[DeTomaso] HP limits for 351C Block & Rotating Assembly, Turbo vs Non-Turbo

[Ken Green]

    I re-read the discussion in Maximum Boost by Corky Bell on an engine's ability to handle HP on a naturally aspirated versus turbocharged engine, and he seems to make some valid points.  Basically, he states that the design point for rods is TDC after the exhaust stroke because the rod is in maximum tension and the power stroke places less stress on the rod than at this point.  He goes on to say that with a normally aspirated engine, you have to increase displacement or RPM to substantially increase power.  A large bore isn't an option with a Cleveland, so we're left with stroking and/or RPM.  Both of these increase the stress at the design point.
   
      He also looks at the peak stress on the power stroke, and it looks like you can double the HP with turbos and only increase the max load on the power stroke by 20%, but doubling the HP with natural aspiration would double the stress (or worse because RPM really increases stress quickly).  This probably is an over simplification, but it does suggest that a lower RPM stock stroke 600 HP turbo motor would place less stress on the block and rotating assembly than a stroked and/or higher RPM 500 HP naturally aspirated motor.  
   
      If this is correct, it may be a cheaper to build a reliable 6,000 RPM 600 HP turbo motor then a higher RPM or longer stroke 500 HP non-turbo motor because you don't need a high dollar rotating assembly, valve train, heads, etc.
   
      Does anyone have experience with the reliability of a stock short block turbo motor?  Can Dave, Dick, ect. comment on this please?  It seems like a carefully thought out motor could be built with a stock Patera long block, and provide great performance and reliability at a reasonable cost.  Of course, none of us seem to be satisfied anything reasonable .
   
  Ken