The Challenge is on!

One of my loyal readers, Hudsonjet has “thrown down the gauntlet.”  Hudsonjet has challenged me to do definitions of “valve sleeves” and “valve shims.”  I can’t back down from a challenge, so hold on for a wild ride!

Dear Hudsonjet,

I am sad to inform you that there is no such thing as the “valve sleeve.”  However, there is a sleeve valve.  I hope that this is what you were thinking of.  If not, than this mistake is on me.  I did some research on sleeve valves, so enjoy.

A sleeve valve is a type of valve that usually has a metal sheet around it.  (This helps the engine rev higher without danger of breaking the catalytic converter.  This type of valve is popular in heavy machinery or heavy-duty trucks.  The exhaust gets so hot that there is danger of damaging the engine valves.  The sleeve valve protects the integrity of the valve.  The sleeve valve also prevents oil from leaking too much.

For the less mechanically inclined, an engine valve forces air into the cylinder, where it is mixed with the fuel, and then the spark injector makes a spark.  There is a small explosion, and then the piston forces the mixture up into another engine valve.  The mixture is then sent to the catalytic converter, which cools down the mixture, and sends it through the muffler and out into our wonderfully polluted atmosphere.  Pretty amazing, isn’t it?

A valve shim is a disc of hardened metal that has a very precisely calibrated height to adjust the clearance of the valve lobe that is on an engine valve.  Without the valve shim, the valve lobe would flop open and stay there.  The valve shim forces the valve lobe to go back down and open when the fuel/air mixture comes out of the cylinder.The valve shim’s part in the engine play is sitting on top of the valve lobe and preventing engine gunk from entering the combustion chamber.  This is a very important part, because without it,  your mechanic would be a millionaire within a few days!  Without the valve shim, your valve lobe would allow engine gunk to enter the cylinder, and blow the piston.  Thank god for valve shims….

So, my readers, how did you enjoy these little answers to Hudsonjet’s questions?  You tell me, was I stumped?  Hudsonjet, were these the correct answers to your questions?  Anything to add?  Anyone else care to try and stump me on ‘Definition Day’?

Tune in Tuesday for a special post!