Ive got a Pica 1/5 scale Spitfire that comes in at 25lb. The guy I bought it from has a US 41 in it. I want more power and I also need plenty of weight up front. Does anyone know which Gas I can go to that will closley match the US 41. I was hoping to keep the muffler side of my cowl from being cut. The US 41 has the muffler in the back. I thought about ZDZ but im trying to keep the price a little lower than that HELP

Quadra 52 has the same footprint (mounting) as the US - you may need to get a pitts type muffler to get the exhaust stacks behind the cylinder head, and, oh yeah, the carb is on the opposite side. Or you might try a Q52 carb and bennet muffler on your US.

Phil

How does a Q 52 stack up in power to the US 41. The US 41 will turn a 20/8 zinger at 6700. The Q 52 having the muff on the opposite side might work because the side for the carb on the 41 is cut pretty good,enough for a bennett muffler. That would mean that I might could cut a small hole on the other side for the carb if I can skip the v stack ext. And your sure its the same foot print on the firewall THANKS LEE

Yes - the mounting holes are the same. I am not sure about the firewall to prop hub length, but you could shim that. I also know you can reverse the exhaust and carb by turning the cylinder and piston. You should get quite a bit more power by using the Q52. If you want a LOT more power get a BME 50 or new 55x. That would take a lot more remodeling work.

Phil

Thanks Phil Im going to look into the Q 52 idea. It fits my budget better. Thanks so much for your advice Lee

Q52 is discontinued from Quadra but you might find a good used one. A tough reliable engine. I have 2 of them but wouldnt part with them.

BH - I agree that the US41 can be "improved" with the larger carb and with ignition, but then it gets lighter so you will need to add weight. Have you looked at a used Quadra 65 or 75? Way too much power, but the muffler is in the rear and you could limit the top end or run a multi blade prop with plenty of power to pull it.
Best replacement IMO would be a ZDZ 40RE to put the muffler in the back - add the weight you need for balance and the engine will be a good for the next airframe (when you get to that point).

Check with Bennet For a Bennet built Q52. Not much difference in weight when you add up the electronics and the batteries required.

Phil

Thanks for all the great advice. These warbirds need plenty of power ,especially when your a little green as I am . The added power is insurance. THe US 41 is a little small for a 25lb warbird.

BunkerHill -

Check out the RCU Classifieds "Gas Engines for sale". I believe I saw a couple of Quadra's listed at reasonable prices. You might also look up and contact William J. Krummel, Jr., you can do a search for him in RCU. He uses hopped up US41's on some big warbirds and swears by them! A real nice gentleman and very helpful.

Phil

How are you Phil? I saw your post about the little US 41 here and see that you gave the right advise. It will fly a 25 pound warbird very well with the modifications you suggested. I believe the carb is a WA 144 Walbro (available at B&B Specialties) My suggestion, if you do not have a noise problem at your field, would be to make a header pipe out of a flat piece of copper and a copper 3/4"elbow for the exhaust. The correct prop is very important on this engine and we have been using a 19x10 carbon fiber prop cut down to 18" diameter. Mine turns this prop at 7800 rpm. That will get your 25 pound warbird up and moving.

Another option is the Quadra Q 400. More power than the US41. A little less than the Q52.