My first mod: grill block
 

Hi all,
I just did the first modification to my car (European Civic Sport 1.4 i-DSI, modelcode FK1): grill block.
Started yesterday, with 60% up and down to work (approx. 20 miles one way). I noted no difference in FE and engine temps (I made a 30 min recording of engine temp, radiator temp, oil temp and vehicle speed). Board computer average FC did not drop yet, stayed at 5,7 l/100 km.
So today I changed to a 90% block ! But only on Monday I will be able to test this one going to work. The 30 % added block can be removed very easy in case of troubles.
If anybody can tell me how to attach pictures in a thread... I will show you what I did. Especially: where should I upload my pictures to, so I can fill in the link that's asked by the system? Sorry for this question.
My question: does anybody ever made a grill block and experienced no (positive) effect on FE ? Or did you all made gains by grill blocking?
Thanks

Hello,

To insert and image to a thread first you have to host it, on photobucket or imageshack. Upload the images you want from your computer to any of those sites and an url link will be added to each image. To place the images in the thread just copy the url's you desire.

To answer your question: I have always experienced positive results due to grill blocking, but you'll have to find out which % of the grill area needs to be blocked. I suppose it's cold now in Belgium, and probably a 90% grill block is fine but keep doing your measures.

Thanks Karr ! I really didn't know on what site to host photo's. I took Photobucket.
Cold in Belgium? Well not really. Very stormy and rainey, but temperatures will drop from tomorrow on. Today still 10?C, tomorrow morning should be 1?C.
Here's a picture. Hope it works.
https://www.fuelly.com/attachments/fo...90542bdfcf.jpg
If you say you had positive results, do you mean your fuel consumption decreased, even in colder wheater?

As I posted in response to your question in another thread, I have not measured any fuel economy improvement from grille blocking. However, I still recommend trying it; it is free, low-risk, and is effective for many people. I do it in the winter just for the quicker warm-up.

With a pic of grill block!
 

Thanks Holy Cow. I just now saw and read your reply.
As you see: picture works.

Yes, that's what I meant. I've confirmed an improvement on the first tank using grill block. But I must say that by "grill block" I mean that I've blocked the air flow through the radiator, because the block is made inside (the inner part) the front bumper. I haven't made any aerodynamic modification. I think I should be saying "radiator block" instead of "grill block", because they might mean different things, according to what I have read in this forum.

First results
 

Drove today to work with the 90% block.
First conclusions:
- the difference with 60% block is HUGE !
- oil temp rose for the first time above 85?C (to 88): good news
- average fuel consumption of this tank went from 5,7 to 5,6 l/100km according to boardcomputer (and tank is 2/3 empty !) on a 2 times 30 km commute: good news
- cooling capacity with 90% block is not sufficient anymore (approx. 6?C outside), I had to turn on the heater 3 times to get rid of >90?C temps of the engine block (I tried to avoid fan activation and succeeded)
- the 90% block makes me nervous because overheating seems possible and I have to watch the temps all the time aftere 20 minutes driving.
- with 60% block radiator temps went only up to 22?C, 90%: >80?C.
=>90% block is only good for less than 20 minutes driving
I will keep you posted about further evolutions and results.

You'll want to slowly make the hole in the block larger until the risk of overheating has been reduced.

Just take it in little steps at a time, and monitor your progress.

Hi Jay,
I did as you suggested.
I did not decreased the amound of block, but slided the extra piece of plastic more to one side on the grille (exterior block part). So the airflow comes straight onto the radiator now by a small square hole. See pic:
https://www.fuelly.com/attachments/fo...3eb0c759ff.jpg
Result so far:
- For daily commute perfect with 6 to 8?C outside temps (30 to 40 minutes one way mixed roads).
- Had to drive one hour 100% highway: not good, heat keeps on building up and that makes me nervous (94?C engine block and 92 at radiator).
- Oil temps go over 90?C on highway (normal value I think and I never measured before on highway the temps).
- Fuel consumption stayed at 5,6 l/100km, but that's normal as the tank is almost empty now and changing this will be quite impossible. Think it's a good value for winter time.
So when I returned home for another 1 hour highway after only 10 minutes rest for car (still hot !) I removed the extra external block and saw as I expected an enourmous temp drop at radiator side (as if there's no block at all, while I'm still having 60% blocked).
For the moment I will keep the 90% block slided to one side so radiator has cooling. I will prepare an extra second external block to see what fits for longer rides (highway or > 45min trips).
I will keep you informed of further results.
Right now my first impression is possitive as my fuel consumption doesn't increase in winter (1 to 8?C outside).

