11bee Posted August 22, 2015 Share Posted August 22, 2015 My US-2B project is plugging along nicely, still working on the nacelles. Have a question for the experts - the Kinetic kit has a part that I have not seen present in pics of the real thing. See the instructions below, it's parts D24 & D25. Looks to be possibly a supercharger intake, it's present on both nacelles, mounting on the lower outboard section of both. Would this part be present on an early model S-2? I'm guessing not and plan to chuck it and sand down the area on the nacelle that it mounts to. Figured I would just check first. Any info is appreciated. John Quote Link to post Share on other sites
DonSS3 Posted August 22, 2015 Share Posted August 22, 2015 I'm with you, I don't think I've seen that detail, either. Quote Link to post Share on other sites
DonSS3 Posted August 22, 2015 Share Posted August 22, 2015 Stupid forum won't let me edit my post, I keep getting a 500 Error... Anyway, I didn't see that on the photos I looked at in this Google Image Search. https://www.google.com/search?site=&tbm=isch&source=hp&biw=980&bih=613&q=Grumman+us-2&oq=Grumman+us-2&gs_l=img.3...2902.7315.0.7794.12.9.0.3.2.0.116.653.8j1.9.0....0...1ac.1.64.img..2.10.624.iugqLlhjFJk Quote Link to post Share on other sites
scottr5213 Posted August 22, 2015 Share Posted August 22, 2015 Hope this helps http://home.wxs.nl/~roden171/index.html http://tailspintopics.blogspot.com/2010/08/stoof.html Quote Link to post Share on other sites
11bee Posted August 22, 2015 Author Share Posted August 22, 2015 I saw these fittings on a single S-2 picture so far. The pic didn't provide enough info to determine what specific model it was. I'm guessing it was a later version (S-2G) or maybe an E-1 that needed the extra power. I've started to sand down the raised mounting plate and will be filling the vent with putty. Not a major task but in looking at the pics of the real thing, there appears to be another vertical cooling slot in this area. I'll need to figure out how to replicate that, which will be a bit more challenging. Just another issue with this kit. I'm glad that Kinetic released this one but I really wish they had done a better job on their research. Having to shorten the fuselage, the wrong profile on the cockpit side windows and engine nacelles and now this.... Just a lot of unnecessary work. Quote Link to post Share on other sites
Tailspin Turtle Posted August 22, 2015 Share Posted August 22, 2015 My US-2B project is plugging along nicely, still working on the nacelles. Have a question for the experts - the Kinetic kit has a part that I have not seen present in pics of the real thing. See the instructions below, it's parts D24 & D25. Looks to be possibly a supercharger intake, it's present on both nacelles, mounting on the lower outboard section of both. Would this part be present on an early model S-2? I'm guessing not and plan to chuck it and sand down the area on the nacelle that it mounts to. Figured I would just check first. Any info is appreciated. John It was introduced on the S2F-3/3S (S-2D/E). It's the inlet and exhaust for CSD (Constant Speed Drive) cooling air so it's not on (nor was it retrofitted to) the S2F-1/2 (S-2A/B). What's more, like the fuel dump pipe, it's located on the right side of both nacelles, not outboard on both. There's a picture of it in my S2f blog post. Quote Link to post Share on other sites
11bee Posted August 22, 2015 Author Share Posted August 22, 2015 (edited) It was introduced on the S2F-3/3S (S-2D/E). It's the inlet and exhaust for CSD (Constant Speed Drive) cooling air so it's not on (nor was it retrofitted to) the S2F-1/2 (S-2A/B)/>/>. What's more, like the fuel dump pipe, it's located on the right side of both nacelles, not outboard on both. There's a picture of it in my S2f blog post. I should have consulted your blog first. Good to know that it doesn't belong on "my" US-2. The funny thing is that Kinetic managed to screw this up too. They have it present on the outboard sides of both nacelles, not as you mentioned above. Looking at your blog, it appears that the the carb intake on the top of the nacelle is smaller on the earlier versions. Another miss by Kinetic and for me, it's too late to fully correct since I've already got these parts installed. Best I could do was to sand down the sides to make them a bit more square in cross section. Question if you happpen to know the answer - do the earlier, smaller aft nacelle versions still have the fuel dump pipe? There aren't that many detail pics of those earlier S-2's and so far, I haven't been able to see if they have this feature or not. John Edited August 22, 2015 by 11bee Quote Link to post Share on other sites
