MAGK944

Your thinking like a air-cooled 911 person, such thinking is not permitted on this forum

fasteddie313

Yeah.. Maybe not "drastically" increase IAT's, but it must by some amount..

This problem could easily be subverted by the donation of 1 air cooled 911..

ideola

Nope, and here's why.

The intake manifold is stationary, the air is not. The air molecules are moving very fast, and there is a boundary layer between the metal and the bulk of the air entering the intake. Why do you think intercoolers have lots and lots of fins (i.e., lots and lots of surface area)? Because that surface area has to come into contact with as much of the air as possible for the heat transfer to take place.

The cooled air from your intercooler that enters the intake manifold creates a boundary layer, and the boundary layer gets some heat exchange with the manifold, making it feel cold to the touch. The manifold is stationary, and eventually cools down through inducted heat exchange.

If it worked in reverse the way you postulated, we wouldn't need intercoolers.

So, regarding the phenolic spacers, they WILL prevent conduction of hot temparatures from the rest of the engine to the intake manifold itself, but the cooler temps of the intake manifold WILL NOT be transferred by inductiion to the vast majority of the air volume that is passing thru the intake at very high speed. There simply is not enough surface area contact or time for the heat exchange to occur, further exacerbated by the insulating effects of the aforementioned boundary layer.

I'm not expert in thermodynamics, but that is my understanding. And until somebody actually measures the AIR TEMP, and NOT the intake temp, before and after phenolic spacers, I won't believe that phenolic spacers do anything to reduce intake air temperature.

There are three or four threads bouncing around across various forums, and I have done extensive (though perhaps not exhaustive) research on the web. I have yet to find even ONE case where anyone has posted before and after IATs. When I've contacted phenolic spacer manufacturers, and challenged them on the physics, not a single one of them has produced any evidence. So I remain skeptical.

If someone can post actual results of before and after IAT disproving my hypothesis, I will be the first to accept it and make some phenolic spacers myself.

Dougs951S

I have datalogging and would love to contribute to science, but unfortunately i need a spacer to even start my car. if someone donated an intake manifold to me, I could chop it up and face it on a mill and make myself an aluminum spacer, then do IAT logs with the aluminum vs phenolic spacer.

Tiger03447

I think that Spencer has a chopped up one for sale...but it might be the wrong flavor for your car..but the flanges should be about the same if you wanted to saw it up even further..

V2Rocket

Doug just bought my one and only spacer, made for an 8v head.