Original Posted By: "Carl D. Vought"
Pietenpol-List: Model A head
Re: Pietenpol-List: Model A head
Original Posted By: Clif Dawson
Subject: Re: Pietenpol-List: Model A headCarl,I bought a Dan Price head, and found the quality very good. These products have been around for awhile, so the bugs are probably all worked out. When I used this higher compression head, I had to use two head gaskets, because the tops of the pistons protruded up past the deck of the block. This was probably due to the fact that the top of my block had probably been surfaced ground at some point in it's life. The 6:1 head is machined flat, with dished out room just in the area where the valves stick up. I ran, and flew the plane in this configuration for maybe 10 hrs, but then went back to the stock cast iron head, and one head gasket. The main reason I went back to the cast iron head was for W & B reasons. I could not tell any difference in performance between the higher 6:1 head, and the stock 4.8:1 head. I used only one Wico magneto, driven off the crank the way the plans show. I can't see any problems with the different size plugs, but you may have to experiment with the heat range of the plugs. It seemed like my Model A plugs didn't last very long. I would have trouble starting the engine, change the plugs, and it would start right up.Chuck G.________________________________________________________________________________Date: Thu, 21 Oct 2004 00:37:37 -0700
Subject: Re: Pietenpol-List: Model A headCarl,I bought a Dan Price head, and found the quality very good. These products have been around for awhile, so the bugs are probably all worked out. When I used this higher compression head, I had to use two head gaskets, because the tops of the pistons protruded up past the deck of the block. This was probably due to the fact that the top of my block had probably been surfaced ground at some point in it's life. The 6:1 head is machined flat, with dished out room just in the area where the valves stick up. I ran, and flew the plane in this configuration for maybe 10 hrs, but then went back to the stock cast iron head, and one head gasket. The main reason I went back to the cast iron head was for W & B reasons. I could not tell any difference in performance between the higher 6:1 head, and the stock 4.8:1 head. I used only one Wico magneto, driven off the crank the way the plans show. I can't see any problems with the different size plugs, but you may have to experiment with the heat range of the plugs. It seemed like my Model A plugs didn't last very long. I would have trouble starting the engine, change the plugs, and it would start right up.Chuck G.________________________________________________________________________________Date: Thu, 21 Oct 2004 00:37:37 -0700
Pietenpol-List: Re: Model A head
Original Posted By: Dan Yocum
"Hope your engineering is better than your math 46.5 - 27 = 19.5 almost 20 lbs."Come on now, don't bash his engineering... he did say 'dang near'. That oughtto qualify as engineering speak. :)Billy McCaskillUrbana, IL/Baker, LA[/quote]Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Tue, 27 Oct 2009 15:11:41 -0500
"Hope your engineering is better than your math 46.5 - 27 = 19.5 almost 20 lbs."Come on now, don't bash his engineering... he did say 'dang near'. That oughtto qualify as engineering speak. :)Billy McCaskillUrbana, IL/Baker, LA[/quote]Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Tue, 27 Oct 2009 15:11:41 -0500
Re: exhaust manifold [was Re: Pietenpol-List: humped center section]
Original Posted By: Jeff Boatright
RE: exhaust manifold [was Re: Pietenpol-List: humped center section]
Original Posted By: owner-pietenpol-list-server(at)matronics.com
For those contemplating stainless steel ehaust systems, let me share alittle pearl of wisdom that I learned just a bit too late:My original exhaust system on my Pietenpol was TIG welded stainless steel,welded by my neighbor (who also welded my aluminum fuel tank). The weldslooked good, but after about 30 hours of operation, the left stack broke offand was only kept from departing the airplane by the SCAT hose on the heatmuff. I had my neighbor re-weld it, with an additional strut to helpdistribute the load. Then I flew the airplane to Brodhead and OSH (this wasin 2005). On the way home, the right side stack broke off and was againheld in place by the SCAT hose. I had to find a local welder make emergencyrepairs so I could make it home.I decided that stainless was simply not a good choice and made a whole newset from plain carbon steel, which I could weld myself. No problem with it,except that it has begun to rust. In another 10 years or so I'll have toreplace it.Meanwhile, I was talking to a fellow who makes exhaust systems for race cars(TIG welded stainless), telling him of my troubles. He asked "What did youdo to shield the inside of the tubing?"I just looked at him with a stupid look on my face (fairly easy for me todo), and said "Huh?"He said, "TIG shields the area around the weld with argon gas to prevent theweld from burning, but with such thin walled material, the metal on theinside of the tube is just as hot as the outside. You've got to shield itas well."He said that when he does a job like this, he plugs one end of the tube,then turns on the gas from the TIG torch and uses it to flood the entiretube with Argon. He tests to see if he has enough by striking a match andinserting it into the tube. If it doesn't go out immediately, he knows hedoesn't have enough Argon to shield the weld.So when it comes time to replace my exhaust system again, I may givestainless another try, using this technique.Jack PhillipsNX899JPRaleigh, NC-----Original Message-----
For those contemplating stainless steel ehaust systems, let me share alittle pearl of wisdom that I learned just a bit too late:My original exhaust system on my Pietenpol was TIG welded stainless steel,welded by my neighbor (who also welded my aluminum fuel tank). The weldslooked good, but after about 30 hours of operation, the left stack broke offand was only kept from departing the airplane by the SCAT hose on the heatmuff. I had my neighbor re-weld it, with an additional strut to helpdistribute the load. Then I flew the airplane to Brodhead and OSH (this wasin 2005). On the way home, the right side stack broke off and was againheld in place by the SCAT hose. I had to find a local welder make emergencyrepairs so I could make it home.I decided that stainless was simply not a good choice and made a whole newset from plain carbon steel, which I could weld myself. No problem with it,except that it has begun to rust. In another 10 years or so I'll have toreplace it.Meanwhile, I was talking to a fellow who makes exhaust systems for race cars(TIG welded stainless), telling him of my troubles. He asked "What did youdo to shield the inside of the tubing?"I just looked at him with a stupid look on my face (fairly easy for me todo), and said "Huh?"He said, "TIG shields the area around the weld with argon gas to prevent theweld from burning, but with such thin walled material, the metal on theinside of the tube is just as hot as the outside. You've got to shield itas well."He said that when he does a job like this, he plugs one end of the tube,then turns on the gas from the TIG torch and uses it to flood the entiretube with Argon. He tests to see if he has enough by striking a match andinserting it into the tube. If it doesn't go out immediately, he knows hedoesn't have enough Argon to shield the weld.So when it comes time to replace my exhaust system again, I may givestainless another try, using this technique.Jack PhillipsNX899JPRaleigh, NC-----Original Message-----
Re: exhaust manifold [was Re: Pietenpol-List: humped center
Original Posted By: Michael Perez