X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-ma05.mx.aol.com ([64.12.100.31] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4485394 for flyrotary@lancaironline.net; Wed, 29 Sep 2010 01:41:16 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.100.31; envelope-from=Lehanover@aol.com Received: from imo-ma04.mx.aol.com (imo-ma04.mx.aol.com [64.12.78.139]) by imr-ma05.mx.aol.com (8.14.1/8.14.1) with ESMTP id o8T5eZg4010469 for ; Wed, 29 Sep 2010 01:40:35 -0400 Received: from Lehanover@aol.com by imo-ma04.mx.aol.com (mail_out_v42.9.) id q.f61.1c607bc (43955) for ; Wed, 29 Sep 2010 01:40:32 -0400 (EDT) Received: from magic-m26.mail.aol.com (magic-m26.mail.aol.com [172.20.22.199]) by cia-dd01.mx.aol.com (v129.4) with ESMTP id MAILCIADD014-abb34ca2d1501e8; Wed, 29 Sep 2010 01:40:32 -0400 From: Lehanover@aol.com Message-ID: <450dc.2ec1609.39d42b50@aol.com> Date: Wed, 29 Sep 2010 01:40:32 EDT Subject: Re: [FlyRotary] Re: Oil Pressure Loss To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_450dc.2ec1609.39d42b50_boundary" X-Mailer: 9.0 Security Edition for Windows sub 5381 X-AOL-IP: 173.88.9.178 X-Spam-Flag:NO X-AOL-SENDER: Lehanover@aol.com --part1_450dc.2ec1609.39d42b50_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 9/28/2010 11:28:48 P.M. Eastern Standard Time, cbarber@texasattorney.net writes: Oh, and maybe this is too obvious, but when I drop the pan, what should I be looking for. Yeah, large metal shards I would figure out, but if it is not that obvious, where do I need to focus. The pressure gage?? The pump?? Something else?? Chris ____________________________________ In the never ending tradition of two step forward and three steps back, I was working on my RPM drop out at 6000 rmp (messed with seveal resistors to no avail). As I was sitting on the ramp at idle for a few minutes, focusing on the RPM's I glanced over at the Oil Pressure and noted it was flashing as an alert and was showing almost NO oil pressure (4 or 5 psi). I instantly shut down the engine. The engine appeared to be running fine before I shut it down. I checked the wire to the back of the engine monitor and all was fine. I also checked the continutiy of the wire to the sensor and it was good. I started the engine again and it started fine and seem to run fine, however, the OP did not kick in so I shut it down again If the 6000 RPM was without a prop, (Unloaded) or just for a few seconds loaded, then no damage has occurred. Cut open the filters and lay out the paper to look for sparkles or brass/copper flakes. No sparkles, no damage. It is difficult to hurt plain bearings. Also in the drained oil, same idea. If it pumps oil but generates no pressure, it can be the pickup tube coming loose from the front iron. I would not use a gasket there. Just lap the flange flat and bolt it up with new bolts that have been drilled for safety wire. Use an inch pound torque wrench. Safety wire the bolts. The second possibility depending on the engine is the "O" ring junction on early 12As and 13Bs will blow out the "O" ring on a quick rev up from cold, then part of the ring gets stuck between the iron and front cover, dumping most of the oil pressure. In later engines this was replaced with a stainless tab with a hole in it, and it cannot fall off. The front cover needs to come off to fix that. The oil pump key shearing and not turning the pump up to speed is a possibility, if the nut had also been left loose. Red Locktite on the nut after torqueing it and folding the soft washer up on one flat. If the nut has been installed with red Locktite and torqued, it would probably work with no key. The tightened nut makes enough friction to turn the shaft, If the nut comes loose, the key (soft) will shear right off. One of the jet holders in the crank came loose? If the balls and springs have been removed from the crank, then hot idle oil pressure will be very low. It should come right up and be above 60 PSI by 2,000 RPM. You can check the oil pump nut from underneath but do little else. The pump drive chain may have enough flex to move the sprocket a bit, but if the key falls off you will never get it back on without removing the front cover. It is possible that a piece of scrap went through the pump and broke a ring, or sheared a key driving one of the lobes. Oil pump came loose from the front iron? Are those bolts wired? The oil level in the sump is very low? The oil pressure relief has debris in it and is stuck open? The oil pressure relief has come loose from the rear iron? The temperature pill in the crank nose has come loose? I will think some more. Lynn E. Hanover --part1_450dc.2ec1609.39d42b50_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 9/28/2010 11:28:48 P.M. Eastern Standard Time,=20 cbarber@texasattorney.net writes:
Oh, and maybe this is too obvious, but when I drop the pan, what sh= ould I=20 be looking for.  Yeah, large metal shards I would figure out, but= if it=20 is not that obvious, where do I need to focus.  The pressure gage??= The=20 pump??  Something else??
 
