Thread: Big Block Oil

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I am wondering what type of oil to use in my 72 454 . The car is never driven in the cold weather . I like the synthetic oil's but they are expensive . I used to run Castrol Syntec 10w-40 in my jet boat . Is synthetic oil suggested for older engines the motor put's out around 450 H.P. what is best 5w-30, 10w30, 10w40 or 20w50 , it rarely see's really hot weather either.I live in the Northeast.

aren't all car engines designed for something around 10w-30?
Here's a little interesting info. on oil. In the past oils only had one viscosity number, and once the oil heated up it got thinner proportionally. With today's technology they can produce blends that theoretically have two different viscosities, hence the 2 numbers.
Lets take 5w-30 for example.
The first number means that when the oil is cold it will flow as well as 5 weight oil. When the oil heats up however, it will only thin out to the point that 30 weight oil would. So basically you get the best of both worlds because if you only had 5 weight it would flow nice when cold, but would turn into water when hot. If you only had 30 weight it would be tar when cold, and work well when hot.
This is all thanks to chemical engineering, they form some kinds of long hydrocarbon strands that stretch out when heated, but hold together.
Your engine was probably designed for 30 weight when hot, so 5 or 10w-30 is probably best.

I am a firm believer in synthetic oils. Synthetic oils don't burn and form carbon deposits and other gunk in the engine like other oils do. I have a 93 Vette with 118k miles on it. If you take off a valve cover, the oil gallery in the head looks brand new. The pushrods, springs and lifters are all bright and shiny.

10W-30 or 10W-40 would work just fine in your climate.

$100 for oil per year compared to $30 or $40 doesn't bother me a bit.

Ditto on the synthetic oil. I've used Mobil 1 in my 2001 Ranger since the first oil change and have 114K on it. The used oil when changed looks better than new Dino oil. I have no leaks, on a good day get 24 MPG, and change the oil every 5000 miles. The stuff works. I use 5W-30.

The only word of caution that I've heard is to let the engine break in with Dino oil to seat the rings before switching to synthetic. I've heard of ring sealing issues when starting out with synthetic (it can work too well).

I use 20-50. I have tried the others mentioned but I have the least oil consumption with the 20-50. My motor is 10.7:1 compression and it in a streetrod. It runs alittle hot at times so I like the protection of the fifty weight.