Engine Bay Temperature

[Pat]

I was wondering if replacing my stock air inlet system (filter, box, ducting) with an aftermarket system (open air filter) was ultimately a trade off.My car now has more air intake capability and more dyno horsepower, no disputing that. But with the hood down and ambient air temps over 105 degrees and my engine bay temps in front of and around the air filter at 140 degrees, I'm wondering if the insulating properties of the stock set up offsets the performance gains of the aftermarket system.I did the following experiment to prove insulating the air filter from the engine bay reduces the temperature of the air entering the engine significantly.As Sgt Mac would say, "elementry my dear Dr. Watson."I mocked-up an air filter cover that completely surrounds the filter, side and rear, so that air only comes in at the front. I positioned this insulation shield flush up againt the forward bulkhead cutout. The shield is about 1" larger in diameter than the filter. Material used was 1/8" corregated cardboard.Previous measurements over the past three weeks showed an unshielded 25-35 degree increase in air around the filter than ambient.With the shield inplace the air temp around the filter was only 10 degrees above ambient after 40 minutes of city driving 35-60 MPH. The outside of the shield was warm to the touch but the airfilter was neutral to the touch. So what does all this mean, first, I think that using a shield at the strip should be helpful. Around town, don't know because the experiment didn't last long enough (at least a couple of tank fulls). Second, raisng the hood after a race dramatically reduces the air filter temp to ambient in less than 45 minutes, maybe even sooner, I only checked after 45 minutes, even though the engine was still too hot to touch. Regardless, I had fun doing this.

[BigCars4Ever]

Great info! Adding a shield to my JLT is on my to do list. I was going to make and aluminum box frame with lexan pannels and then back light the filter with led's just for fun.

[bryanthomas]

Something I wanted to add to this convo: I have not drag raced but I've been to the track many times. I see a lot of people icing down certain components in between runs. All be it, most of these are some big horsepower, low E.T. weekend warriors, but would it have any affect what so ever on my car to ice/cool the intake before a run? My 'rauder has all the basic bolt ons, and gears with the appropriate tune, but do you think this technique would help me if I run it at Marauderville? I have a JLT intake BTW.

:burnout:

[Pat]

The types of intake systems you observed respond better to an ice down because of component design and location. Our intake is an intergal part of the engine with tubes running below the top of the intake so icing that part may not cool the "submerged" part.Raising the hood betwee runs will release the hot air trapped in the engine bay. The air intake filter, tubes and other attaching parts in the airstream should benefit.I'm for sure going to make a home-made filter insulator box to keep the air temp entering the system less than engine bay temp. This will be for drag strip used only until I get the S/C from winning the raffle. I'll also wrap it in heat tape like it's done on headers.