Civic upper grill block questions
 

Fellow civic owners, do most of you block the upper grill area completely or leave a portion or leave a portion open for the radiator? I've been debating if I should block it completely or partially due to the high temps here in Texas?

I don't have a civic but I've seen both on here, from your other thread I saw you have a scangauge II and scangauge E so you could always do some testing to see what you're comfortable with. I recommend trying out a full block just to see. That will give you the biggest gains so it's worth a shot.

My upper block is a complete block. The lower is a little less than half, with the passenger side open. The rad on the passenger side is your cooling radiator. The one in the middle is the A/C radiator. I also ducted the remaining opening to the rad so the air that does get in must go through the cooling radiator. My fan does not come on very often since I did this version. But on long steep hills, the car will get hot enough to turn on the rad fan every time. The fan takes care of it. Brings me right down to normal operating temps.

Your stock t-stat begins to open in the 170s F. It is fully open by the 190s. My car will move between 194 and 199 when fully warm and driving on the freeway or something on a HOT day. If it goes as high at 206 generally the fan comes on right away.

Hope that's helpful to you...

He will not get away with even 50% lower grill block, I can block 100% upper, but lower I only had about a 25% and it got 107F out here and my engine still over-heated (235F). He can try the ducting idea, I didn't do that.

Agreed. By "less than half" I mean it's mostly open. Maybe 60% open, 40% blocked, and the open part is ducted to the rad.

Id do the lower as some hondas use the upper grill for a CAI like to route cool air to the cars cpu and engine intake.

upper grille
 

I wanted full flow to as much radiator as I could get,so I left the nose intact and created a new nose over it and a little further forward which had a reduced entry into an airtight duct which fed everything internally.

To answer the original question, yeah a full upper grill block shouldn't be an issue at all. If you want to start blocking off more than that, you'll have to watch that SG.