You'll definitely need to be less aggressive with that. If it's heating up like that on a normal drive, it'll break that one day when you're in an important hurry.

Maybe you're right Holy Cow, but I thought I was not aggressive as I see some people block 100%.
By the way: my cooling fan never even came up once. That's why I think I'm still on the safe side. If they don't come up it means the temps are still within the normal range (not over 95?C engine block side).
To be honest I would not dare to drive with 90% block without the diagnostic tool to see the temps. With 60% block there seems to be no risk at all and I'll drive it around like that on long distance if I don't use the tool.

every car is different. you can't see my opening for my car because it is underneath. it was designed that way. the grills on the front of my car did very little and were there mostly for aesthetics (to look good)

for that very reason, I blocked off the entire thing. I did do it in steps similar to yourself. I blocked it off using wing nuts so that it could be removed if it was needed.

also, shouldn't your coolant temp be constant? my T-stat regulates the temp within about 5 degrees all the time. hot, cold, it doesn't matter. I always run around 195 F (~90 C) I think my fan kicks in around 210 or 215 F (not sure the C value)

the big point is that all cars are different. unless you have the same make and model as someone else, they can't say whether it will work or not. even then, you have body style changes from year to year that may affect it.

My 2008 VW Rabbit and my 2002 GMC Sierra both work fine with 100% blocking at the grilles (upper AND lower) or at the radiator. However, I would not do it if the temperature was affected more than a few degrees in normal driving.

Thanks for the replies.
My engine temp is nomally 85?C (by thermostat regulation).
If I want to keep it 100% safe, I guess I will have to stick with the 60% block (behind the grill).
I will only mount the extra block when freezing or short distances (no more than 30 min).
You guys are right: it should be safe. It's not worth the risk of damaging my engine.

why don't you put the 60% on the outside of the grill? you could trace the opening on a piece of plastic/rubber with a silver sharpie and cut it with tin snips. drill a few holes in it and use wire ties to hold it in place. you could even use black ones to blend it better.

you get a slight (very very slight) aerodynamic advantage with having it on the outside of the grill vs the inside. also, if you take your time and make it match the opening, it actually looks better.

that's just my opinion.

I do agree that safety is more important than efficiency. if you can double your mileage but you have to replace the car in 6 months, you have accomplished nothing (you may actually be on the negative side of that equation)

I didn't put it on the outside (yet?) because:
- I do not (yet) have a big enough 100% flat black piece of plastic
- I wanted the car to keep its original look
- I think the difference in aerodynamics will indeed be very (!) slight
- It's a testphase and I need to be sure about two things before wasting a few hours only on cosmetics: proven result and the surface% that can be covered.

About the aerodynamics part: I saw somewhere the flow on an apple (top of the apple) and its aerodynamics are still very good as the hole in it is filled with air (water it was in this case).
For your info: the black plastic I use comes from the aerodynamic undersidecover of another car. These are big, but theye are not flat. I don't want to use this on the outside.
I already used black wire ties for the permanent block. You don't see them, don't you?

:thumbup: Test with cardboard, coroplast, or any material you have available...behind the grille. Then when you're ready, if you think you can do it on the outside, great.

Forgot to tell (with pics)
 

I forgot to tell something. Together with installation of initial block I changed the internal airflow to (...through in fact) the radiator). The stock design lets a lot of air pass over the radiator. I blocked this, in such a way that air entering the car is forced through the radiator or at least will bent of to the air intake. Main reason: improve cooling capacity.
On the picture you also see a yellow wire. This is connected with the internal grill block. In case of emergency I can simply cut the wire ties from the outside of the grill an pull out the block. First picture is original, second with the air forced through the radiator.
https://www.fuelly.com/attachments/fo...ce6f15948c.jpg
https://www.fuelly.com/attachments/fo...65ed9ceee3.jpg

I can't really argue with doing it for experimentation.

when you do get to the point where you want it permanent, a suggestion would be to get a garbage can (large, round, plastic one) and cut it up so you will have a large flat piece. I think they come in a variety of colors too. I want to say the one that I bought was $15 or so. they are relatively inexpensive. I used it for an airdam that I have since taken off. it was easy to use and maybe something to consider for the future.

jay2therescue actually used a broken trash can for his grill block since it was big enough for his purposes. I think he paid a dollar or two for his since it was broken.

