KR> Type 4 failures

[Phil Matheson]

Eduardo wrote:
I think in armonic vibrations.
What hapens if you put on it a PSRU?
---
I have been discussing the ongoing questions of Direct Drive and the changes
of a damaged crank.
This is what I got from VW Engines,

Now people might realize that the reality of direct drive engines is the
probability of breaking a crank is high.

Our gear drive engines are not subjected to:
1 The concertina effect of thrust on one end and the thrust bearing on the
other.
2 Direct prop forces acting against the crankshaft placing very high loads
which the crank was never designed for.
3 Cushioning devise minimising or eliminating harmonics back to the
crankshaft.
4  The result of gearing allows the engine to produce optimum hp at a normal
operation rpm range and produce efficient propeller rpm.
The crankshaft is subjected to normal conditions that the engine was
designed for in the first place.

I am talking gear drive not belt drive because this also places a high belt
tension load in one direction and even an out rigger bearing is not the
complete solution in this case either.


Ron  Slender   VW  Engine Centre


Phil Matheson
mathe...@dodo.com.au
VH-PKR ( reserved)
61 3 58833588

See our VW Engines and Home built web page at
http://www.vw-engines.com/
www.homebuilt-aviation.com/

KR> Type 4 Failures

[Orma Robbins]

Good morning Net

This morning I got another update from Steve re his failures.  The following is 
his reply to my request for more details.

Orma

I had 3 failures, they all seemed to crack in the same place. The 2 stock 
cranks cracked just past the bearing. and the crank sort of orbited around and 
spewed out oil out the front seal. I never had a prop strike and I ran my 
engines at 3200 rpm cruise because there was some speculation that if you ran 
them under 3000 rpm there were harmonics that were set up. I really don't know 
but that was why I went a different route. Good luck.
Steve

KR> Type 4 failures

[larry severson]

>
>
>Now people might realize that the reality of direct drive engines is the
>probability of breaking a crank is high.

One might consider the Great Plains Rear Drive (off the fly wheel) as the 
solution. Biggest bearing - isolated prop.


Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
lar...@socal.rr.com 

KR> Type 4 failures

[veedu...@aol.com]

In a message dated 4/21/2004 9:58:56 AM Pacific Daylight Time, 
lar...@socal.rr.com writes:

> Now people might realize that the reality of direct drive engines is the
> >probability of breaking a crank is high.
> 

--

I think the above needs to be qualified by the fact most props get installed 
on the fan pulley end of the crankshaft, on a whimsically small bit of 
shafting never designed for that level of output and an engine away from the 
thrust 
bearing.

I went several broken crank episodes with the Type I more than fifty years 
ago and came to the conclusion that the typical VW 'expert' didn't know his ass 
from his elbow.  Indeed, it took only a modest amount of research to discover 
that of the four accepted experts of that era NONE had actually built a flying 
Volkswagen and only ONE had even flown behind such a thing.

It was my dad who pointed out that he'd never heard of anyone any successful 
conversion in which the prop was attached to the pulley-hub.  (Bernard 
Pietenpol tried it with the Model 'T' with mixed success.  He readily admitted 
the 
'A' model conversion -- with the prop on the clutch-end of the crankshaft -- 
was 
the best way to go.)

After I put the prop on the other end of the crank flying became down-right 
boring :-)

It amazes me that folks don't seem to realize that all of these fantastic 
prop/hub/bearing/crank modifications are band-aid-attempts to make a bad idea 
work.  Expensive band-aids, too.  

To attach a prop to the clutch-end of the crankshaft all you need is a 
matching spacer.  The idea that the engine is more difficult to mount or that 
the 
bell housing gets in the way is blown away the first time you see such an 
installation.  In fact, the only reason they put the fan on the pulley-hub to 
begin 
with was because the original engines were FREE (ie, the 985cc twirler out of 
the 2WD Kubelwagen), only put out about 20hp and weighed barely a hundred 
pounds.  They never lasted very long -- SOP was to replace the crankshaft 
($17.00, 
US) every 200 hours or so, but the result was a flying club hack that could 
give you an hours flight-time for less than $5, a critical factor in post-WWII 
Europe with gasoline going for $2.50 a gallon... when you could get it.  
(Great Britain didn't go off rationing until the 1950's).

