Cooler engine bay.....?

Oldskoolrob

Oldskoolrob

Active Member
Apologies if this should be in the engine section, but what's the best way to bring down engine bay temps? I'd like to get cool air to the engine for sure but it's sooooo hot under there (gauge reads fine though) I reckon some venting couldn't hurt. What are the favoured options to get it venting nicely?
 
It probably depends on what you're main issue is; if you're thinking about heat build up when the vehicle is static or slow-moving a manually controlled electric fan can make quite a difference. If it's whilst driving then it's the same but bonnet vemnts will increase airflow.

Some people use wrap on the manifolds but others say that it can cause or accelerate corrosion - I had it on a Caterham and it did noticeably reduce temperature and I wasn't aware of any issues over a 10-year period. Having said that, I don't use it on my TVR, which gets really hot under bonnet what with the cats. being there, that has a vented bonnet (standard) and I've fitted a manual override to the electric fan.
 
Raising the rear of the bonnet a little with washers under the hinges is supposed to lose a lot of heat with the downside that engine smells/fumes are then exiting over the heater intake.

My experience with heat-wrap:

Heat Wrap.

......which also includes advice on underbonnet heat-loss.
 
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Bonnet flutes/louvres.
We have a series 1 and 20 odd years ago I decided that allowing heat to escape through bonnet flutes might work but our daughter forbade me from desecrating the car. So bought a series 2 bonnet (couldn't get a 1) and had louvres cut in it, to my pattern which included a little scoop in front of the air cleaner intake to allow cooler air in, by a gentleman trading as Tin West in Melbourne. That required it to be totally stripped of paint first. Initially ran it as a summer bonnet in unpainted form, then had it powder coated and later stripped and painted.

It certainly has the engine running cooler on the temp gauge, possibly too cool. When you stop after a run you can feel the heat pouring out through the vents as well.

HOWEVER this did nothing to stop the build up of heat in the firewall and cabin that occurs when you park for half an hour and then get back in.
Our car does not have AC.
Have contemplated ceramic coating the exhaust manifolds, which is not that expensive, but the issue appears to be that it just moves the heat from the engine bay to under the body so make that standing heatsink even worse.

Not sure this answers your question!
 
Very useful information! I also have a series 1 so if I end up cutting into the bonnet I want to be confident it's what I want. At the moment I'm leaning towards a 65 Mustang 350GT bonnet scoop to let cool air in when driving and hot air out when stopped.....
 
This topic has had extensive coverage in previous threads, done to death in fact, I would suggest a forum search.
 
ghce said:
This topic has had extensive coverage in previous threads, done to death in fact, I would suggest a forum search.
Click to expand...

Rover also did a lot of testing, and their conclusion was that fitting louvres in the bonnet gave no appreciable change in under-bonnet temperatures. The only time extra venting worked was with the two outer scoops on the NADA bonnet.
 
The front wheel wells are low pressure areas, how about some vents into those to extract heat. They would need careful positioning in order to keep water and crap from going inward.
 
Hi, There's already holes at the back of the inner wing into the under wing area, which is where the steering goes through. Perhaps modifying or removing the flaps there or maybe putting small fans to help the hot air along.

Colin
 
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Hi. I fitted a electric fan with the idea that Rover would be a little quieter and more economical but found that the temp was either hot or cool and used eight amps when on, so occasional flat battery, so back on went the mechanical fan and I raised the cut in temp of the electric fan so that if he gets hot in traffic he has extra cooling.

John.
 
I have a replica Lotus 7 with a turbo mx5 engine. Wrapped the turbo dump pipe in exhaust lagging (its right in front of the pass toe board), and it keeps the temps well down. Have a couple of vents on the top of the bonnet to allow heat soak to escape as well. Generally lagging exhaust in the engine bay keeps the gas hot and fast moving so it helps the flow. Planning on lagging the P6B manual pipes as much as I can. When I had a TC I wrapped the bend in the headers with alloy flashing to try to reduce the water splash that sped up rusting that area.
 
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