stunthanger.com
Engine basics => Engine set up tips => Topic started by: Ara Dedekian on June 02, 2021, 10:40:17 AM
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I found this engine in a box of RC stuff. It was so fried that the entire engine was an amber color. Trying to start it revealed fuel-coming-out-the-venturi blowby. It's a plain bearing, ABN, 9.6oz (without muffler) engine. Since Thunder Tiger was a clone of OS engines, mounting bolt spacing matched the FP 40 and LA 40 - 46. I scored a new piston and liner on eBay and mounted it, throttle wired open, on a derelict Twister. The runs were a reliable, steady 2 cycle. I have to make a flange mounted venturi and tongue muffler before powering either my Sig Chipmunk or Jetco Dolphin with it.
Seems it will make a really nice stunt engine,
Ara
PS - The 'search' function brought up a lot of info about this engine.
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Ara I think it will make a very nice stunt engine. I aquired six new ones and Jim Lee retrofitted them to CL for me. These took a little ingenuity on his part for the venturi because of how the carb was mounted but he got that down to a science now with my batch. You might just send it to him. I've only run one of them on the bench a couple times but seems quite like the FP .40. These are abundant on Ebay from time to time and go pretty cheap. I have all I want but I hope the CL community will snap these up as an ongoing source for nice IC engines.
Dave
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Ara,
Could you check your math. on the engine weight? 12.8 ounces seems too heavy.
Thanks,
Richard Ferrell
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Ara,
Could you check your math. on the engine weight? 12.8 ounces seems too heavy.
Thanks,
Richard Ferrell
Richard
You're right, 12.8 oz (12.6 oz per the manual) is the all up weight with muffler. Engine only is 9.6 oz. (fixed the original post). Realized the mistake the other day but didn't think anyone was paying attention.
Ara
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Here's the venturi I made for the Thunder Tiger GP42. The inside diameter is .250" with a .137 spray bar and a 10/7 three blade prop. 10% fuel with 22% lube. The angled spray bar worked great as did the engine run. It was a quick three minute flight (a looming thunderhead) but was pretty near perfect on lap time, line tension and a rock steady run.
Ara
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You might want to try something other than that Zingalli prop if the venturi is working out. Try the Master Airscrew 10-5 three blade. They are not expensive and have worked well on all the .40 size engines I have tried it on. Much lighter than the Zingalli I think with a better airfoil. Thunder Tiger must have made a couple of versions of this engine because I think I have one or two that don't have the flanged carb mount. Control line version aside, that looks like an expensive way to make an engine and carburetor!!
Type at you later,
Dan McEntee