Thread: Will a bonnet scoop reduce heat in the engine bay?

Nothing science like

Middle of summer days over 35c
No thermo testing just touch back then...

Prior to scoop couldn’t touch anything under bonnet - especially after some low range work - and couldn’t keep hand on bonnet above suspension towers, let alone in the centre.

Post scoop: easily passed touch test, and on highway the transmission shifter and surround stopped getting as hot.

Originally Posted by Tombie

Nothing science like

Middle of summer days over 35c
No thermo testing just touch back then...

Prior to scoop couldn’t touch anything under bonnet - especially after some low range work - and couldn’t keep hand on bonnet above suspension towers, let alone in the centre.

Post scoop: easily passed touch test, and on highway the transmission shifter and surround stopped getting as hot.

Nice, touch test is very scientific

So general consensus so far is that helps to reduce heat soak which also helps engine not get hot as fast and helps it to recover faster plus may drop engine temps a few degress as well.

Also the size of scoop should be looked at.

This is why 79series style is great, nice and wide, low profile, should let a ton of air in @ 110

I have a 300TDI Disco 1 and one thing I have noticed is that the engine fan does not blow any air down the passenger side of the engine bay thus very little air movement on that side of the engine. All of the fan air exits on the drivers side and top and bottom. So I have fitted a scoop similar to Tombie's but in the position of the passenger scoop on quinny139780's Disco. One of the main reasons for me doing this is because I am running a VNT and the exhaust dump pipe is very close to the back of the alternator and the cooler outside air is forced down between them thus cooling the exhaust dump pipe a little but having cooler air for the alternator. I did this mod on my previous 300TDI Disco as well and the wife said her feet were cooler and I stopped cooking rear alternator bearings. Scoops can be cheap too, just have a look at the bingle sights where boy racers loose control and run their rice burners into the guard rail. That's where I found my scoop so it cost me zilch.
Foxy

Blackrangie,So far yes. I have had no issues at all. In fact in my application I expect it to be more reliable as the engine is always at high revs and a mechanical pump could cavitate whereas the electric pump runs at whatever speed is required. Before I fitted the electric pump I fitted a set of underdrive pulleys to prevent the power steering pump from foaming the fluid and to protect the alternator and water pump.

I have not said an electric water pump will flow more water, I said it can at slow engine speeds, doesn't mean it will. It only flows what is necessary. According to Davies Craig you can run a 30% smaller radiator than standard. The digital controller allows you to select the temperature you want the engine to run at, in my case 80*C. Temperature can be set in 5*C increments from 75*C to 95*C. Another advantage is that when you stop the engine the pump will continue to pump for a few minutes to prevent heat soak and in my case turn on the electric fan if necessary.

The mechanical pump is removed from the system. In my case the shell of the pump remains as it is part of the cooling system as far as directing the water flow.

Originally Posted by blackrangie

LRA tried top mounted intercooling and bonnet scooping Andrews D2 on the 2.8 TD5 project, cooler mounts kept breaking, and they decided to can it due to being complicated etc and just LS'd it. He is very happy with the LS3/6L90 combo.

Factories will avoid using scoops for many reasons,but mostly the clean look, will only use them if 100% nessesary like the Cruisers.

To force fresh cool air onto the top of an engine via scoop will no doubt help to cool engine and parts and could even help to suck more air through rad, will help to reduce heat soak at speed, bonnet scoops will also create a spot for rising hot air to escape when switching off, reducing heat soak.

Cant see many negatives of a sleek good looking forward facing scoop.

Yeah i put a large top mount intercooler on my 4bd1t rangie, wasn't very effective, ran a modified gu patrol scoop with much larger opening.
Ended up binning it and fitting a Plazmaman water to air which works great.

Originally Posted by Vern

Yeah i put a large top mount intercooler on my 4bd1t rangie, wasn't very effective, ran a modified gu patrol scoop with much larger opening.
Ended up binning it and fitting a Plazmaman water to air which works great.

Yes, thats what the LSA runs..they are good

Originally Posted by quinny139780

Hi Folks,

I added two scoops to my D2, Td5, one to send air down either side of the engine was the plan, and reduce overall engine bay temps.

I have an engine watchdog, measuring head temp and gearbox temp (metal temps) and nanocom for water temps, and a before and after had my under bonnet/head temps down roughly 5 deg C. No real change on water temps, as you would expect with a working radiator and thermostat, but with the lower under bonnet temps, I find the temps definitely recover faster when pushing hard or towing, when the ambient air is cooler, I put a couple of solid blanks in.

All up about $75 (paint and scoops) and one grinding disk

cheers lads

And the winner is post #66 - IMHO
Cheers
HunterJ