International Harvester R-Series

The International R series was a pickup truck manufactured by International Harvester. It replaced the L-Series in 1953. It was mostly a facelift of the light and medium models. The front style seen on the L series redesigned for the R line. A simple rectangular opening with a tapered bar running across the center replaced the ornate grill design of the L series, and the IH "man on a tractor" logo was placed in the center. The heavy duty models (R-185 and higher) were changed only slightly in appearance, in that four of the seven vertical bars in the upper grille were removed.

There were few mechanical changes in the R line, other than facelifts. There were twenty-nine engines available. Both Cummins and Buda Diesels were now offered in the RD-190 and RD-200 Series, whereas only Cummins had been available, and even then only in models larger than the 190/200 Series.

A new Black Diamond 282 engine became the standard powerplant for the R-180, RC-180 and RF-170 models, and was optional in the R-175 Roadliner tractor. The new engine had a shorter stroke, a chrome alloy cylinder block, and a higher lift camshaft. It also featured slow rotating Stellite-faced exhaust valves and chromed top piston rings. A new "visible flow" carburetor had a fast idle cam that speeded engine warm up.

The three sizes of Super Red Diamond engines (372, 406, and 450 cid) had improved combustion chambers, redesigned valve ports, rotating exhaust valves with more durable seats and improved rings. The Super Blue Diamond (269 cid) had a new cylinder head with improved valve ports and coolant passages, altered ignition timing for the new 6.5:1 compression ratio, aluminum-alloy pistons, and "visible flow" carburetor.

The little Silver Diamonds (220 and 240 cid) engines featured rotating valves and improved carburetor, plus a ceramic fuel filter and hotter spark plugs. LPG engines, which had previously been offered only in L-185 and larger models, were available in trucks as light as the R-150 in the new line.

There were also totally new trucks available at the IHC dealers in 1953. One was the Tilto Cab R-195 and R-205 with cab-over-engine design. However, only a few units were ever built by Hendrickson. The R-195 had a 24,000 lbs GVW, used a Red Diamond 406 engine, 14-inch clutch, overdrive or direct drive (in top gear) five-speed transmission, and Eaton single reduction rear axle. The R-205 was similar, but featured the Red Diamond 450 engine, heavier transmission and axles, and larger brakes. The standard tire size for both models was 10.00x20 14 ply.

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