From: "lehanover lehanover@aol.com" <flyrotary@lancaironline.net>
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Date: Tue, 3 Sep 2019 03:45:53 +0000 (UTC)
To: flyrotary@lancaironline.net
Message-ID: <199448676.969483.1567482353553@mail.yahoo.com>
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Subject: Re: [FlyRotary] Re: The Story of an unecessary rebuild
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In a message dated 9/2/2019 11:40:12 PM Eastern Standard Time, flyrotary@la=
ncaironline.net writes:

You know that all side seals are a bit too long and need to be fitted in ev=
ery case. My jig is an old rotor with a corner cut off. A drill press with =
a small stone that is the size of the corner seal. This produces the correc=
t shape for the end of the seal. In olden times only one end of the seal ha=
d the right shape. The other end was just square. And all are too long.

Except when the bearing is pushed in incorrectly or misaligned and part of =
the damn tab has missed its slot.
There is not actual contact between the crank and any bearing surface. The =
crank is smaller than the bearing ID by several thousandths of an inch. The=
 gap of course, is for oil. High oil pressure is used to move overheated oi=
l off of the bearing face more quickly, in racing and other high RPM use. I=
t has nothing to do with supporting the crank with hydraulic pressure. You =
must count on the film strength of the oil for that. That is why there is s=
uch a thing as racing oil. Synthetic oils and more so in racing synthetics,=
 absorb heat quickly, and give it up quickly and have stupid high film stre=
ngth. They are also stable at much higher temps than conventional oils.
Bearings are soft. Cranks are hard. The further apart in hardness the longe=
r the bearing will last. Lead Indium, Aluminum, Antimony, Brass, Copper and=
 Tin and many alloys of all are used in plain bearings. All have alarmingly=
 low melting points. The highest oil temps are found in the interface betwe=
en crank and bearing material. So, the oil temp in the sump will not show y=
ou the temp in the interface. Fortunately the bearings have huge area for t=
he loads involved. High oil temps cause lowered HP.=C2=A0 Starting at ambie=
nt and getting bad above 160. Coolant above 180 is the same deal.=C2=A0Half=
 of the engine heat is in the oil.
Duty cycle for a car is about 30%. For a race car its about 90%. For an air=
plane it is closer to 100%.

You do not climb into your RX-7 and go across Texas at full throttle. (100%=
 duty cycle). You do fly across Texas in your plane at full throttle (100%)=
 duty cycle.
Lynn E. Hanover=C2=A0 =C2=A0 =C2=A0 =C2=A0=20


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In a message dated 9/2/2019 11:40:12 PM Eastern Standard Time, flyrotary@lancaironline.net writes:
<div><br></div>
<div class="quotedReply">
<blockquote style="padding-left: 5px; margin-left: 5px; border-left: blue 2px solid;">
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">You know that all side seals are a bit too long and need to be fitted in every case. My jig is an old rotor with a corner cut off. A drill press with a small stone that is the size of the corner seal. This produces the correct shape for the end of the seal. In olden times only one end of the seal had the right shape. The other end was just square. And all are too long.<br></span></div>
<div><br></div>
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">Except when the bearing is pushed in incorrectly or misaligned and part of the damn tab has missed its slot.<br></span></div>
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">There is not actual contact between the crank and any bearing surface. The crank is smaller than the bearing ID by several thousandths of an inch. The gap of course, is for oil. High oil pressure is used to move overheated oil off of the bearing face more quickly, in racing and other high RPM use. It has nothing to do with supporting the crank with hydraulic pressure. You must count on the film strength of the oil for that. That is why there is such a thing as racing oil. Synthetic oils and more so in racing synthetics, absorb heat quickly, and give it up quickly and have stupid high film strength. They are also stable at much higher temps than conventional oils.</span></div>
<div><br></div>
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">Bearings are soft. Cranks are hard. The further apart in hardness the longer the bearing will last. Lead Indium, Aluminum, Antimony, Brass, Copper and Tin and many alloys of all are used in plain bearings. All have alarmingly low melting points. The highest oil temps are found in the interface between crank and bearing material. So, the oil temp in the sump will not show you the temp in the interface. Fortunately the bearings have huge area for the loads involved. High oil temps cause lowered HP.&nbsp; Starting at ambient and getting bad above 160. Coolant above 180 is the same deal.&nbsp;</span><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">Half of the engine heat is in the oil.<br></span></div>
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">Duty cycle for a car is about 30%. For a race car its about 90%. For an airplane it is closer to 100%.<br></span></div>
<div><br></div>
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">You do not climb into your RX-7 and go across Texas at full throttle. (100% duty cycle). You do fly across Texas in your plane at full throttle (100%) duty cycle.</span></div>
<div><br></div>
<div><span style="font-family: arial, helvetica, sans-serif; font-size: 10pt; color: #000000;">Lynn E. Hanover&nbsp; &nbsp; &nbsp; &nbsp; <br></span></div>
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