Sabremech Posted June 15, 2016 Author Report Posted June 15, 2016 HI JJ, Welcome aboard too! Thanks for the kind comments on my cowling project. It's a fair amount of work and I'm looking forward to having it available in the future at a reasonable cost to the values of our vintage birds. The turbo sounds like a nice idea, but probably outside of a project I can afford at this time. Thanks again, David Quote
Sabremech Posted June 15, 2016 Author Report Posted June 15, 2016 Never say never bluehighwayflyer, I have my eye on something for the J's after I'm done with the vintage models. David Quote
Browncbr1 Posted June 15, 2016 Report Posted June 15, 2016 Hi David, i think you mentioned it long ago in your other thread, but couldn't easily find it. Was it just to make it easier to not deal with ram air? In your testing, is there not enough benefit for keeping the ram air? Personally, I don't open mine below about 7000, but it usually gives me about 1.5".. just wondering. thanks craig Quote
Sabremech Posted June 15, 2016 Author Report Posted June 15, 2016 Hi Craig, According to several engineers that I've spoken with, moving the air filter/air induction into the pressurized air inside the cowling gives you the same boost of manifold pressure. That's what they did with the J models. It also does make it easier and more cost effective for my STC. I know some people are not going to buy my STC kits because I chose to not have the ram air and I understand that. I also can't have the kits priced like another STC on the market or I won't sell any. David 2 Quote
Bob_Belville Posted June 15, 2016 Report Posted June 15, 2016 1 hour ago, Sabremech said: Hi Craig, According to several engineers that I've spoken with, moving the air filter/air induction into the pressurized air inside the cowling gives you the same boost of manifold pressure. That's what they did with the J models. It also does make it easier and more cost effective for my STC. I know some people are not going to buy my STC kits because I chose to not have the ram air and I understand that. I also can't have the kits priced like another STC on the market or I won't sell any. David David, I usually note the MAP when I am opening the RAM air on my '66E. It is worth 1.0-1.1". But if your cowl makes the path and pressure through the filter more efficient I would see no reason not to switch. Here's a recent flight @ 9000' PA, OAT 12C, showing RAM air open and 22.0" MAP. I think JetDriver says he sees similar with his J without RAM. Without the RAM I would be slightly under 21", (I have a Challenger filter and PowerFlow exhaust which might help some also.) Quote
Marauder Posted June 15, 2016 Report Posted June 15, 2016 1 hour ago, Sabremech said: Hi Craig, According to several engineers that I've spoken with, moving the air filter/air induction into the pressurized air inside the cowling gives you the same boost of manifold pressure. That's what they did with the J models. It also does make it easier and more cost effective for my STC. I know some people are not going to buy my STC kits because I chose to not have the ram air and I understand that. I also can't have the kits priced like another STC on the market or I won't sell any. David David, I usually note the MAP when I am opening the RAM air on my '66E. It is worth 1.0-1.1". But if your cowl makes the path and pressure through the filter more efficient I would see no reason not to switch. Here's a recent flight @ 9000' PA, OAT 12C, showing RAM air open and 22.0" MAP. I think JetDriver says he sees similar with his J without RAM. Without the RAM I would be slightly under 21", (I have a Challenger filter and PowerFlow exhaust which might help some also.) I would love to get rid of the ram air door just for the sake of not paying for that overpriced rubber duct! Sent from my iPad using Tapatalk Quote
Hank Posted June 15, 2016 Report Posted June 15, 2016 No ram air on my C, but I've usually got 20-20.2" at 10,000 msl. I'm also eagerly awaiting David's finished announcement. Quote
mooniac15u Posted June 15, 2016 Report Posted June 15, 2016 14 hours ago, Sabremech said: Never say never bluehighwayflyer, I have my eye on something for the J's after I'm done with the vintage models. David Are you thinking about a major redesign or just an improved structure to eliminate the weaknesses in the OEM cowl? I'd love to be able to buy a plug-n-play replacement for the upper cowl in particular. Something that has a better fastener plate and is less prone to cracking. Something that fits without any rivets or modifications would keep the cost down. Quote
