Re: Engine Choice

Isaksson Roger <scratchdeeper@...>

There is a guy in the KR field that have done a lot of research, and build up a
massive site on the subject of Corvair engines.

He's been going through about everything you can't wish for, and finally got it
perfected, and you can read all about it, in detail, with a lot of photos.

There was a development process,  that involved broken cranks,  the fix,  the
solution how to put the additional  bearings in place, and as I understand it,
now he has a lot of hours on it.

You should know that before the application of Corvair engines in the KR
aircrafts, there was no broken crankshafts,  they probably started to break
because of the KR's spirited way of flying, ( too fun to fly, too quick to make

The Q aircraft would probably benefit from having the same front bearing
modifications as the KR aircrafts if a Corvair engine is choosen.. It seems with
the bearing modification to run great now. The reliability is there now.

The Corvair engine seem to be a completely worked out car/airplane engine
conversion, and following the tech outlined from people that has gone before
you, you will save a lot of tears.

The appeal with the Corvair engine is with the smoothness it runs, it's relative
strong power, and also a very appealing aspect is the cost.

If you build up a Corvair engine for airplane application, the engine and model
numbers that are not too interesting for the Hot Rodders, are in fact the
engines that are desirable for aircraft applications, and therefore you usually
get a core "on the cheapy"....the "lesser models" is for our purposes, the much
better engine models.

There was about 1.7 million Corvair engines produced, and there is still a lot
of them around in garages. Bearings, gaskets etc is car part store items.

The displacement is really decent, and if you choose to make a big bore version,
you will get a whopping 3.1 liter displacement, very close to an O-200, not
fully, but very close.

You will run higher compression, than a Continental or Lyc ( standard issue) and
as it is a 6 banger, you will run more efficient than a 4 cylinder engine.

Weight wise you will be lighter ( quite a bit actually) than an O-200.

The big bore cylinders are remachined VW cylinders, ( not much machining
necessary) so the availability is plenty. There are on the market VW big bore
aluminum cylinders with either Nikasil coating, or steel sleve, so you can bring
down the weight further that way.

The case is aluminum, so you will not have the VW Magnesium case problem where
you have to check for cracks on regular basis.(well......check anyway)

You should be able to read all about it following this link: is a very interesting engine indeed. You will not get a full fledged
aircraft engine, and you will get your power on a somewhat elevated RPM compared
with a "real" aircraft engine, but it is probably as close as you can get it.

You can probably go to a junkyard and get a Fuel injection system from a junked
6 cylinder engine on the cheapy, that have about the same displacement.

The intake will still be the problematic top configuration, but the exhaust
stack will be much easier to route than a VW.

There are some very easily done reconfigurations of the intake manifold, in
order to make the engine breath much better, but you need to read, enjoy, dream
and plan, when it comes to all those things.

The power pulses are overlapping in a 6 cylinder engine, so you will get a very
smooth running thing.

Overheating may or may not have happened, but unlike like the similar set up
Jabiru that have some cooling issues, , it has never been an big issue with the
Corvair engine.

The Corvair also have a very long track record of flying, It's been up since the
-60's, ( I think Pietenpol went first) , and today you will get plenty of advice
from the experimental field. You will not start as the lone ranger, instead you
can easily duplicate others results.

The power you can expect from the engine, is depending on displacement, I have
seen figures between 90 HP to 120 HP, however, don't steer yourself blind on any
of those numbers though, they really don't mean much, instead concentrate on
getting a well built and balanced engine that will fit your application.

If you do just that, concentrate on building up a very efficient engine, and get
an efficient 2 or 3 bladed prop ,  you will get all the performance you are
asking for.....and then some.

You might want to get some structural advice if you got the VW version of the
Quickie, because this engine will weightwise fall inbetween a VW and an O-200,
however, the power will ( again depending on how you build it), be closer to,
equal or maybe even better than an O-200. so my advice here is, if you don't
have the Q-200 version, to look closely , and duplicate how the Q-200 is beefed

Good luck


From: Martin <>
Sent: Thu, December 23, 2010 2:21:02 PM
Subject: [Q-LIST] Engine Choice

OK, I hope I am not jumping too far ahead, but I like to get things worked out
far in advance. I am considering a few alternative engines for the project. One
would be the Jabiru, which I have talked to a few of you about. The other I am
looking at is the Corvair. Anyone have experience with this set up that they
would like to share good or bad? It looks like a nice engine and with the
bearings supports I have seen maybe not too bad for a Q200. Any information
would be great.

Thanks all and have a Merry Christmas!

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