VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.


Go Back   VAF Forums > RV Firewall Forward Section > Traditional Aircraft Engines
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #71  
Old 12-15-2013, 10:28 AM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default

Quote:
Originally Posted by az_gila View Post
Why is the yellow type around the lower part of the cylinders only?
Its in preparation for paint. The barrels are painted first. Then masked before assembly. Easier to put that on with the cylinders off.
__________________
Kahuna
6A, S8 ,
Gold Hill, NC25
Reply With Quote
  #72  
Old 12-18-2013, 03:34 PM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default

Quote:
Originally Posted by Kahuna View Post
While pulling off the exhaust, I noticed this warpiage located under the heat muff. Hidden for years. My muffs have never been off and I have had no reason to look under them. Hmmm. Whats that?


A quick call to Larry Vetterman... He has seen this before, although rarely. According to Larry, there are 2 cases where this is seen.
1. A wrapped exhaust, or ceramic coated exhaust. I have neither of these.
2. A muff exit blocked where the heat cant get away, either from a scat tube collapse or FW valve that does not dump overboard. Well I have never had either of those.

Either way, it is what it is. A tap with a punch to check wall thickness in the warpage area and Im satisfied that the warpage does not pose any risk so Im leaving it as is. Amazingly, the rest of the exhaust of completely great. I have never had a crack, support arm break, or anything of that nature in its years of service. Im cleaning it up and putting her back on.
Decided to fix this pipe. Fixing this pipe was not difficult. Im fortunate to have friends and resources on the field here. My star smart guy is Mr. Gary Dehart, retired crew chief Hendrix Motorsports. If he cant do it, it cant be done. We set up a jig on his welding table, cut out the offending piece, & fitted in a new one. The joints are not straight by design. With 321 stainless, you also need very tight butt joints before committing rod to metal. Plus he is a perfectionists. I kept telling him we were not going to the moon here. But there is no convincing him that one day this exhaust might have to see duty on the space station or something. I love hanging out with Gary. I always am humbled and learn from the best. Thanks Gary for sharing your shop today.



During the welding process, a remote pressure argon feeder is installed into the pipe to force out air, and allow for a cleaner weld INSIDE and out.


In the end it looks like a simple straight pipe replacement.

__________________
Kahuna
6A, S8 ,
Gold Hill, NC25

Last edited by Kahuna : 12-20-2013 at 07:04 AM.
Reply With Quote
  #73  
Old 12-19-2013, 07:59 AM
TS Flightlines TS Flightlines is offline
 
Join Date: Apr 2010
Location: Ridgeland, SC
Posts: 2,932
Default

Well its not everyone that has a neighbor like Gary Dehart, a Championship winning Crew Chief in the Cup series. I think its great that he was able and willing to help out. Yep---its cool to be able to watch and learn for masters like him!!!!!
Tom
__________________
Tom Swearengen, TS Flightlines LLC, AS Flightlines
Joint Venture with Aircraft Specialty
Teflon Hose Assemblies for Experimentals
Proud Vendor for RV1, Donator to VAF
RV7A Tail Kit Completed, Fuse started-Pay as I go Plan, on hold while we develop new products for RV builders
Ridgeland, SC
www.tsflightlines.com, www.asflightlines.com
Reply With Quote
  #74  
Old 12-19-2013, 09:05 AM
dealfair dealfair is offline
 
Join Date: Feb 2006
Location: George West, TX
Posts: 567
Default

Quote:
Originally Posted by Kahuna View Post
Decided to fix this pipe. Fixing this pipe was not difficult. Im fortunate to have friends and resources on the field here. My star smart guy is Mr. Gary Dehart, retired crew chief Hendrix Motorsports. If he cant do it, it cant be done. We set up a jig on his welding table, cut out the offending piece, & fitted in a new one. The joints are not straight by design. With stainless, you also need very tight butt joints before committing rod to metal. Plus he is a perfectionists. I kept telling him we were not going to the moon here. But there is no convincing him that one day this exhaust might have to see duty on the space station or something. I love hanging out with Gary. I always am humbled and learn from the best. Thanks Gary for sharing your shop today.
His welding hood speaks volumes too. Me likee!!!
__________________
Deal Fair
RV-4 (N34CB)
George West, TX (8T6)
Reply With Quote
  #75  
Old 12-19-2013, 09:39 AM
brodman@strato.net's Avatar
brodman@strato.net brodman@strato.net is offline
 
Join Date: Feb 2005
Location: Sebring, FL
Posts: 14
Thumbs up Case Dowels / Orings / Thru-Bolts

Quote:
Originally Posted by rocketbob View Post
Actually this is an incorrect statement. The reason for the dowels are to bring those holes back up to size, not to prevent leaks. Actually adding a second path around the bushing increases the likelihood of a leak since now there are two paths for the oil to travel. They don't do that to make them stop leaking there. The o-ring counterbore mod is done to prevent leaks.

On the 540 there is an oversize thru bolt available so its just as good to ream the holes to .002 undersize for the larger thru bolt, and then you can counterbore for the o-ring.

