My Head is Spinning!

[Brian Young]

I just setup a Webra MC carb, bolted in and running in
about 4 hours. I still have some mixture tweaking to
do. Its easier to adjust the mixture this way than
with a screwdriver, just turn the knob on the radio
once curve is established. Good background in engine
tuning and operation will help you set this engine up.

So far so good. I only have a few flights on it but,
it sure pulls good and throttle seems more linear and
more responsive.

A very handy resource is this list for anyone having
trouble with a fussy engine, plane setup, equipment
selection......etc...

If only I had wireless internet, and a webcam Im sure
I could get some critiques of my practice
flights......lol





--- Keith Black <tkeithb at comcast.net> wrote:
> 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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