(but still 2-valve) 8R-G, produced from 1969 through 1972. From 1969 to Feb 1971 it was known as the 10R, but along with a removal of the tensioner gear in the interest of quieter operation, it was renamed the 8R-G to reflect the decision that twin-cam engines were henceforth to be identified by a "-G" suffix. 4,931 twin cam engines were built, all installed in the Toyota Corona Mark II (RT72) 1900 GSS. The 10R/8R-G weighed in at and as such was both lighter and more compact than its less powerful predecessor the 9R Applications: 1970–1971 Toyota Hilux, 1971–1973 Toyota Corona 1900 hardtop Toyota Corona Mark II RT72 Corona Mark II 1900 hardtop Toyota Corona Mark II RT72 Corona Mark II 1900 hardtop GSS (8R-G) 9R The 9R was produced from 1967 through 1968. Bore and stroke . It was essentially a 4R with a DOHC head designed by Yamaha. The cam lobes activated the valves directly via a bucket over shim arrangement. This same arrangement was used on the 2M, 8R-G, 10R, 18R-G, 2T-G, 4A-GE and 3T-GTE engines (all designed by Yamaha). Output was at 6,200 rpm and at 5,000 rpm. It was a 2-valve DOHC design with two Solex carburettors and weighed . A total of 2,229 9R engines were built. Applications: Toyota Corona RT55 Corona 1600 GT hardtop 10R The twin cam 10R was produced from 1967 through Feb 1971, when it was renamed the 8R-G. The later 8R-G version did not receive a timing chain tensioner in an effort to make it more silent. Output was at 6,400 rpm and at 5,200 rpm. Applications: Toyota Corona Mark II RT75 Corona Mark II GSS 12R The 12R was produced from 1969 through 1988. It was also built in the Philippines as the 12R-M, by Toyota's local affiliate Delta Motors Corporation. Technical Specs (Finnish Owner's Manual from 1973 Corona Mark 1) – Four cylinder, 4-stroke, OHV – Bore × stroke: – Compression ratio: 8.5:1 – Maximum power: at 5400 rpm SAE The 12R-LPG, was produced from 1969 through 1983. Technical Specs: 1975 redline 4,400 rpm Applications: 1971–1978 Toyota Corona 1971–1972 Toyota Hilux 1977 Toyota Hiace 1975 Toyota Hiace Commercial Camper 1976 Daihatsu Taft (F20) Delta Mini Cruiser/Explorer 16R The OHC 16R was produced from 1974 through 1980. Power output as mounted in a 1980 Mark II was at 5,600 rpm, while a twin carburetted version produced at 6,000