside the empty trailer to see just how hot it was and after a half hour I checked the temp and it was 100 degrees and stayed that way most of the day. I was stunned to see that much difference in the temp but when you think how much area the side and roof present to the sun (420 sq. ft.) to absorb energy it makes since. Sure am glad that my trailer is white on the sides and the top is aluminum colored and not black or some dark color. Is there any chance the trailer was left in a position where the front of your car (specifically the carb) may have been left sitting lower than the fuel tank? I'm thinking of something like the front end of the trailer on the ground instead of the trailer being level... perhaps the tongue wheel sinking or being set really low. No the trailer is stored on a large flat area and is parked with the tongue about an inch higher than the tail of the trailer so that any water will run off of it if we have rain. Good new is that there is just about no chance of damage from just cranking it a bit with a gas/oil mixture. Also no chance of valve damage from Hydro-lock as that is a connecting rod/piston dome issue and a starter motor usually can't come close to that much torque. My Harley used to flood when I parked it in the sun and the tank was near full, was the gas cap not venting "out" and a new cap solved the problem. I have to agree with the gas cap not venting correctly as the rubber in my cap seems to have swollen so a new cap is being sourced along with a fuel shut-off valve to be placed in line to prevent this from happening again. Thinking about it I am glad no one was smoking around the trailer and that there was no spark when I opened the door to the trailer to check the tie-downs as there was a strong smell of fuel and I even looked for a leak but saw none when checking the tie-downs. Our RV has a solar powered fan that fits in the roof vent and I think one is going to get put into the car trailer as soon as I can get over to the RV Service Center to purchase one. This should help keep the temps down inside of the trailer and keep the fumes down to a minimum also. Edited May 10, 2010 by MHKflyer52 Added the word see Link to comment Share on other sites More sharing options...
Ian7 Posted May 11, 2010 Share Posted May 11, 2010 My plan is to fill the engine with oil to coat all the internal parts then hand crank the engine to get the oil and fuel flushed out of all the passages and then drain the oil and replace the oil filter and then fill the oil again and then crank with the starter to get oil pressure and then drain and replace the oil and filter again then start the engine and bring it up to temp and the repeat the oil change again. might be risky; with that much fuel in the oil system, I'd be worried about be able to flush it all out; residual fuel could break down the fresh oil and wreck the bearings.... Link to comment Share on other sites More sharing options...
WestTexasS2K Posted May 11, 2010 Share Posted May 11, 2010 My car that I previously had this se issue with pushed enough fuel thru the carb that the engine was full to the top on a big block chevy it did it in ten days. It had about seven gallons in it. Link to comment Share on other sites More sharing options...
soareyes Posted May 12, 2010 Share Posted May 12, 2010 Our RV has a solar powered fan that fits in the roof vent and I think one is going to get put into the car trailer as soon as I can get over to the RV Service Center to purchase one. This should help keep the temps down inside of the trailer and keep the fumes down to a minimum also.[/font][/color] Martin, back in the day when I use to fly sailplanes, we kept ours in a trailer outside and the solar vent worked very well to keep the temps down. These vents exhaust out so remember to have a passive vent to allow cooler outside air to get in. Link to comment Share on other sites More sharing options...
jimrankin Posted May 12, 2010 Share Posted May 12, 2010 Remember that gas fumes are heavier than clear air so putting a vent in the floor of the trailer will passivly allow the vapors to flow out when the solar fan isn't working at night, and allow cool air from under the trailer in when it is working in the daytime. Marine rated fans are explosion proof (spark protected like marine starters and alternators) so it might well be worth sourcing something from a marine supply store with that label. Always better safe than toasted. Link to comment Share on other sites More sharing options...
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