Manifold pressure/EGT?

[buzzer]

Why is it that when you pull the power back to initiate a descent (from cruise in a fuel injected constant speed prop) that the EGT rises right away? Assume that you are at an altitude where the mixture was pulled back for leaning.
Also in the pattern when you pull the power to slow down the manifold pressure creeps up as you slow (mixture and prop already full foward). I have to pull it back again after slowing to the desired speed. I haven't been around these type of planes for years and I'm sure I dumped some knowledge.

 

[troy]

I believe that the EGT rises after pulling the power back because the cylinder head is still at it's operating temp, but there is no air to cool the metal (the butterfly is closed). It takes a moment for the outside air to cool the metal to the now off-cruise state. That is how I would explain it anyway. Anyone else with a better answer?

 

[troy]

www.avweb.com/articles/pelperch/pelp0015.html

I got this link from somebody in here. Thanks, whoever posted this. It has helped me understand alittle more.

It's a good link about MP and how it works in detail

 

[bigD]

I swear, I owe a lot of my more in depth knowledge of things like MP, CHT, turbocharging, and so on to Mr. Deakin. His columns have always been interesting to me. I just have to sometimes unlearn some of his practices when getting checked out in rental planes!

 

[buzzer]

Troy, thanks. John Deakin has some good reads.

 

[troy]

Is there a web page index of his articles? The only way that I found to read them is to erase the last part of the addy that I posted (up to the / ) It would be nice to get titles of the artices before I load them

 

[buzzer]

Go to the Avweb site and do a search for Pelican...you will get all his articles. One of those is an index to his articles on piston engines...here you go.

http://www.avweb.com/articles/pelperch/perchlinks.html

 

[troy]

Thanks!