blueovalz Posted July 12, 2004 Share Posted July 12, 2004 Any thoughts as to what I could use to measure (dynamically) the under-hood temperatures? I want to direct some cool air to the air filter, but before I do, I'd like to get an idea of what kind of airflow, and temperature distribution, I have under the hood in its present configuration. No air enters the engine compartment from the radiator (because it's vented up and out over the hood), but I do have rear exiting venting on either side of the hood to vent out the hot exhaust header heat. What I'm looking for is some insight into how much air flows from under the front splitter (loose interpretation here), up past the motor, and out the two vents in the hood. I presume that some kind of dynamic sensor arrangement under the hood would provide some of this information, but I'm at a loss as to what device would work best in this situation. Something electronic (solid state even) that could be powered by a battery would be ideal. Any ideas here would be greatly appreciated. I'm Radio Shack savvy, so anything built would be fine as well. Quote Link to comment Share on other sites More sharing options...
johnc Posted July 12, 2004 Share Posted July 12, 2004 McMaster-Carr part number 4141k11 ( http://www.mcmaster.com ) $24.27 each. What I'm looking for is some insight into how much air flows from under the front splitter (loose interpretation here), up past the motor, and out the two vents in the hood That would be a tough one to measure... Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 13, 2004 Share Posted July 13, 2004 How about a GM air temp sensor and a multimeter? Cheap and easy. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted July 13, 2004 Share Posted July 13, 2004 Have you checked with the Airplane Industry? I'm sure they have some neat little gizmo's for taking such measurements. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted July 13, 2004 Share Posted July 13, 2004 Speaking of Radio Shack, I bought a wireless indoor/outdoor thermometer and it works great. Those remote sensors aren't that big, maybe the size of your palm. Since your car is still in primer, you could just use some double sided tape and put the sensor pretty much anywhere you wanted and drive around. Part #63-1033 Click Here !M! Quote Link to comment Share on other sites More sharing options...
Owen Posted July 13, 2004 Share Posted July 13, 2004 I wanted to do the same thing, someone here made a post a couple of months ago and I sent a PM but got no reply. He used Radio Shack stuff, but what I wanted to know was how accurate and how real-time were the sensors? They sell crap at parts stores with remote temp. leads and a cool blue backlit display for like $10.99, but those are crap. I guess I'll have to go with plan 2, attach a smoke flare to the back of a car, drive my Z behind it, and have a third car filming from different angles. Owen Quote Link to comment Share on other sites More sharing options...
dmyntti Posted July 13, 2004 Share Posted July 13, 2004 I was working for an engineering company designing a home thermostat. We used a device called a datalogger (I don't remember where I got it) that you plugged into the computer and programmed for how often to sample when to start and when to finish recording. We put these in the furnace ducts at several points and measured the temperature in the ductwork as the furnace cycled. When done we would pull them out of the duct plug them into a laptop and download the data (they would run for hours). These things were pretty cheap and were quite small. It seems like we got them from either McMaster Carr or Grainger but it was 7 years ago so I don't remember for sure. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 13, 2004 Share Posted July 13, 2004 Look at catalogue pages 519 and 486 at http://www.mcmaster.com/ Tim Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 13, 2004 Share Posted July 13, 2004 Owen, if you're trying to figure out where the air is going like wind tunnel style, you might want to do the yarn thing. Just tape 2" sections of yarn all over the car, then have another car drive along side, in front, behind, and video the yarn. I don't think you'd really get much off of the smoke flare... Quote Link to comment Share on other sites More sharing options...
jhaag Posted July 13, 2004 Share Posted July 13, 2004 Would an anemometer help you? It might be hard, though, to get accurate air flow measurements unless you are measuring the flow in a duct. There might be various paths and speeds of air flow in your engine compartment even when all the radiator air is being ducted over the hood. http://www.electrical-contractor.net/The_Store/EX/Anem_Main.htm I've wondered about this myself but that's all the further I got....just wondering. John Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 13, 2004 Author Share Posted July 13, 2004 Thanks guys!!! The M/C panel meter with a 10' lead appears to be the answer in regards to economy and function. It only has a peak temperature of 300 degrees F, which concerns me, as it seems a bit low for under hood use, but I'm going to give it a try. Again, thanks for the suggestions. John, I had thought about this as well, but the vents in the hood (I feel sure) will provide little incentive for high flow through the engine compartment. On top of this, the fender top-vents will bleed off any pressure and airflow as well. My main goal here is to see what kind of under hood temperature-to-speed correlation I can observe. Obviously, the faster the car goes, the more load will be placed on the engine, thus raising header temperatures, but I'm expecting an increased airflow as well. So I'm looking to see if the temperature drops, remains the same, or increases with speed. With multiple probes, I'm going to attempt to map out where the temperature rises, falls, or remains the same at speed verses at rest. These locations, and their relationship to the primary heat producers in the engine bay, should provide me with some kind of rough picture of how much air is coming from under the splitter, and where it's going once it gets into the engine compartment. Quote Link to comment Share on other sites More sharing options...
Synlubes Posted July 13, 2004 Share Posted July 13, 2004 Please let us know what your results in up being. Quote Link to comment Share on other sites More sharing options...
Owen Posted July 13, 2004 Share Posted July 13, 2004 Owen, if you're trying to figure out where the air is going like wind tunnel style, you might want to do the yarn thing. Just tape 2" sections of yarn all over the car, then have another car drive along side, in front, behind, and video the yarn. I don't think you'd really get much off of the smoke flare... No..too easy. AND I'd have to go buy yarn Thanks for the K-I-S-S reality check! I still want to see how my new hood changes the temperature, but then I'd have to put my old hood back on... Owen Quote Link to comment Share on other sites More sharing options...
johnc Posted July 13, 2004 Share Posted July 13, 2004 It only has a peak temperature of 300 degrees F, which concerns me, as it seems a bit low for under hood use, but I'm going to give it a try. Unless you're measuring air temps with an inch or two of the headers, I doubt you'll see underhood temps over 300F. I was part of a measuring effort underhood of a 2001 Ford Contour SVT. The worst case we saw was 100F over ambient (on a 85 degree day) while letting the car idle for 5 minutes. Once moving at 20mph or more the underhood temps stayed within 10F of outside ambient air. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 14, 2004 Author Share Posted July 14, 2004 Thanks John! Knowing this means I may need to narrow the resolution in mapping the temperature distribution and any changes. Quote Link to comment Share on other sites More sharing options...
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