What would you "war bird types etc." rate the U.S.-41s POWER shown on the Top Flite G/S 85" wing span P-47 plan, as oppossed to the new ZDZ50NG..OK not as new

No contest, the 41 is a good engine but nowhere near the ZDZ50 [8D]

The US 41 is a bang for the buck engine, but just compairing the bang its far down the list.

So the ZDZ is more powerfull, swings a larger prop and produces more 'static thrust with its given propeller..' is that correct[sm=bananahead.gif]

Yes, there is no comparisons between the 2 you mentioned. Even the zdz 40 will out pull the US 41 by a decent margin.

One of the slickest engines for warbirds this size --is the ZDZ40 RE (rear exhaust ) the entire engine will fit in a 3" wide cowl
HOWEVER
Warbird guys--- unless they have a background in performance flying, are notoriously bad about figuring out airflow and the idea of a can or a pipe - seem sacrilege.
here is shot of one of these with a muffler can - which does not limit power and sounds great and is not a tuned device - with this setup a 21x8 Mejzlic prop puts out excellent power - around 7000 rpm (as an example
So depending or your preferences - opt for a good industrial modified engine ( more cooling fins but a side carb and a siade exhaust ) or for full enclosed setup get the 40 but you must do a good cooling flow setup internally or you will cook it .

.

Dick has a good point but I wonder what if any issues a US-41 would have with regard to cooling in a narrow cowl such as a Spitfire and Mustang.

No question about the G-62 a proven winner..however I live in Waldorf know Dave Garrison and continue to be impressed with the ZDZ line of engines that he imports and services.

I am not trying to sell you a G62, just showing an alternative..Sorry, I will delete the post...

I have the plane. My suggestion is to use a g-62. Will fit into the cowl with aftermarket muffler. Lots cheaper than a ZDZ 50, lots more power, which is never bad, no nose weight needed if built to plans. I fly at 5,000 feet so I would expect your plane to be more overpowered than mine so maybe a G-45 would be a good choice.
Larry

Get a Zenoah, either a G-45 or a G-62

Zenoahs are hands down better, more reliable, and last longer than the ZDZ or US engine could ever hope to....

Do you like messing with engines all day, charging ignition batteries, and fixing borken parts ? Get the ZDZ or US...

If you like to fly, and run your engine all day without even thinking about it, then get the Zenoah

JettPilot

The last magneto I ran was a Scintella Vertex -on a blown Olds - back in 1957
So- I guess they have improved?
I am spoiled with just having to add choke , flip lazily a few times and go
I really did not think anyone used the mag stuff anymore.

T Dick,

How far into the fuselage does that muffler can extend? Are there issues with heat inside the fuselage?

-Ed

Its actually CDI "capacitor discharge ignition" now. And yes they are MUCH imporved. Its a solid state unit that never requires maintenance, external power, or anything. It just always works like magic

The can is 12" long .
For a scale setup there needs be an inlet -on the P40 that's no problem and a big angled exit undeneath
I think the P40 had large bottom cowl flaps -
as for can heat - as long as the bottom is open no problem
Heat comes when you try to cram everything in a tunnel

How about a 3W 42i, 4lbs, 4HP and a 22X10 prop??

Yea hands down on the popularity of the G-62---back in the day some race pilot asked about using the ZDZ for racing and I got a no go from Mike @ RCS based on how the racers intended to run the ZDZs and of course now all I see (pretty much) is The G-62 ..kinda says something[8D]

I would go with the 3W 55i. Rear carb, I don't think you would cook it if you leave allot of exit area for the air and don't cut all the front opening of the cowl out. Just enough to let air into the engine.

From what I have gathered its 1-3 ratio for intake area vs area for exit air, or about.

Plus lots a room in that bird for a in cowl muffler, nothing sticking out but pipes I would think.

A simpler setup would be a G62, they are very reliable, and I would get one with electronic ignition, they do start better.