Reality has never been aviation's strong suit.  Nor hard-ball engineering, 
when you get right down to it.  (The maximum sustainable output of ANY 
aircooled 
engine is determined by its ability to cool itself.  Rather than counting 
fallacious horsepower you'd be better off counting the number of fins on the 
heads.)

The fabled superiority of the Corvair over the VW probably stems from the 
fact they put the prop where it belongs.

-R.S.Hoover

KR> type 4 Failures

[Ryan]

This is from another list.
Ryan
6:50.21.04

 http://groups.yahoo.com/group/Q-LIST/message/10392

  From:  HawkiDoug@a... 
  Date:  Thu Jan 2, 2003  8:34 am
  Subject:  VW type 4 fix


  For those who might be interested, here's what we have come up with as a 
fix
  to my prop hub coming off last fall. To recap briefly, the end of a type 4
  crank has a smaller taper on the very end and a "sleeve" is fitted over 
the
  end and then machined for the Force One Prop hub. We are confident this 
was
  the weak link and the source of the failure. Steve Bennett of Great Plains
  and I looked at several solutions and the one both Steve & I liked best 
was
  to have a new crank made the way we want it made. It will actually be 
better
  than the std. VW crank. Cost= $1000.00. The other solutions looked to be
  about half this cost, so it was a no brainer for me to spend the extra 
money.
  I believe I will still have about $5500.00 invested in the engine.

  Steve sent a letter to his type 4 customers offering this option at his 
cost
  on this initial run. If things go as planned (do they ever?), I should be
  back in the air by early summer.

  Now, I have a question to you VW experts. What do you think of using
  Lycoming thread to seal the case halves with? See any problems doing this?

  Doug "Hawkeye" Humble
  Omaha NE
  N25974
  A Sign Above

  ==

  If there are cranks failing I personally really want to know who and why.
  Tweedy and I are both getting older and would like to continue to do so
  without having experienced crank failure.
  So, this post is a call for any one with direct knowledge to sing out.

  Orma L. Robbins Southfield MI
  19 Years flying KR-2 N110LR (Tweedy)
  http://www.aviation-mechanics.com

KR> type 4 Failures

[danhar...@pacific.net]

I have just started my kr2s and i am thinking of using a vw fear drive to 
help eliminate the crank problem. By the way rand  robinson is out of WAF's,
any sugesstions? is there another kr projet in or near lakeport,ca?

-- Original Message ---
From: "Ryan" <rr...@san.rr.com>
To: <kr...@mylist.net>
Sent: Wed, 21 Apr 2004 18:50:58 -0700
Subject: Re: KR> type 4 Failures

> This is from another list.
> Ryan
> 6:50.21.04
> 
>  http://groups.yahoo.com/group/Q-LIST/message/10392
> 
>   From:  HawkiDoug@a...
>   Date:  Thu Jan 2, 2003  8:34 am
>   Subject:  VW type 4 fix
> 
>   For those who might be interested, here's what we have come up 
> with as a fix  to my prop hub coming off last fall. To recap 
> briefly, the end of a type 4  crank has a smaller taper on the 
> very end and a "sleeve" is fitted over the  end and then 
> machined for the Force One Prop hub. We are confident this was 
>  the weak link and the source of the failure. Steve Bennett of Great 
> Plains  and I looked at several solutions and the one both Steve 
> & I liked best was  to have a new crank made the way we want it 
> made. It will actually be better  than the std. VW crank. Cost= 
> $1000.00. The other solutions looked to be  about half this cost,
>  so it was a no brainer for me to spend the extra money.  I 
> believe I will still have about $5500.00 invested in the engine.
> 
>   Steve sent a letter to his type 4 customers offering this 
> option at his cost  on this initial run. If things go as planned 
> (do they ever?), I should be  back in the air by early summer.
> 
>   Now, I have a question to you VW experts. What do you think of 
> using  Lycoming thread to seal the case halves with? See any 
> problems doing this?
> 
>   Doug "Hawkeye" Humble
>   Omaha NE
>   N25974
>   A Sign Above
> 
>   ==
> 
>   If there are cranks failing I personally really want to know 
> who and why.  Tweedy and I are both getting older and would like 
> to continue to do so  without having experienced crank failure.  
> So, this post is a call for any one with direct knowledge to 
> sing out.
> 
>   Orma L. Robbins Southfield MI
>   19 Years flying KR-2 N110LR (Tweedy)
>   http://www.aviation-mechanics.com
> 
> ___
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
--- End of Original Message ---

