Today's Message Index:
----------------------
1. 07:16 AM - Re: Engine boosting (rampil)
2. 07:41 AM - Re: Re: Engine boosting (William Daniell)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engine boosting |
William - Merry Christmas!
It is not wear on moving parts that would be of concern, it is instead
the added stress on the crank, the rods, the pistons and the cylinders/heads.
Remember the rotax gets its performance from light weight alloys which are
designed to just meet expected stress, not the added stress of running at
an MP 10 - 30% higher than design.
The 914 is not just a 912 with a blower bolted on, some moving parts were
also upgraded.
In experimental aviation fooling around with your engine is certainly
permissible, even encouraged, if you know what you are doing. There is
even a Rotax-designated service center in Mississippi that does all
kinds of mods to stock engines for the Highlander / SuperSTOL crowd.
All I said in my initial comments is that for my aircraft, I would not markedly
diminish the reliability of my engine for a small gain in power and an even
smaller gain in speed. Your mileage will vary. I use my 912s Europa for 1000
nm cross country trips from 0 - 1000' MSL airports. I like a reliable engine!
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=436284#436284
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engine boosting |
Ira likewise Merry Christmas.
Yes I had the same thoughts about stress hence keeping the boost to 33" and
reduce power to 30" within 3 minutes of take off. I cruise at 27". Also I
suppose my need taking off at 8500' is slightly out of the normal operating
range and requires extraordinary measures! However the local mechanics
tell me that the internals of the 914 are the same as the 912 and certainly
the anecdotal reliability "stats" would suggest that the mod doesn't over
stress the engine. At 27" I am burning 4 gals and hour.
The downside of the mod in my opinion is weight, complexity and heat
albeit this is less complex than a 914. If I were flying at sea level I
would choose a 912s as an excellent balance weight simplicity and power.
Interestingly enough the only major issue that I have heard of with rotax
here was a 912s on mogas. Even the premium mogas here is of very poor
quality and in a friend's aircraft this caused detonation which cracked a
piston. Quality gas is a must in high compression engines.
Will
William Daniell
LONGPORT
+57 310 295 0744
On Fri, Dec 26, 2014 at 10:16 AM, rampil <ira.rampil@gmail.com> wrote:
>
> William - Merry Christmas!
>
> It is not wear on moving parts that would be of concern, it is instead
> the added stress on the crank, the rods, the pistons and the
> cylinders/heads.
>
> Remember the rotax gets its performance from light weight alloys which are
> designed to just meet expected stress, not the added stress of running at
> an MP 10 - 30% higher than design.
>
> The 914 is not just a 912 with a blower bolted on, some moving parts were
> also upgraded.
>
> In experimental aviation fooling around with your engine is certainly
> permissible, even encouraged, if you know what you are doing. There is
> even a Rotax-designated service center in Mississippi that does all
> kinds of mods to stock engines for the Highlander / SuperSTOL crowd.
>
> All I said in my initial comments is that for my aircraft, I would not
> markedly
> diminish the reliability of my engine for a small gain in power and an even
> smaller gain in speed. Your mileage will vary. I use my 912s Europa for
> 1000 nm cross country trips from 0 - 1000' MSL airports. I like a reliable
> engine!
>
> --------
> Ira N224XS
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=436284#436284
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|