Tailspin Turtle Posted August 23, 2015 Share Posted August 23, 2015 I should have consulted your blog first. Good to know that it doesn't belong on "my" US-2. The funny thing is that Kinetic managed to screw this up too. They have it present on the outboard sides of both nacelles, not as you mentioned above. Looking at your blog, it appears that the the carb intake on the top of the nacelle is smaller on the earlier versions. Another miss by Kinetic and for me, it's too late to fully correct since I've already got these parts installed. Best I could do was to sand down the sides to make them a bit more square in cross section. Question if you happpen to know the answer - do the earlier, smaller aft nacelle versions still have the fuel dump pipe? There aren't that many detail pics of those earlier S-2's and so far, I haven't been able to see if they have this feature or not. John Grumman added more fuel capacity to the S2F-3 but not more engine so fuel dump was incorporated to be used if necessary in the event of an engine failure. Again, the earlier S2Fs were not retrofitted. And yes, the carburetor air intake was larger on the -3 and subsequent. I don't know why that was considered necessary. It wasn't a retrofit either. Quote Link to post Share on other sites
Jennings Posted August 23, 2015 Share Posted August 23, 2015 The S2F had no need for a supercharger. When you're skimming the wave tops looking for Rooskie submarines, a supercharger would be excess weight. Quote Link to post Share on other sites
11bee Posted August 23, 2015 Author Share Posted August 23, 2015 The S2F had no need for a supercharger. When you're skimming the wave tops looking for Rooskie submarines, a supercharger would be excess weight. Yah... wasn't sure what that thing was, looked somewhat like a supercharger, that's why I thought maybe it was only on the E-1 which would have spent most of it's time at higher altitudes. Speaking of - As much as this kit has it's issues, I'd still build another one if someone ever came out with an E-1 conversion. Always thought that aircraft was absolutely freakish. Quote Link to post Share on other sites
dnl42 Posted August 23, 2015 Share Posted August 23, 2015 (edited) I just returned from a week in Cambria, wtih the Estrella Warbid Museum in nearby Paso Robles. Here's a shot of the upper nacelle of their US-2B, 136404. The photo is a link to my PB album on that aircraft. Edited August 23, 2015 by dnl42 Quote Link to post Share on other sites
aweber stoofan Posted August 24, 2015 Share Posted August 24, 2015 (edited) Grumman added more fuel capacity to the S2F-3 but not more engine so fuel dump was incorporated to be used if necessary in the event of an engine failure. Again, the earlier S2Fs were not retrofitted. And yes, the carburetor air intake was larger on the -3 and subsequent. I don't know why that was considered necessary. It wasn't a retrofit either. The top scoop is not the carburetor intake, it is between the cylinders on all versions. I am guessing, but most likely the larger scoop on the -3 was installed to help cool the constant speed generators that were added to the -3. Edited August 24, 2015 by aweber stoofan Quote Link to post Share on other sites
Jennings Posted August 24, 2015 Share Posted August 24, 2015 an E-1 conversion. Stoof with a roof! Quote Link to post Share on other sites
11bee Posted August 25, 2015 Author Share Posted August 25, 2015 Stoof with a roof! Is it me or is that not simply the coolest looking plane in the world. Yeah... it's probably just me... Quote Link to post Share on other sites
Tailspin Turtle Posted August 26, 2015 Share Posted August 26, 2015 The top scoop is not the carburetor intake, it is between the cylinders on all versions. I am guessing, but most likely the larger scoop on the -3 was installed to help cool the constant speed generators that were added to the -3. Oops - Thanks for that. However, I'm pretty sure that the cooling air inlet for the CSD was integral with the unit. My current guess is that the scoop on the top of the nacelle is the air inlet for the sonobuoy heating system. If so, the reason it got bigger is that the S2F-3 got more sonobuoys so more air was required. I'll probably know more tomorrow. Quote Link to post Share on other sites
11bee Posted August 26, 2015 Author Share Posted August 26, 2015 (edited) Oops - Thanks for that. However, I'm pretty sure that the cooling air inlet for the CSD was integral with the unit. My current guess is that the scoop on the top of the nacelle is the air inlet for the sonobuoy heating system. If so, the reason it got bigger is that the S2F-3 got more sonobuoys so more air was required. I'll probably know more tomorrow. Maybe a stupid question but would this have been removed during the US-2 conversion process? I can't seem to find any pics of US-2's that show this area in detail. EDIT - disregard, I did find some pics. Scoop is still there. Edited August 26, 2015 by 11bee Quote Link to post Share on other sites
Tailspin Turtle Posted August 27, 2015 Share Posted August 27, 2015 Oops - Thanks for that. However, I'm pretty sure that the cooling air inlet for the CSD was integral with the unit. My current guess is that the scoop on the top of the nacelle is the air inlet for the sonobuoy heating system. If so, the reason it got bigger is that the S2F-3 got more sonobuoys so more air was required. I'll probably know more tomorrow. Well, that was a bad guess at what the scoop was for at the top of the nacelle. It turns out that I was wrong about being wrong. And 11bee was not wrong either. Early S2F-1s did not have the scoop; carburetor air came from inlets between two pair of cylinder heads. Later S2F-1s got the scoop instead for carburetor air. The bigger scoop on the S2F-3 was also for carburetor air. Quote Link to post Share on other sites
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