I know this as been a subject beatin to death but I did do a search and most of the subject matter was for stock motors. So my question is what wieght oil should I be running in my 454 MAG w/whipple? Plan on sticking with Mobil 1 but want to know what wieght would be the best, air temp ranges from 60-90 with a 75-80 average typical Wiscosin weather.

Thanks
Kyle

FWIW The previous owner ran Mobil 1 (not sure on the wieght) and motor has around 65 hrs.

15W50 or V-Twin 20W50

15w-50.

The V Twin is about twice the cost of regualr Mobil 1 and not as readily available in large quantities.

can't even find the 15w 50 around me.....

Choose an oil with lots of heavy metal eg. zinc it acts as a anti wear agent on internals. EPA limited the amount to be used in conventional oils. Racing oils will have more.

We run Valvoline VR1 20/50 in everything

Thanks guys, ended up going with Mobile 1 15W50 and made a spacer for my filter mount allowing me to run a bigger Mobile 1 filter 1qt I believe.

Mobil 1 is excellent oil. Use it all the time in my cars. However, I have a slightly different approach when it comes to boats. My theory is to use cheaper heavy weight mineral oil and change it often. Reason for this, BBC engines are known for fuel dilution into the oil which reduce viscosity whether it is synthetic or mineral. Second reason and my main reason, you have a better chance at catching a failure until it turns into a big catastophic failure. The oil is the blood of your motor, think of it as routine blood tests. The bigger oil filter is a good idea too.

Forgot to mention, I use castrol 20-50w.

I will be changing oil every 20hrs, I know what your saying about fuel in the oil, my setup is too rich and needs a better tune, I can smell the fuel in the old oil!