KR> type 4 Failures :rand robinson is out of WAF's

[Kevin Angus]

Will she be getting more latter on or what? I'm going south to pickup two
Kr's but if she isn't going to sell parts I might have to rethink this.
Thanks
Kevin


-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net]On
Behalf Of danhar...@pacific.net
Sent: Wednesday, April 21, 2004 9:39 PM
To: KRnet
Subject: Re: KR> type 4 Failures


I have just started my kr2s and i am thinking of using a vw fear drive to
help eliminate the crank problem. By the way rand  robinson is out of WAF's,
any sugesstions? is there another kr projet in or near lakeport,ca?

-- Original Message ---
From: "Ryan" <rr...@san.rr.com>
To: <kr...@mylist.net>
Sent: Wed, 21 Apr 2004 18:50:58 -0700
Subject: Re: KR> type 4 Failures

> This is from another list.
> Ryan
> 6:50.21.04
>
>  http://groups.yahoo.com/group/Q-LIST/message/10392
>
>   From:  HawkiDoug@a...
>   Date:  Thu Jan 2, 2003  8:34 am
>   Subject:  VW type 4 fix
>
>   For those who might be interested, here's what we have come up
> with as a fix  to my prop hub coming off last fall. To recap
> briefly, the end of a type 4  crank has a smaller taper on the
> very end and a "sleeve" is fitted over the  end and then
> machined for the Force One Prop hub. We are confident this was
>  the weak link and the source of the failure. Steve Bennett of Great
> Plains  and I looked at several solutions and the one both Steve
> & I liked best was  to have a new crank made the way we want it
> made. It will actually be better  than the std. VW crank. Cost=
> $1000.00. The other solutions looked to be  about half this cost,
>  so it was a no brainer for me to spend the extra money.  I
> believe I will still have about $5500.00 invested in the engine.
>
>   Steve sent a letter to his type 4 customers offering this
> option at his cost  on this initial run. If things go as planned
> (do they ever?), I should be  back in the air by early summer.
>
>   Now, I have a question to you VW experts. What do you think of
> using  Lycoming thread to seal the case halves with? See any
> problems doing this?
>
>   Doug "Hawkeye" Humble
>   Omaha NE
>   N25974
>   A Sign Above
>
>   ==
>
>   If there are cranks failing I personally really want to know
> who and why.  Tweedy and I are both getting older and would like
> to continue to do so  without having experienced crank failure.
> So, this post is a call for any one with direct knowledge to
> sing out.
>
>   Orma L. Robbins Southfield MI
>   19 Years flying KR-2 N110LR (Tweedy)
>   http://www.aviation-mechanics.com
>
> ___
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
--- End of Original Message ---


___
to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
please see other KRnet info at http://www.krnet.org/info.html

KR> type 4 Failures

[Virgil Salisbury]

Use 3M trim cement to seal the case halves, no thread. The yellow
sticky stuff, Virg

