Grill block / WAI side effect?

[Andrew63]

I installed a partial grill block on the Little Green Car. Now I notice that there is pinging. I don't know why, but I didn't think that a grillblock would cause a Warm Air Intake effect and require a timing adjustment.

Is this in line with your experience with grill blocks?

[California98Civic]

Originally Posted by Andrew63

I installed a partial grill block on the Little Green Car. Now I notice that there is pinging. I don't know why, but I didn't think that a grillblock would cause a Warm Air Intake effect and require a timing adjustment.

Is this in line with your experience with grill blocks?

In a year I don't think I have heard this described once. I think you probably are observing a coincidence, not a cause and effect relationship.

[Ecky]

The 96+ Hondas should all have knock sensors and automatically retard timing, if I'm not mistaken. Something funny is going on.

[California98Civic]

Originally Posted by Ecky

The 96+ Hondas should all have knock sensors and automatically retard timing, if I'm not mistaken. Something funny is going on.

Only the V-TEC models (EX and HX) had knock sensors in the early sixth gen, though maybe they all had them by 99-00. Mine is a 98 DX. No knock sensor. But the car does adjust ignition timing electronically, just not valve timing.

[Daox]

I've watched intake temps on my Paseo with a FULL grill block. It might get warm air while sitting at a red light, but without a bellypan and more sealing the intake temps drop right down to ambient as you get moving. I should also mention my Paseo sucks intake air from the engine bay.

[oldbeaver]

Originally Posted by Andrew63

I installed a partial grill block on the Little Green Car. Now I notice that there is pinging. I don't know why, but I didn't think that a grillblock would cause a Warm Air Intake effect and require a timing adjustment.

Is this in line with your experience with grill blocks?

Did you make a hole for air intake flow?
I made a grill block for my turbodiesel car, but aldo made one opening on it, to allow cold air to get into admission.

Oldbeaver

[Andrew63]

Intake air is taken from the engine compartment. I did not do a full block. I blocked the section that is in the bumper below the license plate mount; the opening above the bumper is completely open.

I suspect that LittleGreenCar needs a timing adjustment or a knock sensor.

[brucepick]

These Civics can also get a hard carbon buildup on the cylinder tops that the valves hit against when they open. It sounds a heck of a lot like "knock" or ping.

My wife and my carpool buddy both insisted my Civic was pinging. I tried retarding the timing to various degrees with no success. At one point I had it retarded so much that it ran poorly and gave a check engine light due to lousy combustion; I promptly set it back to a more normal amount of advance. Still made the noise but ran stronger.

Mine finally had enough valve trouble that it needed a head rebuild, and when my buddy got the head off I found a huge buildup of hardened carbon on all the cylinder tops. Easily a 1/16 inch thick of HARD stuff, which I removed with considerable effort. After the head rebuild the persistent "knock" was gone.

[ojman873]

How do these deposits build up? Are there means to prevent or correct it without physically disassembling the head and/or rebuilding it? Is the problem unique (or uniquely worse) in Hondas?

[ps2fixer]

Originally Posted by ojman873

How do these deposits build up? Are there means to prevent or correct it without physically disassembling the head and/or rebuilding it? Is the problem unique (or uniquely worse) in Hondas?

From what I have read, it seems it is a large side effect of idling too often. For how most people drive on ecomodder, it might be a fair idea to loose mpg once every 2-3 months and drive a bit harder on the car (freeway for example) to help clear out the engine.

Seafoam helps a TON with carbon build up.

Back on the main topic, I gained a WAI effect with my grill block, but prior to the last part of the block (lower) I sealed the hood and installed an upper grill block. I have no belly pan yet. Engine temps went from 202 to about 213-220 and intake temps went from about +5F over outside temp to around +50, not quite as hot as some WAIs, but still it is warmer. I notice no ping or timing changes via scan gauge, just a MPG increase and lower engine loads .