Gaui engines and DB Hurricane

[Nigel R]

I completely agree. The simple answer is almost always the best.

The Hurricane does look tricky to get the tank low enough. Does it need chopping out some of the wing centre section? I must admit, if it did need that I'd be looking to the hopper tank option, as the second simplest answer.

[Jon H]

Posted by Nigel R on 30/05/2019 15:07:21:

Does it need chopping out some of the wing centre section?

I will be checking that later today

[Don Fry]

Here is a copy of Jon's customers installation. For information, HobbyKing do fuel tanks with the necessary plumbing for chicken hopper tanks, To fill this, you ideally  close the pipe to the carb. To empty, use fill and drain pipe, and then turn aircraft upside down, and use the spill and drain..

Edited By Don Fry on 30/05/2019 15:24:32

[Nigel R]

<edit, moved to the proper thread>

Edited By Nigel R on 30/05/2019 16:24:43

[Jon H]

Well..last night was a head scratcher.

I found my plan, my engine, my model and with a pencil and measuring stick to hand got to work.

I very quickly remembered why its taken me 10 years to decide on what to do with this model as there really is not much room for manoeuver. After 4 hours faffing about i came up with a half decent solution.

The problem is that you can either have perfect tank placement or perfect cooling, you cant have both. I chose the best cooling route and as a result the tank position is slightly compromised but should be within the range the engine can tolerate. I might be necessary to fit pressure nipples to the exhaust. I dont like doing it and i think it will be ok, but in this case it might be required. Flight testing will be the only way to be sure.

Anyway my solution is as below. My paper tank is a slec 11oz and two of these will sit side by side between the side frames. For cooling i decided that i would just remove the section of leading edge between the wing dowels and replace it with a tunnel. This tunnel will be made strong enough to compensate for the loss of the leading edge and tthe wing spar 302 will also get some additional structure. The tanks sit above, within a box which is also set into the wing leading edge.

On the fuselage side, the cooling tunnel will come forward into the engine bay. I will cut off the firewall at the level on the current tank bay floor to give additional clearance to the carbs and help guide the air past the engine. I will then build something or other to tidy it all up and meet the cooling tunnel.

Note that with the engine in this position (ie, totally hidden in the cowl) you need an extension piece made for the crank. If you shove the engine forward to prevent this tank positioning is easier but the heads poke out of the cowling.

Edited By Jon - Laser Engines on 31/05/2019 07:36:09