flat head Question

I am going to do an oil chang on my 1951 mercury with original flat head in it and wanted to know what you guys were using ?Im still new to working on flat head so any advice will be appreciated.I keep hearing to run valvalin 20w 50. Its an old motor but runs really strong.As far as i know its never been opend or gone throw but it does have some smoke coming from the breather is there some sort of additive i can put in it when i do the oil chang?How about lucus will it do more harm then good.school me ready to learn.

 

I use the Valvoline racing 20-50w. Has more zinc for the older engines. I started a thread not to long ago and that seemed to be general anger without ordering zpp or the brad penn stuff. Also you can get it at most local auto parts store pretty reasonable.

Also on the bottle I have been seeing a yellow sticker even advertising the extra zinc.

 

make sure the valvoline says "off road use" on the bottle so its not subjected to the normal standards for road use

NAPA has it, i know

 

thanks guys

 

how about the lucus

 

FYI, any 15W40 meant for diesels is the oil you want. It has the right amount of zinc. Use the Lucas if you want, but it wont take away the blow by. Modern engines us a PCV so you dont see the blow by. Some blow by will not hurt anything, and is expected in an older engine.

 

I'm not sure that's a requirement any longer...Valvoline VR1 all seems to claim they have the increased zinc now...at least on their MSDS

 

Not quite true. Diesel oils are having their ZDDP levels reduced too.

 

True, the CJ oils do have reduced zinc, but they are reduced to levels comparable to the SL & previous auto oils...1000-1200ppm