Venturi heat dissipation on an M
Discussion
Been thinking about this a bit, would it be possible (technical/space) to put 2 (small) venturi' at both sides of the engine, say under/next to the exhausts to expel hot air and thus lower the under bonnet temps? Could it possibly affect (pos/neg) the handling/grip/steering ? Your views welcome
15 years as an Aerodynamicist.
I'd say no. Although I'm not entirely sure what you mean. Are you considering utilising the air flow going under the car?
I once spent months trying to develop a solution to keep a 330 bhp twin turbo intercooler Porsche motor cool in an almost static aircraft (well, airship) installation. Got there in the end but it wasn't easy.
Do you actually have an overheating problem or are you just musing that it gets hot in there?
P.
I'd say no. Although I'm not entirely sure what you mean. Are you considering utilising the air flow going under the car?
I once spent months trying to develop a solution to keep a 330 bhp twin turbo intercooler Porsche motor cool in an almost static aircraft (well, airship) installation. Got there in the end but it wasn't easy.
Do you actually have an overheating problem or are you just musing that it gets hot in there?
P.
Hi ATE399J (and all)
No, no overheating (upright/later type rad, no bonnet ducts or side vents) but thats not the objective. Under bonnet gets obviously warm, and so are thus the intake temps (less dense/hot air) The idea is to install double venturi' effectively 'driven' by the air flow under the car, say under the exhaust collector, to draw hot air produced by rad and exhausts from the engine compartment > hence drawing in cooler air via the front grille.
Another thing might be to insulate the exhaust manifold, enhancing the chimney effect, thus allowing the engine to breath out more easily (only hate the job to install that insulator-tape and ceramic coating is to expensive)
Another story is to design such venturi' (heat-resistent material, shape, dimensions)
Just kicking 'round an idea, please forgive....
No, no overheating (upright/later type rad, no bonnet ducts or side vents) but thats not the objective. Under bonnet gets obviously warm, and so are thus the intake temps (less dense/hot air) The idea is to install double venturi' effectively 'driven' by the air flow under the car, say under the exhaust collector, to draw hot air produced by rad and exhausts from the engine compartment > hence drawing in cooler air via the front grille.
Another thing might be to insulate the exhaust manifold, enhancing the chimney effect, thus allowing the engine to breath out more easily (only hate the job to install that insulator-tape and ceramic coating is to expensive)
Another story is to design such venturi' (heat-resistent material, shape, dimensions)
Just kicking 'round an idea, please forgive....
Wouldn't it be easier to have a heat-shielded intake.
So you could run a pipe up to the front grill, either with a filter down there, or a filter box on the carb. And then wrap it in heatshield.
I'd imagine that would be easier for the gain you'd receive.
I can't imagine it'd make much difference, whatever you did, unless of course it's on a full on race car/engine, where every little bit counts.
I think I'd want to look at the actual temp under the bonnet when running, as I think it might be lower than you'd think. It's a lot of air hitting it at 60mph.
So you could run a pipe up to the front grill, either with a filter down there, or a filter box on the carb. And then wrap it in heatshield.
I'd imagine that would be easier for the gain you'd receive.
I can't imagine it'd make much difference, whatever you did, unless of course it's on a full on race car/engine, where every little bit counts.
I think I'd want to look at the actual temp under the bonnet when running, as I think it might be lower than you'd think. It's a lot of air hitting it at 60mph.
A lot of hot air gets trapped at the upper part of the engine against the bulkhead. I had an SE vent cut in my bonnet, and when at stationery in traffic with the fans on, when you put your hand out the sunroof you could feel the really hot air being blown up the windscreen. I think that a rear bonnet vent makes a lot of sense, not sure about venturis on the side though.
As always it appears to be the static case that's the problem and obviously any aero solution based on the dynamic pressure created by the car's motion won't help you.
Stating the bleedin' obvious: Hot air rises. So, any venting to let heat out to help the static case needs to be at the top! Later Vixens / Tucans have wing and bonnet vents to let the heat out and I'm sure they help.
If you're wanting to ensure cold air is fed into the induction system then I'm sure I've seen some nice installations where trunking has been moulded onto the inside of the bonnet so, when it's shut, it nestles around the carb intake and leads to a cold air source. This could be down ahead of the radiator. But you need to ensure that you're not making the system LESS efficient by making the carb suck the air through really inefficient ducting.
Phil.
Stating the bleedin' obvious: Hot air rises. So, any venting to let heat out to help the static case needs to be at the top! Later Vixens / Tucans have wing and bonnet vents to let the heat out and I'm sure they help.
If you're wanting to ensure cold air is fed into the induction system then I'm sure I've seen some nice installations where trunking has been moulded onto the inside of the bonnet so, when it's shut, it nestles around the carb intake and leads to a cold air source. This could be down ahead of the radiator. But you need to ensure that you're not making the system LESS efficient by making the carb suck the air through really inefficient ducting.
Phil.
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