No oil on start-up

I did a stroker about 4500 miles ago, and am running Rotella 15w40 oil. If its cold outside the engine makes a lot of noise like all the oil has seaped down. Once it runs for a few seconds the oil pressure comes up like normal and the sound goes away. It didnt have the problem at any period during break-in, or when I was running Brad Penn 10w30 racing oil. The old engine didnt do this either, any ideas? Does Rotella not stick?

Switch to 10W30 Rotella and you should be fine. If it is to cold out the 15-40 is to thick unless you have a block heater. In fact a lot of people run the 15-40 when they don't need to just because its thicker doesn't mean its better for your engine. I have a new motor also and run the 10-30 rotella no problem and my local napa stocks it now so it is no problem getting it.

oil pressure should be up in say, less than three seconds. If the delay is much longer and started last oil/filter change,then it sounds like a bad filter. Anti-drain back failed. Avoid Fram. Good Luck.

Yeah the oil pressure comes right up, its just once the engine has caught there is a moment of racket. I switched to a Wix filter from a mopar chasing a no oil pressure problem. The oil pressure was dropping at idle after highways speeds or just running it hard with Brad Penn racing 10w30 and the mopar filter. Ive noticed some other noises popping up here and there so I will probly be avoiding rotella thick stuff from now on.