I have a sort of undertray on my Plus8. It doubles as a numberplate holder then folds back to form an under tray that goes back past the bottom of the rad. It is fitted to the front over rider extensions from the chassis. It actually blocks air from getting to the bottom of the rad.
I’ve never been convinced that it helps airflow in any way. My fan has always been coming on preventing overheating. However the system seems very sensitive to reduced airflow when in slow traffic. I have tried a jury rigged duct to feed air to the bottom of the rad that seems blanked off by the whole design. Enough improvement to warrant more experiments. Morgan grills are not the best for providing good airflow to the rad.
Recent drives are showing a coolant gauge reading of 80deg with slower rise from cold and lesser increased reading when in slower traffic/ waiting at lights etc. This is the norm for winter. Summer, with higher ambient temperatures results in normal running between 85 and 90deg with faster warm up from cold and when in slow traffic/lots of stop start driving.
I’m going to retry extra ducting to reduce average coolant temp to reduce fan cut-ins or even remove the numberplate/undertray and stick numbers on the wing.
Just had a thought.......cut the undertray and fit a mesh replacement section. Protects rad from debris and lets air up.
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Last edited by sospan; 27/02/22 07:20 PM.
