Belly Pan slowing me down

[wildfire8]

I taped up the opening in the grill.
I put my front licence plate back on cuz everyone at work told me I need it on they got tickets for it.

[NeilBlanchard]

Hiya,

So, how's it working as you adjust the grill blocks? I'd get some foam gasket and try it all the way along the hood gap, including over both headlights. It comes in various thicknesses, and it has a (mild) self-adhesive -- it sticks to the edge under the hood, and compresses pretty easily.

[wildfire8]

Originally Posted by NeilBlanchard

Hiya,

So, how's it working as you adjust the grill blocks? I'd get some foam gasket and try it all the way along the hood gap, including over both headlights. It comes in various thicknesses, and it has a (mild) self-adhesive -- it sticks to the edge under the hood, and compresses pretty easily.

I have yet to test the new cuts.

Cool. Where do you buy it at?

[QuickLTD]

Anywhere that sells home improvement supplies will have a great selection.

[MechEngVT]

I apologize for being late to this thread, but a few pages back there was discussion regarding location of front opening in a grille block and I remembered some things I had learned during powertrain development cooling tests for an off-highway vehicle.

To maximize effective cooling from a minimum of grille flow area the opening should be as close as possible to the radiator hose that delivers the hot coolant to the radiator. On most production vehicles this would be the "top" radiator hose. It will depend on your vehicle where exactly this hose is, in one of my trucks it is top and center and the other delivers to one end of the upper tank. In a cross-flow radiator it may be near the top of one side or the other. The reason you want your opening near this hose is that the coolant is hottest at this point. For a given mass air flow the most heat exchange will occur with the highest temperature delta between the coolant and the air.

Corvettes and similar GM vehicles switched years ago to a "reverse-flow" cooling system. These vehicles pull air from underneath the bumper via a set-back air dam to flow through the radiator without a "grille" opening. Since most of the air flow is at the bottom of the radiator they experienced more efficient cooling by delivering hotter coolant to the bottom of the radiator which is traditionally the "suction" hose in the system.

My personal experience revolved around a diesel application that could be overheated because it could be loaded to 100% power at low vehicle speeds for long periods of time. This vehicle underwent a body restyling without a change in powertrain. There was concern about the potential reduction in effective cooling area (went from about 6x10 unobstructed rectangle to a 5x18 perforated cover). Dyno tests showed lower coolant stable temps at full load (when corrected for ambient). The flow area on the old body was at the bottom center of the radiator and the new body placed the flow area at the top of the radiator where the hotter coolant entered.

[wildfire8]

Originally Posted by MechEngVT

I apologize for being late to this thread, but a few pages back there was discussion regarding location of front opening in a grille block and I remembered some things I had learned during powertrain development cooling tests for an off-highway vehicle.

To maximize effective cooling from a minimum of grille flow area the opening should be as close as possible to the radiator hose that delivers the hot coolant to the radiator. On most production vehicles this would be the "top" radiator hose. It will depend on your vehicle where exactly this hose is, in one of my trucks it is top and center and the other delivers to one end of the upper tank. In a cross-flow radiator it may be near the top of one side or the other. The reason you want your opening near this hose is that the coolant is hottest at this point. For a given mass air flow the most heat exchange will occur with the highest temperature delta between the coolant and the air.

Corvettes and similar GM vehicles switched years ago to a "reverse-flow" cooling system. These vehicles pull air from underneath the bumper via a set-back air dam to flow through the radiator without a "grille" opening. Since most of the air flow is at the bottom of the radiator they experienced more efficient cooling by delivering hotter coolant to the bottom of the radiator which is traditionally the "suction" hose in the system.

My personal experience revolved around a diesel application that could be overheated because it could be loaded to 100% power at low vehicle speeds for long periods of time. This vehicle underwent a body restyling without a change in powertrain. There was concern about the potential reduction in effective cooling area (went from about 6x10 unobstructed rectangle to a 5x18 perforated cover). Dyno tests showed lower coolant stable temps at full load (when corrected for ambient). The flow area on the old body was at the bottom center of the radiator and the new body placed the flow area at the top of the radiator where the hotter coolant entered.

Is there any specific marking that tells you if it is the inlet hot or the outlet cool hose? If not how would I figure this out?

[lunarhighway]

i assume this is why most vehicles still retain a small top grill even when the opening is much smaller than the lower one. this is good information to bare in mind while doing partial grillblocks etc

[wildfire8]

Last night went out and was almost to 3/4 tank. When I got to my destination it read just above 3/4 139.2 miles. Usualy I try to get 100 miles per every 1/4 tank. When I saw that I was way past 100 miles for the 1/4 I thought wow I have improved my FE. When I got home from my destination it read just under 3/4 155.3 miles. I was surprised. I just got home tonight and it reads 199.3 miles and not even at 1/2 tank. I was just going to go inside then I thought I should look at how many miles I have till empty. My car and SG show about the same number off by 2. 325 and 327 miles

Pic 1 dash 139.2 miles
Pic 2 dash 155.3 miles
Pic 3 dash 199.3 miles
Pic 4 car and SC reading the same miles till empty 325 and 327
Pic 5 a test for a bumper block

The bumper pic block was tanken earlyer today I drove to a frew places and my temps where getting hot 215f. When I got to my first stop I took of one of the inner strips of tape off. Then when I left for my next destination temps where down but still too hot for me 202f. When I got to my second stop I took another inner strips of tape off. On my way home the temps where doing better still a little to hot for my liking but I am letting it slide for now. It was 195-197f.
I did touche up the tape on the grill block to hood. Added more to cover the hood gap. And when doing that noticed that my right front head light does not sit flush with the car like the left one does. I need to look in to that.

[MechEngVT]

Originally Posted by wildfire8

Is there any specific marking that tells you if it is the inlet hot or the outlet cool hose? If not how would I figure this out?

The outlet hose connects the radiator to the suction side of the water pump. These hoses are usually reinforced with an internal spring to prevent collapse from the pump's suction. You can typically squeeze the hose in a few places and feel this reinforcement. The other hose connected to the radiator will be the inlet where the heated coolant from the engine is first delivered to the radiator. You can typically squeeze this hose in the middle of a straight run and it will collapse rather easily. Don't try to figure this out with a hot or running engine though.

[NeilBlanchard]

Hi,

That's great that you are seeing positive results!

On the radiator inlet/outlet discussion -- I thought that most radiators feed the hot fluid in at the bottom of the radiator? I'm not sure that this matters really -- the heat is extracted from the coolant and transferred to the air *somewhere* in the radiator. From what I know about cooling, it is far more important to have good, efficient air flow; and the lower opening (near or below the stagnant point) is the best one both for the cooling and certainly for the air flow on the outside of the car.