Revmaster damage report


Dave Dugas
 

Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










Robert Cringely
 

My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










Jay Scheevel
 

Looks like the piston pin boss “unzipped” the skirt around the oil ring groove. Thanks for keeping us in the loop, Dave.

Cheers,
Jay


On Oct 15, 2021, at 7:07 PM, Robert Cringely <bob@...> wrote:


My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.
<IMG_20211015_165818.jpg>

<IMG_20211015_165711.jpg>

<IMG_20211015_165639.jpg>








Dave Dugas
 

Hi Robert. 
I don't understand what a Teflon button is. I'll be looking for the connecting rod bolt to see if it broke or loosened up, when I get the case apart.


On Fri, Oct 15, 2021 at 9:07 PM, Robert Cringely
<bob@...> wrote:
My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










Jon Finley
 

Just WOW!  That's crazy Dave!  😲

I hope you find the piston pin in the sump so we can see what it looks like. However; I bet some kid in Oklahoma is running around with it telling his friends that a UFO dropped it when it flew over... 😉

Jon Finley
Somewhere in the Southwest flying an RV-4


Robert Cringely
 

Rex Taylor of HAPI was the big proponent of teflon buttons, which replaced circlips to retain the piston pins: https://www.jbugs.com/product/4074.html?utm_content=shopping&gclid=CjwKCAjw8KmLBhB8EiwAQbqNoFUHSImPaKlE29RpiaEvFrGreHUI792ro5diBbVNMPLMmEVZuIGWtBoCkQcQAvD_BwE

Look for a broken circlip in that sump, too.


On Fri, Oct 15, 2021 at 6:38 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Hi Robert. 
I don't understand what a Teflon button is. I'll be looking for the connecting rod bolt to see if it broke or loosened up, when I get the case apart.


On Fri, Oct 15, 2021 at 9:07 PM, Robert Cringely
<bob@...> wrote:
My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










Dave Dugas
 

You could be right Jon regarding cylinder pin being discovered by someone in the middle of nowhere. Something really hot must of been setting on the bottom of my cowl for a few seconds because the paint is bubbled up there.
Robert... the piston has signs of traveling to far and hitting the edges of the combustion chamber, which I think may have been caused by a broken or loosening of one of the connecting rod bolts. I'll be looking for a clip or pieces of one. No Teflon buttons used on my engine. Thanks for the suggestions. Plenty of aluminum pieces when I removed the sump cover, but so far nothing looks like a piece of clip. I'll going to run a magnet through everything I find.
Dave D


On Sat, Oct 16, 2021 at 7:59 AM, Robert Cringely
<bob@...> wrote:
Rex Taylor of HAPI was the big proponent of teflon buttons, which replaced circlips to retain the piston pins: https://www.jbugs.com/product/4074.html?utm_content=shopping&gclid=CjwKCAjw8KmLBhB8EiwAQbqNoFUHSImPaKlE29RpiaEvFrGreHUI792ro5diBbVNMPLMmEVZuIGWtBoCkQcQAvD_BwE

Look for a broken circlip in that sump, too.


On Fri, Oct 15, 2021 at 6:38 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Hi Robert. 
I don't understand what a Teflon button is. I'll be looking for the connecting rod bolt to see if it broke or loosened up, when I get the case apart.


On Fri, Oct 15, 2021 at 9:07 PM, Robert Cringely
<bob@...> wrote:
My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










Jim Patillo
 

Hi Dave, 

Teflon “buttons” keep the rod pins in place from contacting the side walls, instead of relying on metal clips. Was there a really loud bang? 😮
That was one hell of an explosion. 

Jim 



From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Dave Dugas via groups.io <davedq2@...>
Sent: Friday, October 15, 2021 6:38:45 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
Hi Robert. 
I don't understand what a Teflon button is. I'll be looking for the connecting rod bolt to see if it broke or loosened up, when I get the case apart.


On Fri, Oct 15, 2021 at 9:07 PM, Robert Cringely
<bob@...> wrote:
My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










Dave Dugas
 

Hi Jim
Headset was on and I still heard it pretty good. Felt it really good though. When I get the fuselage flipped over l will take pictures of the damage from the heat / fire.


On Sat, Oct 16, 2021 at 11:09 AM, Jim Patillo
<Logistics_engineering@...> wrote:
Hi Dave, 

Teflon “buttons” keep the rod pins in place from contacting the side walls, instead of relying on metal clips. Was there a really loud bang? 😮
That was one hell of an explosion. 

Jim 



From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Dave Dugas via groups.io <davedq2@...>
Sent: Friday, October 15, 2021 6:38:45 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
Hi Robert. 
I don't understand what a Teflon button is. I'll be looking for the connecting rod bolt to see if it broke or loosened up, when I get the case apart.


On Fri, Oct 15, 2021 at 9:07 PM, Robert Cringely
<bob@...> wrote:
My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










smeshno1@...
 

