Gas in crankcase?!

So I installed a new fuel pump (electric) hooked up to a boat tank, pushing between 5 and 9 psi. Ran for a bit, then stalled out. Couldn't figure out what the problem was, so I figured this was a good time to change the oil anyhow. Much to my surprise, after pulling the filter, it reeked of gas. Pulled the drain plug, and out come a mixture of gas and oil! Can't seem to figure out why all that gas ended up in my oil. Maybe too much fuel pressure forced past the float and ran down the intake into the engine? I don't think I hurt the engine too bad, it only ran for a short period before it stalled out. I'm getting a couple oil filters tomorrow and am gonna fill it back up with some non-detergent 30 wt and see what happens. Figure I'll let it run, then shut it down and pull the dipstick and see what it smells like. Anyone have any suggestions (fuel pressure regulator?), let them spring forth.

9 psi of pressure is WAY TOO MUCH and will push right past the float seats, and when it's pumping before it's running, it's flowing down the intake, into the cylinders, right into the crankcase. You wouldn't have hurt the engine internally (normally), but you might need to check your float valve, seals etc. now that pressure has been run through them. A street carb motor rarely needs over 5 psi, and anything past that normally means trouble, unless your starving the motor, but in this case, it's a case of drowning!!

Just what type of vehicle is this? If its a old dodge gas engine . If you didi not remove the old fuel pump it could have been putting gas in the crankcase that way? Diaphram goes bad and dumps it in the engine.
You said "filters" like its a diesel? So it would be "fuel"in the crankcase not "gas"
What engine you talking about?

My bad. I still have to fill out my signature. It's a 52 GMC deuce and a half. I figured that it may have gotten too much pressure and did just that.

As I recall, the max input fuel pressure on the Holley on the GMC is about 2-3 pounds - you'll need a pressure regulator.

HTH,
David Doyle

Is the mechanical fuel pump still in the line? Is it unhooked and plated over? You are probably right about to much pressure but it could have been dumping gas into the crankcase before this happened to. Did the original fuel pump quit? I know lots of questions but I just picked up one of these old gassers and am curiouse how you make out and what is happening. Mine runs but the fuel pump looks kinda rough electric sounds like the way to go.. Where did you get the pump? 24 volt?

Towman is exactly right. Try about 3 psi with a bypass regulator and you should be fine. Be careful when you restart the truck, you may want to pull the plugs just to make sure you do not "hydraulic" the enginge. Just crank it over with the plugs out to make sure that there is no gas in the cylinders. Your connecting rods will thank you!

Also, make sure that the new pump did not push any debris into the inlet needle in the carb and that the floats still float!

The old 302 jimmy's are fed by either an electric fuel pump, or are pressure fed via air. There is no mechanical fuel pump. I'll be sure to put a regulator on it tonight. On mine, one of the PO's converted it to 12 volt already (I think), so all I had to do was run a wire from the battery to a fuse block, then on to the pump from there. The pump is an Autozone universal. They actually have fuel pumps that pump with less pressure, so I may go and get one of those, and just keep the other one for my mud truck.

Engine should be nice and clean on the inside now. Might want to change the oil a couple of times to make sure you remove any sludge that has broken loose.

That's kinda what I was thinkin. While I have your attention, what's the capacity of the engine for oil, and also the tranny for oil?

Don't have the capacities in front of me. I'm sure a 211 owner will chime in. Here's a site with a 24v external pump conversion kit if you decide to go back to 24v. Lots of other parts too. http://www.alfaheaven.com/Military Section/M135Mech.html

if i remember I think it hols 12 quarts. I believe i remember putting in 3 gallons when I changed the oil in mine.

I also bought the oil filter at napa.

There`s NOS fule pumps on Ebay all the time too...I got one last year.

Just checked the manual and it says 11 qts. for the crankcase,(coulda swore Dave was right with 12) and approx. 16 qts for the trans BUT to go by the markings on the stick and don't overfill as it can cause erratic shifting and oil leakage. There's a detailed description of draining and refilling the trans in TM 9-8024

Engine oil

A word to the wise. I once put non-detergent oil in a car that had detergent oil in it before. After I did that it smoked like freight train on a 4 percent grade. I don't know why, being young and foolish I just got rid of the car.

RE: Engine oil

Make sure you run the fuel pump through the ignition switch. Direct to the battery is another good way to fill up the engine with gas.

RE: Engine oil

Well, got it all figured out. First, measured the psi of my pump; it ran 5 psi, so I first tuned it down to 3, but I guess that wasn't enough to keep the bowl full, so I set it at 4 and that seemed to work just fine. Ran it thru a switch off the battery, so now, I've got an ignition switch and a pump switch. I put in 11 qts of 30 wt non-detergent Valvoline, and it smokes just a tad until warm-up, then nothing at all. Sits there an idles like a kitten with a VERY loud purr, but that's because the organic doughnut between the exhaust manifold and the tailpipe is shot. I'm thinkin I might trash the exhaust pipe, and run new stuff thru a tubular-type muffler (like a purple horny or a cherry bomb) and put a new chrome shield around the stack. Since it was converted to 12 volt, none of my electric-driven gauges (temp, air pressure, battery) worked, so I installed a 12-volt volt meter and a mechanical water temperature gauge, so now I'm getting somewhere. The oil pressure gauge was already mechanical, so that was cool. Heck, has between 30 and 40 psi of oil pressure at idle! Anyone have a clue as to where I can locate a direct, or 12-volt, air pressure gauge? That's definitely next on my list. I'm thinkin I might check out the local truck stops or the KW dealer to see what they have. Another question; while the engine is running, I'm getting a noise under the dash, sometimes hissing, sometimes an annoying dying-cow sound. I assume that this is the low-air pressure warning, but even after idling for 5-10 minutes, I would think that it would kick off. Does that just mean that I've got a massive air leak somewhere in the system? I'm gonna have my Vietnam-era Army mechanic give it a once-over tomorrow, but if any of you can shed some light on the subject, I'd be appreciative.

I know that this topic has been beaten like a dead horse over and over, but what should I put in the tranny? It's still got motor oil in there; I can tell that from the dipstick. Should I leave well-enough alone, and just drain it and put in more 30 wt, or switch to ATF? I forget what kind, so lemme know, in case I do decide to switch to ATF. Is there a drain plug on the torque convertor?

RE: Engine oil

Current deuces use a mechanical air pressure gauge, should be perfect for your ride.

RE: Engine oil

My 211 had a mechanical air pressure guage in it already. Assume it came that way. But i dont knwo for sure. I would think that a mechanical oil presusre guage would work just fine for the air pressure guage, its still measuring pressure. I had the original electrical oil pressure guage in mine and converted it to mechanical gauge actually. Mine also had a mechaical water temp guage in it, obviously an add on from a previaous owner.