Merlin guys....

Dodd's himself has vassilated over the years - often a merlin, sometimes a meteor and once a combination of merlin and meteor parts. I personally plumb for meteor.

 

If you take the supercharger off a Merlin, does that automatically make it a Meteor? I'm pretty sure there are a few other differences.

 

No idea but on this car a T400 auto sits where a supercharger would go.

 

The main one is the reversed rotation (but you wouldn't see this from outside) so different cam lobes, etc...

https://en.wikipedia.org/wiki/Rolls-Royce_Meteor

Rgds

 

Local fellow is building a Meteor engined car. Bought the engine with a hole in the side of the block.

 

I had to read up on this one. Meteor used a lot of lesser quality parts for cost control because they felt they could. While some were actually recycled aviation motors no provisions were needed to attach prop reduction housing or the blower drive system. It was in production until 64 but RR washed their hands of it pretty early on. Also I didn't know Merlins used a different prop drive to reverse props where desired for counter rotation. This whole thing was reversed in rotation. Seems like an expensive way to make a tank engine. So much of the engineering was to make it light and thats spelled expensive and complex, 2 characteristics just not needed in a tank. Pretty surprised they used a gas engine that long. Terrible fuel for a tank.

 

Big difference in size with all the junk hanging off the ends.
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The one in the picture at top of page has Merlin intake manifolds. Between the manifold design and the head design those things would not have made any power if not for the blower pushing things through.

 

While not specifically related to the Merlin or Meteor discussion, the comments on "reverse rotation" caught my interest. I remember reading about the very early Allison V-1710-B (US Navy designation V-1710-4) designed for use in Navy airships. This engine could reverse the direction of rotation, from full power to full power, in eight seconds (source: Vee's for Victory! by Daniel D. Whitney, pg 37). Reverse rotation....how the heck did they do that?? Unfortunately, that book does not go into the technical details. I would figure that cam timing and ignition timing would be a complicated problem to solve in that type of application.

 

Edit - I just found this description at enginehistory.org:

The V-1710-B was intended to replace German Mayback VL-2 engines that powered the airships USS Akron and Macon. No supercharger was required since the engines operated at low altitude. The V-1710-B had to be reversible and capable of going from full power forward to full power reverse in just eight seconds. This was accomplished by the introduction of 24-lobe cams that translated when engine direction was changed, magnetos capable of maintaining correct timing in either direction, and an accessory gear train that drove the accessories in one direction regardless of engine direction. A set of controls at the engine's rear controlled these reversing features. Although the V-1710-B passed a 150-hr type test, the project was cancelled after the USS Macon was lost.

Interesting stuff.

 

Dumb. Would have been smarter to have symmetric reversible props. No big surprise it was cancelled.

 

Affirmative, you do not need the engine to run backwards, just the part that provides the thrust. The Maybach Mb.IV engines that powered Zeppelins and Rumpler C.IV/VII aircraft in WW-I were designed way before electric props came into use and the VL-2s may have been evolutions of very old technology.

 

Ok, yes...I'll agree that it may be "dumb" from the historical and technological perspective that we enjoy in "the now"...but you don't know what you don't know, and I guess that is just how they did things back then. I'm sure that airships or dirigibles or blimps or Zeppelins or whatever they called them back in the 20's and 30's had a whole slew of requirements that might seem foreign, or even idiotic to us today. But it's the technology that I find interesting. I had never heard of a "reversible" 4-stroke engine before I read about that Allison engine, and I think it's pretty neat even if it isn't practical in a modern sense. Translating, 24-lobe camshafts...? Come on, that's kind of cool!

Yessir, I just read about the Maybach VL-2. It was fully-reversible as well. And it's a beautiful work of art....

https://airandspace.si.edu/collection-objects/maybach-vl-2-v-12-engine/nasm_A19350052000

 

Looks very much like two inline 6 Mb.IV engines on the same crank.

 

I don't know if I should mention this since it has no bearing on reversible engines but I saw the Akron and Macon at different times cruising around Washington D.C. when I was a kid. It was a sight and sound that one cannot visualize now and I'm glad that I could witness it along with the Hindenburg. I don't know what has happened here but in the last two years the sound of the R-670's, R-985, and R-1340's has disappeared. Then John Sessions and Paul Allen's stuff leaving with all of the big cubic inch stuff completed the void. Really miss the summer action and active museums.

 

One of the things I love about being in Palm Desert regularly is the sound of the P-51 and DC-3 from the Palm Springs Air Museum flying over regularly on weekends!

 

Where I lived in the SF Bay Area we had a couple of P51 owners at both Livermore, and Buchanan Field and they would spend a little time buzzing their neighborhood when out. We were in a valley so it sounded good.

 

In 2002 looked at one of those. Non-supercharged, which was advertised as a "Meteor". I just moved continent. I had no storage, so I left it in Queenstown, South Africa. It is gone. I followed up some time before Covid for a local "special". He used a Meteor and eventually moved to UK.

 

Could very well be. Common practice on industrial engines. Even late in piston aviation engines. Look at all the weird Allisons. X3420 was 2 1710's on a common crankcase.

Thank God Whipple had a better idea.