Hector Posted June 15, 2016 Report Posted June 15, 2016 No ram air on my C, but I've usually got 20-20.2" at 10,000 msl. I'm also eagerly awaiting David's finished announcement. I get 21 at 10,000 in my C but I have a challenger air filter. Do not recall what I got before I changed but looks like it's good for about an inch. Quote
MyNameIsNobody Posted June 15, 2016 Report Posted June 15, 2016 PUSH- David any updates on the compatible spinners with your Mod? Quote
Marauder Posted June 15, 2016 Report Posted June 15, 2016 DAVID -- I'm so ready! I installed your cowl on my plane and it looks great! I need to find a way to fasten it better, but I am READY! 4 Quote
Marauder Posted June 15, 2016 Report Posted June 15, 2016 What do you all think? A little paint and I'm good to go? 1 Quote
Danb Posted June 16, 2016 Report Posted June 16, 2016 55 minutes ago, Marauder said: What do you all think? A little paint and I'm good to go? Nice! Real nice! Quote
Sabremech Posted June 16, 2016 Author Report Posted June 16, 2016 Very nice! I'll try to find a picture before I painted the stripes on so you can fill it in with your colors. I'll try to post a list of spinner part numbers that will fit the cowling. Thank you, David 4 Quote
Bob_Belville Posted June 16, 2016 Report Posted June 16, 2016 1 hour ago, Marauder said: DAVID -- I'm so ready! I installed your cowl on my plane and it looks great! I need to find a way to fasten it better, but I am READY! Someone has way too much time on his hands. 3 Quote
Hector Posted June 16, 2016 Report Posted June 16, 2016 What do you all think? A little paint and I'm good to go? Beat to fit, paint to match! 1 Quote
Browncbr1 Posted June 16, 2016 Report Posted June 16, 2016 On June 15, 2016 at 9:54 AM, Sabremech said: Hi Craig, According to several engineers that I've spoken with, moving the air filter/air induction into the pressurized air inside the cowling gives you the same boost of manifold pressure. That's what they did with the J models. It also does make it easier and more cost effective for my STC. I know some people are not going to buy my STC kits because I chose to not have the ram air and I understand that. I also can't have the kits priced like another STC on the market or I won't sell any. David If the filter relocation provides half of what the ram air would, it would be worth it because 90% of my flying is below 7000 and i prefer to run at 65% so for me, ram air is not that all important if I can get slightly better without it. . Thanks for the update! Quote
jetdriven Posted June 16, 2016 Report Posted June 16, 2016 (edited) Cowl pressure is only .2 PSI. That's .01" of MP. N But an optimized intake tract with the filter inside the cowl is ideal. The RV-8 intake plenum is a carbon copy of the J intake. I think they got it right. So did David. Edited June 16, 2016 by jetdriven 1 Quote
macosxuser Posted June 29, 2016 Report Posted June 29, 2016 Yet RV8 guys still mod to have a Ram air door, and gain MP....? I agree there are ways to have an optimized intake system, but you will always have losses across a filter, and in turn, you may have gains with a properly designed ram air duct. Quote
Sabremech Posted June 30, 2016 Author Report Posted June 30, 2016 There are a lot of things I would love to do with this cowling mod, but it is a compromise to keep the cost inline with the values of our vintage birds. I'd like to get this compromise certified and on some airplanes to gather more data. Who knows, in the future after colecting more data, I could modify it again to take advantage of what was learned. David 4 Quote
Browncbr1 Posted June 30, 2016 Report Posted June 30, 2016 I saw a photo of an F on trade-a-plane or somewhere that had the stock cowl, but sort of a rectangle piece of aluminum air scoop at the bottom of the bracket air filter... Almost like the cool air scoop on the top of the cabin. Does anyone know what that is ( if they have seen it) and if there is any real world benefit for it? Quote
Sabremech Posted July 13, 2016 Author Report Posted July 13, 2016 Here's a list of spinners that will work with my modified cowling: Hartzell 2 blade: A-2295-5, A-2295-5P Hartzell 3 blade: A-2295-4P McCaulley 3 blade: D-6504-P David 1 Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.