One last little detail before I refit everything was to replace the rubber seal on the back of the bonnet.
I couldn't find anything which was quite the same (mind you....didn't look very hard!) but Clark Rubber had a D-section foam extrusion which looked like it might do the job.
First perfectly, and with the new cowl gaskets in place, the view through the vents is as the factory intended
Since the thermostat and fan switch were sorted, the new radiator's been working a treat. We've had a few really hot days and the Hako managed to sit in traffic without losing its cool. But one thing I have noticed is that the temps at cruise are usually maybe 2 or 3 degrees hotter than before. And oddly, when the car is moving (say at 50km/h) the temps are quite slow to fall. But when the fan kicks in, the temps plummet immediately. I had a theory that maybe this was because the natural airflow through the radiator isn't so great. Sure, the Hako has this huge grille, but there is no ducting in the engine bay like a modern car has. The incoming air is welcome to flow over the radiator support and thus bypassing the rad. I figure that the aerodynamics of the engine bay are probably a bit of a mess, with that big vertical panel in front of the radiator probably doing a great job in deflecting a lot of the air upwards over it. And I guess whether you like it or not, the old engine-driven fan probablu did a lot to straighten the incoming airflow.
Now that the engine driven fan is gone, I figure some ducting wouldn't hurt. First step was to fill in that gap between the radiator support and the rad itself. The gap probably isn't doing much harm, but it wasn't a difficult thing to do anyway. First I start by bending up some 1.6mm aluminium strap.
Add some dinky little brackets...
...a pinchwell rubber seal (so that the aluminium doesn't scratch the new rad!)
Grind the ends of the strap to suit the gap between rad and bodywork, and it's done.
Next step was to make some ducting to go in front of the radiator, which starts with a lot of mucking around with cardboard until I felt I had the right shape.
Draw the pattern onto the aluminium sheet (this time 1.0mm) and cut out with a jigsaw.
To bend it up, I sandwich the ally between two planks of wood, then use another piece of wood to force the metal over. Not sure if this is the best way to do it, but it does get decently straight folds as long as the metal isn't too thick.
To make the folds a little bit more crisp, as a last step I use a little rectangle of wood, press it behind the fold and give it a few smart taps with the BFH.
Mock up some side brackets with more cardboard...
In the end there wasn't much space to play with, so eventually I made templates of each little area needed, then taped it all together into one template.
I'm so pleased that I bought the big belt sander/linisher...I use it a lot. It turns this rough and ready bit of metal into...
THIS in a matter of seconds. Saves so much time and it's fun to shape the metal on the linisher.
Test fit the side brackets...which bolt to the bonnet hinge mounts.
31Gun was joking that since I'm making a radiator duct, that we can't use the dimple dies, since making holes in the duct would defeat its purpose...but when there's a will, there's a way
...the dimple holes are in the brackets
Test fit and shave a bit off here and there with tinsnips
Pop rivet the side brackets and the top panel together...
Polish it up and it looks great!
It'll be interesting to see if this makes any difference at all....I suppose in theory it should ensure that the radiator gets a steady uninterrupted flow of air when the car is moving. But if it doesn't do anything...well it looks purdy anyway
There's a bit of a gap where the top panel doesn't sit flush against the radiator support, but I think a little finessing of the side brackets is all that's needed.
For the top panel, I folded a triangle shape in the middle, since it would otherwise be a bit floppy without those creases. And I suppose visually it makes it a little less boring than one straight long flat panel.
From the front you can see the brackets quite nicely.
Pretty happy with how it turned out....I have to say I'm really enjoying this phase of the Hako project, where we're fabricating stuff and not just fixing things.
No Kev, you are eating a duck fetus.