I posted a message the other day asking if a small section of the water
pump rear housing was missing (as a result of being damaged by the impeller
as it broke) would it affect the engine cooling (the piece broken in the
housing is part of the thin section that is a 2.25" dia hole by the front
of the cylinder head). I didn't receive any replies, however, cannot
believe that I am the first person to encounter this problem, so thought I
post my findings. Back to the question - the answer is yes, it does!
Installed the new pump, buttoned up everything and went for a drive: temp
gauge came up very quickly (faster than before), and the gauge steadied
about .2" off center toward the hot side, and seemed to remain at that
point with moves upwards when idling at the lights. Overall, it was
running hotter than before, and the ambient temps were not too dissimilar
to last week, so that wasn't a factor.
I don't have a spare pump housing, so I decided to repair the break in the
rear circular aperture. Started by checking the dimensions to see if I
could replace the missing section of the thin backwall without interfering
with the impeller. After carefully measuring with calipers and mikes, it
is clear that there is about a .125" clearance between the impeller and the
circular casting at the rear of the housing. Measured the O/D and I/D of
the rear of the housing and then looked for a piece of steel that would be
suitable - settled upon a Stanley craft knife blade - HSS, fairly rigid,
and more importantly, lying there on my workbench. Ground it to a crescent
shape, and then glued it into place with 2000lb epoxy resin.
Did it work? Like a charm. The engine temps are now normal! Pity I
leaned on the fuel line to the front carb at some point and disturbed the
compression joint ... and then spent the next few hours replacing the
damaged fuel inlet pipe into the front Stromberg. Ah, one step forward,
two back ... and not a DPO in sight: LBC pleasures, to be sure.
72 TR6, Midland, MI