Engine guru's...
I have a 72 cutlass with a 350 rocket, and am having a hard time solving the problem of gasoline in my oil.
Here's what I've done so far, in order I completed.
1. New Carter mechanical fuel pump, didnt fix
2. New AC Delco mechanical fuel pump, didnt fix
3. New Holley 750 double pumper(thought K plugs were bad in quadrajet) didnt fix

Car runs great, but still gaining an inch on my dipstick every 10 miles.

Another fuel pump? Im nearly ready to put a 455 in the car.

 

You've got an inch of gas in your oil and you're driving 10 miles?

 

Professur,
I have made an 8-10 mile round trip after changing a part I was hoping the culprit of the issue. I have changed the oil each time I have changed a part (2 fuel pumps, 1 carb.)
The car has gained an inch up the dipstick with a new Holley carb, and new AC delco fuel pump.. I test drove, still gas getting in oil. Hence why I am baffled.
I had a mechanic friend ask me if its possible I may have bought a fuel pump that could have been on the shelf for a long time. Only 2 places to enter the crank case that I know of..

 

Hows your engine vacuum?

 

Could you elaborate a bit.. Most of the vacuum lines have been removed. Is there something fundamental I'm missing that could cause this?

 

Since you already changed your fuel pump twice I'm going to eliminate it and move on to a possible intake leak? A long shot. Other things are too much fuel pressure flooding the carb, bad rings, stuck float, or float set too high...

 

I figured it would run poorly if it was sucking air through the intake. Car starts right up, runs great, but as I drive it I loose oil pressure as the oil thins out with the added gas. I have stayed close to home, as I feel like Im gonna trash the motor if I dont resolve this soon. I took it to a local mechanic (idiot, but has a shop) he couldnt figure it out. I thought Id try here before leaving it with someone else.

 

Are you positive it's not coolant? Have you checked your coolant level?

 

Can you smell fuel in the oil? Is the car an automatic? Does it smoke at all? Longshot, but easy check, look at the modulator valve on the trans.

 

Im sure its not coolant, smells like gas. Looks like super thin oil.. gas/oil mixing

 

What if you were to rig an electric fuel pump and take the lines right off the mechanincal pump and see what happens

I would be looking closely at the FP as that is the main place where engine oil and fuel meet in any sort of quantity.

Did you run the FP outlet line directly to the PCV vacuum nipple? :-)

 

I had this problem once with a brand new Autobone unit. Seems the diaphragm was bad.
Probably from sitting on the shelf for to long. Are you sure it isn't trans fluid? If the modulator goes bad the engine can suck fluid up through the steel line on the intake. But that would more than likely just make it smoke like hell, (burning the fluid.)

 

Hard to imagine he would have the exact same problem with 3 different pumps if it was coming in that way.

 

I'll go way out here on a limb. Give me some slack.

You don't have the pump installed upside down do you? The fittings should be on top. Not on the bottom like chevy.

Thats all I got. You guys pretty much covered it.

 

I found out my 350 was full of sludge, not sure how it explains my fuel in oil issue, but there is a major loss of oil circulation.

I have decided to pull it and put in a 1968 455 F block with C heads I am having rebuilt. I can't believe I found one, and complete one for $375 out of a small town in Northern Missouri.

Any tips/pointers on the rebuild?
I'm thinking pretty much keep the motor as factory as possible with a new Holley carb and HEI.