Yes, I was at Lowe's and saw 2 cracked black trash cans. Got them for $1/ea after taking them to the service desk and explaining what I wanted to do with them.

Yeah, I know ! I read this already weeks ago on this site. That's when I was preparing my mods. Nice stories.
I can get some more black plastic undercover of a car that's going to be thrown away. I will stick with that I think, and maybe even make a sumpcover for my wife's little car.
If somebody's interested: today I filled up my Civic's fuel tank! First time after mounting grill block =>
EXACTELY the same fuelconsumption as the time before (6,07 l/100 km), also boardcomputer showed exactely the same as previous time: 5,6 l/100 km.
After all, I'm not unhappy with this result given the circumstances (compared to my previous fill up 3 weeks ago):
- very stormy wheater
- a lot of rain and water on the roads
- always headlights on (morning and evening) and wipers
- grill block only 1/3 of tank on it
- winterpetrol gives less energy/liter
- 80 km after mounting grill block BC showed -0,1 l/100km for average consumption of this tank
More news next time !

if you can keep summer mileage through the winter, you are doing good.

BTW, I really like your car. the back doors look similar to the chevrolet spark that should be coming to the states next model year. I wish honda would bring that style car to the US.

Love it! That's how I got wiring for my stereo. The store had irregular lengths for sale for pennies on the dollar.

It's amazing what you can get if you just ask - and keep your eyes and ears open.

Keep us posted, your research is very interesting.

You can count on it, I will post my findings for some coming fuel tanks. I'm lucky I don't drive a lot, so 1st complete tank with grill block is still 'going on'.
Situation after approx. 65% of this tank: BC is on 5,6 l/100 km and that is according to me a success as temperatures are low (for Belgium...that means right now just freezing -1 to -5?C).
As Beef already said: I should consider this mod successful if I can keep a steady fuel consumption in winter.
Because of the freezing temps I now have the grill covered for approx. 95%.
I'm monitoring the temps very carefully with a diagnostic tool and in this wheater there's no risk for overheating. The cab heating on its own is taking all the exessive heat of the engine. Radiator temps hardly reach 25?C when freezing and the engine reaching its normal 85?C takes almost the full 30 minutes commute. Oil doesn't reach its normal 85?C. I've noticed the oil has a real cooling function: from the moment on the oil does reach its 85?C the cooling capacity is unsufficient when blocking 90 or 95%. But as said: no risk for this when freezing. With the diagnostic tool in the car I take no risk and can experiment 'unlimited'.

My '04 Dodge Dakota 4.7L V8 used to overheat because of a bad aftermarket thrermostat. I would just crank the heater up and roll the windows down to cool the engine off quickly.

I suggest cracking a window on the passenger side to give the heat a place to go. :thumbup:

Block grille too much and use heater and open window to vent extra heat seems like a pointless procedure, now you're still getting rid of the same heat and you've got the aerodynamic disadvantage of an open window instead of an open grille.

I know man,
I will remove (a part off) grill block the moment on my engine can't get rid of its heat on a normal way.
As it is now I never had to open a window and I only had to turn up cab heating one time to cool the engine (with closed windows, it's winter and a few degrees more in the car don't hurt).
Thanks for your care and tips!

Brings back memories of a day years ago, in a 1962 Rambler American (basically a 1939 Nash with a more modern body) midsummer, about 105 degrees, on the Ventura Freeway in LA, puttin' along at about 2 MPH (there was a chemical spill, and traffic was backed up for miles and miles) and I sat there, watching the temp gauge creep up and up (belt-driven fan, turning slowly), finally had all the windows down and the heater at full blast...sweat so much I lost about 10 lbs!

Back to subject at hand...I am trying a 1/2 grille block on the Geo...so far haven't noticed much gain (in fact, my MPG has actually dropped, but I think it is because I have been driving faster lately...)

