NA big block chevy 572's w/14 qt oil pan barely broken in (12 hrs & 6 hrs) was run in gulf waters now resides south Jersey.
When in Fl. was run on 40w oil.............considering that it's still breaking in and lives now in the cooler NE ...What should
the choice of oil be?............and would synthetic oil be a no no before full break in?...................Thanks, Scippy

Straight 30 weight. I use Rotella. If you want to get fancy you can run straight 40 in the summer and 30 in the spring/fall but straight 30 year round will be fine for Jersey. Unless you're boating below 40 degrees or so you don't need a multi weight.

No need for synthetic and I've heard a conventional is actually better. Don't know the technical details but most synthetics contain stuff that breaks down easier from fuel and water dilution.

A synthetic will give better protection on cold starts. They also won't break down at 6500+ RPM but we don't run that high.

It's 43*F where I live right now as I type this. Meaning, I'm a good amt further north than you. We typically boat till mid October. Granted, when temps are say *65 or higher. Add the Windchill factor and it's not too comfortable under that.

Many of us here use 20W-50.

My personal favorite is Valvoline VR1 racing.

https://amzn.com/B00DJ4FIPQ

Sometimes can be found locally for a little cheaper. Especially when being on sale, Oreilly's, Napa sometimes, etc.

Borgie? Where are you?????????

I'm a Brad Penn guy. 20-50 or 10-40, sometimes a mix of those two if I'm feeling frisky.

"Most of us use 20W-50.
My personal favorite is Valvoline VR1 racing."

This is what I use also. I live in the north so the multi-viscosity gives some start-up protection. It gets changed twice a season so no need for synthetic.

Break-in only takes about 15 minutes not hours. I re-built one of my motors end of July. Ran 10w40 conventional pennzoil first time out. Changed oil immediately. First oil changed will have a lot of fine metal in the filter if honed properly. Replaced with 15w40 Amsoil Diesel and Marine full synthetic. Motor has closed cooling 180* water temp oil temp after the cooler is 150* if I beat on it for miles and miles. .0035 clearance on mains and rods 60lbs oil pressure 50 lbs hot idle. I've put 60 hours on this motor since July oil still looks brand new. Im not going to change the oil before the season is out. I will have a uoa done and post results after winterization...

x3 on the VR1 .

I was told. Joe Gibbs mr 50 is awesome oil. Then I talked to Gordy at pfaff said synthetics oils are too thin. Run a good conventional oil. I was confussed. But that easy to do

If a synthetic oil is SAE rated as a 20w50 and a petroleum oil is SAE rated as a 20w50.

They both are the same viscosity or "thickness".

One is not thinner than the other because of it's base stock.



I am a Semi-synthetic 20w50 user.

Ken

Kind of.