Zinc Rich Oil for Flat Tappet Cams
@71DodgeDemon340 If you can find the 10-40 vs 30 chart that's missing, the text would be easier to understand.
If not, here's a similar pair of charts snipped from Widman's Oil for Corvairs.
I've added some notes to show why multi-weights are better for starting and warm up in cold and moderate temperatures.
Once an engine is warmed up, we have to zoom in to see the differences.
In terms of viscosity at operating temperatures, a straight SAE 30 and a multi-weight 10W-30 will be almost the same.
The graph is just representative. For any 30, 10W-30, or even 0W-30, the viscosity at 212 F can be 9.3 to 12.5 cSt. If you want to know exactly, then you need to get the spec sheet or have the oil tested.
Note: I've taken the liberty to extend Widman's 'Zone of Protection' from 12.5 cSt. to 15 cSt to represent the wider range Chrysler seemed to have allowed for its water cooled engines versus the air cooled Corvair engines.
@71DodgeDemon340 If you can find the 10-40 vs 30 chart that's missing, the text would be easier to understand.
If not, here's a similar pair of charts snipped from Widman's Oil for Corvairs.
I've added some notes to show why multi-weights are better for starting and warm up in cold and moderate temperatures.
Once an engine is warmed up, we have to zoom in to see the differences.
In terms of viscosity at operating temperatures, a straight SAE 30 and a multi-weight 10W-30 will be almost the same.
The graph is just representative. For any 30, 10W-30, or even 0W-30, the viscosity at 212 F can be 9.3 to 12.5 cSt. If you want to know exactly, then you need to get the spec sheet or have the oil tested.
Note: I've taken the liberty to extend Widman's 'Zone of Protection' from 12.5 cSt. to 15 cSt to represent the wider range Chrysler seemed to have allowed for its water cooled engines versus the air cooled Corvair engines.