On Wed, 21 Apr 2004 18:50:58 -0700 "Ryan"  writes:
> This is from another list.
> Ryan
> 6:50.21.04
> 
>  http://groups.yahoo.com/group/Q-LIST/message/10392
> 
>   From:  HawkiDoug@a... 
>   Date:  Thu Jan 2, 2003  8:34 am
>   Subject:  VW type 4 fix
>  
>
>   For those who might be interested, here's what we have come up 
> with as a fix
>   to my prop hub coming off last fall. To recap briefly, the end 
> of a type 4
>   crank has a smaller taper on the very end and a "sleeve" is 
> fitted over the
>   end and then machined for the Force One Prop hub. We are 
> confident this was
>   the weak link and the source of the failure. Steve Bennett of 
> Great Plains
>   and I looked at several solutions and the one both Steve & I 
> liked best was
>   to have a new crank made the way we want it made. It will 
> actually be better
>   than the std. VW crank. Cost= $1000.00. The other solutions 
> looked to be
>   about half this cost, so it was a no brainer for me to spend 
> the extra money.
>   I believe I will still have about $5500.00 invested in the 
> engine.
> 
>   Steve sent a letter to his type 4 customers offering this 
> option at his cost
>   on this initial run. If things go as planned (do they ever?), 
> I should be
>   back in the air by early summer.
> 
>   Now, I have a question to you VW experts. What do you think of 
> using
>   Lycoming thread to seal the case halves with? See any problems 
> doing this?
> 
>   Doug "Hawkeye" Humble
>   Omaha NE
>   N25974
>   A Sign Above
> 
>   ==
> 
>   If there are cranks failing I personally really want to know 
> who and why.
>   Tweedy and I are both getting older and would like to continue 
> to do so
>   without having experienced crank failure.
>   So, this post is a call for any one with direct knowledge to 
> sing out.
> 
>   Orma L. Robbins Southfield MI
>   19 Years flying KR-2 N110LR (Tweedy)
>   http://www.aviation-mechanics.com
> 
> 
>  
> ___
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
> 
> 


Virgil N. Salisbury - AMSOIL
www.lubedealer.com/salisbury
Miami ,Fl

KR> type 4 Failures

[Orma Robbins]

Hello Steve and KR netters,  After a few posts that I put on the net about the 
rebuild of my type 4,  Mark L. suggested that I should talk to you and others 
about you crank failures.  My experiences with the type 4 have been really good 
and others have been the opposite.  Your experiences could help me prevent from 
some future failure. I would like to ask a few questions of you and anyone else 
that has had a failure of a type 4 Crankshaft.  
1.  What part of the crank failed.
2.  What size was the crank
3.  Was it a stock VW crank
4.  Was it in any way modified, ie for the prop hub, and how was it modified
5.  Was it damaged prior to failure, such as prop strike etc.
6.  Any significant history from the engine in it prior usage, such as sudden 
stoppage from an auto accident or engine dropped #3 valve etc.
I appreciate any and all comments.

KR> type 4 Failures

[Orma Robbins]

Hello again Netters.

I just finished reading the Archives search for Crankshaft failures.  I
entered the dates present to 1990.  There were 31 hits on the subject.
There was a lot of discussion on failures, but not ONE posting by anyone
with a failure that gave any details at all.  This is significant.  Some
members make decisions based on the word of the net.  I have flown my type 4
off and on now for over 19 years.  My 66 mm crank looks as new.  I am moving
up to a  stock 71 mm crank in what will be a completely different engine.
If there are cranks failing I personally really want to know who and why.
Tweedy and I are both getting older and would like to continue to do so
without having experienced crank failure.
So, this post is a call for any one with direct knowledge to sing out.

Orma L. Robbins Southfield MI
19 Years flying KR-2 N110LR (Tweedy)
http://www.aviation-mechanics.com

KR> type 4 Failures? What failures

[Serge F. Vidal]

My 2 cents worth, as an operator of and a strong believer in the Type 4.

