I drive Ol' Roy in 90-100 weather in rush hour traffic in downtown Atlanta with no vapor lock. Rebuilt glass bowl fuel pump (after two new ones failed), Carter YF carburetor with phenolic spacer, properly working heat riser flap, original radiator, 160 T-Stat. Engine temp stays at 180 and may creep to 190 if stopped in traffic.

First do a fuel pump test to check output volume and pressure. Make sure your heat riser flapper is working. Pick up an infrared thermometer and start shooting temperatures all over the engine, radiator, carb and fuel lines. Make sure water is flowing and engine is cooling properly.

I also believe you have other problems, none of which are vapor lock. Or, if vapor lock is present, your engine is not cooling itself properly.

Last edited by Phak1; 07/06/2025 5:51 PM. Reason: Typo
1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)