Another option you may consider is to throw together a cheap six port or 84-85  four port and fly it until you have several flying hrs on it and all systems are functioning perfect and then install the big buck four port on it and then you will have a new engine that has not gone through the torture of sorting out all the cooling problems in the early days and that way you will also have a spare sitting there on the hanger floor in case you need it.

 

 

Mornin Ken,

 

I can't see swapping back and forth between 4-port and 6-port, because the intake ports don't match up.  I also don't see any significant risk to the new engine as far as cooling problems go.  After all, what did in my last engine was a sudden event, that happened long after I figured everything was reliable.  I would have installed the good engine by that point, and ruined it anyway.  I think most of my serious teething pains are over, though I still don't quite trust the evap cores for water.  

 

The spare engine idea has some merit though.  If I had a good turbo core, I could install a 9.4 rotating assembly that I have, and end up with a functional spare.  I probably wouldn't bother porting it, since it would only be a backup.  This idea will go into the hopper to help sort out the best use of parts between the current engine repair, single rotor, and spare engine. 

 

Thanks,

Rusty