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-   -   Summer grill block: how hot will you go? (https://ecomodder.com/forum/showthread.php/summer-grill-block-how-hot-will-you-go-26050.html)

knochenhauer 06-02-2013 08:50 PM

Summer grill block: how hot will you go?
 
Greetings! I was curious, how hot will you let your engine run in the summer heat with your grill block.

Currently running my Focus with full grill block at ~217f, max. Thinking of partial grill block.

How hot will you go?

Rango318 06-02-2013 09:34 PM

With my car being OBD1, I don't have any exact numbers. I know when the weather is cold, it usually sits just below the half way mark. At half way, the fans kick in. I have had it this year get up to 3/4 the way up, but that was in almost 90 degrees and with low coolant. If it gets any hotter than that, i will pull over to let it cool.

Xist 06-03-2013 02:12 AM

I only tried a full grill block at 5am and my engine was too warm. I think that it spent too much energy cooling itself because it actually got worse mileage than without a grill block.

slowmover 06-03-2013 09:20 AM

Diesel_Dave points out that the grille block has become a problem, not a solution, if coolant temps rise above thermostat opening because of it.

I work a 6/2 week. The short runs to/from work weren't a problem, bu the days off with errands to run finally got me to remove the lower of four portions of the GB once we became full-time in A/C season (May 1 last yer, June 1 this year).

Over-inflation of tires and blcoking heat exchangers can have some serious consequnces (braking for one, engine longevity on the other).

.

.

Diesel_Dave 06-03-2013 12:51 PM

Yes, you always want your thermostat to control your final operating temp. If your temps rise beyond the full open temp of the thermostat, then you've blocked the grill too much--a scary situation, because there's no longer any closed-loop control of coolant temp.

knochenhauer 06-03-2013 08:23 PM

Quote:

Originally Posted by Diesel_Dave (Post 374489)
Yes, you always want your thermostat to control your final operating temp. If your temps rise beyond the full open temp of the thermostat, then you've blocked the grill too much--a scary situation, because there's no longer any closed-loop control of coolant temp.

At what temperature does a typical thermostat open fully?

Gealii 06-03-2013 08:55 PM

Quote:

Originally Posted by knochenhauer (Post 374582)
At what temperature does a typical thermostat open fully?

Depends on the temp of the thermostat

And as far as the original question i keep it around 189F as after 205F my efans kick on which only happens with a full grill block

redpoint5 06-03-2013 09:07 PM

My T-stat is fully open at 190 in my TSX, and the fan kicks in at 213. I initially did a full grill block during the winter and had no issues with trips of 30min or less, but driving an hour on the freeway had the fans cycling on every minute. Since then I have opened it up 25%.

I'm curious if blocking could cause other problems due to under-hood temperatures rising. Has anyone done a before and after comparison of under-hood temps? I'd hate to loose a PS pump, AC compressor, or some engine management computer due to a grill block. There are electronic ballasts for my headlights in the engine compartment and I'm concerned about the heat there as well.

On top of all this, the AC radiator relies on airflow from the grill for cooling. I'm wondering if the cabin cooling efficiency can drop too low even if the engine radiator is getting sufficient airflow?

UltArc 06-03-2013 09:08 PM

I keep 100%, my temp gauge temperature gets to 220* at its very highest, once in the past (v6 fascia, NO aero mods, I hit 223* on a 3 hour trip with the entire front of my car covered with tape) it went to 223, but not since. My temp gauge meter shows a 89.9*. Just a tiny little hair from being directly straight up, it leans towards cool. It has never been towards the hot end, so until I am further educated, I think I am good with my setup. She has seen as hot as 90*s outside.

I hope to learn from this thread, as I am trying to be careful, yet keep the engine warm.

mcrews 06-03-2013 10:13 PM

225 starts to worry me.
I went w/ just a lower grill ojn the kia sportage. Had a partial on upper and hit 225 so I removed it.
now I get 217 as a high

Diesel_Dave 06-03-2013 10:18 PM

Quote:

Originally Posted by knochenhauer (Post 374582)
At what temperature does a typical thermostat open fully?

