I have a Systems 1 filter which has the stainless steel screen 45microns screen, and the ball bearing relief in the base, used it recently while dynoing the engine, has a small pressure loss, as we measure pressure pre filter and engine block. All engines make metal to varying degrees especially race engines, and I was really surprised at the small amount of metal and a wee bit of lint, probably from me as I took the alloy pan off to modify!
I thought the 30 micron would be better but I am told by people who have what I consider far more experience than I the 45 screen does a great job, when I see a lineup of Formula 5000, and other engines most with System 1, the balance is to have flow and remove the harmful contaminants.
With cold start up we are going to heat the
oil tank and use a water (thermosyphon heater in the water system) so I cant emagine the engine running on bypass for any amount of time, and
oil pressure equalises and it will have pressure on the back side of the relief valve (ball bearing/seat) for cold
oil start after the initial cold burst of oil and the system stabilizes I cant see a problem there.
This is a bit like the BS oil tests done with friction and loading bearing surfaces, some are better than others, and people saying their oil or filter choice is better, most dont know I deal with the most successful race service provider here in NZ, and have access now to their facilities and they only advocate what has worked for them, and if that is less tear downs, winning the championship last year. They seem to buy parts and oil that are designed for high performance and racing eg buy a diagnostic screen filter that has more flow than an over the counter paper filter, because its more important to have flow than maximum filtering, the same for oil they use mineral 20-50 in the GM Formula 5000 engines and Race
synthetic in most other smaller etc engines, what that tells me is most products will work well!
We used Chevron Delo 400 on the dyno and reading all the oil bible and others opinions, this oil is designed to run in petrol as well, so I will take with a grain of salt that it is no good in petrol as some say. I will use this for about 2000miles and then go onto either Scheaffer semi-
synthetic or Castrol mineral oil, maybe after 4000miles I could use Motul but I think with our type of V8 engine technology a mineral or semi-
synthetic, and one the manufactures states has taken into account flat tappet camshafts. Also I have used the Oberg screen type filters, which appear to be good, but I think System 1 is a good product for my application. High mileage road cars are different but I reckon System 1 would do a good job there as well, just go down to the finer filter element.