Heavy Mod - 1/18 21st Century Toys P-47D Razorback

[Shawn M]

that engine is a jewel!

[JayW]

That is one hellovan engine.  Great show.

 

'. . . from hex plastic stock; wish there was a better and easier way'

There may be:

http://www.hiroboy.com/Rivets_Nuts_Connectors_etc_--category--149.html

 

https://www.prime-miniatures.co.uk/

 

https://model-motorcars.myshopify.com/collections/small-parts-hardware

 

Sincerely,

Mark

well now, I was wondering if any of the brass stuff was still around!  All it takes is money and plenty of it.  Thanks Mark!

[Troy Molitor]

Damn. That looks awesome Jay. Well done.

 

Troy

[Joel_W]

 "I've seen a lot of super detailed engines over the years, and a good many of them were R-2800s, but yours in a class by itself."  So says Joel.  Thanks Joel for a super complement.

 

But have those engines been 1/18 scale or nearly so?  It is just amazing what I can do at this scale and not be able to do at smaller scales.  It's like cheating.  I think anyone with basic scratch building skills, ability to study up on the correct configuration, and with some patience can do at least this well.  The scale is the key!  The people that really impress me are the ones who can super detail at small scales.

 

Jay,

   I've seen detailing to the nth degree in my old 1/48 scale, but it doesn't compare to what you've achieved in 1/8 scale. Yes, the scale makes it possible and practical to create smaller details, and larger details mimic the real life part that much closer, but the skill set and level is the same. The skills that you have can't be learned, just refined and honed to a razor edge.

 

  Guys like me can only learn to do so much at that's it.  Honestly, I couldn't even copy your work to duplicate the R-2800 to date.  

 

   I've been following a guy on an automotive forum who scratch builds 1/8 scale Porsche race cars to the smallest detail. Each one to date takes over 3 years.  Every single piece is built by hand, not even a dremel is used. He can look at a gearbox, and in his mind see it as individual shapes, and create it perfectly. I couldn't figure out even where to begin the process. That's the difference. He also can't understand why 99% of us can't do what he does. Many have tried, and none have succeeded to date.

 

Joel

Edited May 8, 2017 by Joel_W

[JayW]

So it is on to the aft end of the R-2800.  Recall that I will end this engine at its attachment to the engine mount ring and the pre-heater.  The pre-heater fairing hides everything in the aft engine compartment, and that stuff is beyond the scope of this P-47 model!  So what I will build is the engine mount ring itself (its truss support is aft of the pre-heater fairing, and hence out of scope, thank goodness), engine mount fittings with Lord couplings (there are six but I will model only the four which can be seen), some semblance of the pre-heater fairing, and of course the exhaust manifold.  The exhaust manifold is by far the biggest challenge.

 

First, I already completed the engine mount ring, four engine mount fittings, and the lip of the pre-heater fairing:

 

 

 

This all-revealing picture shows the aft end of the engine with two of the engine mount fittings which attach to the zinc-chromate green ring (made of trusty and heavy 1/8 inch solder).  That ring fits nicely in a lathe-turned acrylic pre-heater "lip", which in turn will one day mount on a fuselage bulkhead and the pre-heater fairing will be complete.  The fittings are just little pieces of plastic, and are mounted between the intake manifold pipes.   And those really paying attention will see two of the exhaust stack stubs, ready to be spliced to the exhaust manifold pipes.

 

Speaking of which - here is the drawing of the exhaust manifold assembly, complements of Republic Aviation:

 

 

My next task is to try to duplicate this octopus, keeping in mind it is nearly hidden even with cowlings off.  It hides underneath the cowl flaps which do not come off with the cowlings themselves.  That is probably why they are usually not modeled at all.  For me, that means it doesn't have to be perfect, so I will take a few short-cuts here and there.

