There you go again, out-anoraking yourself this time!Not trying to out-anorack anyone. By the way, the guy behind Tony is John Pett who did 'Price Of A Record'
He is talking to Leo who is on the otherside of the boat. That interview is included in the documentary.
Still can't think of any reason why the jet pipe cooling duct on that side was blanked off.
The reason the hole was closed in the side...
On the Orph' jetpipe cooling is effected by having an inner jetpipe made of Nimonic stainless surrounded by an outer, aluminium shroud with a bright (316-probably) stainless tailpipe for heat resistance that is a smidge longer than the inner pipe and a couple of inches larger in diameter. The efflux hurtling out of the inner pipe causes a negative pressure at the annulus where it ends and ambient pressure air then flows through a pair of inlets on either side at the other end of the shroud to flow down the gap between shroud and jetpipe cooling the jetpipe as it goes.
On the aircraft installation there's two inlets to the duct. One is for ram-air when the aircraft is moving and the other, on the opposite side, has a spring loaded, one-way flap so it will open on the ground purely due to the pressure gradient between ambient and the negative pressure in the shroud then, when the ram-air pressure overcomes ambient the flap closes to stop ram-air leaking out through that inlet and down goes the ram-air to cool the jetpipe. Simple but effective.
But on the boat they left both inlets open then cut a hole in the side directly opposite them in the side of the engine cover. We know they had trouble getting rid of heat at the back because of the lashed-up heat shields held in with finest string so the theory was good - in theory.
Now remember when the Tribute Act sank? They'd imploded their inlet trunk so they took its upper half off and allowed the engine to vacuum the inside of the hull - then a panel came adrift and the lake was Hoovered in until it sank.
K7 running with a hole in the side and the jetpipe cooling arrangement slurping straight from the volume inside the hull would create exactly the same effect (though not as pronounced) so I suspect that the reason it was blanked is because a thousand zillion gallons of water went through it because a gale of wind was blowing inwards through that square cutout.
The final configuration was with that cutout blanked (that's the ram-air side, by the way) and the other inlet to the shroud was ducted to the outside to another opening in the hull so at least if it sucked water in the water would go straight into the jetpipe shroud. The ram-air inlet could suck for all it was worth but it couldn't suck water into the hull and that, in my opinion, is why it was blanked off.