Bonnet vents

Miles on the clock

My round trip to work is 84 miles, so over the last couple of weeks taking in the Zero now and again plus some spins out with colleagues at lunchtime has helped push the total milage past 1000 miles.

Good testing - need to keep an eye on the limited milage insurance though...

Everything has been fine, even in the summer heat & stop start of the M25; engine seems happy and the cooling system is just about able to hold the temperature when in standing traffic. The one big notice though is the engine heat has nowhere to go except finding holes in the pedal box into the footwells and down through the transmission tunnel to slowly cook the driver.

Vents

I'm fitting some bonnet vents to try and give the hot air an escape route and hopefully make things a little more comfortable when driving. I mocked up some options:

Eventually deciding on the last option: two or three small discrete vents on the trailing edge to also have mesh behind when I find the right product.

The sheet metal punch ordered and arrived from Ebay, it winds up with an allen key & punches through the stainless as if it was paper. First up a test on the bonnet cutout to check/confirm which way produces   a clean cut & that I'll end up with a half decent job. 20mm punched holes joined to make the slots:

Then on to marking up the offside. The slots are 20mm high with 10mm spacing. 

Drilling pattern is 4mm pilot holes, widened to 10mm then followed by the punch itself:

Holes all set:

Joined the dots with the Dremel cutting disc & then tidied & de-burred  with one of the Dremel stone wheels & sanding drum. Looks pretty much as expected, this has just been wiped with WD40 to take off the masking tape glue - it will get a proper clean when back on the car:

Both sides done & bonnet back on - all set pending some grille arriving to sit behind the holes. They're not right at the top so won't directly let the hottest air out but might setup a flow under the bonnet from the radiator and at least start moving air through:

Update - I've been out a couple of times in similar heat - nothing definitive, the holes make a some difference - nothing dramatic - good job they look good! I think the next step will be wrapping the exhaust under the bonnet and/or even a vent in the top of the nose just behind the radiator.