<VV> Turbos

[Smitty]

Smitty Says;  I have had at least one turbo in my possession since 69.  My 64 has over 200 K miles behind it.  Others racked up many thousands before I let them go.  I’m not going to claim that I didn’t have to train myself to deal with the idiosyncrasy's of the YH carbs.  Once I understood a few things, my ownership of them all has been a pleasure.  Two problems self trained mechanics have to learn.  First is that the flimsy accel pump diaphragms do leak eventually.  You just can’t make them like a two ply tire sidewall and expect them to work.  They need to be thin and flexible to allow stroking of the linkage.  Second, is choke adjustment.  The carb is equipped with an effective choke and a choke “dump” that pulls the choke open after start.  It has a hot start capability that opens the choke so it won’t work under a certain odd set of circumstances when restarting a hot engine.The air heater for the choke that runs around the base of the turbo must be open to flow and properly hooked up for the choke to go full open.  All linkage and adjustments must be right.  In addition to their other attributes, they are fairly tunable by changing metering rods and jets for best performance. 
I have enough comfort with the carbs that I chose to use two of them on a “Y” manifold to feed my racer.     
    Turbo engines are not overly touchy in disposing of heat.  Yeah you can get them hot if you abuse them.  There are always a few idiots that don’t understand that when you work an engine harder they generate more heat.  If you don’t pay any attention to what your engine is saying, then you deserve what you get.  Corvair racers will be the first to tell you that heat disposal when you work an engine hard is just as real in an NA engine as it is in a turbo.  In the simplest terms I can, I will explain it like this.  You run an NA engine of a certain displacement as fast as it can go, and when it is topped out a same displacement turbo will truck on past it.  And it will get hotter.  Woops, big surprise.  So use the capabilities judiciously and for short periods of time and you will have no trouble.  I just can’t get past someone saying they over heat.