Sorry about the upper case. PL

"c.l. smale" wrote:

I RECENTLY DISCOVERED THIS WEB SITE. INTERESTING!
I THOUGHT I MIGHT RELAY MY EXPERIENCES WITH A 13B IN A DEFIANT AIRPLANE. THE PLANE HAS NOT FLOWN YET BUT I HAVE 50 HOURS WITH THE ENGINE ON A TEST STAND.

THE ENGINE WAS MODIFIED TO THE EXTENT THAT IT HAS STREET PORTING. IT WAS BUILT FOR ME BY A MAZDA RACER. THE INTAKE SYSTEM IS A AIR BOX MOUNTED OVER THE SPARK PLUG SIDE OF THE ENGINE WITH LONG TUBES GOING OVER THE TOP OF THE ENGINE AND SPLITTING TO GO TO THE INTAKE PORTS IN THE BLOCK. FUEL IS BY A BOSCH CIS UNIT WITH INJECTORS MOUNTED AT THE JUNCTION OF THE INTAKE MANIFOLD AND BLOCK POINTING DIRECTLY INTO THE PORT IN THE BLOCK. A SINGLE BUTTEERFLY VALVE AT THE AIRBOX CONTROLS THE AIRFLOW. THE EXHAUST IS  321 SS HEAVY WALL TUBING DUCTING THE EXHAUST TO A TURBO. THE EXHAUST ALSO SUPPORTS THE TURBO WITH ADDITIONAL BRACING TO PREVENT EXCESSIVE LOADING OF THE EXHAUST TUBING. THE TURBO OUTLET goes INTO A MUFFLER WHICH RUNS ALONG SIDE of THE BLOCK JUST BELOW THE EXHAUST OUTLETS ON THE BLOCK. THE MUFFLER IS DIRECTLY ATTACHED TO THE TURBO OUTLET. IT HAS AN INNER TUBE WHICH RUNS FORWARD. AN OUTER TUBE ENCLOSES THE INNER TUBE AND RUNS AFT. ENDS ARE CLOSED SUCH THAT THE GAS FLOW IS FORWA!

RD THEN REVERSES AND RUNS AFT TO A TUBE MOUNTED AT RT ANGLES TO THE OUTER TUBE  WHICH DUMPS THE EXHAUST OUT OF THE COWL OF THE AIRPLANE. THIS WORKS VERY WELL WITH MARKED ATTENUATION OF THE HI FRENQUENCY BARK Of THE MASDA. SOUNDS MUCH LIKE A LYCOMING.

THE PROP IS DRIVEN THRUOGH A GEARBOX WITH ABOUT A 8 INCH OFSET OF THE OUTPUT SHAFT TOWARDS THE TOP OF THE ENGINE. THE GEARS ARE STRAIGHT CUT. THE GEARBOX IS SELF CONTAINED. NO ENGINE OIL IS USED TO LUBRICATE IT. THE FIRST TRIAL WAS USING A STRAIGHT SHAFT TO CONNECT THE ENGINE AND GEARBOX. THE SHAFT WAS SMALL DIAMETER AND IT WAS HOPED THAT THE TORSIONAL VIBRATION WOULD BE TAKEN UP IN TWISTING THE SHAFT. HOWEVER THE GEARS REALLY WERE NOISY. THE SECOND TRIAL USED A HAT SECTION RUBBER-FABRIC COUPLER BETWEEN THE ENGINE AND THE GEARBOX. THE PIECE IS BUILT LIKE A AUTO TIRE WITH

THE FABRIC EMBEDDED IN THE RUBBER. THE PIECE TAKES NO RADIAL LOADS ONLY TORSIONAL LOADS. THE GEAR NOISE COMPLETELY DISAPEARED. I CAN TELL THAT THE RUBBER PIECE IS TWISTING BECAUSE THE INPUT SHAFT HAS BEEN MARKED BY THE NEEDLE BEARING IN THE END OF THE EXCENTRIC SHAFT.

THE ENGINE IN ITS CURRENT STATE TURNS A 180 HP WOODEN LYC PROP AT 3000 RPM STATIC AT 5 PSI MANIFOLD PRESSURE. A 180 HP LYCOMING TURNS THE SAME PROP 2500 RPM STATIC. AT FULL BORE  THE PROP NOISE IS FAR GREATER Than THE ENGINE AND GEARBOX NOISE. THE FUEL INJECTION SYSTEM WORKS VERY WELL.
EGT IS EASILY CONTROLLED BY THE MIXTURE CONTROL ON THE INLECTION UNIT.

IF ANYBODY HAS FURTHER INTEREST I WILL WRITE A MORE DETAILED LETTER IN THE FUTURE.

smale@ncvinternet.net

 
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