My Head is Spinning!

[Keith Black]

Lance, I need to correct your correction. The Webra Aero X (1.45 and 1.60) being sold today by Horizon, Central Hobbies and Radio South, etc. all have the aluminum sleeve and weight 28.5 ounces. This feature did not disappear when Piedmont stopped selling the engine.

That being said, the Webra is only .8 oz under the Mintor 1.70 and that's hardly a good sole reason to go with the Webra.

The truth is if price and compatibility with my existing planes/parts wasn't taken into account I'd probably go with the Mintor. Smooth transition, awesome power, excellent workmanship, no need to fiddle with the MC carb (I like to keep things simple). However, my post wasn't to convince anyone of what to buy but rather to layout my understanding of the differences and the options to help Scott make his own decision. Until my post prompted your detailed reply none of the "experts" had given him much to sink his teeth into. Having been in his position not that long ago I can relate with his dilemma.

Keith Black

  ----- Original Message ----- 
  From: Lance Van Nostrand 
  To: discussion at nsrca.org 
  Sent: Thursday, January 08, 2004 11:22 PM
  Subject: Re: My Head is Spinning!


  Thanks Keith for laying out the basics.  In following Bob P's advice (before he even gave it), Keith got the Webras when we were flying them and learned from us how to balance pump pressure and needle.  Now He's the expert.
     I want to correct that the Webra 145 requires the AeroX/AL sleeve to be lighter than the OS/Mintor.  The standard steel sleeve leaves it about 1.5 oz heavier.  If you buy an engine from Horizon now, or a sleeve, it will be steel.  The AeroX was available from Piedmont and Swift, but may no longer be available, except as an aftermarket upgrade.
    Once you add the weight of the MC servo, its arm, mounting bracket and setup time, I don't see the attraction to that engine.  If one was willing to do all that, one could get an OS160FX for even less money and get all the power with the same amount of fiddling.
    I think the fuel economy is more similar than was stated.  but my measurement is being able to fly the Masters sequence twice on a 21oz tank.  Isn't that enough?  There's actually a lot more throttle management in Masters than Intermediate, so maybe things balance out.
    Here are some other comments based on my experiences: Webras with the steel sleeve burn bearings the fastest, with the AL sleeve it is tied with the OS (which is next), and the Mintors last by far the longest as long as the engine is used.  Nothing stops corrosion, but the double row angular contact bearing of the Mintor has twice the load capacity, which virtually eliminates load related wear.
     Mintors pack a punch and as a result shake a bit more.  More care needs to be taken in the header/pipe mounting if softmounting the engine.  The Webra is taller and, even though it shakes less, can more easily bang the cowling if clearances are close.  Webras have a big square head which makes this even worse.
    OS and Mintors (post June 30 production) break in fast (about 3 tanks to flight worthiness), Webras take longer to break in right (> 1 gal).  I know many have claimed flying Webras out of the box, but none of the FIVE I own(ed) ever broke in that easily.
     OS and Mintors share the same mounting holes, nose ring, prop distance and, exhaust mounting and headers.
     Mixture control can be made linear for all engines but the Mintor has a leaner midrange to start with so the rest of the tuning is easier. Obviously the OS140EFI or MC carb on the webra can compensate.
     The brass fitting into the aluminum case on the Webra has failed on my several times.  I prefer the bolt together carbs of the other two.  However, the Webra has more low end adjustment than either the OS or Mintor which can be useful in a pinch (long term, extreme needle positions indicate other problems to be solved).
     you need to carry a drive washer puller with you for the Webra if you need to change the bearings at a contest.
     the Webra 145 still has the front mounted needle, the OS is permanently positioned in the rear, the Mintor has a repositionable rear needle.  Obviously the 160 MC carb has a servo.

  OK, no need for me to post offlist.  Please accept my experiences as genuine and based on real life (not comparing datasheets).  Others may have different experiences, but as least mine are based on multiple engines all subjected to the same care system.
  --Lance
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