- All the literature (engine rebuild manuals, etc.) I could find on the
subject states that the Type 4 is by far the best VW air cooled engine.
Better than Type 1, 2, 3, and 4. No wonder: it is the most recent one, and
it is the fruit of a redesign.
- Therefore, it should be less failure-prone than the other VWs
- Moreover, we tend to make our VW air cooled less reliable by increasing
their power output one way or another. With the Type 4, you start with a
block tha was designed for an output of 65hp; therefore, an increase up to,
say, 80 to 100 hp is still fairly reasonable.

Conclusion:

- The VW is not the best engine in the world, but it is still a very
affordable and fairly proven solution;
- If you have to choose a VW engine, choose a Type 4; you'll be on the safe
side;
- Have the block and the crankshaft tested, and you'll stand even better on
that safe side;
- Have the engine rebuilt and modified by people who know what they are
doing, and you'll really be entrenched on that safe side;

In any case, your Type4 will be as safe (or even safer) as a rebuilt
Lycoming or a Continental... Even more if you give it a decent ignition
system, to replace those Cavemen's magnetos.

Serge Vidal
KR2 ZS-WEC
- Taildragger, VW powered (2.4 liter, dual electronic ignition)
- Total aircraft time: 390h
- Aircraft hangared at: Orleans, France
- Pilot moaning in: Tunis, Tunisia
E-mail: serge.vi...@ate-international.com
<mailto:serge.vi...@ate-international.com>





-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net]On
Behalf Of Orma Robbins
Sent: Tuesday, April 20, 2004 13:22
To: Orma Robbins; KRnet
Subject: Re: KR> type 4 Failures


Hello again Netters.

I just finished reading the Archives search for Crankshaft failures.  I
entered the dates present to 1990.  There were 31 hits on the subject.
There was a lot of discussion on failures, but not ONE posting by anyone
with a failure that gave any details at all.  This is significant.  Some
members make decisions based on the word of the net.  I have flown my type 4
off and on now for over 19 years.  My 66 mm crank looks as new.  I am moving
up to a  stock 71 mm crank in what will be a completely different engine.
If there are cranks failing I personally really want to know who and why.
Tweedy and I are both getting older and would like to continue to do so
without having experienced crank failure.
So, this post is a call for any one with direct knowledge to sing out.

Orma L. Robbins Southfield MI
19 Years flying KR-2 N110LR (Tweedy)
http://www.aviation-mechanics.com


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KR> type 4 Failures

[Mac McConnell-Wood]

- Original Message - 
From: "Orma Robbins" <o...@aviation-mechanics.com>
To: "KRnet" <kr...@mylist.net>; <srmak...@aol.com>
Sent: Tuesday, April 20, 2004 12:33 PM
Subject: KR> type 4 Failures
Hello Orma,- from over the pond ,the only crankshaft failure that I heard
about was Dan's, and I believe his was a type 4.  Revmaster told me recently
they'd never had a 4340 chrome /moly?failure-so I bought one.Gullible or
what!
Regards,   Mac   UK

> Hello Steve and KR netters,  After a few posts that I put on the net about
the rebuild of my type 4,  Mark L. suggested that I should talk to you and
others about you crank failures. > ___
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html

Fwd: KR> type 4 Failures

[fixerjo...@aol.com]

my viewpoints on the use of the type 4,for reliable service all aspects 
must be set up properly ,not guess work or it's close.  my type 4 is a stock 71 
mm crank, with a big bore kit, the bore size is not important,,the 
compression ratio is!  i use 8 to 1 comp. to make the engine live a long life,, 
8 to 1 
comp. or less .  also the timing set to 26 degrees or less! also a egt & cht on 
all 4 cyls.  i run 1200 egt max& 375 cht max sensed on the plugs.  another 
point is to balance the engine.  the prop must be wood & balanced on the engine 
too.  i run 100ll avgas only& the oil press @ 50psi @ 3000rpm which is max in 
flight.  i cruise @ 2400 to 2600 rpm.  this is my method of type 4 survival & 
durability,   steve jones   n212kr
i almost forgot to thank greatplains for there quality parts,,without the 
force 1 hub setup, it wouldn't work as well,,,

KR> type 4 Failures

[o...@aviation-mechanics.com]

Thanks for the feedback

Orma

KR> type 4 Failures

[Mark Langford]

 Below is a message from the CorvAircraft archives (
http://www.maddyhome.com/corvairsrch/index.jsp ).