Chris
In the never ending tradition of two step forward and three= steps=20 back, I was working on my RPM drop out at 6000 rmp (messed= =20 with seveal resistors to no avail).  As I was sitting= on the=20 ramp at idle for a few minutes, focusing on the RPM's= I=20 glanced over at the Oil Pressure and noted it was flashing as an alert= and was=20 showing almost NO oil pressure (4 or 5 psi).  I instantly shut down= the=20 engine. 
 
The=20 engine appeared to be running fine before I shut it down.  I checke= d the=20 wire to the back of the engine monitor and all was fine.  I also ch= ecked=20 the continutiy of the wire to the sensor and it was good.&nb= sp; I=20 started the engine again and it started fine and seem to run fine, howev= er,=20 the OP did not kick in so I shut it down=20 again
 
If the 6000 RPM was without a prop= , (Unloaded) or just for=20 a  few seconds loaded, then no damage has occurred. Cut open the filt= ers=20 and lay out the paper to look for sparkles or brass/copper flakes. No spar= kles,=20 no damage. It is difficult to hurt plain bearings. Also in the drained oil= , same=20 idea.
 
If it pumps oil but generates no= pressure, it can be the=20 pickup tube coming loose from the front iron. I would not use a gasket the= re.=20 Just lap the flange flat and bolt it up with new bolts that have been dril= led=20 for safety wire. Use an inch pound torque wrench. Safety wire the=20 bolts.
 
The second possibility depending= on the engine is the "O" ring=20 junction on early 12As and 13Bs will blow out the "O" ring on a quick rev= up=20 from cold, then part of the ring gets stuck between the iron and front cov= er,=20 dumping most of the oil pressure. In later engines this was replaced with= a=20 stainless tab with a hole in it, and it cannot fall off.
 
The front cover needs to come off= to fix that.
 
The oil pump key shearing and not= turning the pump up to speed=20 is a possibility, if the nut had also been left loose. Red Locktite= on the=20 nut after torqueing it and folding= the soft=20 washer up on one flat. If the nut has been installed with red Locktite and= =20 torqued, it would probably work with no key. The tightened nut makes enoug= h=20 friction to turn the shaft, If the nut comes loose, the key (soft) will sh= ear=20 right off.
 
One of the jet holders in the cran= k came loose?
 
If the balls and springs have been= removed from the crank,=20 then hot idle oil pressure will be very low. It should come right up and= be=20 above 60 PSI by 2,000 RPM.
 
You can check the oil pump nut fro= m underneath but do little=20 else. The pump drive chain may have enough flex to move the sprocket a bit= , but=20 if the key falls off you will never get it back on without removing the fr= ont=20 cover.
 
It is possible that a piece of scr= ap went through the pump and=20 broke a ring, or sheared a key driving one of the lobes.
 
Oil pump came loose from the front= iron? Are those bolts=20 wired?
 
The oil level in the sump is very= low?
 
The oil pressure relief has debris= in it and is stuck=20 open?
 
The oil pressure relief has come= loose from the rear=20 iron?
 
The temperature pill in the crank= nose has come=20 loose?
 
I will think some more.
 
Lynn E. Hanover
 
 
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