Franklin Oil Bypass - Revision history

Bferrell at 18:13, 22 November 2011

2011-11-22T18:13:35Z

Bferrell at 18:07, 22 November 2011

2011-11-22T18:07:48Z

Bferrell at 18:07, 22 November 2011

2011-11-22T18:07:16Z

Bferrell at 16:20, 22 November 2011

2011-11-22T16:20:31Z

Bferrell at 16:20, 22 November 2011

2011-11-22T16:20:16Z

Bferrell at 16:19, 22 November 2011

2011-11-22T16:19:38Z

Bferrell at 16:16, 22 November 2011

2011-11-22T16:16:31Z

Bferrell at 16:15, 22 November 2011

2011-11-22T16:15:56Z

Bferrell: Created page with "The topic of oil cooling on the Franklin engine comes up quite often. Here are some tips shared on the Reflector. ''The franklin engine I have in my 173LW is running high oi..."

2011-11-22T16:15:21Z

Created page with "The topic of oil cooling on the Franklin engine comes up quite often. Here are some tips shared on the Reflector. ''The franklin engine I have in my 173LW is running high oi..."

New page

The topic of oil cooling on the Franklin engine comes up quite often. Here are some tips shared on the Reflector.

''The franklin engine I have in my 173LW is running high oil temp, 245+. Having read recent posts, I am planning to install a larger oil cooler with a vernatherm. I would appreciate comments from those who have done this. Is there a modification necessary for the factory oil bypass valve? 
Grover McNair 
N832AB 
 

Grover, 
You still haven't said where you are measuring the oil temp. As PZL memo states, you should be measuring it at point 7.1, just before the oil return to the engine.� I modified my plenum by splitting it in two and sealing the base of the cylinders. Now, in Florida's heat, I can take of and climb to 5000 ft with CHT's remaining below 390 F. and oil temps hovering between 215 and 220 F. Attached is a PZL bulletin of what Brian is saying.'' 

Click for a larger image. 

<gallery>

[IMAGE:PZL_Oil_Temp.jpg]

[IMAGE:Sevice Letter No PZL-F_1_98 page 1 (F6).jpg]

[IMAGE:Sevice Letter No PZL-F_1_98 page 2 (F6).jpg]

[IMAGE:franklin_oil_system.jpg]

[IMAGE:franklin_injection2.jpg]

[IMAGE:Franklin_Split_Plenum.jpg]

[IMAGE:franklin_exhaust.jpg]

[IMAGE:franklin_injection.jpg]
</gallery>

@@ Line 1: / Line 1: @@
 The topic of oil cooling on the Franklin engine comes up quite often.  Here are some tips shared on the Reflector.
 ==Oil Temp==
 ''To all Franklin drivers,''
@@ Line 7: / Line 7: @@
 ''Larry Coen''
 ==Oil Bypass==
-''The franklin engine I have in my 173LW is running high oil temp, 245+. Having read   recent posts, I am planning to install a larger oil cooler with a vernatherm. I  would appreciate comments from those who have done this.  Is there a modification necessary for the factory oil bypass valve?
+''The franklin engine I have in my 173LW is runnin
 Grover  McNair
 N832AB''<br/><br/>

@@ Line 2: / Line 2: @@
 ==Oil Temp==
-To all Franklin drivers,
+''To all Franklin drivers,''
- The misinformation is getting way too deep for me to remain silent.  Lycoming engines have "Vernatherms", Franklins do NOT. A vernatherm  works somewhat like a thermostat in an auto only backwards. In an auto  the thermostat is closed when cold and opens on temperature rise. The  vernatherm is open when cold allowing oil to bypass the oil cooler and  go directly to the oil galley. When the oil gets hot it closes the  bypass forcing the oil to flow through the oil cooler. The Franklin  works on a different principal. The external oil hoses are connected to  an oil control housing on the copilot side of the engine. This housing  contains two spring loaded valves. The one that faces away from the prop  is the oil pressure regulator valve and comes set at 80 psi. The second  valve facing toward the prop is the oil cooler bypass valve that is set  to open at 15 psi. When the oil is cold it is viscous (thick) which  causes a large pressure drop in the oil cooler loop forcing the bypass  valve to open and allowing oil to flow directly into the oil galley. Hot  oil flows more easily allowing the bypass to close. The Franklin  in Velocity problem is the length of the oil lines to the nose cooler  causing an excessive pressure drop that in turn limits flow through the  cooler. Mike did the two things that solve this problem. Bigger lines  and a stouter spring on the bypass valve. Oil pressure and temperature  are both measured where the oil enters the galley, after the oil cooler.  That applies to Lycoming too. The oil pressure will always read less  than 80 psi because of the pressure drop in the external loop so 60 psi  is a good number.<br/>
+''The misinformation is getting way too deep for me to remain silent.  Lycoming engines have "Vernatherms", Franklins do NOT. A vernatherm  works somewhat like a thermostat in an auto only backwards. In an auto  the thermostat is closed when cold and opens on temperature rise. The  vernatherm is open when cold allowing oil to bypass the oil cooler and  go directly to the oil galley. When the oil gets hot it closes the  bypass forcing the oil to flow through the oil cooler. The Franklin  works on a different principal. The external oil hoses are connected to  an oil control housing on the copilot side of the engine. This housing  contains two spring loaded valves. The one that faces away from the prop  is the oil pressure regulator valve and comes set at 80 psi. The second  valve facing toward the prop is the oil cooler bypass valve that is set  to open at 15 psi. When the oil is cold it is viscous (thick) which  causes a large pressure drop in the oil cooler loop forcing the bypass  valve to open and allowing oil to flow directly into the oil galley. Hot  oil flows more easily allowing the bypass to close. The Franklin  in Velocity problem is the length of the oil lines to the nose cooler  causing an excessive pressure drop that in turn limits flow through the  cooler. Mike did the two things that solve this problem. Bigger lines  and a stouter spring on the bypass valve. Oil pressure and temperature  are both measured where the oil enters the galley, after the oil cooler.  That applies to Lycoming too. The oil pressure will always read less  than 80 psi because of the pressure drop in the external loop so 60 psi  is a good number.''<br/>
-Larry Coen
+''Larry Coen''
-==Oil
+==Oil Bypass==
 ''The franklin engine I have in my 173LW is running high oil temp, 245+. Having read   recent posts, I am planning to install a larger oil cooler with a vernatherm. I  would appreciate comments from those who have done this.  Is there a modification necessary for the factory oil bypass valve?
 Grover  McNair

