TheMagikMan

How does everyone have their hood insulation set up? My biggest theory to my engine heat issues right now is that hot air is getting in but not out, and I was wondering if anyone else still has their hood's rear seal and insulation installed, or if it's common to delete those for better cooling performance.

1989karr

I have a Formula and opened up the bulge so heat comes out... quite a bit comes out and you can feel the LS1 fans pulling the air and what not. and pushing it out the opening...I imagine that removing the rear hood would cause water to go right onto the distributor.. Never heard of anybody doing that.



I heard you can make the TA side vents operational... i dont know how much that would do sionce they are esentially just slits.... ... but I never heard of anybody removing the seal for cooling.

Tom 400 CFI

I don't think that is happening. The car is as GM designed it, right? Don't all of the other 100'000's of Firebirds that were build in those 10 years extract air sufficiently to cool their engines? I mean, the entire underside of the car, under the hood is wide open. Plus the fender vents. I think that there might be a larger space for air to escape, than there is for air to get in.

1989karr

Unfortunately, the fender vents are just for looks

TheMagikMan

Unfortunately GM designed these cars very poorly for airflow, and I have also taken the hood on and off several times, so it may be out of adjustment or something similar. I can't feel any air escaping anywhere when I have the car idling in the driveway with the fans on, not out of any of the vents or the underside, and it cools fine when the hood is open, but when I close it the temperature creeps. Heat rises, and unless I'm moving and ramroding enough air into the front end, it has nowhere to go, especially with all the clutter in my engine bay. My car still has all the emission equipment intact to pass a PA emissions inspection and has headers. My underhood temps are extraordinarily high to the point where my glasses fog up when I open it, similar to like when I open an oven.

Tom 400 CFI

Yeah? How do you know that? How are "everyone else" getting along w/this poor air flow issue? I had a SBC 400 in a Trans Am, with stock rad, water pump Taurus fan, and underdrive pulleys, even. It cooled good enough, in all conditions.


The majority of air escaping w/the fans on should likely be felt exiting under the driver's side of the car behind the front wheel. If you can't feel air blowing out there w/the fans on, I'd say that the fans are insufficient.

That stuff is ALL "normal", stock type stuff/environment/operating conditions. Car should be able to stay cool enough with ALL of that; the emissions (that's stock), the headers, my car had headers, tons of people have 'em, etc. Any car will cool better w/an open hood. That's also "normal". All cars should and do cool good enough w/the hood closed though, and yours should too.

When the temperature "creeps up", what's it creeping up to?

dabomb6608

iTrader: (3)

*cough* airflow problems *cough cough* inadequate fans contributing to airflow problems *cough*

1989karr

THIS! Stand by your door and you should feel a ton of air coming out from this area. especially with LS fans... I got LS fans but I actualyl use the TPI fan motors and I feel a lot of air. here

dmccain

iTrader: (2)

TheMagikMan

@1989karr you might want to hear this as well, but when I stand on the drivers side with both fans on and the hood closed I get almost zero airflow out the bottom. However, I get a whole lot coming out of the passenger side wheel well and the corners of the hood. If I open the hood and I put my hand in to feel for airflow, my driver side airflow is stagnating right behind the AC compressor and above the header. What is a Taurus fan rated at for CFM and amperage? @dabomb6608

1989karr

It could be the way the Trans Am is with the GFX etc... I think I get a bunch on the passenger side as well. I'll have to check actually.



The taurus fan is probably the highest output fan you can get from a stock vehicle...it takes a LOT of power though.. I think its like 3,000 CFM on high

Airwolfe

iTrader: (1)

The under hood insulation pad is there to protect the paint on the hood from the oven under the hood trying to cook it and to absorb some of the under hood noise making the car quieter.

The rear hood to cowl seal helps to cool the car when driving down the road at speeds above about 35 MPH. It also prevents hot under hood air from being drawn into the HVAC intakes on the cowl at lower speeds or sitting still.

At low speeds and sitting still removing the hood to cowl seal will allow hot under hood air to escape and the engine can run cooler but as the speed increases to about 35 MPH the windshield to hood interface at the cowl becomes a high pressure area and it will force airflow backwards into the engine compartment. This will cause dead air in the engine compartment and the engine can run hotter at speed or overheat.

blacksunshine'91

iTrader: (10)

Hmmm. You think that might have an impact on your underhood temps? Have they been ceramic coated or some other method of reducing the heat those things give off?

TheMagikMan

Yes. Headers almost always have a negative impact on underhood temperatures, because they effectively increase the surface area of the exhaust tubing in the engine bay. More area = more heat emissivity. They were painted with what I believe is a ceramic coating from the SLP factory, but I have not wrapped them yet in an attempt to lower underhood temps.

Tom 400 CFI

Tons, and tons, and TONS of people run headers and don't "run too hot" or have temperatures "creep up"

Let's try this again:

TransamGTA350

iTrader: (2)

With everything working correctly, there should be no issue with cooling. The airflow through the radiator comes out the bottom of the car. No need for additional hood vents for that purpose. If the car is overheating, it's not because of the hood.

Hood venting these days is typically done to reduce aerodynamic lift, not for cooling.