---------------------------------------------------------- M14PEngines-List Digest Archive --- Total Messages Posted Wed 02/08/12: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:27 AM - Vanishing oil (Bradly Banks) 2. 12:17 PM - Re: Vanishing oil (Monty Barrett Sr) ________________________________ Message 1 _____________________________________ Time: 10:27:09 AM PST US From: "Bradly Banks" Subject: M14PEngines-List: Vanishing oil Hello All , this topic has probably been thrashed to within an inch of its life , but here goes again. Our =9252 has 1600 hrs TT on the engine and 400 smoh (top set), running her up, we get the occasional white puff from the 6,7,8,9 manifold. She is not the freshest 52 around but none the less great fun to fly. The problem starts , when we come in to change passengers or refuel. After standing for 5 or six min I have taken to rotating the prop carefully through 2 rotations before starting again , we get a pint of hot oil deposited on the ground from no6. After the days flying we run her up for 30-45 sec ant 60% and shut down for the week. Usually loosing 1-2 litres for a 2-3 hours boring holes in the clouds. On return , the following week , the oil tank has lost 9-10 litres on the dip stick. Rotating the prop we get , around =BE of a litre loss at nearly 10 usd /litre , I need to find the problem . I have replaced the oil pump with a used serviceable unit , and the problem persists. I have stripped the old oil pump, it is truly a genius piece of thinking with the scavenger pump and the main oil feed gears being driven off the same shaft and rotating at different speeds and in opposite directions. An amo looked at it and pointed me to a relief valve with a hectic spring holding it down, im not convinced that this relief valve is the problem as the oil is only under the pull of gravity? I will post pics of the pump in the next post Any ideas , would be appreciated. Bradly Banks Merlin Aviation Services Cell:0825083200 Tel :0333308580 Email :Brad@runawaymedia.co.za Skype: bradly.banks ________________________________ Message 2 _____________________________________ Time: 12:17:07 PM PST US Subject: RE: M14PEngines-List: Vanishing oil From: "Monty Barrett Sr" I think you have 2 separate problems. The first is: the bottom rocker boxes do not scavenge oil. A loose guide on either valve, ( most llikely the exhaust ), will allow oil to seep thru the guide into the port and / or the cylinder. This can happen on any of the lower cylinders. The top cylinders will also loosen up with time in service but they drain down the pushrod shroud tube and therefore do not accumulate as much oil. Secondly: There is a considerable amount of head above the oil pump check valve; about .6 meters. A leaking check valve will let oil from the tank into the engine when it is sitting. It is also a good idea to open the drain cock on the sump at the end of your flying day and catch the oil in a suitable container to pour back in the oil tank or discard, your choice. There will be about a liter or maybe a little more in the sump. The reason for doing this is the sump is not quite large enough to hold all the oil that will drain from the engine after it is shut down. It takes a few minutes for all the oil to drain from the reduction gear, crankcase and accessory section. If the sump is over full the surplus oil gets above the skirt (s) on the lower cylinders, runs over into the piston and enters the combustion chamber by the rings and the oil return holes in the piston. Your oil consumption agrees with what I have heard reported from other M14 operators, about a liter in 2 hours. There are ways to reduce this consumption to a liter in 8-10 hours. Contact me off list and I will discuss this with you. Monty Barrett Barrett Precision Engines, Inc. Monty@bpaengines.com -----Original Message----- From: owner-m14pengines-list-server@matronics.com [mailto:owner-m14pengines-list-server@matronics.com] On Behalf Of Bradly Banks Sent: Wednesday, February 08, 2012 12:19 PM To: m14pengines-list@matronics.com Subject: M14PEngines-List: Vanishing oil Hello All , this topic has probably been thrashed to within an inch of its life , but here goes again. Our '52 has 1600 hrs TT on the engine and 400 smoh (top set), running her up, we get the occasional white puff from the 6,7,8,9 manifold. She is not the freshest 52 around but none the less great fun to fly. The problem starts , when we come in to change passengers or refuel. After standing for 5 or six min I have taken to rotating the prop carefully through 2 rotations before starting again , we get a pint of hot oil deposited on the ground from no6. After the days flying we run her up for 30-45 sec ant 60% and shut down for the week. Usually loosing 1-2 litres for a 2-3 hours boring holes in the clouds. On return , the following week , the oil tank has lost 9-10 litres on the dip stick. Rotating the prop we get , around =BE of a litre loss at nearly 10 usd /litre , I need to find the problem . I have replaced the oil pump with a used serviceable unit , and the problem persists. I have stripped the old oil pump, it is truly a genius piece of thinking with the scavenger pump and the main oil feed gears being driven off the same shaft and rotating at different speeds and in opposite directions. An amo looked at it and pointed me to a relief valve with a hectic spring holding it down, im not convinced that this relief valve is the problem as the oil is only under the pull of gravity? I will post pics of the pump in the next post Any ideas , would be appreciated. Bradly Banks Merlin Aviation Services Cell:0825083200 Tel :0333308580 Email :Brad@runawaymedia.co.za Skype: bradly.banks ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message m14pengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/M14PEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/m14pengines-list Browse Digests http://www.matronics.com/digest/m14pengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.