A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Home Built
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Corvair conversion engines



 
 
Thread Tools Display Modes
  #11  
Old January 19th 06, 05:49 AM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines - cracked crank link



Morgans wrote:


"Cal Vanize" wrote


The article does indicate that the cranks were from engines in planes
that were flying. That's the good news. But does that also mean that
the engines need a teardown and inspection as part of every oil change?



If you are running a conversion that is different from William's
conversions, it could be a good idea. g

If people take the time (yeah, lots of it) to read the whole article,
you will notice a few things, and I will attempt to point out some of
the more significant (to me) points.

Biggest point. Do not use corvair engines outside of the recommended
operating parameters. Some sub points.

Biggest one, don't use longer prop extensions. Big time no-no.

Others include, don't use heavy props, or hand carved props. Don't
overstress the prop with some aerobatic maneuvers, or hard landings.
Make sure the crank is properly ground. Oil systems must provide for
consistent oil flow to all parts, at all times; stay away from two line
cooler and filter systems. Use low RPMs and big props, rather than
smaller props and higher RPMs. Avoid detonation, which is easy to let
happen, if treated like an aircraft engine.

Obey all points of his conversion manual. Nitrated cranks are a good
way to add an extra margin of safety, when obeying the conversion
manual, but the other examples that have followed the manual have been
OK for long operational periods, even without the nitrated cranks.

Avoid other's add ons, like extra bearing hubs, as they have not been
tested.

I am sure I missed some points, or miss stated some, but if you are
using corvair power, it would be wise to investigate what this man has
to say, and not take my word on it.

I remember saying a long time ago, that I would feel better (or
something like that) if a redrive was used to take the stress off of the
crank. I think I will still stand by those words. Of course, It would
need to be a properly researched and tested redrive, which at this time,
does not exist.


Good points all.

The point that stood out most for me was the part about the crank from
the engine that William built for his own demo 601. From the article:
"This engine represents a standard installation, albeit one that was
flown at its limits by Gus"... "showed stress fractures on both sides of
the area in question." at 200 hours. "no nitride"

Note with particuclar interest the phrase "represents a standard
installation" regardless of how his pilot flew the plane (it was HIS
pilot after all). The statement goes on to say that the engine "was
flown at its limits" not beyond its limits.

What William wrote is that an engine he purposefully built himself for
his own 601 demo plane had a not insignificant crank issue. If he was
following his own recommendations, why did he use a crank that wasn't
treated?

He may be the Corvair conversion expert, but I'd like to read an
explanation as to why he wasn't following his own specs.

I have read every word on William's web site. It would appear that he
has done his homework and research. He may be the most credible source
for Corvair conversion aircraft engines. But yet, this discrepency
sticks out sorely.

Ads
  #12  
Old January 19th 06, 06:48 AM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines - cracked crank link


"Cal Vanize" wrote

Good points all.

The point that stood out most for me was the part about the crank from the
engine that William built for his own demo 601. From the article: "This
engine represents a standard installation, albeit one that was flown at
its limits by Gus"... "showed stress fractures on both sides of the area
in question." at 200 hours. "no nitride"

\
Yes, that paragraph does seem to run contrary to the rest of the _long_
website's information. So what gives, others in the know?
--
Jim in NC

  #13  
Old January 19th 06, 10:05 AM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines - cracked crank link

Morgans wrote:

"Cal Vanize" wrote

Good points all.

\
Yes, that paragraph does seem to run contrary to the rest of the _long_
website's information. So what gives, others in the know?


Or could it be that it's just taken a few years to rack up 200 hours?

I didn't catch a time span reference on any of the example engines.
But I thought it has been years?
  #14  
Old January 19th 06, 01:39 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines - cracked crank link



Richard Lamb wrote:
Morgans wrote:


"Cal Vanize" wrote

Good points all.

\


Yes, that paragraph does seem to run contrary to the rest of the
_long_ website's information. So what gives, others in the know?



Or could it be that it's just taken a few years to rack up 200 hours?

I didn't catch a time span reference on any of the example engines.
But I thought it has been years?


First flight of William's 601 was 13 May 2004. That engine had 200 hours.

The article implies that all the engines were torn down at about the
same time. It must have been fairly recently because one of the engines
was a 2005 engine with 71 hours. The previous "crank update" was 15 August.

  #15  
Old January 19th 06, 04:40 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines

But would you have to replace the engine?
Maybe just a crank overhaul every 4-500 hours, in the middle of
winter, after a good snow storm, nothing else to do.

  #16  
Old January 19th 06, 06:00 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines


I just think hanging a prop on a crank directly is a non-starter in
the first place...especially on a crank and case not specifically
designed for this in the first palce. Maybe a good redrive and flywheel
would be a better way to go?

  #17  
Old January 19th 06, 06:14 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines


"Lou" wrote in message
oups.com...
But would you have to replace the engine?
Maybe just a crank overhaul every 4-500 hours, in the middle of
winter, after a good snow storm, nothing else to do.


Good point what would a like new, best for the engine, crankshaft cost?


  #18  
Old January 19th 06, 06:43 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines

$50-76 on ebay,
$600 to have Bill Wynne modify it.

  #19  
Old January 19th 06, 08:15 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines


"Lou" wrote in message
ups.com...
$50-76 on ebay,
$600 to have Bill Wynne modify it.


Replace it every year or two at annual it's still a great deal.


  #20  
Old January 19th 06, 09:12 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default Corvair conversion engines - cracked crank link

Morgans wrote:

"Cal Vanize" wrote

Good points all.

The point that stood out most for me was the part about the crank from
the engine that William built for his own demo 601. From the article:
"This engine represents a standard installation, albeit one that was
flown at its limits by Gus"... "showed stress fractures on both sides
of the area in question." at 200 hours. "no nitride"


\
Yes, that paragraph does seem to run contrary to the rest of the _long_
website's information. So what gives, others in the know?


My read was that he was updating his policy based on new data. He even
mentioned one of his customers reminding him of a sentence in his
conversion manual saying something like "I reserve the right to get
smarter."
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Book Review: Converting Auto Engines for Experimental Aircraft , Finch Paul Home Built 0 October 18th 04 10:14 PM
P-3C Ditches with Four Engines Out, All Survive! Scet Military Aviation 6 September 27th 04 01:09 AM
What if the germans... Charles Gray Military Aviation 119 January 27th 04 12:20 AM
Corvair Engine Conversion Breakin Success Dick Home Built 1 January 11th 04 03:06 PM
Corvair Conversion Gig Giacona Home Built 17 October 27th 03 10:43 PM


All times are GMT +1. The time now is 07:13 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2004-2020 AviationBanter.
The comments are property of their posters.