1977 OMC 190 Ford 302 mystery oil consumption

[Crappie killer]

First off, I'm a mechanic by trade, but I'm new to marine engines. I bought (stole, actually) a 20' Formula with a 1977 OMC 190 outdrive. I tuned it, it runs great. However, it is using engine oil...like to the tune of a quart an hour. Here's the kicker...it's not burning it (all plugs clean as a whistle), it's not leaking it anywhere that I can see, and the oil is staying very clean, no traces of contamination. No smoking. No rainbow in the wake. The intermediate housing oil level remains constant. I have 2 theories at this point:

1. The Saudi army is coming at night and stealing my oil
2. Rear main seal is leaking oil into the "adapter housing" between the crankcase and the intermediate housing.

Anyone ever experienced anything like this? So far I've poured 2 1/2 quarts of oil in after 2 runs. You would think that amount of oil would show up somewhere pretty quick. If this keeps up I'll never have to change my oil!

 

[a70eliminator]

Re: 1977 OMC 190 Ford 302 mystery oil consumption

I don't know man, I guess it could be collecting in your engine adapter but after two quarts it's got to be close to the starter, My 351 has a similar pan I'll tell you it's very sensitive to being off level, I mean the difference in checking the dipstick with the boat floating idle as compared to sitting on the trailer makes a huge difference with my set up, just something to think about.
Also if your oil returns in the head are gunked up the oil could be hanging up topside but would eventually drain down and show your overfilled now.

 

[thumpar]

Re: 1977 OMC 190 Ford 302 mystery oil consumption

Only 2 ways out. Burn it or leak it. If you truely don't think it is burning you need to look hard to find out where it is going.

 

[chiefalen]

Re: 1977 OMC 190 Ford 302 mystery oil consumption

You do a compression test? Or a vacuum test?