So I have a '74 chevy 350 engine with about 30k on it. The other day I was cranking the car over and it wouldn't fire (the butterfly on the carb got stuck shut) not realizing this I continued to try and start it. So a new battery and butterfly adjustment later the car fires up bit will not idle and the car has started bubbling oil out of the dipstick, valve covers etc I'm curious to if the engine flooding has caused this insane crank case pressure and I'm curious on how to fix this? Sent from my SM-G920W8 using The H.A.M.B. mobile app
Also the car ran perfect last time it ran (two weeks ago) Sent from my SM-G920W8 using The H.A.M.B. mobile app
Don't run the engine any more till you get things sorted out! To get the oil to start "bubbling out" of the valve covers and dipstick the crankcase would have to be seriously overfilled and/or the oil drain back ports in the heads are completely plugged. The stuck choke and possibly a bad needle and seat could be allowing excess fuel to leak past the rings into the crankcase and diluting the oil. A failed mechanical fuel pump diaphragm will also allow fuel to enter the crankcase. Get a big drain pan under it and drain the oil before you do much of anything else. If the oil seems thin and smells of gas then you're on the right track to figuring out the problem. Also, this should have been posted in the main forums. One of the mods will probably move it there for you. Hopefully an oil change and a fuel pump and/or a carb rebuild will put you back on the road.
Thank you, also I'm sure stuffing the foot to the floor flooding the engine was the main component to the problem Sent from my SM-G920W8 using The H.A.M.B. mobile app
Under normal operating conditions, holding the accelerator to the floor should engage the choke unloader on the carb. This should at least partially hold the choke air valve open even when it wants to be closed to help alleviate a flooding condition. Pumping the accelerator won't open the choke valve and will pump additional fuel into the engine making a flooded condition worse. But if you drain much more than 5 quarts of oil and gas out of the crankcase you've probably got other issues working against you. Some crud stuck in the needle and seat, a sunk float, excessive fuel pressure, a ruptured mechanical fuel pump diaphragm, or something like that. Are you running an electric fuel pump? If so, how is it plumbed and how is it wired up. What kind of carb do you have and do you know your current fuel pressure?
I don't know the current fuel pressure, I am currently running the holley 600cfm carb with an electric choke. And the fuel pump is mechanical Sent from my SM-G920W8 using The H.A.M.B. mobile app
smell gas on oil dip stick? if so, drain pan immediately - gas/oil mix will damage internals - be very careful when draining because it will be a thinner mix that will come out very quickly - do not have a drop light or anything that has heat around it while doing this - flammable
Floats got stuck resulting in the electric choke leaving it closed. Drained the oil, runs perfect now thanks guys. The insane crank case pressure came from the gas in the oil from the flooding Sent from my SM-G920W8 using The H.A.M.B. mobile app
I like to be in control of the choke, so on my older cars I remove them and install a manual choke. That way I always know the position of the butterfly.
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