Unlucky wheater conditions yesterday and today.
Now the freezing temps are no longer alone. Snow accompanied them. And believe me: not a bit!! Exceptional wheater in Europe (Belgium, France, the Netherlands, Germany...). Took me one way 15 minutes longer to go to work + very slippery roads with loads of snow + slipping wheels + windowdefrosting + aerodynamic advantage of grill block doesn't play at these low speeds.
So my fuel consumption increased first time with grill block: BC shows now 5,7 l/100 km (was already a long time 5,6). This is less than 2% increase. Tank isn't emptied yet, but the weather forecast is clear: this weahter continues the coming days. I read on European Civic forums that fuel consumption in winter can increase from 10 to 20%. So my 2% doesn't look bad.
It's a pity I can not compare the car's fuel consumption with last years winter as I drive her only since mid September.

1st complete grill block tank emptied
 

I'm happy!!
Even in the worst possible wheater conditions my fuel consumption decreased a little bit (1,5%).
I know one fill up is to early to make any conclusions, but this looks good.
Have a look at my gasslog for details.

I would wonder why it takes 30 minutes of driving, even in freezing weather, and especially with a grille block, for the engine temp to reach 85C. My '83 Cad (which has a feature on its computer to get diagnostic info, such as coolant temperature) will reach that in about 5 miles of driving, or maybe 10 minutes of sitting in the driveway.

I haven't used a grille block on the Cad because, living in the desert, the idea of blocking air flow to the radiator just seems wrong.

JoeBob, I think it's because :
- the way I drive. I don't waste much energy
- the very efficient engine (the more efficient an engine, the slower it warms up)
- freezing weather: the cab heater takes the heat from 50?C on (than the fan comes on for the cab).
In warmer conditions (18?C ambient) and some sunshine I reach 85?C much quicker (less than 10 minutes) => no cab heater on.
Without grill block, I didn't even reach 85?C after 30 minutes.

I've blocked my radiator 90-95% with some cardboard between my radiator and AC condenser. I have some slits cut in it so the cooling fan will do something when it kicks on.
For the most part i wouldn't know it was there. The water temp doesn't get out of it's normal range, except when i'm driving up hill for 1.5+ miles or when I drive over 65mph (not often for me). But in these cases all i have to do is blast the heat to bring it back down.

I don't have any scanning equipment yet, and i can't say i've notices any FE improvements. I do like the quicker warm up time, which must save some fuel.

Dr. Jerryrigger, you should put notes in your gaslog so that it's easier to remember when you did things like that, and also so it's easier for other people to see how it affected your fuel economy.

That is true. I should also enter gas logs more often, so i remember those things. I think i'll add that note in to approximately when i did that.

Have you tried toughing it out without the cab heater, at least at the beginning of the trip? Speeding up the warm up time should improve economy. It may even heat up the cabin quicker. That may be a matter of perception, but I prefer waiting for a blast of heat instead of getting a trickle from the start.

I didn't because my car does it 'automaticaly' for me. If I don't set my heating on a safety related position (defrost for windows) AND it is set on automatic, than the system will wait to blow warm air until engine coolant temp is 50?C. And that is according to me hot enough to let the engine run rather economical. The moment the cabfan comes on it's right away pretty warm.
I also checked the heatercircuit: there's no valve in it that stops the coolant from circulating to the cabheater if you don't need heat. So there's a loss anyhow the first minutes, even if you don't need or ask heat.
To be honest: for safety reasons I don't want to drive uncomfortable (cold, with a thick jacket). I like it to be in a sweatshirt maximum. Makes me feel much better behind the wheel.

I agree. Comfort is of the utmost importance to me. I can drive safely when uncomfortable, for a short time, but as I get tired of discomfort my driving can suffer. Efficiency suffers much more quickly; if I'm uncomfortable, I get impatient.

I've never been a fan of automatic climate controls in cars. I'm usually happy, weather permitting, with just ambient airflow through the vents. Most auto systems I've come across don't let me do this without risking heating the air, or turning on the compressor to cool it. It's great that your system waits for warm up.

Systems without a valve to control coolant flow to the heater core instead control air flow over it. Don't call for heat and there is no airflow. There is still loss over a coolant control system, but it isn't drastic.

I agree comfort is important. Perhaps I am more temperature tolerant than most, but I'm usually fine going a mile or two without heat. Past week I have also been taking advantage of the remote start while walking up to the car.