Original Posted By: "Rodger & Betty Childs"
Subject: Pietenpol-List: Braking pistons in my Model AGents,Does anyone know why pistons would break? I have broken 2 pistions in my model A engine; one in flight. The aircraft has 100 hours. The pistons which break tend to pull apart separating the bottom section from the top section at the bottom of the ring groove area. The bore, ring end gap, and piston clearance appear to be in spec. Doug Bryant Wichita Ks________________________________________________________________________________
Pietenpol-List: Braking pistons in my Model A
Re: Pietenpol-List: A little help
Original Posted By: "John Dilatush"
>> Alright, all this discussion on DAR's vs. Federalies forces me to come out> of lurkdum and throw another spanner at the machine....>> But first, since I'm gonna do this, I figure I better introduce myself a> bit.... my airport too, and it seems like most folks don't quite understand how it> all works.>> Chris House> Jack of all trades, Master of none (and looking forward to Corky's take:) )>> It must be the heat.....105 today!Chris (aka Ignitor),You're beginning understand the situation and to make sense...and that's scary. And, No, it has nothing to do with the heat.Rodgerenjoying a "cool" 86 deg day________________________________________________________________________________
>> Alright, all this discussion on DAR's vs. Federalies forces me to come out> of lurkdum and throw another spanner at the machine....>> But first, since I'm gonna do this, I figure I better introduce myself a> bit.... my airport too, and it seems like most folks don't quite understand how it> all works.>> Chris House> Jack of all trades, Master of none (and looking forward to Corky's take:) )>> It must be the heat.....105 today!Chris (aka Ignitor),You're beginning understand the situation and to make sense...and that's scary. And, No, it has nothing to do with the heat.Rodgerenjoying a "cool" 86 deg day________________________________________________________________________________
Pietenpol-List: A little help
Original Posted By: "Terry D. Morgan, Sr., MCP"
Cy,Thanks for getting a reply from Earl Lawrence.I know that the EAA is busy with many other issues, especially the SportPilot license. However I had the impression after reading the letterthat the EAA has become as much of a bureaucracy as the FAA.Mr Lawrence is mistaken that he only receives about one complaint amonth re: certification. I know that our chapter wrote at least 3letters of complaint in one month alone, multiply this by the 1200 pluschapters in the EAA. No one else has complained? He also says that weare informed monthly about what the EAA is doing about the certificationissue. I have carefully reviewed the last seven issues of SportAviation and found one article about certification in the November 2000issue and one small reference back to the November article in theDecember issue. These are hardly monthly updates as he states in hisletter! I could find nothing on their website about certification.And Randy Hansen in is office was the one who evidently "lost" the fileI sent and addressed to him regarding my problems and correspondencethat I had with the FAA. It was only after I wrote a critical letterabout the EAA to Paul Poberezny that I got anyone to answer me. Thatanswer came from Paul Poberezny who turned it over to Robert Warner,Executive VP. Mr. Warner took more than 3 weeks after this initialcorrespondence to reply. I have heard or read nothing since. All ofthis seems to demonstrate a poor regard for "service to the membership".I know that the EAA is hampered by the FAA rules and regulations, andthat it is tough to get anything done, but I can't help but wonderbecause of the delays and obstacles now in the certification process,how many homebuilts are now flying without a C of A, and how many arereally airworthy without having this final inspection? Is this servingthe Safety God that everyone in the EAA and FAA proposes to worship?It seems to me that Earl Lawrences' letter is a lot of self servingeyewash. Are they truly working for us?John Dilatushdilatush(at)amigo.net________________________________________________________________________________
Cy,Thanks for getting a reply from Earl Lawrence.I know that the EAA is busy with many other issues, especially the SportPilot license. However I had the impression after reading the letterthat the EAA has become as much of a bureaucracy as the FAA.Mr Lawrence is mistaken that he only receives about one complaint amonth re: certification. I know that our chapter wrote at least 3letters of complaint in one month alone, multiply this by the 1200 pluschapters in the EAA. No one else has complained? He also says that weare informed monthly about what the EAA is doing about the certificationissue. I have carefully reviewed the last seven issues of SportAviation and found one article about certification in the November 2000issue and one small reference back to the