Engine Compartment Venting

[freebeard]

Surface radiators. No evaporation.

The Original Poster is asking about a Saturn SC1. There is no "vacumn[sic] on the front of the hood".

Edit: I read further on in Wikipedia. There *were* airplanes that used Evaporative cooling, notably Heinkels in the 1930s.

[arcosine]

Humm, only 2400 feet of tubing for 1000 hp, that would be 240 feet for my 100 hp engine. I guess they learned in 1929 that it wasn't such a good idea.

I think the coolant boils in contact with the head before it overheats. I like air cooled engines.

[Shepherd777]

We decided to vent the 955 cubic inch (15L) Cummins engine compartment heat from the BulletTruck to a vent on top of the wheel well. I don't really have any good close-up pics, but these pics below should give you the idea. Underhood air temp ranged from 105F in the spring, to 165F in Denver on a 105F ambient summer day.

Not blatantly obvious from these photos is where we rolled-in the the front of the skirts right behind the steering tires. This was to speed up the air and blend with the expelled hot air from the engine compartment.

[radioranger]

I Imagined there might be a lower pressure area right behind the leading edge of the hood, so used to older vehicles airflow. where front of vehicle just pushes air up and over and then it whacks the windshield

[basjoos]

Originally Posted by jime57

According to Hucho's text reference to the research of Buchhein, et. al., the over hood venting is far and away better than any other venting. It is widely used on race cars, but isn't very practical for street cars, since it dumps lots of hot air right into the climate control intake at the windshield base.

Also dumps rain water onto the engine through the hood vents, the main reason I decided not to go with it. Also any exhaust leaks, hot oil smells, etc. from the engine compartment would be fed straight into your cabin air intake vents.

The paneling under my engine compartment keeps road water/dirt from entering the compartment, so I didn't want the engine to be getting wet from above by cutting vents into the hood. The only way water can enter my engine compartment is through the radiator and the adjustable opening radiator openings in the nose of the aerocivic catches most of the water entering through these openings before it gets to the radiator so my engine remains dry even when driving in wet weather.

[radioranger]

I think if you have any exhaust leaks they'll find their way through the firewall somehow, mine do !! LOL My 66 Mustang was notorius for high lift at the hood surface, i installed a pretty radical front spoiler and killed the lift and also made the engine run much cooler in the summer, I ran a pinned on hinge less glass hood, and with the spoiler off and the rear pins removed the back edge of the hood would lift off the supports at around 40 mph , with the spoiler on ,the hood would stay flush with the fenders all the time , thus indicating no buildup of air under it. pretty well unused Mustang mod.

[radioranger]

Chevy Corvettes had a real problem with front end lift on the 68 Models when developed, and actually delayed production of the car until they installed vents in the sides of the fenders to vent some of it ,

[radioranger]

Back in the 70's I was enamored of Can Am racing and had the idea of using a more viscous gas to lubricate the surface of the car with strategically placed air jets, seems that pure nitrogen is slicker than regular air, , later found out many electric generators use nitrogen to fill their cases and reduce air drag, might be some other reason also but pretty radical , might be possible now to use a bank of pressurized air to inject onto hollow spaces on the air flow,

[freebeard]

Originally Posted by arcosine

I think the coolant boils in contact with the head before it overheats. I like air cooled engines.

Originally Posted by radioranger

I think if you have any exhaust leaks they'll find their way through the firewall somehow, mine do !! LOL

Originally Posted by radioranger

...might be possible now to use a bank of pressurized air to inject onto hollow spaces on the air flow,

Gee, the thing it sounds like you'd want would be a rear-engined, air-cooled car that can dump, oh, say 1000-1200cfm of hot engine air directly into the wake where it will do the most good.

Let me check my carport.

[arcosine]