I had one with the magneto, it could be stubborn at times. Plus you have to slap the prop hard to get a good spark, and it could kick back if ya did not slap it just right. [&:]

The G62 is in a different class, it's the required by the rules stock engine...There are presently 2 ZDZ engines being tried for racing, an 80 single and a 160 twin...the 80 will have to run on methanol and turn at least 11,000 to compete with GT80s that turn almost 12,000 in the air...The 160 twin will have to compete with DA 150s, Aerrow 200s, and Herbrandson 289s...The DAs and Aerrows are turning 10,000 with 21x25 race props, the 289 is turning a 21x27 at 9400...No tuned pipes are used, just stacks shorter than 8 inches....
We'll see how they did after the race in the last week of this month..
No engine has yet beat the "overweight, underpowered, boat anchor" (conventional wisdom) GT 80s at this game..
Y'all are welcome to try
Sachs 4.2s, Husky 4.4s, and Quadra Aerrow 75s, 3W twins, prepared by some pretty fair tuners, have failed...
Someone tried a ZDZ 210 twin a few years ago, looked promising, didn't win....

You will be most dissapointed in the final performance levels of any of the 40cc class engines for the P-47. I don't care how you go about putting it together two things are going to happen. You will need nose weight to balance and you will need power to fly it to maintain a comfortable thrust to weight ratio. The same holds very close for the lower class 50cc engines. I'm not speaking of extreme aerobatics, I'm talking about flying it like a warbird.

I'm very familiar with this plane, it's equipment options, weights, and performance. If you always want to be concerned about energy management in the turns, make long take off runs, and do lopsided loops because you had to trade altitude for aispeed, and sweat stalling the plane all the time, get a 40 to 50cc engine. If you want excellent power levels at all times and an average to relativly short t/o run, get a 55 to 62.

Underpower the 47 and it won't be long before it becomes just another smokin' hole in the ground.

let's be candid - the engine designs are not the same and not really setup for same purposes
In my 33% edge and my 42% Extra ,the glo fueled 62 or the big Herbie or any of the racer setups woud be completely out of their elements
My ZDZJ engines easily hand flip and start at 1000rpm are absolutely linear in output and smooth as glass on the optomized ignition setup.
I tried a Chev 6 carb, log manifold setup once in my Austin Healey. terrific Hp but not drivable - changing to different manifolds carbs , progressive linkage -ignition curve etc - it ran extremely well on the street - not as fast flat out but fit the use much better .
Oh yeh --for those whoever really built stuff from the ground up and raced it -- go rent or buy a copy of he "World's fastest Indian" starring Anthony Hopkins
It is about a guy who built up an old Indian twin bike (under 1000cc ) and proceeded to kick arse wif it
You kids may even like it --

Dick,

With all due respect, and that was said in sincerity, you always seem to be having to pipe your engines in order to pull every last possible rpm out of the darn things to get the performance you need. Along with that, they are a lot lighter than what will be needed in a warbird like the T/F -P-47. They always come out tail heavy, often quite a lot.

Yes, the ZDZ 40 and 50 will pull it, but you will be adding a pound or more of ballast to the nose to make up the weight difference. That puts a pretty big hit on the ZDZ. Warbirds also do not usually have the open fuselage space for cans like th H-9 Extras and stuff do. Fact of life, aerobats and warbirds are different, and have different requirements regarding engine weights, exhaust types, and power levels. I, for one, would absolutely not want an engine with a rear carb on a warbird. What a P.I.T.A. to work with in that type of an installation.

Personally I'd rather see you set up someone as a happy ZDZ owner, not one that may well be wishing they had got the other engine shortly into the first flight.

yep -I expected a similar reply - and I understand the reasons - not at all offended
I have built warbirds for others- (Dave Platt P51's etc.. and was appalled at the construction.)
I have plans waiting for a Brit designed Spit I will do someday
The typical kit for a warbird is frankly a stone but some of the new ARFS are very good - I did a big H9 Mustang (for a customer) and stuck a Roto 35 in it . It worked fine.
I know that most warbird guys ar not into quiet engines and aerobatic setups - but there are some that are -
The Spitfire was a pretty good aerobat in original form and the 40, completely fitted in and with a smooth exhaust note, really appeals to me.

Sent you a PM[8D]