So unless one could not ream to fit to size for an oversize thrubolt, I would not do this mod.
I agree that the installation of the dowels is an approved repair for excessive wear at the thru bolt hole main bearing area. If the interference fit is diminished (Fretting occurs at the center mains) then thru bolts leak and a repair is required. As you suggest a basic mod is available (Lycoming) to improve leaking by only installing an oversized thru bolt and machining an o-ring groove in the case to fit around the thru bolt only. This repair is an approved fix that works for low horsepower engines but never holds up for long on higher horsepower engines.
In the past 30 years we found that with the installation of the center dowels and most important the addition of an o-ring groove around the dowel works best as a proper prevention and repair for case fretting. This improved modification results in improved leak prevention. These two Lycoming Service Instructions cover some of this information SI 1290 / SI 1123

I'm sure that opinions from engine builders may vary on this subject and no disrespect to rocket or his opinion/experience building engines..
Any questions jimmy@jbaircraftengines.com
__________________
Jimmy Brod
www.jbaircraftengines.com
Superior XP Engine sales / Custom Engine Overhaul / Redline Engines
863-655-5000 shop / 863-381-1530 cell
Reply With Quote
  #76  
Old 12-19-2013, 10:05 AM
rocketbob's Avatar
rocketbob rocketbob is offline
 
Join Date: Jun 2006
Location: 8I3
Posts: 3,768
Default

Not disagreeing but if it were my engine and the studs were necessary I would do both. That is, put the o-ring counterbore in along with the stud, and use a larger oring. On the high HP 540's usually at the third main where you see the most fretting/throughbolt hole wear, the others are usually fine.
__________________

Please don't PM me! Email only!

Bob Japundza CFI A&PIA
N9187P PA-24-260B Comanche, flying
N678X F1 Rocket, under const.
N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
N8155F C150 flying
N7925P PA-24-250 Comanche, restoring
Not a thing I own is stock.
Reply With Quote
  #77  
Old 12-27-2013, 04:28 PM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default Engine arrives

The engine was shipped Yellow Freight. Took 24 hours to get from Sebring to Charlotte for me to pick up. Thats pretty fast trucking. My wife Amy picked it up for me on her way to work 5 days ago. She is very supportive. YF placed it in the truck with a forklift. It arrived all created up. A little rain shower on the drive home.


Getting it off the truck can be a bit tricky. My hoist is no where near tall enough to snag it off the truck. So I put my by-fold door power to use. The dogs are not as enthusiastic as I was.







Upon unwrapping, I found this beautiful engine. We have installed 4 new engines on the team this year. Looking at these new motors never gets old.







JB asked me what I wanted for colors. I told him he could surprise me with anything other than pink! It is purtty. He swapped over some of my old accessories like my starter, governor, remote oil adapter, inverted oil adapter, etc. New injection lines and the rebuilt spider and servo. It was time to get to work. Fights on!
__________________
Kahuna
6A, S8 ,
Gold Hill, NC25
Reply With Quote
  #78  
Old 12-27-2013, 04:54 PM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default Heat mod

During my original build, I came up with the idea to pick up the fresh air for the heat muffs from the intercylinder baffles below the cylinders. I had a few things in mind with this.
1. Big engine, more heat, no change in inlet sq inches. I did not want to rob cold air off the rear baffles for heat.
2. Seemed like a good idea to pull heat from the warmer air that has already been warmed by the cylinder fins.
3. I could think of no downside.

This served me well over the years with plentiful heat even in sub zero conditions. The mod is pretty simple. Rivet a 2" flange to the intercylinder baffle and install. I could not reuse the ones from my lyco cylinders as the Titan tapered finned cylinders are a bit different. It does require some rebending of the valve cover drain lines that return oil back to the sump.





You will notice below that the cylinder wrap is safety wired to the cht probe insert on the right side of the picture. This is necessary since you cant tie the 2 wrappes together with that big 2" flange in the way. I had no problems with this in the first 2000 hours so I consider this a good working solution.



I forgot to take a picture of the final install but it looks just like my original one below.

__________________
Kahuna
6A, S8 ,
Gold Hill, NC25
Reply With Quote
  #79  
Old 12-27-2013, 05:12 PM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default Back in the air

After 5 days of work, plus stick in family time at xmas, my wonderful super 8 is back in the air. Everything fit back to where it was. I had one kinked oil line that Tom at TS Flightlines immediately rectified. Thanks Tom! Baffles are new. Geez I hate baffle work. Sealed up every nook and cranny with black RTV. Only issue I had on initial start was 2 plug wires reversed. I can live with that. Put 2 uneventful hours on her today. Fuel flow was a staggering 25gph. I cant even look at it. Cool temps here kept cyl temps below 330. Thats pretty good given brand new cylinders.





This is what it looks like to break in an engine. Dizzy!


Everything works. Nothing to do now by fly it hard and fly it fast.
__________________
Kahuna
6A, S8 ,
Gold Hill, NC25
Reply With Quote
  #80  
Old 12-27-2013, 05:17 PM
Mike S's Avatar
Mike S Mike S is offline
Senior Curmudgeon
 
Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 16,110
Default Congratulations!

Mike, good job
__________________
Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


All times are GMT -6. The time now is 11:05 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.