Fender Vents

[Old Crows]

Any thoughts about adding vents to the inside of the front fenders (in front of the front tire) to draw high pressure air out of the engine compartment?

[GasSavers_BEEF]

wouldn't that cool off the engine?

I have gone through great pains to keep the heat in my engine compartment

[optix]

Many car manufacturers do this already.

[Old Crows]

Originally Posted by BEEF

wouldn't that cool off the engine?

I have gone through great pains to keep the heat in my engine compartment

I should have clarified. Rather than going to all the intake blocking work to reduce the airflow into the compartment why not work with the existing ducting but add some fender well vents to get the air out of the compartment. Seems simpler and easier to do.

[theholycow]

That's an interesting thought, but most engine comparments already have plenty of outbound ventilation at the bottom. Grille blocking keeps heat under the hood and prevents the air from having to flow through the engine compartment.

[GasSavers_BEEF]

I would also think that it would be better to simply deflect the air in the first place than to send it through a maze where it could slow down and then output the slower air into the regular air stream. I would think that it would cause turbulence.

not an expert so I don't know for sure.

oh....and welcome to the site.

[Old Crows]

Originally Posted by theholycow

That's an interesting thought, but most engine comparments already have plenty of outbound ventilation at the bottom. Grille blocking keeps heat under the hood and prevents the air from having to flow through the engine compartment.

I think the idea is to keep the air flow from going under the car where it creates drag and diverting it to the low pressure areas in the fender wells.

Regarding grill blocking. An excellent idea to keep the openings as small as possible. However, I'd rather not go that route here in Texas where the ambient can be well over 100F and even hotter down near the pavement. Keeping the ICE hot enough is only an issue for several months when the weather is cool.

Better, I think, to exhaust the engine compartment.

[GasSavers_GasUser]

Heat rises, so wouldn't vents in the hood work better to let heat out and reduce under hood temperature?? If that is the purpose.

[theholycow]

Heat does not rise, and that's especially true in enclosed and/or turbulent environments. When you have layers of cold air and warm air that are not moving and not obstructed, the denser, heavier cold air will sink and displace the warm air, which will float on top of the cold air.

This cannot happen in an engine bay because there are no layers of cold and warm air (the air is all warm, from radiant heat from the engine); there is turbulence pushing the air around; and the space is entirely obstructed by the engine and body.

[Old Crows]

Originally Posted by GasUser

Heat rises, so wouldn't vents in the hood work better to let heat out and reduce under hood temperature?? If that is the purpose.

It would depend on where the hood vents are placed. Usually the hood represents a high pressure area and that would cause the air flow into the engine compartment. Placing them at the rear of the hood is definitely not the way to go.... really high pressure at the base of the hood/windshield.

I installed a fender liner vent on my 2001 Turbo Beetle using a later model fender liner. It was highly effective at reducing the heat sink on the turbo's intercooler... especially in traffic.... as it allowed the air to pass directly through the intercooler and out into the wheel well.

I've seen a number of cars ... no rhyme or reason to it... that have factory installed fender liner vents. It would appear to be a good idea to help extract the air out of the compartment.

Blocking the grill area may be a good idea but not here in Texas, I think. No problem getting the engine and drive train hot enough almost all year long.
I'd worry that it would be restricted too much and over cook something important ... and expensive. Accidentally! Besides, the XYL drives the thing and I'm not sure she'd pay strict attention to the temp gauge.

Cheers!