Geoff 2
Well-Known Member
66 Sat,
Post #10. If your engine builder recommended 25/70 oil for a recond engine with factory clearances, then he is still a dope. For two reasons:
- the oil is too thick when you want oil to flow quickly to new parts
- break in oil has the correct additives in it for new parts to break in. If break in oil was not needed, why would they make it????
Penrite recommends 25/70 for worn engines with wide clearances, not newly rebuilt fresh engines.
The benefit of a 10/60 oil over a 20/60 oil is that the 10 oil will flow more quickly [ thinner ] @ 0*C than 20/60.
Zinc/Ph amounts vary between companies as there does not seem to any std. 800-100 ppm or more is good.
Non-friction modified. Thank the US EPA for that! Myself & friends racing in the 70s used to use BP Corse +. It was considered one of the best at the time. Over a period of a few months, we noticed our idle oil pressure had dropped. All our engines were suddenly not faulty! I rang BP & was told the oil was NOW friction modified. The oil was made thinner to pass EPA mileage tests in the US. Penrite performance oils are proudly non-FM & do not thin out as much when they get hot.
In the general engine section of Speedtalk.com, there is currently a thread on oils with an expert commenting. He would NOT be happy to hearing about 25/70 oil.....
Post #10. If your engine builder recommended 25/70 oil for a recond engine with factory clearances, then he is still a dope. For two reasons:
- the oil is too thick when you want oil to flow quickly to new parts
- break in oil has the correct additives in it for new parts to break in. If break in oil was not needed, why would they make it????
Penrite recommends 25/70 for worn engines with wide clearances, not newly rebuilt fresh engines.
The benefit of a 10/60 oil over a 20/60 oil is that the 10 oil will flow more quickly [ thinner ] @ 0*C than 20/60.
Zinc/Ph amounts vary between companies as there does not seem to any std. 800-100 ppm or more is good.
Non-friction modified. Thank the US EPA for that! Myself & friends racing in the 70s used to use BP Corse +. It was considered one of the best at the time. Over a period of a few months, we noticed our idle oil pressure had dropped. All our engines were suddenly not faulty! I rang BP & was told the oil was NOW friction modified. The oil was made thinner to pass EPA mileage tests in the US. Penrite performance oils are proudly non-FM & do not thin out as much when they get hot.
In the general engine section of Speedtalk.com, there is currently a thread on oils with an expert commenting. He would NOT be happy to hearing about 25/70 oil.....