Gas Smell in Oil

I noticed that when I checked my oil level in my 440/496-6 bbl today it smelled like gas. The engine was completely rebuilt and driven until mid December and has only 1100 miles. I replaced the oil with Shell Rotella 10W40 and Lucas break-in treatment, and put about 100 miles on it before parking it in the garage for the winter.

I never ran the engine over the winter, but last week I wanted to go for a spin. I pumped the pedeal several times to get the car to start, which it did. However, while idling during warmup, I could smell gas at the exhaust pipes and figured it just needed to clear out. Drove the car for about 25 miles and parked it back in the garage.

Checked the oil today, and smelled gas--which I never noticed before.
The oil appears thick and does not flow on the dipstick. I have the stock '71 closed crankcase system (PCV valve/3-nipple breather cap with all hoses connected). Just wondering whether this is due to the trapped gas vapor in the closed crankcase system, or something worse...like a leaking fuel pump, etc.

Have you pulled any spark plugs to see if they are fuel fouled? Could have some crap holding a needle off the seat. Were the carbs adj & the jetting checked after the rebuild. May be running rich & washing the cylinders down with fuel. That's a good place to start.

You should be concerned, it is not a good sign. If the problem is an over rich carb, or dirt in the carb, the excess gas will wash the oil from the cylinder walls and the rings will burn up.

If you have a mechanical fuel pump, that can also be a sign that the pump diaphram has torn and gas is going directly into the crankcase that way.

Get busy. , good luck

x 2 .... rich mixture from your crab will mess-up your rings DIRECTLY ....

R U a Berri Bum ?

My 440 has similar symptons on occasion. I refer to it as "occasional use disease. When used regularly no problems. I keep Sta-Bil on hand and try to use the car often and always take to full warm up and beyond to boil out the contaminents.

I'd change the oil and drive it. AmsOil 10-40/Wix Filter.

You can have a sample of your oil tested. I did it once a few years back. I sent mine to Pennzoil (sp?) and they tested it for free. The results were very detailed with percentages of everything contained in the oil, and if any problems were noted. I got a phone number off the back of a quart of Pennzoil.

Yep, that's a classic sign of fuel dilution in your motor oil. Either your carb(s) are running a bit rich or short distance stop-and-go driving; not letting the oil get up to temp. My car does it too as shown by Used Oil Analysis (UOA).

I've heard you need to drive for at least 30-min each time you do a choke activated cold start. If that doesn't make since for you to do, then change the oil more often.

I get my oil tested by the private label program through Polaris Laboratories as provided by Oil Analyzers, Inc. - link

Thanks for all your feedback. To answer some of your comments, I'd like to add that the car was stored with a full tank, but I didn't add any Sta-bil. The carbs were installed right out of the box...no jet changes. In fact, last fall I thought the engine was running lean and I was going to wait until the Spring and have HPMike in Morristown, NJ set them up for me.

I will check the spark plugs for fouling and have the oil tested before driving it again. If anyone has some other thoughts, please let me know.