X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-da04.mx.aol.com ([205.188.105.146] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4530146 for flyrotary@lancaironline.net; Sat, 23 Oct 2010 12:32:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.146; envelope-from=Lehanover@aol.com Received: from imo-da03.mx.aol.com (imo-da03.mx.aol.com [205.188.169.201]) by imr-da04.mx.aol.com (8.14.1/8.14.1) with ESMTP id o9NGW1N7017656 for ; Sat, 23 Oct 2010 12:32:01 -0400 Received: from Lehanover@aol.com by imo-da03.mx.aol.com (mail_out_v42.9.) id q.e38.b09f13c (37106) for ; Sat, 23 Oct 2010 12:31:58 -0400 (EDT) Received: from magic-m23.mail.aol.com (magic-m23.mail.aol.com [172.20.22.196]) by cia-db08.mx.aol.com (v129.5) with ESMTP id MAILCIADB084-90f24cc30dfe378; Sat, 23 Oct 2010 12:31:58 -0400 From: Lehanover@aol.com Message-ID: <7a1aa.726292b.39f467fe@aol.com> Date: Sat, 23 Oct 2010 12:31:58 EDT Subject: Re: [FlyRotary] Re: Oil pressure norms To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_7a1aa.726292b.39f467fe_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_7a1aa.726292b.39f467fe_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 10/23/2010 10:49:07 A.M. Eastern Daylight Time, cbarber@texasattorney.net writes: As you may remember, a couple of weeks ago I lost most oil pressure. I dropped the pan and found the problem. I safety wired the culprit up and put my engine back together and back on the back of the Velocity and cranked her up and got significant oil pressure as expected. I could see it pumping freely out a hose I left open when I cranked the starter with pumps/coils/injectors off earlier. Now, my question is, what is considered correct oil pressure at different power settings? Before when I ran the engine at idle (on my engine, usually 1500 - 1650 rpm, my oil pressure would be around 33-35 psi. I remember this cuz, on my EM2 it is preset to start flashing an alert if the oil pressure goes below 35 psi, so I was always bumping up the idle a bit to keep it from flashing the alert. Now, however, it seems that at about the same RPM I am getting only about 30 ish PSI at the same RPM and have to rev up to about 2200 rpm to get the pressure to 35 or above. IIRC, when I apply power to about 6200 rpm the pressure goes up to the mid 50's or a little more...maybe hitting 60. I had thought I read somewhere that the EM2 was set to alert on oil at 30, but Tracy has had my unit a couple/few times, so I am thinking the 35 must be correct for low pressure. I am still sorting some final engine details out and this was noticed. There are only 2 oil pressure relief pressures used in stock engines. 1971-1991 (All) is 71.1 PSI. 1993-1995 Twin turbo 110 PSI. The early relief valve can be disassembled and cleaned. Washers may be added under the spring to increase oil pressure. 80-85 PSI cold would be nice. Check relief pressure with shop air. Be sure the bleed holes are fully exposed with the plunger fully compressed. This may be possible with the later (welded) valve but I have never had one to play with. The pumps are powdered metal, so I would not go much above 85 PSI for long life. Unlike most engines, the rotary regulates oil pressure with a relief valve in a leg near end of the system. So, the lowest pressure fed into the oil filter stand and thus the filter is the relief pressure. Or, 71.1 pounds. Measuring oil pressure from the stock locations gives you a reading of how much pressure there is in the vertical gallery from the Banjo fitting (a flow disaster) to the filter adaptor. So a pressure drop through the tiny filter is not reported. Keep in mind you plan to use the engine at nearly 3 times the RPM of the normal street engine. With 40 or 50 weight conventional oil, or 30 or 40 weight synthetic you should show the relief pressure right after start up at fast idle say 1,500 RPM. This with standard day ambient. As oil warms and drainback improves, oil pressure should be rock steady at about 71 pounds. As oil temps go up, expect at least a 5 pound loss of pressure due to oil foaming. The recorded oil pressure is not what the bearings see. All of the bearing flow is after the filter, so pressure drop in the filter element and galleries reduces the reported number. The front rotor bearing failures can be attributed in part to lower oil pressure. Thus in racing both ends of the crank are oiled with an extra hose. The other problem is that the top oil gallery is also the top dowel gallery, and the dowels have threads inside so a puller works. And then 3 drilled 90s. A poor design for flow. This data and much much more is available for free download from Racing Beat's web site. Also the Mazda Competition manual (old and poorly done) is available for free download from the "Nopistons) web page. Multigrade conventional oils foam readily, and burn poorly. So, if you must use the OMP, then a straight weight conventional oil, or better yet, a conventional racing oil like 40 weight Valvoline. The racing oils have more Zink antiscuff and more anti foaming agent. If you premix, or have one of Richard Sohns gadgets to feed the OMP from a container on the firewall, then you can use a synthetic racing oil in the sump, and an ash free 2 cycle top oil. Got to work with a 20B this week. Oil pan and pickup a disaster. Lynn E. Hanover --part1_7a1aa.726292b.39f467fe_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 10/23/2010 10:49:07 A.M. Eastern Daylight Time,=20 cbarber@texasattorney.net writes:
As you may remember, a couple of weeks ago I= lost=20 most oil pressure.  I dropped the pan and found the problem. = =20 I safety wired the culprit=20 up and put my engine back together and back on the back of the=20 Velocity and cranked her up and got significant oil pressure as=20 expected.  I could see it pumping freely out a hose I left ope= n when=20 I cranked the starter with pumps/coils/injectors= off=20 earlier.
 