List-Post: krnet@list.krnet.org
Date: 29-Jan-04 6:14 AM

From: srmak...@aol.com

Subject: CorvAircraft>VW Cranks

Hi all. The subject of these cranks has been a sore spot with me since I
broke a type 4 scat 78 mm in flight. at exactly 220 hours. I broke the next
stocker too in about the same amount of time. Bob Lester (another vair Kr
driver broke a revmaster crank at 200 hours or so. This seems to be the
MAGIC number. Someone told me that this is why Hapi engines went under
because they had to replace 80 thousand dollars worth of bad cranks on their
engines. I don't know how true this is, but it must have some truth to it. I
finally had Steve Bennett put in a force one hub and did not have a problem
after that and it ran until I went with another conversion. Great Plains
stuff seems to work well and Steve  is a good friend of mine and a straight
shooter.Regards, StevePS> Dan Diehl broke his type 4 crank on the way back
from Oshkosh to Tulsa, same setup as mine and about the same
hours._

KR> Type 4 failures

[Orma Robbins]

The following arrived this evening from Steve Makish about his type 4 failures.

Orma

Hello, Steve here. My crank was a 78mm scat. It broke across the # 3 rod (I 
think, it was so long ago) The crank was brand new and no mods were done to it. 
It broke at about 220 hours. Dan Diehl broke one on his type 4 engine also 
right about the same amount of hours. I also cracked a stock 71mm, but I found 
that out on the ground and not in the air. I rebuilt the engine again with a 
stock crank but had Steve Bennett put in his force one hub. I flew it for about 
25-50 hours before I sold it to a guy locally who was building a kr2s. Strange 
sidenote. Last week at sun and fun a beautiful kr tri gear pulled in from 
Venice fl. We got talking and he was a real nice fellow. Come to find out he 
bought the guys project, finished it and is flying with my old engine (110) 
hours so far. He was not happy with the performance and was looking into 
putting in a corvair. funny how things work out. Hope this answers your 
questions,
Regards,
Steve

KR> Type 4 failures

[Eduardo Iglesias]

I think in armonic vibrations.
What hapens if you put on it a PSRU?

- Original Message -
From: "Orma Robbins" <o...@aviation-mechanics.com>
To: "KRnet" <kr...@mylist.net>
Sent: Tuesday, April 20, 2004 11:00 PM
Subject: KR> Type 4 failures


> The following arrived this evening from Steve Makish about his type 4
failures.
>
> Orma
>
> Hello, Steve here. My crank was a 78mm scat. It broke across the # 3 rod
(I think, it was so long ago) The crank was brand new and no mods were done
to it. It broke at about 220 hours. Dan Diehl broke one on his type 4 engine
also right about the same amount of hours. I also cracked a stock 71mm, but
I found that out on the ground and not in the air. I rebuilt the engine
again with a stock crank but had Steve Bennett put in his force one hub. I
flew it for about 25-50 hours before I sold it to a guy locally who was
building a kr2s. Strange sidenote. Last week at sun and fun a beautiful kr
tri gear pulled in from Venice fl. We got talking and he was a real nice
fellow. Come to find out he bought the guys project, finished it and is
flying with my old engine (110) hours so far. He was not happy with the
performance and was looking into putting in a corvair. funny how things work
out. Hope this answers your questions,
> Regards,
> Steve
>
> ___
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
> ---
> [This E-mail scanned for viruses by Declude Virus]
>
>

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