November article in theDecember issue. These are hardly monthly updates as he states in hisletter! I could find nothing on their website about certification.And Randy Hansen in is office was the one who evidently "lost" the fileI sent and addressed to him regarding my problems and correspondencethat I had with the FAA. It was only after I wrote a critical letterabout the EAA to Paul Poberezny that I got anyone to answer me. Thatanswer came from Paul Poberezny who turned it over to Robert Warner,Executive VP. Mr. Warner took more than 3 weeks after this initialcorrespondence to reply. I have heard or read nothing since. All ofthis seems to demonstrate a poor regard for "service to the membership".I know that the EAA is hampered by the FAA rules and regulations, andthat it is tough to get anything done, but I can't help but wonderbecause of the delays and obstacles now in the certification process,how many homebuilts are now flying without a C of A, and how many arereally airworthy without having this final inspection? Is this servingthe Safety God that everyone in the EAA and FAA proposes to worship?It seems to me that Earl Lawrences' letter is a lot of self servingeyewash. Are they truly working for us?John Dilatushdilatush(at)amigo.net________________________________________________________________________________
Re: Pietenpol-List: Braking pistons in my Model A
Original Posted By:
Doug Do the pistons break in the bottom of the oil ring groove?Is there any sign of galling or metal transfer in the ring land area betweenthe rings?I have not had this happen to a Model A but I have seen other engines do itand it usually is a result of the pistons fitted too tightly.The expansion of aluminum is approximately three times that of iron andsteel. If the top area of the piston the ring land area expands enough tocontact the cylinder wall. the pistons if machined correctly have a reduceddiameter in the ring land area.Has the block been bored and resurfaced? If so, did you check to see if thepiston to deck height is right. Telltale evidence would be marking on thepiston crowns. Rod length center to center can also lead to piston to headinterference. The other area I would check is timing. detonation can dostrange things and wouldn't likely be heard in the aircraft application.Hope this helps.John Mc----- Original Message -----
Doug Do the pistons break in the bottom of the oil ring groove?Is there any sign of galling or metal transfer in the ring land area betweenthe rings?I have not had this happen to a Model A but I have seen other engines do itand it usually is a result of the pistons fitted too tightly.The expansion of aluminum is approximately three times that of iron andsteel. If the top area of the piston the ring land area expands enough tocontact the cylinder wall. the pistons if machined correctly have a reduceddiameter in the ring land area.Has the block been bored and resurfaced? If so, did you check to see if thepiston to deck height is right. Telltale evidence would be marking on thepiston crowns. Rod length center to center can also lead to piston to headinterference. The other area I would check is timing. detonation can dostrange things and wouldn't likely be heard in the aircraft application.Hope this helps.John Mc----- Original Message -----
Re: Pietenpol-List: Braking pistons in my Model A
Original Posted By:>
Subject: Re: Pietenpol-List: Braking pistons in my Model AIn a message dated 5/11/01 5:19:34 PM Pacific Daylight Time, jmcnarry(at)escape.ca writes:> Doug> Do the pistons break in the bottom of the oil ring groove?> Is there any sign of galling or metal transfer in the ring land area between> the rings?> > I have not had this happen to a Model A but I have seen other engines do it> and it usually is a result of the pistons fitted too tightly.> The expansion of aluminum is approximately three times that of iron and> steel. If the top area of the piston the ring land area expands enough to> contact the cylinder wall. the pistons if machined correctly have a reduced> diameter in the ring land area.> > Has the block been bored and resurfaced? If so, did you check to see if the> piston to deck height is right. Telltale evidence would be marking on the> piston crowns. Rod length center to center can also lead to piston to head> interference. The other area I would check is timing. detonation can do> strange things and wouldn't likely be heard in the aircraft application.> > Hope this helps.> John Mc> > ----- Original Message -----
