grille blocks, fan kicks on
 

i made some grille blocks for my tercel the other day...

http://c4.ac-images.myspacecdn.com/i...a5c811edef.jpg


at first, the opening under the tag was not there, until after the first drive, the car kept getting over 200* & kicking the fan on, i thought the small gaps on the sides would be enough...so i slowly trimmed a hole under the tag until i notice the fan basically only really comes on in slow moving traffic...is that acceptable??

whats the rule of thumb?

if i had more material left over from the Caliber's undertray, i would have filled up the whole grille without the gaps on the sides

that reminds me, i forgot to get garden edging at Lowe's for a front air dam

I think anywhere from 20 to 40 sq inches of opening would be good. But, it all depends on how you drive (city/highway/pulse and glide/DWL/etc.) Its possible you could need more.

I think you took the right approach. You started with too much, then trimmed back until it was just right. Now you know you have the maximum block while still having good temperatures.

I kept my grille block a little on the too-much side too. When i came to a hill or heavy traffic, i turned up the heating a little to dump excess heat. It worked well. The reason i did this was that i mostly drive at night or early morning so i need the extra blocking in place. The odd time i drive during the day but didn't want the hassle of constantly re-installing the extra bit.

ollie

I too had an over-aggressive rad/grille block setup for a while this winter.

A cardboard shipping box, when completely flattened, provided a near-perfect cover of the radiator.

In my case, the rad is behind the A/C condenser, which allowed the cardboard to completely cover the radiator as a sandwich. Consequently, even in temps in the single-digits F, caused the FWT to rise to "levels of concern" and required a robust heater blast to maintain proper cooling.

The plan is to hack away at the center sections of the cardboard to allow some flow (right now I pulled it entirely, until I get a "Round Tuit" to cut and re-install the cardboard.) On cold-starts without an EBH hookup, it takes quite some time to sufficiently warm up, especially with the Arctic blast lately. TC engagement is still a problem...

On nearly all brand new cars I've tested, the torque converter will engage when the coolant temp is literally 10F and sometimes below! What gives? I have to have 190F+ and IATs in the 90's for that to happen. Argh. :mad:

At any rate, there is a compromise, but significant testing can only reveal what works best in each individual application as far as the block is concerned.

-Rick

Your experience is similar to mine. I have a large lower opening and a small upper opening like yours. I started by covering the entire lower opening. In warmer weather this proved to be too much, cruising temps were higher and the fan often came on when idling or moving slowly. I made an opening about the width of the license plate and things pretty much returned to normal. For the winter I have the entire lower opening covered. What I want to do is put an insulating blanket on the bottom of the hood. I noticed one day after it snowed and my hood had about 2" of snow still on it that the engine had no trouble maintaining normal temps even under low throttle. Interestingly enough, my Firebird has a hood insulating blanket, which is completely counter productive since it is only driven in warm weather. I plan to assess the feasibility of moving it to the Escort, but I probably won't be able to until the weather is warmer and it is no longer needed.

Hi,

Since I am using tape for my grill block, it was easy to keep adding to it, until it was too small.

You'll want to remember, though, that if the grille block is sized right now, it'll be too large come July.

The opening(s) for the grille block will yield the most cooling per square inch if they are directly in front of the radiator fan. Better to block the sides, and open the center.

How much over 200* F? Does the fan cycle on an off in slow moving traffic or just run constantly? I'd want the former or be d**m sure my temperature gauge read accurately and never climbed over 202* F??? (No good source/reason for choosing that number. But there would be a number and it sure would be well under 210* F.)

If you go to History : Weather Underground, you can page through charts of the high/low temperature for you're area during the last year - like this -
http://www.wunderground.com/cgi-bin/...pe=3&width=500

and thus make an educated guess if size of the current opening will be a reasonable compromise for the next couple of months.

I had a '90 Pontiac Subird, where-in the controller for the TC went bad, and once it locked up, it would not unlock until the car cooled down. I ended up cutting the wire to the controller and just using a switch to operate the TC manually. May be worth it to consider that if your TC is a simple one that operates from 12V.

As for my grill block, I have my radiator 100% blocked. Doesn't cause an issue until the temps rise above 40F. But then my engine is out in the wind, getting air cooled. I don't worry about it going over temp, my gauge has been tested to being fairly accurate, and it hits the red at about 260F. Last winter I was forced into using the highway for a short period during a not-so-cold day, and I was in the red for the last mile before getting off to surface streets. Engine is still running fine, though. So I don't worry if I get between normal and the red, as it usually starts warming my intake at that point.

the fan barely kicks on at all now temps right now in the 20-30s range, fan kicks on at around 205*...but 95% of the time, it chills right at 177-184 range

how about 215*F- 220*F temperature range. Is that would be still safe?. I can adjust my fan switch with dial any temp I want. Is higher temp is more efficient?

You're right Daox, driving style DOES matter.
About 3 weeks ago it was -24 deg.C here and my Dad-in-law muttered something about blocking his radiator because his engine was taking its sweet time to reach operating temperature. So that evening I put cardboard on two of his three grill openings. When the temperature outside rose to -10, his fan started turning on by the time he would get to work. So I reduced one of the grill blocks. Today it was warmer still (around freezing) and his fan was on and off as soon as his speed dropped below 80kph. I'll have to totally unblock the grill this evening.
Now, when I put cardboard on his grill, I blocked mine with plastic (from old windshield fluid containers - there's something for Christ's recycling thread). I also clogged the holes in the front of my engine tray. With these mods, my temp. needle starts budging after only 4-5km. My car sleeps outside and has a diesel engine and I read somewhere that diesels take longer to warm up. This may be because gassers are less efficient and waste more energy as heat, I dunno.
Compare: My Dad-in-law's car has no undertray, no blanket under its hood, open grills and weights under 1 ton. And his temp. gets into the red zone whenever he slows down. My car has an undertray under the engine, a blanky under the hood, almost totally blocked grill and weights 1.5t and I've never heard the fan, even standing in a gigantic traffic jam when it was still warm.
Driving style: Dad's right foot is pretty heavy. Not only on the gas pedal, but also on the brakes. He accelerates all the way until he has to start braking hard. Even when he sees the red light in front, and knows he'll have to stop anyway. He doesn't coast. He hardly does any engine braking. His hearing isn't perfect anymore, so he doesn't mind the engine wailing way above 3000rpm. He doesn't see a reason to throw in fifth gear at 90kph or even fourth at 70kph. The best reaction to me talking about ecomodding and driving style at dinner is that "it's not worth it", "it doesn't work", etc. On the other hand, I do my homework, read about new techniques and try them myself. Sure, I floor it or drive fast sometimes, but not when I'm zeroing in on a red light. The best time to see the differences in our driving styles is when he borrows my car. I reset the FE-ometer before giving him the keys, and check it when he gets back. It's about 20% higher than when I do a similar trip. He can see the readout. But it doesn't register as bad, since my diesel will always use less fuel than his gasser. His car gets 8-9 l/100km (26-29mpg), while my car gives him 6-6.5 l/100km (35-39mpg). I get 4.5-5.5 (43-52mpg). When I drive his car, I hardly hear the fan, and somehow do 600km on one tank instead of 450km.
Going easy on your engine will keep its temp. below the red zone. But, of course, your gril block has to be sized just right.