Oil Weight Recommendation

[Lindy]

Keith,

What oil weight do you prefer/recommend for your engines?

I am still breaking in the 331 that you built for us recently, and have been running 10-40 (non-synthetic) as recommended. I am planning on switching over to 20-50 synthetic at about 2,500 miles unless you would suggest otherwise.

Thank You!

[Bob In Ct]

Why so heavy?

Use the lightest oil you can that will give you the pressure you need. Don't sacrifice flow for pressure, you need both.

Bob

[michael cesario]

I suggest you check with your engine builder as to the appropriate oil to use in your area. Here in Reno, I found that 15/50 weight synthetic works good from a lubrication standpoint but that pressure suffers a bit. I use 5/30 in the cooler seasons and 15/50 Mobil 1 in the summer.

[Lindy]

I have always used 20-50 in my engines. I typically only drive these cars for a few months out of the year when it is relatively hot.

Hopefully Keith Craft will have a chance to fire off a quick reply, as he built this engine.

[CWizard]

Michael C. - You have a PM.

[Keithc8]

I recommend that the engines be run in on 10W40 oil. If you are in a hot climate or it is summer I do not see a problem with the 20W50 oil. Most people do not drive these cars when it is real cold out but if the temperature was at or below about 40 degrees much I would stay with the 10W40 during this time. The only problem I have seen with the synthetics is that they seem to seep through some of the gaskets when regular oil will not. I feel that the 2500 miles should be enough break in time for the engine. Thanks and good luck, Keith Craft