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Legalities of driving without a bonnet??!!??
Kerr205 - 25/7/14 at 07:51 PM

Hi, I have a quick question. My formula 27 zx9 carb gets quite hot when I've been driving hard. Does anyone know how legal i'd be to leave the bonnet at home to keep it cool?????

[Edited on 25/7/14 by Kerr205]

Brook_lands - 25/7/14 at 07:57 PM

Not illegal in its self but you are likely to fall foul of general C&U requlations as most police or VOSA inspectors would deem it a danger to pedestrians.

02GF74 - 25/7/14 at 08:33 PM

If the water temp gauge is working and reading normal then dont worry about it .

If you are then look at waysy of venting the heat out of the engine bay.

Or you could make a bonnet from chicken wire .

I have seen more than a few hot rod type vars as well a vw beetle buggies with exposed rngines.

Slater - 25/7/14 at 09:12 PM

Motorbikes and older tractors have exposed engines, also what about aerial atom, do they have engine covered?

snapper - 25/7/14 at 09:19 PM

Hot Rod fraternity run open engines
Your problem would be if you mashed a pedestrian
I propped the rear of the bonnet 10mm made a huge difference

Kerr205 - 25/7/14 at 09:35 PM

Thanks for your help.

I know a traffic policeman sargeant who called me this evening after speaking to his friend at VOSA and apparently i'm absolutely fine to run without it. As mentioned tractors, motorbikes etc etc are the same so i'm fine. The general rule was if its dangerous to an innocent passerby then its illegal but if its only dangerous if said paserby intentionally sticks their hand in then you're ok!

coozer - 25/7/14 at 10:00 PM

If you get pulled and they point "wheres the bonnet/" just say it blew off and sailed into away..

Should be OK imo tho..

snapper - 26/7/14 at 07:10 AM

If it blew off the offence is one of insecure fitment, your better off saying you didn't put it on
Propping the rear edge is just as good and doesn't ruin the airflow as much if at all

Slimy38 - 26/7/14 at 08:55 AM

quote:
Originally posted by Kerr205
As mentioned tractors, motorbikes etc etc are the same so i'm fine. The general rule was if its dangerous to an innocent passerby then its illegal but if its only dangerous if said paserby intentionally sticks their hand in then you're ok!


But both tractors and motorbikes have different regulations covering them. The MSVA is so much easier to pass than the equivalent IVA, and the tractor test only ensures that they are suitably equipped to disrupt traffic at any time.

Coming back to the original issue though, wouldn't it be better to sort out airflow and cool it that way? I was under the impression that a good entry and exit point for cold air is more effective than relying on radiated heat?

designer - 26/7/14 at 09:35 AM

Removing the bonnet is only a temporary solution.

You have to evacuate the hot air. Copious amounts of air going into the engine bay is no good if it can't get out.

Vents in the side are the best solution.

40inches - 26/7/14 at 09:51 AM

Side and rear bonnet vents will work better than leaving the bonnet off. The air will flow through the engine bay, not over the top.
Vents
Vents

Kerr205 - 26/7/14 at 04:22 PM

Thanks for all your help.

Its a fair point about making air flow round the engine and not just leave the bonnet off, i'll look into getting that done.