 

My plan is to hog it out of thick plastic - something I do alot of.  Here is my 3-times-size layout of the manifold, with hole locations for all the pipes that route forward to the 18 cylinder heads:

 

 

 

What the heck you say?  All will be revealed.  Here is the beginning of the parts (a LH part and a RH part):

 

 

You see .125 inch thick blocks of plastic, separated by a sheet of .030 thick plastic sheet for a total thickness of .28 inch.  The peripheries of the two manifolds have been etched into the top layer and bottom layer, and I will dremmel them into shape soon.  Then I will sand in a tapering thickness, max thick at the bottom, and min thickness at the top.  Then the corners get rounded off and hopefully it looks a bit like the drawing.  Also, 1/8 inch holes for the individual exhaust pipes have been drilled. You see only 11 holes.  The other 5 are actually off the manifold proper - with tenticles that reach around to far off cylinders.  If you look at the lower RH corner of the engineering drawing above, you will see what I mean.  They will be a big challenge too.

 

Next post should show a complete exhaust manifold, I hope.  Later!

Edited May 20, 2017 by JayW

[JayW]

OK - this might bore some of you because it is fairly basic scratch building, and a bit inelegant at that, but I am going to take you through the process of creating a P-47 exhaust manifold.  It started with laminating together three pieces of plastic sheet to get the right thickness (in this case .28 inch), and etching in a shape, and drilling holes for each pipe.  Last post you saw that effort, and it's an important one.  Then of course the parts have to be cut out by any means possible (in this case a dremmel):

 

 

 

And after some finer work with files and sanding sticks you get this:

 

 

That part is constant thickness, but it has to be tapered (by vigorous sanding).  Also I drilled a hole in one end:

 

 

From there the part is sanded and filed to a round(ish) cross-section except for the fat end where an angled exhaust extension is added (.28 inch dia plastic tube).  This is where t he manifold turns aft toward the waste gate, where it splits  - one part goes to the waste gate, and one part goes all the way to the tail where the supercharger is (exhaust pipe details that I will not be modelling).  Also a .156 inch dia alum tube is added to the other side:

 

 

Some more shaping and some putty yields this:

 

 

And now the fun begins with addition of the pipes (mostly .118 inch dia silver solder).  Each one is dry-fitted to the engine :

 

 

The end pipes were the toughest because two pipes emanate out of one hole.  So a good bit of filing was necessary.  Then more fine work with epoxy to get the pipe entry shapes right, addition of some details to simulate splices, and a coat of primer and you get this:

 

 

Final paint and do the other manifold the same way, and the parts are done:

 

 

A picture from the parts catalogue for comparison:

 

 

OK I will post this, and then post on the installation of these little beasties.

Edited May 30, 2017 by JayW

[Guest]

OMG, this is fantastic Jay !!.........Harv

[TorbenD]

Loving the scratch show-and-tell, very nicely done

 

Torben

[JayW]

So a while back Kevin says this:

 

"That would surely be a sight to behold if you could pull that off, Jay!".  That was in regard to my expanded plan to show the back of the engine with the intake and exhaust manifolds (something I had previously not intended to do).

 

Well how's this mate?

 

 

 

 

This R-2800 in 1/18 scale is now officially complete, after nearly 6 months of tedious work.  Here is an obligatory shot with the part it will replace:

 

 

I hope you all like the result.  There are inaccuracies for sure.  But the back of the engine will be practically unseen unless hunting for it through all the clap-trap that will be in the way. 

 

Time to take a break, as this project has been stressful at times (my own fault - I am just impatient).  I am not sure what I will tackle next, but probably it will be the bulkhead on which the engine will be attached, and some more stuff in the forward engine compartment.  Take care, will post later. 

Edited May 30, 2017 by JayW

[Joel_W]

Jay,

 I'm speechless  I've never seen scratch building like that. Simply amazing.   

 

Joel

[Shawn M]

holy *%@$

 

 

you made that look easy and I know its not!

[LSP_Kevin]

Yeah, that's so awesome I can barely comprehend it.

 

Kev

[Jim Barry]

Over the top, Jay. I've been hard at work on my  P&W R-2800 project for 1/24 and and I've become quite a fan of it . This is just incredible. You have to be really proud.

 

--Jim

[Shaka HI]

Crazy good! 

[Gerhard]

Threads like these should not be allowed,  you make us all feel incompetent. Just brilliant.