Steve you have to know I have to bite my tongue all the time on this one. I've been in two garage fires and have had to extinguish a good friend who was badly burned. My burns were quite minor, his were disfiguring (face, neck, and arms). Both of these fires were the result of gasoline leaks from vehicles that no one thought was going to get ignited but they did. Mike McComas of Pampa Texas would be dead today if I hadn't put him out as he was running blind, on fire from the waist up from getting fuel on his t-shirt. Tell me to get real when gasoline is non-flammable.
I know that overflow tubes are the best guaranty against hydrolock. That's not exactly rocket science. But I believe I've seen as many hydros as you have and have seen how much fuel is generally on the ground. It just isn't that much in my experience. I've seen bikes with a gallon in the crankcase and probably another quart in the airbox, cylinder and head, but still only have a two foot radius or smaller wet spot under them. Sure, any fuel on the floor is a hazard, but the more there is the risk is exponential. How big would that spot be if the whole two gallons was on the floor? Two gallons loose on the floor, heck one gallon, with a surface area of ten or maybe fifty or more square feet is going to create a highly volatile atmosphere. ANd then you're going to have to show me a garage that doesn't have an ignition source... even if it's just you walking in and turning on the lights, or an air compressor kicking on, or the block heater on your truck parked nearby, or who knows what all. I generally turn off my compressor, but like petcocks, I forget to do it sometimes and it may be on and cycle many times over the course of a week before I notice it.
My son came over last week and wanted to replace the fuel pump on his 1986 Brat. I made him do it outside after he started pulling stuff apart and leaking gasoline on the shop floor. Gasoline on the ground outside is much less likely to be ignited and then the initial flare up will be smaller and the chances of being trapped by flames is tremendously reduced. Yeah, my 06 is outside right now. I rode her today, but she's outside and will remain out there. You tell me to get real, but just look at how many gasoline fires take out garages, homes, and shops everyday. THe news is full of them. Firefighters say the reason they are so devastating is because folks don't think it'll light as easily as it will or flare as explosively as it will.
When the McComas fire happened we were in his garage working on our cars. I didn't have heat in my shop at the time so he invited me to come use his shop to assemble a big block I was putting together. He was swapping out the fuel from his AMX making a switch from gasoline to methanol and wound up with a gasoline spill of a little less than a gallon. He was out from under the car looking for a fire extinguisher (because I was telling him about how strong the fumes were) when the fire went off. Three other people were in the single car garage and pushed their way past Mike and out the door while he was spinning on fire.
I tried to get him down, but the little sucker(probably only about 5' 5") was supercharged, adrenaline strong and I couldn't get him off his feet. So I just stuffed him in the corner against the door and covered him up with my body. and covered his head and face as best I could with my hands, arms, and face trying to shut off the oxygen. The smell of burning flesh and hair was putrid. When I thought he was out and stepped back, he immediately flashed back into flames as did the front of my shirt and one arm. I grabbed him again and this time got the fire out and got him outside without either of us re-igniting.
At that point there were shards of skin hanging off his ears and face maybe eight inches long. I had lost my beard and eyebrows, and had some blisters, but he was really burnt badly. I went back in and got the fire put out with several bags of floor dry and a lucky throw of it under the car. Most of the fuel on the concrete had already burned by that time and I was able to put out the objects (broom, cardboard boxes, wood and plastic shelves) in the room that were still burning or throw them outside in the snow. All of that took less than three minutes I suppose, but it seemed an eternity. Rodney, Billy, and the other guy (his name escapes me) once outside, realized we didn't come out and they tried to re-enter, but I had Mike against the door and they couldn't force their way back in because of it. Rodney took him to the hospital that was only a few blocks away. Mike's wife was in their kitchen cooking his lunch 20 feet away and never knew any of this was going on. Had no one been there with Mike there's no telling what would have happened. Most likely he would have perished and his house been lost over a little gasoline on the floor that he had said, "You don't really think that could light do you?" A few minutes later he was disfigured for life. Because we got the fire out and he received excellent medical treatment in minutes, his scars have largely faded from their earlier dark brown to an almost normal flesh tone color which makes it much less noticeable. But that took a dozen years or better.
Maybe because of that or because I've been in funny cars on fire or because my workplace burned to the ground once because of a fuel tank leak (I was not involved or even present when it started) or whatever, maybe because of my experience I am over-sensitive to the possibilities, but I do not think that I am being unreal at all. I've seen what's REAL when gasoline (or alky or nitro or paints or thinners) combust. I wouldn't intentionally put any vehicle in my shop or garage that I KNEW had a fuel leak. So if hydrolock is not a matter of IF but WHEN, why would I put one in there that used a fuel leak as a so called "safety" measure? That, to me, is what is unreal.
What worries me most about overflow tubes is that a bunch of guys up north have garages under their homes in their basements which is also where their coal or oil fired furnaces are. That scares the bejeebers out of me and I'm thousands of miles away from that situation. I'll take a bent rod and a ruined engine to a fire any day. That's my opinion and obviously not shared by anyone else. That's fine. I really do try to bite my tongue and deal with that. But I don't think I'm being unreal.