US radial engine crankcases: colour?

[Seahawk]

One of those questions you always thought you knew the answer to!  I have long assumed that the crankcases of US radial engines were painted, logically enough, in Engine Gray FS16076 (or its predecessors).  However Xtracolor X128 Engine Gray is very dark, near black.  Looking at photos, it appears to be a lighter colour, closer to Gunship Gray FS16118.  I have seen photos of preserved engines or aircraft where they have appeared to be even lighter, more like Neutral Gray.  However one never knows the effect of flash and preserved artifacts are not always in authentic colours anyway.  

 

So, was there a standard colour for the crankcases of US radial engines during the WW2 period (with special reference to B-17s and Hellcats)?

 

Many thanks in advance.

 

[Ivor Ramsden]

If it's any help I've found that Humbrol 27 is very close to samples of paint from parts of the crankcases of the engines of two B-17Gs which crashed here in the Isle of Man.

[dnl42]

I use that Engine Gray color too.  But just recently, I saw a contemporaneous close-up photo of a B-29 engine with a blue-gray color. I'm fairly certain i saved it, so I'll try to find it. 

[72modeler]

Seahawk,

 

IIRC Seaplane/Engine Grey FS26081 was not a WW2 color. There was a grey enamel that was made by Testors in the small glass bottles years ago that matched the good color photos I could find perfectly, but sadly, my bottle  has dried up. When it was still liquid, I compared it to my FS595a color chips and it was almost a dead match for FS35164, Intermediate Blue. If it's any help, the Eduard Brassin CW R-1820 B-17F-G engine set also calls for FS35164 for the crankcase covers. See if  this color looks right to your eye. I would imagine Curtiss-Wright, Pratt & Whitney, Jacobs, and Kinner all used their own locally-sourced "engine grey" enamel for their crankcase and magneto covers, as you can see differences in the greys used for the crankcase covers in many color photos,( almost all of which are restored engines) some having a more blue cast than others. I don't know if there was an ANA standard color for these during the war, but maybe one of our resident paint experts might know.

Mike, 

[pat d]

The NMUSAF does good research here are some shots of the restored engines on the Memphis Belle, plus an R-2800. Also shown first a couple period color shots from WW2    HTH, Pat D

 

Edited December 5, 2018 by pat d
additions

[stevehnz]

You wouldn't be too far out using PRU Blue or even the old, too dark & too grey Hu 157 Azure Blue.

Steve.

[dogsbody]

A number of years ago, sometime pre-Internet, I read of a mix that I think was Tamiya X-3 Royal Blue and XF-54 Dark Sea Grey. I'm not sure about the grey, but definitely Royal Blue. It looks like this:

 

 

 

 

Chris

[dnl42]

5 hours ago, pat d said:

The NMUSAF does good research here are some shots of the restored engines on the Memphis Belle, plus an R-2800. Also shown first a couple period color shots from WW2   

Pat D, thanks for posting this, it's the photo I mentioned above.

[Dana Bell]

Hi gents, 

 

I wrote this up about 20 years ago, but I've not yet found anything to contradict or confirm what I understood back then.  It seems to fit this discussion:

 

Here's the rather limited paper trail I've been able to find on engine colors.  It offers more questions than answers, but perhaps it will help.  In 1930, the Army and Navy used separate color cards (of course!).  The Army seems to have used Spec 3-1 color #12 Blue Gray (glossy,  and a bit darker and yellower than 36307) while the Navy may have had its own Engine Gray. (A chip with that name was certainly issued by the Philadelphia Navy Yard in 1932, and is reproduced in Jack Elliott's Monogram Volume 1).

In 1932 the Army created a set of porcelain color plates including a new Blue Gray (reportedly from "Cobalt-Chromium-Iron Black" and Tin Oxide White).  This new Blue Gray is the only chip missing from my set, so I can't comment on the value of the color.

In 1933 the Navy issued a new Engine Gray chip based on Windsor Newton Mars Black, Windsor Newton Paynes Gray, and Liquitix Titanium White.  My chip seems a little lighter than the earlier sample in the Elliott book.  This Navy chip was officially accepted by the Army as the basis for the ANA standard color Engine Gray, even though the Army would delay implementation of the ANA system for six more years.  The ANA chips were released in July 1936, and the Engine Grey seems a good match for the Navy 1933 chip.  Pratt & Whitney reported switching to this ANA color shortly after its release.

