The silvertop shares the same 48mm diameter thermostat as the 16V models while the Blacktop uses a significantly larger 56mm. - Blade / butterfly diameters: While both engines have round throttle blades, however the Blacktop throttle blades are larger at 45mm compared to the 43mm of the Silvertop. Blacktop 20v also had upgraded lighter flywheel, gears and other internals leading to rev quicker.
All South African Rsis and RXis only came with blacktops Any car with a silvertop has had the motor replaced because the silvertop is cheaper from importers.
Blacktop vs silvertop Blacktop Larger ITBs 45mm Larger degree cams Different shaped intake ports on head Difference in combustion chambers Lighter rods with oil relief Hydraulic cam tensioner Higher compression 11:1 / Silvertop is 10.5:1 Different valve pockets/dome on pistons Lighter flywheel Better Branch manifold
The throttle sizes black is 45mm silver is 43mm their oil pumps are different aswell - I know the Hydraulic tentioners are different and the codes aswell , the Black top has a much mkre airflow therefore stands out more .
Thanks. I bought an f30 last year and was just curious as I’m impressed with its power. Keep up the great content, I’m watching from Perth, Western Australia.
