I am near the end of my annual condition inspection and will soon be ready to reinstall the cowl. I have a relatively small but adequate separation space where the rubber sleeve seals the gap between the cowl induction air inlet and the filter air box inlet on our RV-6A. It is a fairly tight but I tape my file folder sleeve around the NLG strut and my file folder "toilet seat cover" around the crankcase behind the spinner to get the lower cowl on without scraping the paint and I do it myself without assistance ... However, I feel the alignment between the FAB and the cowl at the induction inlet could be better. I eyeballed it with a scale and the fab is low by maybe as much as 0.2" probably due to engine sag but the spinner to cowl alignment after years of use is visually perfect. I have worked out the angle as 1.43... deg. and the misalignment could be fixed with a 0.1 shim between the mounting plate and the two carburator rear mounting points. I have quite a few 0.005 thick pieces of stainless steel tape that I could laminate into a shim of that thickness with a 0.2 stagger with each of 20 layers back to the rear of the mounting surface then after installation seal the area externally with Dow 736 hi-temp RTV. Cutting the flow port in the stainless steel is not without risk.
As I am still noodling this idea I wondered what other builders have done and what they learned in the process.
Bob Axsom
Last edited by Bob Axsom : 02-18-2012 at 12:34 PM.
Put one layer of stainless steel on the mounting plate that mates with the carb. It didn't lay well even with the adhesive back so I made a tapered shim out of aluminum.
It is rough at this point but I'm not going to file it much more before I install it and trial fit the cowl.
Bob Axsom
Last edited by Bob Axsom : 02-19-2012 at 10:21 PM.
Reason: Fixed the bolded header for ya' Bob
FAB and Cowl alignment change over time
Linear Mode