It was a catastrophic..looks like a no warning fail. Jay has a good point..be looking at the rod cap bolt in hopes it's not down in the Pawhuska woods. Curious to see what the initial failure line looks like. So the point being, likely even when the engine was assembled, there would be no indication of a problem.  Could be where the bolts were made and more critically, by what process. ARP are the only acceptable rod bolts in Corvair conversions specifically because they are made to and exceed aerospace requirements. Do you know who made your rod bolts? In the decades I drove the hell out of my Corvairs, not once was there a rod bolt failure. I did have valve seat and valve spring retainer fails. My first 65 the day I got it from the car auction I purposely tried to grenade the engine, and at the time being 17 and 18 years old I did my flying on the ground drag racing A Gas class 427 Nova/Chevy II. I blew up all kinds of parts but the pancake 6 proved it was a tuff critter, even against my right lead foot! Drag racing found out quickly that Cubic Dollars, which I did not have in endless supply, was the only way to endure in that game. 11 moving violations on the street in one year and had to trade in the fast cars for a city bus with city driver included. But I learned some about how metals fail and aftermath still is interesting so to mitigate future incidences. 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Dave Dugas via groups.io <davedq2@...>
Sent: Saturday, October 16, 2021 11:44 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>; Jim Patillo <Logistics_engineering@...>
Subject: Re: [Q-List] Revmaster damage report
 
Hi Jim
Headset was on and I still heard it pretty good. Felt it really good though. When I get the fuselage flipped over l will take pictures of the damage from the heat / fire.


On Sat, Oct 16, 2021 at 11:09 AM, Jim Patillo
<Logistics_engineering@...> wrote:
Hi Dave, 

Teflon “buttons” keep the rod pins in place from contacting the side walls, instead of relying on metal clips. Was there a really loud bang? 😮
That was one hell of an explosion. 

Jim 



From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Dave Dugas via groups.io <davedq2@...>
Sent: Friday, October 15, 2021 6:38:45 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
Hi Robert. 
I don't understand what a Teflon button is. I'll be looking for the connecting rod bolt to see if it broke or loosened up, when I get the case apart.


On Fri, Oct 15, 2021 at 9:07 PM, Robert Cringely
<bob@...> wrote:
My VW experience was back in the 70s and 80s when I rebuilt the engine in my $1300 KR-1 MANY times. It never failed or even hiccoughed, but I always wanted more power. 1600, 1835, then 2180 lasted 1100+ hours until the hangar roof failed in a storm, crushing my little KR. I used it one year to commute from Palo Alto to Van Nuys for a teaching job. Oh, to be young again...

Snapping back to reality, it's clear that you broke a rod bolt but I think the piston pin failed first. It's also gone, and from the shape of that little end I'd say the big end was still intact when the (now pinless) little end started smashing into the bottom of the piston. Either a circlip failed or a teflon button melted. Sometimes those teflon buttons aren't really teflon, which is why Steve Bennett wouldn't touch them



On Fri, Oct 15, 2021 at 5:11 PM Dave Dugas via groups.io <davedq2=yahoo.com@groups.io> wrote:
Here's pictures of the pieces from the #1 cylinder, along with a picture of the crankcase. A lot of aluminum material of various sizes also found in the sump when I removed the oil drain assembly from the bottom of the crankcase. I'm going to split the case, hoping to see what's left of the connecting rod bolt, which I think was what failed.










smeshno1@...
 

That's funny Jon..in the sticks of Oklahoma almost any airplane is a UFO! Per Capita median income in the County the town of Pawhuska is located is less than 18k a year. One reason I moved to rural eastern Oklahoma. My SSA goes a lot farther than it did in Taos. 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jon Finley <jd@...>
Sent: Saturday, October 16, 2021 6:51 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
Just WOW!  That's crazy Dave!  😲

I hope you find the piston pin in the sump so we can see what it looks like. However; I bet some kid in Oklahoma is running around with it telling his friends that a UFO dropped it when it flew over... 😉

Jon Finley
Somewhere in the Southwest flying an RV-4


Raphael SF Zvetkoff
 

If it was the wrist pin keeper it's surprising the cylinder wall doesn't have deep scoring and didn't squeal as it wore a grove on the cylinder wall.  It would have been smoking like crazy.  The bolt sounds more plausible.


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of smeshno1@... <smeshno1@...>
Sent: Saturday, October 16, 2021 12:18 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
That's funny Jon..in the sticks of Oklahoma almost any airplane is a UFO! Per Capita median income in the County the town of Pawhuska is located is less than 18k a year. One reason I moved to rural eastern Oklahoma. My SSA goes a lot farther than it did in Taos. 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jon Finley <jd@...>
Sent: Saturday, October 16, 2021 6:51 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
Just WOW!  That's crazy Dave!  😲

I hope you find the piston pin in the sump so we can see what it looks like. However; I bet some kid in Oklahoma is running around with it telling his friends that a UFO dropped it when it flew over... 😉

Jon Finley
Somewhere in the Southwest flying an RV-4


smeshno1@...
 

When Dave told me in Enid it was still running on final approach, and now seeing the photo's, to me it was near a miracle it wasn't a sudden lockup and instant dead stick prop. The proverbial "suddenly went all silent after the bang!" Scares me and I ain't afraid of nuthin but Kryptonite. 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Raphael SF Zvetkoff <echopark1@...>
Sent: Saturday, October 16, 2021 9:41 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
If it was the wrist pin keeper it's surprising the cylinder wall doesn't have deep scoring and didn't squeal as it wore a grove on the cylinder wall.  It would have been smoking like crazy.  The bolt sounds more plausible.

From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of smeshno1@... <smeshno1@...>
Sent: Saturday, October 16, 2021 12:18 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
That's funny Jon..in the sticks of Oklahoma almost any airplane is a UFO! Per Capita median income in the County the town of Pawhuska is located is less than 18k a year. One reason I moved to rural eastern Oklahoma. My SSA goes a lot farther than it did in Taos. 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jon Finley <jd@...>
Sent: Saturday, October 16, 2021 6:51 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Revmaster damage report
 
Just WOW!  That's crazy Dave!  😲

I hope you find the piston pin in the sump so we can see what it looks like. However; I bet some kid in Oklahoma is running around with it telling his friends that a UFO dropped it when it flew over... 😉

Jon Finley
Somewhere in the Southwest flying an RV-4