USN/USMC Superprops

[perttime]

The T40 is twice as long as a R2800. About the same weight and pretty slim, though.
Don't know about weight distribution. The length might make the Bearcat too nose heavy?

[Spino]

The T40 is twice as long as a R2800. About the same weight and pretty slim, though.
Don't know about weight distribution. The length might make the Bearcat too nose heavy?

That's the main thing I'm worried about, making it too nose-heavy.  It's also going to have to have a gearbox in front of it if it's going to drive contra-rotating props, which will add even more to the length.  This Bearcat would really start to look like an American version of the Westland Wyvern with the kind of nose that would be required for an Allison T40.  Perhaps tricycle landing gear could solve the issue on the ground, but nose-heavy airplanes aren't very maneuverable at best, so I'll have to think about it.  Also I have to figure out where to route the jet exhaust from the T40.  This one's going to require some consideration to say the least.  For now I will proceed with the F2G and AU-2 since they are more straightforward.

I'd call the ground attack Wasp Major Corsair A2U if it weren't for the F7U Cutlass apparently getting the A2U designation at one point 

[Spino]

Okay so we've got a problem here.  I estimate that the cowling for an Allison T40 is going to be about 180 inches long IRL by the time you add a gearbox to connect to the props and exhaust pipes.  Might be able to squeeze it down to 170 inches if you push the exhausts into the existing Bearcat fuselage a bit, but that's still almost a 15 foot long cowling!  That translates to the nose being about four inches long (maybe a bit more) at 1:48 scale, whereas right now it's more like one inch for the R-2800!  At this point I'm tempted to just use a Wasp Major instead of a turboprop and call it a day.  I just want more power than an R-3350 can deliver (seems to be about 3,700hp maximum), and it seems the only way to do that without making the nose excessively long is to fit the R-4360-53 with 3,800hp or the R-4360-51 VDT with 4,300hp.  And I so wanted a turboprop 

[Spino]

Here's what I'm dealing with:

You cannot view this attachment.

Maybe 4 inches is a bit high of an estimate, but it's still big for an aircraft like this.

[zenrat]

With a nose that long it'll look like a caricature or a cartoon...

...excellent.  Go for it.   

[Spino]

With a nose that long it'll look like a caricature or a cartoon...

...excellent.  Go for it. 

All right then, challenge accepted!

[perttime]

From photos of the T40, I get the impression that the transmission accounts for a big part of the length. Some other turboprops managed with much shorter gearboxes.

[Spino]

Hmm, I wonder if the gearbox could be re-designed to be a bit shorter...  That is really the issue here.

[chrisonord]

Would a double mamba not work? A front end off a Gannet could work, I have put them on 2 skyraiders.

[Spino]

Well I think I can shorten things and cram the T-40 in there because I forgot about the supercharger location.  Like the Corsair, the Bearcat has a supercharger behind the engine, so I have a bit more space in the existing aircraft's fuselage to work with than I thought.  It's still going to be a rather long nose, but I think I can make it work.

[zenrat]

With a nose that long it'll look like a caricature or a cartoon...

...excellent.  Go for it. 

All right then, challenge accepted!

 

[Spino]

Front end model done, time for a test print!
You cannot view this attachment.
You cannot view this attachment.

[PR19_Kit]

Looks just like a Wyvern. 

[Spino]

I will admit it rather does.  Kinda what I was going for to be honest, a USN take on the Wyvern.  Here's a look at it with the twin contra-rotating props installed. 

You cannot view this attachment.

My plan is to let the T40 be mounted in the space created by the new long nose and the removal of the R-2800 and its supercharger.  I think with a redesigned gearbox it just will fit.  I will add jetpipes to both sides of the fuselage just in front of the cockpit (pilots, watch out!) and maybe a couple of other little additions.  There will be considerable space in the upper nose, so might could fit a pair of machine guns up there (though I suspect that would be problematic with contra-rotating tandem props).  I'll probably just let that be empty to save weight, we're already adding a fair amount to the front end and quite a bit of length.  Still working on a backstory for this beast.

[kerick]

I'm not sure that vise is strong enough to hold all that power!
I wouldn't worry about the length of the nose. Turboprops always end up sticking much farther forward than the piston engine they replace. They're so much lighter than the piston engine so they have to be forward to maintain balance.