additional cooling to accommodate full grill blocks
 

Ever since the Paseo got its full grill block, I've been waiting for it to overheat the engine. Thankfully, it never has and I don't believe it ever will. However, the fan does come on more than I'd like it too, especially as speed increases.

Over this weekend's trip I mostly drove on 55 mph roads. Pulse and gliding from 60 to 50 made the fan come on once every 10-15 minutes @ ~70F outside. However, once I had to make my jump to the freeway (65 mph zone), I P&Ged from 65 to 55, and the fan was coming on every 3-5 minutes. I can definitely live with 10-15 minutes, and even 3-5 minutes isn't really THAT horrible. I'll explain why.

The fan on the Paseo runs at about 7 amps. 7 amps is roughly 84 watts. The headlights on my car alone are 55 watts each, so 110W total. So, the fan running every 3-5 minutes for 15 seconds or so really isn't even remotely close to sucking as much power as just having your headlights on constantly.

That being said, it is still going to get warmer this summer, and I would like to avoid additional fan usage. So, I am thinking about adding some additional cooling for the Paseo. Since it doesn't have a bellypan on it yet, I was thinking of incorporating the cooling into the bellypan in the form of copper tubing brazed to aluminum sheeting. My concern here would be with heating up the oil and tranny. So, the other idea would be to do the same thing, but line the wheel well since it is an area of high turbulence.

Doing this would allow me to retain the full grill block and all its benefits.

So, whatcha guys think? Too much work for too little gain?

You've got two options that aren't. . .terrible as far as difficulty and cost.

I'm not familiar with the paseo itself.

What you could do to rather heavily increase cooling would be to add an oil cooler. If the paseo has the bolts(like extra dran bolts) either on the block, or the oil pan this is guaranteed your best option. If it doesn't. . .then its more complicated. Either way you'll need another small oil pump to make sure you don't starve the motor for oil in the extra tubing you will also either way want more oil because the lag time between oil drain and being pumped back into the engine now is a good bit longer.

If it doesn't have the handy dandy oil cooler bolt holes you'll need to find your oil pump and direct the flow through a radiator(wherever you like near the tire might be bad for it bottom mounted right above and behind the lower lip of your front bumper would be an alright place or if you wanted to look like a tuner you could cut out your fender and mount it there lol). You then want to put the other pump on the other side of the radiator to return the oil flow back to its original piping and the engine.

If you go with a second coolant radiator its much easier because you have feed lines and return lines that are easily accessible. More or less you do the same thing as the oil cooler.

If I were you I'd go with the oil cooler(I'd pull the grill blocks but thats not an option for you ^_^). The reason is. . .your radiator is dissipating a ton of heat. The only way to make it perform better would be to add a higher flow pump from the resevoir and pump it through another large radiator(I again I would avoid getting too close to the tire because its going to cause one tire to have a much higher pressure if its only a few inches away. . .)

If you are worried about the transmission getting to hot its alot easier to add a cooler for that. It has a fill bolt hole and a drain that are unused. On your next transmission fluid change slide some tubing and screw them into those bolt holes small pump radiator and return line goes to the fill bolt. Of course you want to add oil directly into the radiator to fill it and then add whatever it takes to fill your trans.

The oil cooler(s) would provide the most cooling. Your oil is hot and sits in the oil pan which has very little surface area for the volume of heat trapped. It is also connected to the engine casing in a metal box. If you went with oil coolers for the transmission and engine I doubt your fan would come on while moving. But. . .you would have to pay for the 2 small pumps, but you won't be running your engine up to such high temps reducing its lifetime.

Another added bonus is your engine has a larger supply of oil to muck up or leak out ^_^.

You could make an actuated grill block, even hand operated from inside the cabin. When the fan comes on, the grill block gets opened, when it turns off, the grill block gets closed. That may cut your 15 seconds of on time down to 5. If you hand operate, you may find a good setting for different speeds and outside temps so the fan never comes on.

On corvettes they have a nifty design that may work for you. There is an airdam that covers the left and right sides lined up with the bumper, but the middle is lined up with the front of the radiator. This builds a little high pressure on the front of the radiator from the nasty air that is going under the car.

You could put in your belly pan and fold down a strip of it that lines up like the corvette's little scoop. Then you could terminate the belly pan with a slight downslope at the back of the engine bay to create a sucking effect so that air isn't expelled out the wheel wells, fenders and hood top.

How's that sound?

I guess the engine oil isn't a problem. Its cooled with the coolant itself. The tranny would be more of a concern, but I have no idea what kind of temps it currently sees.

An actuated door I'm sure would work fine. I still have the automatic one I had designed for the Matrix and haven't installed. I was just hoping to find a way to improve aero and cooling at the same time.

I'm not sure how I'd use an oil cooler and reduce aero?

Got any pics of that Matt? I'm not exactly sure what you're saying.

Okay, i just scoured google for a while and i can't find a pic of what I'm talking about.

Maybe it wasn't a corvette, but some other american muscle.

Many cars have an air dam just behind the front face of the bumper. In the design that I'm refering to, the center section of the airdam is set further back - it has been pushed back to the radiator and has an open top. So air going under the bumper near the middle will go between the side portions of the air dam and strike the center portion, where it is then pushed upwards to the radiator.

If you looked at the nose of the car from below, the airdam would be shaped like this:

-------_______------- where "up" is the front of the car.

I'm sorry for my textual description abilities... :p

The reason you want the oil cooler. . .is because the oil isn't actually cooled by anything. It flows next to the jacket but most of the heat exchange is between the cylinder itself and the coolant.

The hot oil acts like a giant thermos trapping heat against the block.

If you drop the temperature of the oil to lower than the temperature of the block you acquire some cooling effect of the oil.

The radiator is already dissipating a substantial amount of heat with virtually no air circulation just because ambient air is about 40 degrees C on a really hot day and the coolant is 100. Improving the coolants specs are small gains because the coolant at best will get down to 40 degrees c before being recirculated.

The oil that is heat soaking your block and all of its parts comes out into the oil pan, sits at 100+ c and then goes back into the engine with virtually no heat exchange with the incoming air.

You might be able to get your coolant down from 80C to 60C with a second radiator. . .but you can drop your oil temps from 2-300 to 100 with an oil cooler. So for the virtually the same effort you get a 200 degree temp drop or a 20 degree temp drop. Anything thats less than 400C is going to cool the block some and 100 degree c oil and 300 degrees is a big difference.

You don't neccessarily need to mount the oil radiator out in front or create frontal area with it. Alot of tuners put their charge cooler along the bottom of the engine bay just behind the radiator. Its just up inside the engine bay so it gets some exposure to the turbulent air under your car, but it doesn't create substantial drag.

It's likely it would also slightly increase AITs because any air that comes up through the bottom of the engine bay is going to be slightly preheated. . .

The point here is not worrying that the components are going to degrade the oil itself. . .but using the extra contact area of the oil/engine as additional heat sink instead of trying to squeeze more chilling out of your already pressed coolant surface area because thats the actual problem. The coolant only has so much engine contact to absorb heat and can only absorb so much before it boils. Oil has tons of contact space and can survive much higher temps for longer exposure.

Man, just open up a cooling hole a little bit and call it good. FE isn't going to change from something that small.

Thats kind of what I was thinking originally. :)