Now, my question is, what is considered correct oil pressure at dif= ferent=20 power settings?  Before when I ran the engine at idle (on my engine= ,=20 usually 1500 - 1650 rpm, my oil pressure would be around 33-35 psi. = ; I=20 remember this cuz,=20 on my EM2 it=20 is preset to start flashing an alert if the oil pressure goes below 35= psi, so=20 I was always bumping up the idle a bit to keep it from flashing the=20 alert.
 
Now, however, it seems that at about the same RPM I am getting= only=20 about 30 ish=20 PSI at the same RPM and have to rev up to about 2200 rpm to get the pres= sure=20 to 35 or above.  IIRC, when I apply power to about 6200 rpm the pressure= goes up=20 to the mid 50's or a little more...maybe hitting 60.
 
I had thought I read somewhere that the EM2<= /A> was set to alert on oil= at 30, but Tracy=20 has had my unit a couple/few times, so I am thinking the 35 must=20 be correct for low pressure.
 
I am still sorting some final engine details out and this was=20 noticed. 
 
 
There are only 2 oil pressure relief pressures used in stock engines.=
 
1971-1991 (All) is 71.1 PSI.
 
1993-1995 Twin turbo 110 PSI.
 
The early relief valve can be disassembled and cleaned. Washers may= be=20 added under the spring to increase oil pressure. 80-85 PSI cold would be= nice.=20 Check relief pressure with shop air. Be sure the bleed holes are fully exp= osed=20 with the plunger fully compressed. This may be possible with the later (we= lded)=20 valve but I have never had one to play with. The pumps are powdered metal,= so I=20 would not go much above 85 PSI for long life.
 
Unlike most engines, the rotary regulates oil pressure with a relief= valve=20 in a leg near end of the system. So, the lowest pressure fed into the oil= filter=20 stand and thus the filter is the relief pressure. Or, 71.1 pounds. Measuri= ng oil=20 pressure from the stock locations gives you a reading of how much pressure= there=20 is in the vertical gallery from the Banjo fitting (a flow disaster) to the= =20 filter adaptor. So a pressure drop through the tiny filter is not reported= . Keep=20 in mind you plan to use the engine at nearly 3 times the RPM of the normal= =20 street engine. With 40 or 50 weight conventional oil, or 30 or 40 weight= =20 synthetic you should show the relief pressure right after start up at fast= idle=20 say 1,500 RPM. This with standard day ambient. As oil warms and drainback= =20 improves, oil pressure should be rock steady at about 71 pounds. As= oil=20 temps go up, expect at least a 5 pound loss of pressure due to oil foaming= .=20
 
The recorded oil pressure is not what the bearings see. All of the be= aring=20 flow is after the filter, so pressure drop in the filter element and galle= ries=20 reduces the reported number. The front rotor bearing failures can be attri= buted=20 in part to lower oil pressure. Thus in racing both ends of the crank are= oiled=20 with an extra hose.
 
The other problem is that the top oil gallery is also the top dowel= =20 gallery, and the dowels have threads inside so a puller works. And then 3= =20 drilled 90s. A poor design for flow.
 
This data and much much more is available for free download from Raci= ng=20 Beat's web site.
 
Also the Mazda Competition manual (old and poorly done) is available= for=20 free download from the "Nopistons) web page.
 
Multigrade conventional oils foam readily, and burn poorly. So, if yo= u must=20 use the OMP, then a straight weight conventional oil, or better yet, a=20 conventional racing oil like 40 weight Valvoline. The racing oils hav= e more=20 Zink antiscuff and more anti foaming agent. If you premix, or have one of= =20 Richard Sohns gadgets to feed the OMP from a container on the firewall, th= en you=20 can use a synthetic racing oil in the sump, and an ash free 2 cycle top=20 oil.
 
Got to work with a 20B this week. Oil pan and pickup a disaster.
 
Lynn E. Hanover  
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