Each thermostat is different. Typically thermostats are specified by their crack open temp, i.e. a "190 deg stat" starts to open at 190 deg F. For most stats I've seen, full-open temp is ~20 deg F above the crack open temp.

knochenhauer 06-04-2013 11:50 AM

Quote:

Originally Posted by Diesel_Dave (Post 374598)
Each thermostat is different. Typically thermostats are specified by their crack open temp, i.e. a "190 deg stat" starts to open at 190 deg F. For most stats I've seen, full-open temp is ~20 deg F above the crack open temp.

Those numbers make sense. I removed my upper grill block yesterday to test a warm engine temperature difference from full grill block. My max operating temperature was ~20f higher than when thermostat would crack open.

Full grill block operating temp: normal range 200-214f; max 217f
Partial grill block (~70 square inch opening): normal range 172-176f; max 178f

Three important details I noticed:

1. Even with a full lower grill block my oil temperature barely approached a number that would open the thermostat.

2. The operating temperature dropped dramatically with just a minimal grill opening. It seems, for this Ford Focus at least, that a grill opening of ~20 square inches would allow sufficient cooling without operating fan.

3. For those of you running a grill block without a ScanGauge or Ultra Guage, be careful. Although the UltraGuage registered the full range of operating temperatures, my dashboard temperature gauge did not move noticeably (even while approaching 220f). Your in car temperature gauge may not tell the whole story; don't ruin your motor because of some stupid grill block.

Diesel_Dave 06-04-2013 01:36 PM

Quote:

Originally Posted by knochenhauer (Post 374664)
Full grill block operating temp: normal range 200-214f; max 217f
Partial grill block (~70 square inch opening): normal range 172-176f; max 178f

I repeat, the grille block should NOT influence the final operating temperature.

The thermostat in your engine works basically the same way as the thermostat in your house--if you insulate, open a window, etc. it'll effect the efficiency of your HVAC system, but the final temperature should end up in the same place. If your grille block is increasing the final operating temp the equivalent scenario would be like turning on your fireplace and oven in your house during the middle of summer--if your AC system isn't big enough the thermostat will keep the AC on all the time but will never be able to get the temperature down to the setpoint.

FYI, here's a plot of coolant temp vs. time for my truck:
http://ecomodder.com/forum/member-di...ture5237-a.png
After warm up, the temperature should stay between the 2 bands (crack open temp & full open temp). I have a 190 deg thermostat. There's a little bit of funkyness that happens the first time the thermostat opens, because the fluid has just started to flow through the radiator the first time. Shortly after that, however, the temp should stabilize between the two temps. If it still climbs and goes above the full open temp, then all the coolant is being sent to the radiator and the engine still isn't being kept cool enough--a scary situation.

Mods like grille blocks, pre-heating, etc, may affect the inital rise, but should not affect the final operating temp. The only exception I can think of is in really cold environments with very light loading, the engine may not be able to get up to the crack open temp at all without a grille block.

Diesel_Dave 06-04-2013 01:45 PM

Here's a plot comparing pre-heating vs non pre-heating.
http://ecomodder.com/forum/member-di...ture5238-a.png
As you can see, the preheating affects the rise to the final temp, but not the final temp.

Miller88 06-04-2013 02:00 PM

On my Focus, blocking off 2/3 of the lower grille openings LOWERS the coolant temp by a consistent 2 degrees celcius ...

NeilBlanchard 06-04-2013 02:01 PM

My thermostat opens at 184F (though after a change in the black box it may be 186F). I have never seen a temp above 204-205F; which is where the electric fan kicks on.

I have a partial grill block that only has a ~15"x4" opening in the center part of the lower grill. I also have blocked of the "escape vents" that normally allows air to bypass the radiator. All the air that comes in through the opening in the lower grill then goes through the radiator.

knochenhauer 06-04-2013 02:26 PM

Quote:

Originally Posted by Diesel_Dave (Post 374691)
I repeat, the grille block should NOT influence the final operating temperature.

