Engine Compartment Temps

[Spindrift]

Now that the summer camping season is upon us, I fabbed a cold air intake system that dumps additional fresh air directly into the engine compartment through a 4" duct system. My thinking was that cooler, fresh air can't be a bad thing. In fact, under normal driving conditions (no trailer) I'm now reading engine coolant temps about 6+* cooler than before the system was installed. I'm looking forward to seeing the results when we hit the road for the long weekend. Now, if I can only figure a way to direct some of the air from the duct to my airbox...

Do you think the dumping of this much fresh air into the engine compartment will have a negative impact on the operation of the fan clutch? Or, has the lowered coolant temps that I've seen already answered that question?

For the summer only, I'm thinking about removing the weather strip which is located at the top of the firewall. This strip meets the underside of the hood front. This will create an opening to the engine compartment and the forward motion of the truck will create a low pressure gradient across the entire back edge of the hood. The gradient will draw air across the top of the engine and out through the opening. Any flawed reasoning here?

[gmctd]

The fresh air vent system is between the hood and the windshield - might not want hot engine fumes force-fed into that area.

[CleviteKid]

The angle between the windshield and the cowl is a HIGH pressure area from outside air flow. Many NASCAR type racers pick up their combustion air from this area for a bit of aerodynamic supercharging. This is also why your fresh air intake is on the cowl, to help force air into and thru the cab.

If you take out the weatherstriping, you will be flowing air INTO the engine compartment, and discouraging air from flowing thru the radiator and into the engine compartment. That could be a bad thing.

But at idle, or stopped in traffic, you will be exhausting hot air out this gap, and into the cab of your truck. The A/C system will not like that, and you might even object to the hot fumes.

Consider these concepts as you decide what to do.

Dr. Lee :cool:

[matt-max]

thanks, that is good info to have! i have been considering a functional cowl induction hood on the tahoe to take advantage of the air at the base of the windshield and keep those temps down

dr lee-
love the look of your truck. very sharp. obivously a lot of work has gone into it.

looking forward to your 2000th post.....

matt

[Spindrift]

My initial post may have been confusing. There are two separate issues here. The first one is the new duct system that originates under the front bumper. This system dumps fresh air into the engine compartment. Any adverse impact on fan clutch operation?

The second issue is removal of the weather stripping. Based upon the two posts by gmctd and Dr. Lee, I now know this is not a good thing to pursue.

[sidedump]

You could try Dynamats under hood liner. Had friends that used it on there cars. They said it really worked at quieting engine noise down and the hood was cool to the touch. It doesn't absorb the heat. It reflects the heat sending it on its way. Summit Racing sells it.
Has anybody ever used? How do you like it?

[ucdavis]

Sounds like you have both things right up to this point- 1) cool air "ram" fed into engine compartment in addition to that which by design goes thru radiator is good; as long as it doesn't interfere w/radiator flow & fan clutch operation when you need it, NP. 2) removing weather strip would likely steal air from the radiator flow by allowing it around top instead.
Your post brings up an interesting thought: you could also bleed off hot air that contributes to the heat soak by adding one of the stainless steel rimmed solar vents used on yachts. They have a convex profile and are solar powered so no batt drain:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=26448&item=2479932322
eBay item 2479932322 (Ends May-28-04 20:09:11 PDT) - SOLAR VENTILATOR VENT FAN BOAT POLYCRYSTALLINE BROWN
Interesting idea.

[Spindrift]

Originally posted by ucdavis:
as long as it doesn't interfere w/radiator flow & fan clutch operation when you need it, NP. Prior to the installation of my new ram air intake my fan would kick in around the 200* mark. Not to state the obvious but if I now see coolant temps beginning to rise beyond the 200*, and I don't hear the fan kick in, I can assume that my new system is interfering with the proper operation of the fan clutch. Correct, or is it more complicated?