I have a 61 Biscayne with a 235 ci 6 and for some reason, the old oil is half full in the canister. I am perplexed since gravity should drain it into the pan. I checked to see if there was sludge and there was none. Does anyone know why? I am a newbie to a straight six!
Not that I really know but I'll take a guess. I'd say that the flow direction is from the pressure side of the system into the bottom of the canister and the second line goes to the "low" side of the system. The pressurized oil would flow up through the filter element's center then out to the outer part of the canister. That would require the drainback (or inlet at the bottom) to pass through the pump and any bypass it may contain.
235 six should have a canister filter with an O-ring seal that uses a disposable inner filter. I assume you have converted over to a spin on filter?
If so there should be an antidrain back valve that prevents any oil from being sucked out due to siphoning from the motor's oil system bleeding down. This is to keep the filter full of oil at all times for start-up.
There are known issues with this valve with a certain orange filter that is heavily advertised as being the greatest oil filter since the invention of paper. Most racers prefer Wix filters which put their money into quality control and producing a better product.
Thanks Ya'll. I figured this out as Dave Bradley said. I used a turkey baster to remove the old oil and wiped clean. Big Dave...I thought about a spin-on conversion, but I want to keep the car all original. Thanks again for your help! Kyle