thunder669
Active Member
I've spent hours going through the archives and all I can say is man some of you guys are artists with composites and huge wealth of knowledge. so I just recently bought an RV-4 with an O-360 A1A in it. as we all do I am putting a bunch of time and work into personalizing it and making it mine. If everything goes to plan my goal is to completely repaint and fix up some of the fiberglass components. I was planning to do a sam james cowl but they have a 6 month back log and that would make it spring so that would push the paint off for another year.
Over the weekend me and a good friend who has flown an RV4 for several years got into a conversation about drag reduction. His thoughts are the primary drag reduction from the Sam james cowl is due to the plenum design and reduction in cooling drag and that the parasitic form drag is probably nearly the same. This makes sense to me since it is common knowledge that cooling drag is a very high percentage of overall drag. so this conversation and reading all of your posts on plenum building has me thinking about making my own plenum and fitting it to the factory cowl. the cowl will also need some work because the original builder cut it too short so there is a large gap between it and the spinner. and speaking of spinners this one is also not cut or fitted properly and will need to be replaced, but it is one of the early 12" ones that vans no longer supplies. needless to say I have big plans for this bird, just hope i have the skills to make it all happen.
Over the weekend me and a good friend who has flown an RV4 for several years got into a conversation about drag reduction. His thoughts are the primary drag reduction from the Sam james cowl is due to the plenum design and reduction in cooling drag and that the parasitic form drag is probably nearly the same. This makes sense to me since it is common knowledge that cooling drag is a very high percentage of overall drag. so this conversation and reading all of your posts on plenum building has me thinking about making my own plenum and fitting it to the factory cowl. the cowl will also need some work because the original builder cut it too short so there is a large gap between it and the spinner. and speaking of spinners this one is also not cut or fitted properly and will need to be replaced, but it is one of the early 12" ones that vans no longer supplies. needless to say I have big plans for this bird, just hope i have the skills to make it all happen.