X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-m21.mx.aol.com ([64.12.137.2] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2699302 for flyrotary@lancaironline.net; Wed, 30 Jan 2008 01:05:09 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.2; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m21.mx.aol.com (mail_out_v38_r9.3.) id q.cc0.286bd1f8 (41810) for ; Wed, 30 Jan 2008 01:04:21 -0500 (EST) From: WRJJRS@aol.com Message-ID: Date: Wed, 30 Jan 2008 01:04:21 EST Subject: Re: [FlyRotary] Re: Emailing: damage24.jpg To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1201673061" X-Mailer: 9.0 SE for Windows sub 5044 X-Spam-Flag: NO -------------------------------1201673061 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Ed and group, This assembly problem is vexing. We really need to avoid these types of foul up! When I built race cars and motorcycles the assembler (usually me) would try to learn what kind of force it should require to turn over a newly built engine. That is, how much friction to expect when turning over a brand spanking new engine for the first time. Cosworth even has a torque table that suggests you use a dial torque wrench for that first rev or two. If you see higher than suspected torque do not turn the engine over or even through the tight spot! Learning these forces saved one of my best customers a completely mangled engine! (Anecdote warning!) Guy M. my customer informed me that he would do the basic assembly of the "long block" including putting on the head so all I would have to do was time the cams. (Engine was a Kawasaki 900 with considerable modification to run in an SCCA C sports racer.) Guy was an EXCELLENT mechanic in his own right so I thought, "great that part is easy but tedious so I won't have to do it." I installed the cams correctly, and did the all important first revolution by hand. At TDC there was a very small change in friction, that would have been easy to miss if I had not been super familiar with that engine. Guy wanted to just run it, but I wouldn't do it because that is where the engine has nearly no piston movement for about 20 degrees. I made him pull the head and was super glad I did. Guy had installed all four pistons reversed on the piston pin. The large valve cut out was on the exhaust valve side rather than the intake as was normal. The "tick" was the intake valve rubbing on the side of the piston cutout! If we had started the engine it would have run for a few seconds until the intake valves bent! We corrected the problem, and thankfully the intakes were not even bent. Believe me we checked. The result was a few hours lost rather than a destroyed engine. We need to develop a data base here. So if you do a new build up, or any build up for that matter, do us all a favor and put a dial torque wrench on there and record your max turn over torque. Oh yea, do that with the plugs out of course. On a rotary with plugs out you should get a pretty even torque with no compression so if you get any spikes in there you may want to pull it apart again before you do some serious damage. Mistakes can happen even to very competent mechanics so it would be a great help to everybody and might even save you some cash. Just a good idea. My $0.02. Bill Jepson In a message dated 1/29/2008 7:32:20 AM Pacific Standard Time, eanderson@carolina.rr.com writes: I agree, Bob, there is no way that apex seal could come out of its recess without that part of the rotor being broken off. Those small parts can be illusive, particularly when you turn the rotor upside down to place it on the e shaft - make certain you use good Vaseline or halomire stickum {:>). Ed **************Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 -------------------------------1201673061 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Ed and group,
This assembly problem is vexing. We really need to avoid these types of= =20 foul up! When I built race cars and motorcycles the assembler (usually me) w= ould=20 try to learn what kind of force it should require to turn over a newly built= =20 engine. That is, how much friction to expect when turning over a brand spank= ing=20 new engine for the first time. Cosworth even has a torque table that suggest= s=20 you use a dial torque wrench for that first rev or two. If you see higher th= an=20 suspected torque do not turn the engine over or even through the tight spot!= =20 Learning these forces saved one of my best customers a completely mangled=20 engine! (Anecdote warning!)
 Guy M. my customer informed me that he would do the bas= ic=20 assembly of the "long block" including putting on the head so all I wou= ld=20 have to do was time the cams. (Engine was a Kawasaki 900 with considera= ble=20 modification to run in an SCCA C sports racer.) Guy was an EXCELLE= NT=20 mechanic in his own right so I thought, "great that part is easy but=20 tedious so I won't have to do it." I installed the cams correctly, and did t= he=20 all important first revolution by hand. At TDC there was a very small change= in=20 friction, that would have been easy to miss if I had not been super familiar= =20 with that engine. Guy wanted to just run it, but I wouldn't do it because th= at=20 is where the engine has nearly no piston movement for about=20 20 degrees. I made him pull the head and was super glad I did. Guy had=20 installed all four pistons reversed on the piston pin. The large valve=20= cut=20 out was on the exhaust valve side rather than the intake as was normal. The=20 "tick" was the intake valve rubbing on the side of the piston cutout! If we=20= had=20 started the engine it would have run for a few seconds until the intake= =20 valves bent! We corrected the problem, and thankfully the intakes were not e= ven=20 bent. Believe me we checked. The result was a few hours lost rather than a=20 destroyed engine.
 We need to develop a data base here. So if you do a new build up,= or=20 any build up for that matter, do us all a favor and put a dial torque wrench= on=20 there and record your max turn over torque. Oh yea, do that with the pl= ugs=20 out of course. On a rotary with plugs out you should get a pretty even=20 torque with no compression so if you get any spikes in there you m= ay=20 want to pull it apart again before you do some serious damage. Mistakes= can=20 happen even to very competent mechanics so it would be a great help to=20 everybody and might even save you some cash. Just a good idea. My $0.02.
Bill Jepson
 
In a message dated 1/29/2008 7:32:20 AM Pacific Standard Time,=20 eanderson@carolina.rr.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I agree, Bob, there is no way that apex seal could= come=20 out of its recess without that part of the rotor being broken off.  T= hose=20 small parts can be illusive, particularly when you turn the rotor upside d= own=20 to place it on the e shaft - make certain you use good Vaseline or halomir= e=20 stickum {:>).
 
Ed
 



Start the year= off right. Easy ways to stay in shape in the new year.
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