Fun with Air !!

[bstockum]

All the effort so many are putting into getting cooler air into their engines has gotten me interested in exploring how much heat is picked up by the air from the hot-hot path it takes over the engine and radiator hose. If I sample the air at the cleaner and then at 5 more places along its path, we should be able to see how much temp is absorbed or conducted into this fast moving air on its trip to the combustion chamber.

I was reading some good debates on the subject on some other posts. I am not out to prove anyone right or wrong, just maybe enlighten us, to the nature of the heat and how it effects the intake air.

I plan on testing the air temps in the intake track, from the air cleaner, to the port runner, just before it enters the engine. To do this I will have to drill & tap, Three small holes, ( 10-32 ), in the plastic manifold. One in the Bottom half, just before entering the port of the cylinder head. One right over the radiator hose that goes by and one up near the throttle body. One will be in the tube just before the T.B., one in the air cleaner. The sixth one will be right out of my intercooler. I have already established that the intercooler delivers 90-100 degree air to the T.B., no matter how hard I run it. ( that was with 81 f outside air temp). I should have the tests done by Sat. afternoon.

If someone has some other ideas on things we could learn from and it is a test I have the tools to perform, ..... let us know!

........ like, .... how many Tacos will fit in the compartment under the radio, ........ things like that .......... "NOT !!"

thanks, ..... Bob .... ....

[Capt_Dan]

bstockum (28 Aug, 2001 10:32 a.m.):

........ like, .... how many Tacos will fit in the compartment under the radio, ........ things like that ..........

two crispy, three soft.

[bstockum]

Here is the way I have ended up with my strips. I tested the temp of the AC air, coming in the top center vent.
With the strip in place, running at 35 mph, the air was 3-5 degrees cooler with the strip on, than with it off completely.
Placing a 24" strip just in front of the fresh air intake, leaving about 12" open in the middle, dropped the temp back down to the same as with the complete strip.
Having the sides shortened 18" on each side, keeps the under hood temps as cool as any test I've done, plus the air cleaner is breathing almost outside temp air. Last weekend I ran through a bad storm with heavy rain on the interstate and found no water in the bay with all the rubber out!. I had to stop under an overpass cause I just could not see safely, so I pooped the hood to look.

Use your own judgement on all this info, ... just letting you know!
I haven't forgotten the CO test, there is something wrong with the battery, so we have ordered a new one. It is a spec fit in the unit.

Later, ..Bob

[Powertrip]

[b]... I just could not see safely, so I pooped the hood to look.

Man, that must have made a MESS!

[bstockum]

HEE,...... hEEEE..... Heeeee .....

spellcheck didn't catch that one, .... glad I had my Depends on!!


Thanks for pointing out my "crappy typo", Ptrip .....

I'm laughing so hard, ... I think I wet myself !..?...*#@

[naeS_TP]

I removed my strip completely on the weekend to test (no measurements or thermos or fans... just to play). I think I will add that 18" back on the passenger side as your notes suggest that warm air is being sucked in the cabin intake thus raising the temp....

Getting cooler here as we are approaching Fall, but there WILL be a few more 25+ days before the snow comes. (perhaps a good time to add the strip back anyways!!) (I store mine so no big here)

[bstockum]

COOL ! ..... oh, .. pardon the pun.

Thanks for the reply! Our collective input and trials, in different conditions and situations, is sure to help us zero in on the best combination. Even if it is back stock!! .... That's ok with me! In my line of work, I face many more failed tests, than I do successful ones. I have never been afraid to try, even at some costs.


Bob

bstockum (28 Aug, 2001 09:15 p.m.):
Here is the way I have ended up with my strips. I tested the temp of the AC air, coming in the top center vent.
With the strip in place, running at 35 mph, the air was 3-5 degrees cooler with the strip on, than with it off completely.
Placing a 24" strip just in front of the fresh air intake, leaving about 12" open in the middle, dropped the temp back down to the same as with the complete strip.
Having the sides shortened 18" on each side, keeps the under hood temps as cool as any test I've done, plus the air cleaner is breathing almost outside temp air. Last weekend I ran through a bad storm with heavy rain on the interstate and found no water in the bay with all the rubber out!. I had to stop under an overpass cause I just could not see safely, so I pooped the hood to look.

Use your own judgement on all this info, ... just letting you know!
I haven't forgotten the CO test, there is something wrong with the battery, so we have ordered a new one. It is a spec fit in the unit.

Later, ..Bob

Bstockum: I am afraid I need to play catch up here. Do I understand that you removed an 18 " strip from each end of the hood seal and you were able to achieve lower underhood temps? Sorry, but I was not keeping up with this message string.Please enlighten if you would.

Thanks,

[naeS_TP]

Moorecruizin (29 Aug, 2001 10:03 a.m.):
Bstockum: I am afraid I need to play catch up here. Do I understand that you removed an 18 " strip from each end of the hood seal and you were able to achieve lower underhood temps? Sorry, but I was not keeping up with this message string.Please enlighten if you would.

Thanks,

lemme see if I can answer- the cabin air intake is on the passenger side cowl. By having NO seal there, the hot engine air is being sent inside. Putting 18" back on hopefully reduces this. Perhaps even any CO (carbon monoxide).

For the driver's side- CO and perhaps any grease or oil that may make its way out of the engine compartment, onto the windsheild in the driver's view.

My take on it anyways.

Sean

[bstockum]

This thread is a slightly different focus of the "too hot to handle" thread. I have been asked by some members to show some pics of how I have the rubber strips on my PT now. If you check out the "too hot to handle" thread, you should see where we started and hope to end up with this experiment. I am really trying to explore what the very high temps in this small engine bay, are doing to the various engine systems. My personal drive is more intense because I have a turbo back behind the engine, near the firewall and have seen some fairly high temps. Nothing has melted, but I would like to work out a shielding system before something does melt or burst. To do this effectively, I feel I need to understand the problem completely first.

But more than that, the idea of cooling off the intake charge by wrapping the radiator hose and ducting cooler air in from another breather location are the main thrust of this post. How much heat does this very fast air, inside the manifold, really have time to absorb from the limited surface contact it makes with the nylon intake runners. At wide open throttle, the air is moving almost at the speed of sound! The intake material, seems strange to us, but was chosen because it conducts heat poorly. It may feel hot on the outside, but it is not on the inside. Not like aluminum gets! Drawing the air from a cooler spot is obviously a good idea, but as mentioned on another post, the engine uses up the small volume of hot air in the bay very quickly. So how does this air get replaced? From anywhere it can find a way in and it doesn't spend much time in the engine bay before it is gobbled up too! Through the radiator, is the single biggest source of replacement air in the engine bay. So now we are talking about the engine breathing pre-heated air from the radiator. I found the average air temp under the hood to be around 130 f, while moving above 45 mph. The factory hole in the frame supplied air at or very near ambient. So it is a good source for cool air.

Thanks for your question, Bob