CamPro 1.6L (S4PH)

The S4PH is the original CamPro. Proton built it with Lotus Engineering and put it in the Gen-2 first, which makes this the engine that started the national maker’s in-house engine line. It is a 1,597 cc four cylinder with a cast iron block, an alloy head and 16 valves, and it revs cleanly to its 6,000 rpm power peak.

The number that matters to an owner is not the peak, it is the hole below 3,000 rpm. The fixed-cam S4PH is soft there, so a manual Gen-2 asks for a downshift on a hill or when joining a main road. The 2008 facelift replaced this engine with the IAFM and CPS versions, which is where the later cars’ extra pull comes from. Those cars are outside this page.

Oil capacity is listed as 3.75 litres as a service fill. That figure comes from a third-party capacity database, not a Proton owner’s manual, so treat it as a guide and check the dipstick rather than pouring a whole container in. The oil grade, coolant capacity, spark plug gap and firing order printed in the 2004 owner’s manual are not verified here, so they are left out instead of estimated.

Spark plug: Proton lists PW811750, an NGK BPR6EF-11. The “-11” in the NGK code is the 1.1 mm gap, but the gap figure is not separately confirmed against a Proton document, so it is not stated as a specification above.

Verified against the Proton Gen-2 manufacturer specification table (110 hp at 6,000 rpm, 148 Nm at 4,000 rpm), reproduced in the Wikipedia Proton Gen 2 article, and the paultan.org 3 August 2005 CamPro report, which gives the same 110 hp and 148 Nm, checked 2026-10-26.