Subject: Re: Pietenpol-List: Braking pistons in my Model AIn a message dated 5/11/01 5:19:34 PM Pacific Daylight Time, jmcnarry(at)escape.ca writes:> Doug> Do the pistons break in the bottom of the oil ring groove?> Is there any sign of galling or metal transfer in the ring land area between> the rings?> > I have not had this happen to a Model A but I have seen other engines do it> and it usually is a result of the pistons fitted too tightly.> The expansion of aluminum is approximately three times that of iron and> steel. If the top area of the piston the ring land area expands enough to> contact the cylinder wall. the pistons if machined correctly have a reduced> diameter in the ring land area.> > Has the block been bored and resurfaced? If so, did you check to see if the> piston to deck height is right. Telltale evidence would be marking on the> piston crowns. Rod length center to center can also lead to piston to head> interference. The other area I would check is timing. detonation can do> strange things and wouldn't likely be heard in the aircraft application.> > Hope this helps.> John Mc> > ----- Original Message -----
Re: Pietenpol-List: Braking pistons in my Model A
Original Posted By:> Doug413(at)aol.com
Is there a ridge on the tops of the cylinder walls? This must be removedas a new set of rings will hit the ridge (the original rings wear with thecylinder wall so they don't do this) and tend to take off the top of thepiston. I would suspect that pinging could also tend to crack the piston. I know from experience that it will eventually break up the top pistonring. Can't think of anything else off hand. Plse bear in mind I havezero experience with model A engines.Wayne Sippola----------
Is there a ridge on the tops of the cylinder walls? This must be removedas a new set of rings will hit the ridge (the original rings wear with thecylinder wall so they don't do this) and tend to take off the top of thepiston. I would suspect that pinging could also tend to crack the piston. I know from experience that it will eventually break up the top pistonring. Can't think of anything else off hand. Plse bear in mind I havezero experience with model A engines.Wayne Sippola----------
Re: Pietenpol-List: Braking pistons in my Model A
Original Posted By:
----- Original Message -----
----- Original Message -----
Re: Pietenpol-List: Braking pistons in my Model A
Original Posted By: "Rodger & Betty Childs"
Subject: Re: Pietenpol-List: Braking pistons in my Model AIn a message dated 5/12/01 3:47:08 PM Pacific Daylight Time, jmcnarry(at)escape.ca writes:> The ERDL pistons would be a better choice. You might want to browse> through Grant MaClarens old site. I think it is still on line. There is an> article there on a B engine using modern pistons from either Ford or Chevy I> don't remeber which. Most engine rebuild shops have catalogs that list> pistons and other parts by dimension. Perhaps you can find a forged piston> with close enough compression height to work. The pin diameter can be> matched up at the wrist pin with a steel sleeve. Good luck and let us know> John,Thanks for the response. I have heard of using other pistons (forged), but didn't have the confidence I could choose a correct match. I will look into that and Grants webb sight. I havn't checked into Grants sight for quite a while. Doug Bryant Wichita Ks________________________________________________________________________________
Subject: Re: Pietenpol-List: Braking pistons in my Model AIn a message dated 5/12/01 3:47:08 PM Pacific Daylight Time, jmcnarry(at)escape.ca writes:> The ERDL pistons would be a better choice. You might want to browse> through Grant MaClarens old site. I think it is still on line. There is an> article there on a B engine using modern pistons from either Ford or Chevy I> don't remeber which. Most engine rebuild shops have catalogs that list> pistons and other parts by dimension. Perhaps you can find a forged piston> with close enough compression height to work. The pin diameter can be> matched up at the wrist pin with a steel sleeve. Good luck and let us know> John,Thanks for the response. I have heard of using other pistons (forged), but didn't have the confidence I could choose a correct match. I will look into that and Grants webb sight. I havn't checked into Grants sight for quite a while. Doug Bryant Wichita Ks________________________________________________________________________________
> Pietenpol-List: Braking pistons in my Model A
Original Posted By: "John McNarry"
> > > Gents,> > Does anyone know why pistons would break? I have broken 2 pistons in my> model A engine; one in flight. The aircraft has 100 hours. The pistons> which break tend to pull apart separating the bottom section from the top> section at the bottom of the ring groove area. The bore, ring end gap,and > piston clearance appear to be in spec. Doug Bryant Wichita Ks> > > > > ________________________________________________________________________________
> > > Gents,> > Does anyone know why pistons would break? I have broken 2 pistons in my> model A engine; one in flight. The aircraft has 100 hours. The pistons> which break tend to pull apart separating the bottom section from the top> section at the bottom of the ring groove area. The bore, ring end gap,and > piston clearance appear to be in spec. Doug Bryant Wichita Ks> > > > > ________________________________________________________________________________