You are right. Based on your temperature vs time graphs, it seems I may not have run the engine long enough. Each of my test trips were 38 minutes with an operating temp difference of 25f. I didn't realize that it could take that long to warm the engine up. Sorry about the misinformation!

Your figure were very helpful.

Just for my clarification: For the safest engine operation, temperature should not exceed the temperature when thermostat is fully open, ~20f>thermostat initial crack.

Diesel_Dave 06-04-2013 04:08 PM

Quote:

Originally Posted by knochenhauer (Post 374698)
I didn't realize that it could take that long to warm the engine up.

It typically doesn't but that's what happens when you get 50+ mpg with a 6.7L that's basically 1,100 pounds of cast iron plus 13 gallons of coolant.

RedDevil 06-04-2013 04:13 PM

I find the grill block starts to affect FE negatively long before the fans kick in.
The reason is air intake temp.
The Insight has its air intake behind the rads, but it takes in fresh air from a snorkel above the rad.
The grill block means very little air flows to the rad, so when it gets hot the heated air rises up to the snorkel rather than flow through. While a hot air intake can give good benefits, it does not work fine combined with an EGR as the recycled exhaust gas obviously is also quite hot.

On cars that do not have an EGR and work well with a hot air intake, it may well be so that the benefit of a grill block has more to do with raising the intake air temp than with actual lower air resistance...

slowmover 06-05-2013 09:42 PM

Wow, D_D, I knew that pre-heating was a help -- and that my times s. distance would be different -- but that is one impressive graph commentary on the way you drive!!

That graph would be my like leaving home and essentially coasting downhill for 25-miles.

.

Diesel_Dave 06-06-2013 09:23 AM

Quote:

Originally Posted by slowmover (Post 374963)
Wow, D_D, I knew that pre-heating was a help -- and that my times s. distance would be different -- but that is one impressive graph commentary on the way you drive!!

That graph would be my like leaving home and essentially coasting downhill for 25-miles.

.

A lot of that is the engine-off coasting. That's the "sawtooth" signature that you see imposed on top of the traces--the engine cools down somewhat during the engine-off portions.

modproductions 06-06-2013 12:18 PM

Toyota matrix 2013

Normal temps without any grill block = engine 87°C

With upper grill block:
outside temps lower than 25°C = engine 89°C
outside temps between 25°C and 30°C = engine 90°C to 95°C
outside temps 31°C+ = engine from 95°C to 98°C

I don't worry as long as the engine is in the 2 digits temp.

echo-francis 06-06-2013 02:18 PM

how hot will I go? if my radiator fan is not running its good:D

pjbgravely 06-07-2013 05:42 PM

At least on my two vehicles I found the blocking the decorative upper grill improved cooling as some of the air was coming out of the grill after it entered through the bottom intakes.

So my case the grill block resulted in ~1MPH increase and better cooling for both vehicles.

Xist 06-07-2013 06:01 PM

Quote:

Originally Posted by pjbgravely (Post 375326)
At least on my two vehicles I found the blocking the decorative upper grill improved cooling as some of the air was coming out of the grill after it entered through the bottom intakes.

So my case the grill block resulted in ~1MPH increase and better cooling for both vehicles.

How did you figure out that?

pjbgravely 06-07-2013 06:37 PM

For the Mustang I did 3 tank averages with block on and block off and the MPH increased 1 MPG with it on. I didn't know about the cooling effects until I hit a deer. When it was repaired I noticed the AC wasn't as cold as I remembered. When I reinstalled the grill block The AC was ice cold again. So the block helped with cooling.

For the Dodge truck, it had cooling problems climbing hills with heavy loads. After the block the temp gage never moves off normal and I even when climbed a large hill that is known to over heat trucks with a 800# load and the gauge never moved off normal. The MPG gain was tested with a scan gauge since it only gets filled every 3 months or so. The increase was around a 1/2 MPG but at 13 tops it is still a 3% increase. Even without the increase the grill block is still well worth the effort.


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