Unless your puller is extremely efficient, and I'm sure it is more efficient
than the twin pushers on my factory V8, I'd expect to have greater problems
at idle with no forced draught then when running when you have forced
draught *plus* potentially the fan(s) if the temp goes high enough, that is
certainly the case with my (factory standard rubber bumper) V8 in the
current high 80s and 90s temps.
Have you checked the mixture and advance at speed? Maybe you aren't getting
enough advance, or too much, which will make the engine inefficient and
generate more heat than it should.
Air forced in through the rad will exit under the car - indeed this is the
only place it *can* exit. If you have the original valance which curves
down and backwards under the car then this *may* tend to increase the
pressure under the car and hence restrict the rate at which hot air can
exit, a scoop front spoiler - which I have - may well reduce pressure
underneath and tend to *suck* air from the engine compartment and so improve
cooling.
I also have a 4-row uprated radiator, but this had much less effect then I
expected. Once the air has been past the first three rows it is going to be
pretty hot, and so will not extract much more from the 4th row - the law of
diminishing returns. I've heard that is why some performance cars have
single-row rads. The extra row may well add some restriction, but overall
it does seem to cool slightly better, but nowhere near as much as 25% or 30%
better.
Both the original and the uprated radiators extend below the lower radiator
duct panel, and the oil cooler is also below this. The scoop holes in the
spoiler have a fibre-board panel between them that *should* duct air from
them directly onto the oil cooler and lower half of the rad. However mine
was more of an arch than a rectangle and hence allowed a lot of ram-air to
escape past the radiator, until I put a strut around it to force it into a
rectangular shape. I wasn't expecting this to make much of a noticeable
difference, but it seems to have, although direct comparisons are difficult.
But finally, if it isn't steaming or losing coolant it isn't overheating.
I've had mine idling in the red on a 90 degree day before I changed the rad
and greatly improved the fan electrics and the only noticeable effect was a
slightly rough idle. I also had the choke on fast idle to keep the revs and
hence oil pressure up a bit. Since doing the fans I've had it on test in
the garage, 90+ degrees outside, 40+ degrees inside, and the temp gauge only
got slightly above mid-way from N to the red, fans running all the time
unable to get it lower than that. On the road the temp will go up when
stopped, but come down again pretty quickly once underway again. Slow
moving and/or heavy traffic will tend to increase running temps as it
increases the effective ambient - your rad is 'breathing' the heated air
from the vehicles in front.
PaulH.
----- Original Message -----
> Engine temp was very good at idle no load, but it would get hot (220F -
230F) even on a highway drive at 65 - 75 MPH.
> As soon as I stop and let the car idle for 8 to 10 minutes, it would
"cool" back down to 180F - 190F.
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