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Old 06-05-2020, 03:33 PM
fox88gt is offline
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Gas engine selection for VQ Warbirds Dauntless (62")

Hi all,

New to the site here, and hoping to dip my feet into gas RC engines on a new project.

I recently picked up a 62" Dauntless ARF from VQ Warbirds (now Legend Hobby). So far I've been an electric-only pilot, but have always wanted a gas powered plane, and was considering a gas engine for this project. When it comes to RC, I'm completely new to gas engines. I have worked on gas engines in cars, boats, and power equipment as a hobby for years, so I know my way around a full size engine, but not an RC gas engine.

I'm looking for suggestions on a gas engine (not nitro, the fuel is too expensive in my opinion). So with that out of the way, I'm looking for 2-cycle gas engines. I was originally planning to go with electric power for this Dauntless, but have always wanted to try a gas engine.

Here's a link to the plane: https://vqwarbirds.com/product/vq-sb...-46-size-epgp/

I was looking at the NGH GT9 9cc and NGH GT17 17cc at Motion RC, but have no idea if either of them are a decent choice for this plane. I was also looking at the RCGF 10cc and VVRC 10cc. I'm hoping to find an engine that will turn a 3-blade propeller for scale reasons.

I'm also curious about setting CG with a gas plane (electric is easy since you can alter CG with battery placement).

Thank you in advance!
Jeff
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Old 06-05-2020, 05:15 PM
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Displacement wise... a 10 cc engine is vis a vis recommended, I think the 17cc engine will work beautifully in this application.
I ordered a 17 cc for a seagull supermarine seafire, 64.4 in and 8 lbs.

Regards,
Patricio
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Old 06-06-2020, 09:45 PM
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Nothing shows up for the link.
For a 46 size plane id go with the new 10 cc stinger engines from rcgfusa.
Or their 15 cc if it can fit and would need the nose weight and as long as prop clearance is not a issue.
Check out the gas engine section for some good info regarding tuning and throttle servo setup , if you haven’t already.
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Old 06-07-2020, 02:06 PM
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The stingers might also fit.. what I don't like is the rear carb... on tight small cowls are a pain to fit...the NGH have their carbs up front.
Valid option.
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Last edited by Swampflier; 08-16-2020 at 06:21 PM. Reason: Grammar
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Old 06-08-2020, 08:53 AM
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Sorry for the dead link to the plane you guys, try this one instead:

https://vqwarbirds.com/product/vq-sb...-46-size-epgp/

Good point about the rear carb on the the RCGF engines. The instructions for the plane call out 110-115 mm for the dimension from the firewall to the front of the crankcase, and the RCGF 10cc is 118 mm long from the end of the carb to the front of the crankcase.

The dimensions of the NGH 9cc work much better since it doesn't have a rear carb, but I worry that engine won't have enough power to turn a large enough prop. I worry about not having enough experience (and budget) to try an untested combination in this plane. I saw a video of the NGH 9cc used in a Hangar 9 Valiant, but I worry this plane will be much heavier due to retractable gear, extra servos for the dive flaps, scale cockpit/canopy including tail gunner etc.

Thank you guys for chiming in and offering your input to a complete gas engine newbie. I haven't ruled out gas yet for this project, but when I compare to the specs for the Hangar 9 Hellcat (64") they call for a 15cc 2-stroke, but I just don't think that engine will fit in this cowl (and I'm concerned about weight).
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Old 06-08-2020, 10:49 AM
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The NGH 17 will fit in the cowl @ 113 mm , included diagram shows NGH 17 on the left, ang NGH9 on the right.
Will have plenty of powr if needed and big flat prop for landing safelyu.
They can be put inverted in the cowl, and with the pitts, the cowl looks good
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Old 06-08-2020, 01:41 PM
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Thank you Swampflier for those images, very helpful seeing them side by side. I am concerned about lack of room between the cylinder and firewall even if using the wrap-style Pitts muffler. It looks like the stock muffler will not clear the firewall at all. I included the dimensions shown in the Dauntless manual for reference.
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Old 06-08-2020, 03:41 PM
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If you make allowances for the engine mount, I think that larger engine will be tough to fit on that plane. Just my guess. Also getting a muffler to fit.
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Old 06-13-2020, 06:55 PM
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If you're concerned about the rear mounted carb you can open up the hole in the firewall to push the carb thru the hole.
I like to run all my gas engines on one mixture.
The NGH engines require a higher oil content than what i run my engines, they all have needle bearings.
NGH i believe is bushed and requires 20:1 oil.
So depending on future engine choices you may need to keep 2 separate mixtures of gas.
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Last edited by Bcolici; 06-13-2020 at 07:17 PM.
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Old 06-13-2020, 07:36 PM
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Regarding Cg, Place your fuel tank as close to the cog as possible. This way cg is not affected much at all when tank goes from full to empty.
Gas engines have fuel pumps to pull fuel,no worries how far back the tank is placed to get it near the cog.
Set your cg with moving your batteries or battery depending on what you go with, rx and what ever else you can to get it where you need to be,
Also get yourself an ignition kill switch.
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Old 03-23-2021, 01:08 AM
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Ngh gf17

Hey Jeff,

I do not know if you made a decision bout the Dauntless but i will share my experience with the ngh gt17.
Mine runs on a black horse at6 with 72“ wingspan an 4,4kg flight weight. The plane is well motored and maby a little to much but thats fine and because of that its a warbird, you may need the nose weight anyway...

So the gt17 would be also nice for you Dauntless too...

Let us know bout the sbd 🤗

Here‘s a flight video of my at6.

Regards,
Dave

Black Horse AT-6 Texan 185cm // NGH GT-17 (3 min 19 sec)
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