Nope, you want the coolant to flow
faster, not slower [ post #41 ]. See link below.
Retarded ign timing &/or lean cruise mixture will cause hot running. W/pump. The gap between the impeller blades & the pump body should be minimal, almost touching. This ensures that the coolant captured by the blades has no escape route & that the coolant gets pumped into the engine.
Nothing pulls air like a 19+ inch, steep pitch, mech fan. Replace your clutch fan if old or questionable.
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