Radial engine cylinders.....

[Bozothenutter]

Dark colour with metallic drybrushing?

Metallic colour with a dark wash?

 

And why?

 

[bentwaters81tfw]

Depends who made the engines, and the model.

[dnl42]

 

GIYF and beware of restorations.

[dogsbody]

Pre-WW2, wartime or post-war? 

 

Civilian use or military?

 

 

 

Chris

[Mike]

If the instructions tell you to paint them metallic, I tend to do as I'm told, then use a dark wash to bring out the detail on the fins and other areas.  For other colours, just sub the metallic for that colour

 

 

 

 

 

I've really got to do a few more jets

[Giorgio N]

The why is simple: to make the cooling fins more visible in a model. The contrast between the metallic fins and the dark recesses will make the former "pop" instead of disappearing in the little room inside a scale model cowling. 

Regarding the two techniques, it's a matter of taste and which one each modeller finds easier. Personally I prefer a metallic coat followed by a wash. Working in 1/72 I generally paint the engine parts in their colours and then apply a dark wash to the whole engine, essier for me than trying to drybrush each cylinder. However I've seen others using the drybrush technique and achieving great result

[dogsbody]

Also, whose engines? American, British, German, Japanese? Different countries did different things at different times.

 

 

 

Chris

[pigsty]

Another thing to think about is whether you have a one-piece engine, or fourteen separate cylinders and a crankcase.  Dry-brushing is a lot harder with a one-piece because you have to get the brush between the front row cylinders to do the back row - and even if it's just one row, your efforts will stand out better on the tops than down the sides.  Normally that's not too great a problem within a cowling.  But for an even effect all over, a wash is likely to be easier.  I've just used neat Tamiya Smoke (X19) over some Mr Metal Stainless on a couple of BMW 801s and it's just the effect I wanted.

[Kiwidave4]

The best way to answer your own question is to do what all scale modellers should do all the time - find contemporary reference pics and follow them.

 

Most of the radials I have worked on have had aluminium cylinders/heads/rocker boxes in natural cast finish, usually with bake black enamel baffles and push rod covers. However there are  engines with black painted cylinders, and/or cylinder heads.

 

As already mentioned it also depends on the country of origin and the manufacturer so it is really a question that is in the 'how long is a piece of string category?'

[dogsbody]

So, these are Wright R-2600's for a B-25:

 

 

 

This is a P&W R-1830 on a C-47:

 

 

And apparently, so is this:

 

 

 

This is a Bristol Mercury:

 

 

A Bristol Hercules. All Bristol engines were basically the same,

 

 

 

 

 

 

Chris

 

 

[bentwaters81tfw]

Nice pair of Bristols: Note how the barrels are only half painted on the Mercury. This was my first thought when reading the OP.

[Giorgio N]

In any case the problem for the modeller is the same, no matter if the finned area of the cylinder was left unpainted or was painted: how to make such areas recognisable, particularly in the smaller scales. And the solutions are the same: wash or drybrushing. The only difference would be in the colour used for the cylinder. Even on an engine with these painted black, I would use a dark grey for the cylinders and then apply a black wash to achieve the needed contrast. Similar with drybrushing, a black base coat followed by grey to highlight the cooling fins

[dogsbody]

7 hours ago, Giorgio N said:

In any case the problem for the modeller is the same, no matter if the finned area of the cylinder was left unpainted or was painted: how to make such areas recognisable, particularly in the smaller scales. And the solutions are the same: wash or drybrushing. The only difference would be in the colour used for the cylinder. Even on an engine with these painted black, I would use a dark grey for the cylinders and then apply a black wash to achieve the needed contrast. Similar with drybrushing, a black base coat followed by grey to highlight the cooling fins

 

What about a gloss or semi-gloss paint with a flat black wash?

 

 

Chris

[Giorgio N]

18 hours ago, dogsbody said:

 

What about a gloss or semi-gloss paint with a flat black wash?

 

 

Chris

 

You mean having the same colour overall and using a wash of the same colour but matt ? Not sure this would give enough contrast, might be worth a try but I doubt it would replicate the effect

 

[JWM]

The other aspect is the difference in appearance between a brand new clean engine from an exhibition in museum and the worn one from a heavily exploited machine on a front line at war...

Cheers

J-W

 

[kiseca]

There's a third option I've used from time to time to highlight raised detail, and I tend to prefer this over dry brushing (but not over a wash): That is, "prime" the whole part in a hard wearing metallic enamel instead of a regular primer. Then spray the whole part with the second colour, black or whatever, using a softer acrylic paint. Then gently sand the raised detail back to the metal finish.

 

Personally I am happier with the results I get from that than from dry brushing. I feel like I have more control and get a more consistent finish, and it's faster (if I ignore time wasted waiting for it to dry). I haven't tried it on a radial engine but I expect it will give the same access challenges as dry brushing.

 

EDIT: That would give a purpose prepared look but I'd use a wash if I wanted a used look. Also, I see I've just replied to a thread that is 3 months old! Oops.

 

Edited January 20 by kiseca