---------------------------------------------------------- RV4-List Digest Archive --- Total Messages Posted Sun 11/13/05: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:41 AM - Re: Cowl flap (rob ray) 2. 07:53 AM - Re: Cowl flap (PGLong@aol.com) 3. 08:25 AM - Re: Cowl flap (rob ray) 4. 08:19 PM - Re: Cowl flap (RVFOURME@aol.com) ________________________________ Message 1 _____________________________________ Time: 06:41:50 AM PST US From: rob ray Subject: Re: RV4-List: Cowl flap --> RV4-List message posted by: rob ray Hi Pat, I agree with Jim in that you should check to see if your temp sensors are accurate. The first thing I would check is your vernatherm. It's located on the back of the accessory case either at the bottom of the Lycoming oil filter adapter or the screen housing. It looks like a large bolt head and has a copper crush washer under it. You can remove it and boil it as well. It should expand (open) at 195-200 degrees. When it opens it actually closes the oil pathway, causing the oil to bypass the journal and going directly into the oil cooler. Without a vernatherm the oil would freely flow into the cooler and never heat, similar to a car without a thermostat. My RV4 for the past 10 years has run 195 degree oil temps with the stock cowling regardless of altitude year round including some Idaho cold weather. If all the above are accurate I would still not install a cowl flap, I would close off part of the exit airflow at the base of the cowl lip. The cooling experts tell me cooling inlet area should equal exit area. Slightly less exit area will warm things up, slightly more will cool things down. In 10 years of flying my RV4 I have never seen an RV with a cowl flap, hopefully yours won't be the first....see ya! Rob Ray PGLong@aol.com wrote: --> RV4-List message posted by: PGLong@aol.com Looking to make a cowl flap that I can operate from the cockpit for my RV-4. Does anyone have any pictures or plan I might look at? I have my oil cooler blocked with aluminum tape and also restricted the cowl inlets approximately one third. Finally got my oil heated up to 185 F. Without the cowl inlets restricted, can only get about 120 F on the oil. Not sure whether to restrict the inlet or outlet flow. Any advice? Thanks in advance. Pat Long PGLong@aol.com N120PL RV4 Bay City, Michigan 3CM --------------------------------- ________________________________ Message 2 _____________________________________ Time: 07:53:17 AM PST US From: PGLong@aol.com Subject: Re: RV4-List: Cowl flap --> RV4-List message posted by: PGLong@aol.com Thanks Rob Next oil change I'm going to swap vernatherm's. Sounds like mine may not be working and I have a spare from a friend. Use to have a screen but opted for a oil filter and vernatherm assembly last year. Good to hear you don't need a cowl flap to heat things up. Thanks for your help..........Pat Pat Long PGLong@aol.com N120PL RV4 Bay City, Michigan 3CM ________________________________ Message 3 _____________________________________ Time: 08:25:52 AM PST US From: rob ray Subject: Re: RV4-List: Cowl flap --> RV4-List message posted by: rob ray No worries, my pleasure... RR PGLong@aol.com wrote: --> RV4-List message posted by: PGLong@aol.com Thanks Rob Next oil change I'm going to swap vernatherm's. Sounds like mine may not be working and I have a spare from a friend. Use to have a screen but opted for a oil filter and vernatherm assembly last year. Good to hear you don't need a cowl flap to heat things up. Thanks for your help..........Pat Pat Long PGLong@aol.com N120PL RV4 Bay City, Michigan 3CM --------------------------------- ________________________________ Message 4 _____________________________________ Time: 08:19:25 PM PST US From: RVFOURME@aol.com Subject: Re: RV4-List: Cowl flap --> RV4-List message posted by: RVFOURME@aol.com Pat: Are your engine cylinder temps up to snuff? You should be reading around 1300 degrees EGT on climbout (full rich) and roughly 1500 after leaning. CHT's should be registering around 300~350 degrees ideally. Anyone else out there concur on these numbers? Craig P