@@ Line 6: / Line 6: @@
 N832AB''<br/><br/>
-''Grover,<br/>
+''Grover,''<br/>
-You still haven't said where you are measuring the oil temp. As PZL memo states, you  should be measuring it at point 7.1, just before the oil return to the engine. I modified my  plenum by splitting it in two and sealing the base of the cylinders. Now, in Florida's heat,  I can take of and climb to 5000 ft with CHT's remaining below 390 F. and oil temps hovering  between 215 and 220 F. Attached is a PZL bulletin of what Brian is saying.''<br/><br/>
+''You still haven't said where you are measuring the oil temp. As PZL memo states, you  should be measuring it at point 7.1, just before the oil return to the engine. I modified my  plenum by splitting it in two and sealing the base of the cylinders. Now, in Florida's heat,  I can take of and climb to 5000 ft with CHT's remaining below 390 F. and oil temps hovering  between 215 and 220 F. Attached is a PZL bulletin of what Brian is saying.''<br/><br/>
 Click for a larger image.<br/>

@@ Line 2: / Line 2: @@
-''The franklin   engine I have in my 173LW is running high oil temp, 245+. Having read   recent posts, I am planning to install a larger oil cooler with a vernatherm. I  would appreciate comments from those who have done this.  Is there a modification necessary for the factory oil bypass valve?
+''The franklin engine I have in my 173LW is running high oil temp, 245+. Having read   recent posts, I am planning to install a larger oil cooler with a vernatherm. I  would appreciate comments from those who have done this.  Is there a modification necessary for the factory oil bypass valve?
 Grover  McNair
 N832AB''<br/><br/>
-''Grover,
+''Grover,<br/>
-You still haven't said where you are measuring the oil temp. As PZL memo states, you  should be measuring it at point 7.1, just before the oil return to the engine.� I modified my  plenum by splitting it in two and sealing the base of the cylinders. Now, in Florida's heat,  I can take of and climb to 5000 ft with CHT's remaining below 390 F. and oil temps hovering  between 215 and 220 F. Attached is a PZL bulletin of what Brian is saying.''<br/><br/>
+You still haven't said where you are measuring the oil temp. As PZL memo states, you  should be measuring it at point 7.1, just before the oil return to the engine. I modified my  plenum by splitting it in two and sealing the base of the cylinders. Now, in Florida's heat,  I can take of and climb to 5000 ft with CHT's remaining below 390 F. and oil temps hovering  between 215 and 220 F. Attached is a PZL bulletin of what Brian is saying.''<br/><br/>
 Click for a larger image.<br/>

@@ Line 2: / Line 2: @@
-''The franklin   engine I have in my 173LW is running high oil temp, 245+. Having read   recent posts, I am planning to install a larger oil cooler with a  vernatherm. I  would appreciate comments from those who have done this.  Is there a  modification necessary for the factory oil bypass valve?<br/>
+''The franklin   engine I have in my 173LW is running high oil temp, 245+. Having read   recent posts, I am planning to install a larger oil cooler with a vernatherm. I  would appreciate comments from those who have done this.  Is there a modification necessary for the factory oil bypass valve?<br/>
-    Grover  McNair<br/>
+Grover  McNair<br/>
-    N832AB<br/>
+N832AB''<br/>
 <br/>
-Grover,<br/>
+''Grover,<br/>
    You still haven't said where you are measuring the oil temp. As PZL memo states, you  should be measuring it at point 7.1, just before the oil return to the engine.� I modified my  plenum by splitting it in two and sealing the base of the cylinders. Now, in Florida's heat,  I can take of and climb to 5000 ft with CHT's remaining below 390 F. and oil temps hovering  between 215 and 220 F. Attached is a PZL bulletin of what Brian is saying.''<br/><br/>

@@ Line 12: / Line 12: @@
 <gallery>
-[IMAGE:PZL_Oil_Temp.jpg]
+IMAGE:PZL_Oil_Temp.jpg
-[IMAGE:Sevice Letter No PZL-F_1_98 page 1 (F6).jpg]
+IMAGE:Sevice Letter No PZL-F_1_98 page 1 (F6).jpg
-[IMAGE:Sevice Letter No PZL-F_1_98 page 2 (F6).jpg]
+IMAGE:Sevice Letter No PZL-F_1_98 page 2 (F6).jpg
-[IMAGE:franklin_oil_system.jpg]
+IMAGE:franklin_oil_system.jpg
-[IMAGE:franklin_injection2.jpg]
+IMAGE:franklin_injection2.jpg
-[IMAGE:Franklin_Split_Plenum.jpg]
+IMAGE:Franklin_Split_Plenum.jpg
-[IMAGE:franklin_exhaust.jpg]
+IMAGE:franklin_exhaust.jpg
-[IMAGE:franklin_injection.jpg]
+IMAGE:franklin_injection.jpg
 </gallery>