I have an issue that I need help with and hope someone could help me with. I have a highly modded 302 that I put in my 54 f100. The motor runs just fine (still doing adjustments to carb). The problem is I went out to start it up after reinstalling the stupid holley fuel pump that I have rebuilt several times now, and it shot flames out of the pcv hole on the valve cover. I also checked the oil and it had a fuel smell to it.My first thought is a head gasket gone bad but wanted to get any other thoughts before I do a teardown. Any help would be greatly appreciated.
Most unlikely a head gasket,to check do a compression test. Carb flooding ,fuel getting past the rings to the pan.
Its a Holley blue eletric fuel pump. I just adjusted the floats after installation. It is a holley 750 cfm and a Aeromotive fuel regulator set at 5 psi.
Don't run the engine until you change the oil and figure out why fuel is being dumped into the crankcase. As John said, could be too high of fuel pressure with no regulator, float level too high. Maybe the inlet valve isn't shutting off...could be a small piece of debris holding it open.
The carb is really clean. I bought it used at a swap, and the first thing I did was rebuild it. I did clean it in the parts washer before I put it back together.
You most likely have either a stuck needle and seat,float/floats set too high,or a blown power valve.Either way you are getting fuel leaking through the carb,find it before you ruin your engine,gas makes a terrible lubricator!!! ROY.
Thanks every body for the ideals on the cause to the problem. It gives me a few more things to look at. Like I said my first thought was head gasket. I did think of the rings because it is smoking through the pipes BAD.
It smokes because the cylinder walls are totally washed down, they have little to no oil on them. And your oil is diluted. Don't run it until you get the carb sorted out. Bob
New oil,I would use 3psi not 5,and with a 12volt pump you can check with out motor running by looking down carb if its drippeling gas
Before you restart it pull the plugs and squirt some oil in the cylinders and turn the motor over to get the cyl walls oiled again.
I had a fuel pump go bad many years ago it filled the oil pan with fuel....I caught it in time. Drain the pan put in new oil & filter. I have been using Carter electric pumps now for 30 yrs plus, they work great. JMO Jim
Thanks again. I think I will just bench the 750 and get a 600/650 to run. I will figure out the 750 and use it on my stroker motor for my 27 t coupe. Hopefuly with a new carb and new fuel pump things will be good. Guess its bsck to suspension for now.
A buddy of mine was trying to start a fresh rebuilt motor once. It was hard starting and he pumped the pedal over and over, flooding the motor. It forced gas passed the rings and into the oil. It ignited the gas in the oil and actually blew off the finned aluminum valve cover which hit him in the face. It cut lines in his face and broke his nose. Drain your oil and replace it with new before you go any further.
Check the power valve gasket. I got the gasket gimped up when I rebuilt a Holley once and had a similar result as yours.
Oh I've been there I was 18 and put a Vertex in my 337 roller motor, didn't know it had a locked advance,kept turning the distributor and cranking while pumping the gas it had a Scorpion intake with the oil fill tube behind the carb. I happen to look down and see the eternal flame coming out of the hole so being a long haired 18 yr old rocket scientist I jump up on the fender and blow down the hole to blow it out.Nothing like the smell of hair burning and scorched skin.
I knew that a 750 was to big, it was the only one I had not in use so I stuck it on. When I bought it, the guy unbolted it from the top of his chevy 350. It came with a Percy's adjust-a-jet metering block. I bought the whole thing for $75.00. I couldn't pass it up.
The problem is not that the 750 is to big, (although you don't need it that big) gas is leaking into the manifold either bypassing the needle and seat or a gasket problem, but just putting a 750 on a 302 is not going to cause this.
Well I got the oil changed today. There was about 3 gal. of oil/ gas mic in the pan. Shot some oil in each cylinder disconnected coil and fuel pump and turned it over. Took off the carb and fuel pump to get ready for new ones so when they get here I can bolt them on. Hopefuly it solves the problem. I will bench test the old parts tomorrow to see what the problem is. Thanks for all the help.
Three Gallons don't leak down the carb. Is there a mechanical pump on the car too? I had a bad diaphragm on a mechanical pump fill my pan once.
I use 2stroke oil for this type of thing (also wet compression tests). It lubricates but also has a lower flash point so the engine will start easier and won't smoke as long or bad.