grille blocks, fan kicks on

[malibuguy]

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




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

[Daox]

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.

[PaleMelanesian]

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.

[vtec-e]

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

[RH77]

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.

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

[Formula413]

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.

[NeilBlanchard]

Hi,

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

[jamesqf]

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

[TestDrive]

Originally Posted by malibuguy

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

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 -


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

[The Atomic Ass]

Originally Posted by RH77

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.

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.