In 1938 Sherwin-Williams commented that the ANA Engine Gray was much lighter and cleaner than the old Blue Gray (supposedly compared to the Army porcelain color chip).

In January 1939 the Navy requested an unspecified radical change to the engine gray color.  Pratt and Whitney requested clarification, and though I've never found the Air Corps' reply, P&W agreed they would switch to this color on all parts shipped after June 1, 1939.  Whatever the case, the 1945 ANA chip for Engine Gray doesn't differ all that much from the 1933 Navy chip - I've never found any evidence of the type of gray the Navy was requesting.  The 1945 ANA chip is a good match for 16081.

In August 1942 the AAF reported that 3-1 color #13 (Dark Gray) was considered a satisfactory match for engine gray.  Dark Gray was glossy and a bit stronger and browner than 36081 - not a bad match for the ANA color.

There are bound to be many other pieces to this puzzle, but I haven't yet been able to find them.  Hope this helps!
 

Cheers,

 

 

Dana

[Corsairfoxfouruncle]

Ive personally always used Neutral grey for crankcases. Is it correct ? It looks right to my eye though.

 

Dennis 

[Toryu]

Isn't this a bit an academic discussion? Apart from the many colour changes and sources that Dana mentions, I'm pretty sure that manufacturers choose whatever 'engine grey' was available and looked reasonably close to (which?) specification.

Then, once in service, the crankcase was the most exposed part of the engine and quickly received all kind of filth (oil, smoke, sanding, repaint....). Although being a meticulous modeller, I never worried about exact engine colours - just took some dark/blue grey that was at hand.

[Seahawk]

Thanks everyone for your engagement.  Pat D's photos illustrate the problem: the first could pass for Engine Gray (but has the colour been affected by Kodak's lush colours?), the second shows the bluish tinge several of you have picked up on, the Fortress engines look pretty close to the colour we now know as Gunship Gray (but preserved artifacts) and the last is close to Neutral Gray (but a preserved artifact)   The oracle, Dana, has spoken and the answer, as far as he has been able to ascertain from a limited paper trail, is the colour we now know as Engine Gray 16081.  Thanks, Dana.

 

PS There appears to be something unusual on the wing pylon of the A-20 in the background of Pat's 5th photo.  What is it?

[Paul J]

I usually use Humbrol gloss Dark Admiralty grey tin no 5. It looks close enough in 1/72nd for me. ( Or similar)

[Joe Hegedus]

54 minutes ago, Seahawk said:

 

 

PS There appears to be something unusual on the wing pylon of the A-20 in the background of Pat's 5th photo.  What is it?

Smoke/chemical dispensing tank.

[72modeler]

2 hours ago, Joe Hegedus said:

Smoke/chemical dispensing tank.

Yep- you beat me to it! IIRC A-20's laid smoke during the D-Day invasion.

Mike

[Corsairfoxfouruncle]

I’ve seen them used in the SWP theatre for beach landings and strafing. Seems the smoke hindered the AA gunners ability to target low flying aircraft.  

This clip is from this film. 

https://www.gettyimages.co.jp/detail/動画/douglas-a-20-havocs-flying-low-emitting-smoke-screen-over-owen-ニュース動画/514394599

 

Dennis

[Enrico Chiambalero]

I use soviet AMT-11 blue-grey for american radial engine crankcase, from Hataka acrylic range. In my opinion it seems to be a good approximation, judging the pictures of real engines.

[11bravo]

I used good old Model Master Engine Grey for my Corsair motor.   Seemed to be a pretty good match with the period color pics I've seen.   Only thing I needed to add in the pic below was a gloss coat.   

[Seahawk]

17 minutes ago, 11bravo said:

I used good old Model Master Engine Grey for my Corsair motor.   Seemed to be a pretty good match with the period color pics I've seen.   Only thing I needed to add in the pic below was a gloss coat.  

 

I think that's what I happily used for years and years: the colour looked right to me and I liked the semi-gloss finish.  My doubts only started when I used it up.

[PhantomBigStu]

I've always painted mine black or silver, good to know thats wrong being about to paint the ones on my b-17....