rv969wf
Well Known Member
A few of the pilots and builders on the James / Holy Cowl RV Forum ask me to post Pics and things that I've done to my -6 on VAF,,,, so now I'm finally getting around to doing this. BTW I've never attended a Forum of any sort until I joined the yahoo/james/holy/cowl/ forum and then finally a little over a month +++ ago joined this awesome VAF Forum because I just never got around to it and because of issues with my job or an ex wife over a year ago and her not understanding???? enough said about her... I'm single now and I have the time to do what I love to do now and that is experiment, fabricate, share things with friends and RV builder / pilots. So I'm on the computer now sharing what I've built and modified on my RV-6. I made these mods before I ever knew about what Bob Axsom did with his lower cowl mods BTW. I finally found a thread awhile back about what Bob Axsom had done and he had already done it but with aluminum. I visited with Bob on the phone a few weeks ago and he is a very open and honest and I like that. He's as good as GOLD. We have the same interests just like many of us and that's what makes great friends, sharing ideas and getting our RV's more effiecient or better MPG. I wished that I had been on this forum a long time ago to follow up with Bob and other builder mods but I was off doing my own things and never looked around on the computer. Most of my lower cowl mods were done at the early part of this year and I've seen many improvements over the past few months. To date: at 4,125ft MSL, 27.1" MAP, turning 2,680 rpm. GPS ground runs of N:248mph, E:222mph, S:195mph, W:220mph. Average of 221.25mph. I know these numbers do not give a TAS but you get the idea. Barometric Pressure today was low btw.... Running at these settings were with outside air temps around 70F air temps Indicating 205-208 mph, rough windy air today in Oklahoma,, ,,, CHT's temps were #1-282F, #2-283F, #3-283F, #4-278F. These temps were with 2 3/4" round diffuser cowl inlets. I posted another thread yesterday with higher CHT's ,,, but the CHT's are around 350-360F temp range with 2 1/8"" cowl inlets. I've made a few changes sinces then so some of the numbers do not apply with the recent mods to the cooling system. For numbers!!! Here they are,,, Cowl inlet area for the engine cooling needs and not the oilcooler included is 7.09 Inches total inlet area with the 2 1/8" inlets. Oil is fed by a 4" NACA DUCT mounted at a very sweet spot on the right side of the lower cowl catching much prop blast on climb out and is a very good location for climbout and cruise. This location required much tuft work to find the right spot and keeping it at the correct angle for a NACA duct to work efficient was very critical! Total area on the oil cooler inlet is 12.56 square inches at the full open range if needed. It's a Big Stewart Warner Oil Cooler, Dual Bypass 11 Row and is an excellent oil cooler. YES they cost $$$$ The Oil cooler has a 4" NACA Duct feeding to it that I can control Via an inlet door to control temps. I can control the temps at any setting I want. I can keep the oil temps at 190F in a climb on 100F++ days mostly because of prop wash because the oil cooler inlet is placed much further out from the centerline of the crank radius / prop hub. OK,,,Numbers: Cowl outlet is 25.14 square inches. Detonation is another concern of mine because I'm running a TRUE 10:5;1 comp and the cooler CHT temps will help in this area along with keeping EGT's on the rich side---100-125F ++++ range rich of peak over 75% or more. Sorry it took so long to post this from everyone asking questions from along time back. Anyone have any questions feel free to ask. AJ
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