How Possible would it be to Invert an Auto V Engine?

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Tom Kay

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Wally;

At 400+ pounds and cubic inches, I think this is too big for a Titan-like engine used on a scale BF-109. Thanks though.

Dan; Yeah, I hate reading something and then losing it when you need it later. I'm not perfect at this, but if I have a feeling it might be remotely useful later, I try to bookmark it. Again, not perfect at it.

I have a sneaky feeling you might be talking about the Falconer V-12, which is a marine engine and also the engine used in the Thunder Mustang.

So far, if I have this correct, the biggest item stopping a typical auto V6 from operating inverted, is the oil splashing around. It would be very tough to install cylinder liners that extend deep enough into the crankcase to keep oil from dripping down into the combustion chamber. Plus some new scavenger system would be needed. This is assuming, of course, that we could install a couple of threaded plugs to allow the coolant passages to be air pocket-free, and that all carburetor-related equipment could be flipped and somewhat relocated. Piece of cake.

Thanks, Tom.
 

Dan Thomas

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Wally;

At 400+ pounds and cubic inches, I think this is too big for a Titan-like engine used on a scale BF-109. Thanks though.

Dan; Yeah, I hate reading something and then losing it when you need it later. I'm not perfect at this, but if I have a feeling it might be remotely useful later, I try to bookmark it. Again, not perfect at it.

I have a sneaky feeling you might be talking about the Falconer V-12, which is a marine engine and also the engine used in the Thunder Mustang.

So far, if I have this correct, the biggest item stopping a typical auto V6 from operating inverted, is the oil splashing around. It would be very tough to install cylinder liners that extend deep enough into the crankcase to keep oil from dripping down into the combustion chamber. Plus some new scavenger system would be needed. This is assuming, of course, that we could install a couple of threaded plugs to allow the coolant passages to be air pocket-free, and that all carburetor-related equipment could be flipped and somewhat relocated. Piece of cake.

Thanks, Tom.
Much of what I remember from reading was stuff I came across in pre-internet days, and much of it still comes from books. If I kept every book I found somethig useful in I'd be like some of those folks who die in their houses when the heaps of junk collapse and trap them. And I still wouldn't be able to find the article anyway.

The V-12 I remember reading about was an engine very closely related to the Merlin, adapted many years ago for larger boats, and apparently had considerable commonality among the parts. Would be interesting to know if my memory is right or if senility is setting in.

The oil running into the cylinders of an inverted auto engine would be very difficult to stop. If you take one apart you'll see that the piston skirts most often extend out of the cylinder at BDC, and the skirts themselves are cut away to clear the crankshaft counterweights. Everything runs awesomely close to everything else in auto engines as a result of the engineers trying to make the package as small as possible. With those crank counterweights flying a small fraction of an inch past the end of the cylinder, there's no room for any sleeves or extensions of any sort. And that's why the little video of Wittman's inverted Buick V-8 shows it belching gobs of blue smoke when it starts up.

Go look at the two animations on this page to see just how closely things run in the typical auto engine:
http://www.carsensation.com/how-car-engine-works.php

The geometry of an inverted inline aircraft engine, like the Gipsy I had, places the crankshaft farther from the pistons and the con rods are much longer. This allows the cylinders to extend into the case for oil control. There's nothing like having the right design in the first place, though I'm still tempted to fool with some sort of conversion someday, knowing full well that I would probably spend 500 hours on it for every flying hour I get out of it and the cost would be larger than if I just went out and bought a new Lycoming. The experience I had with a Subaru and redrive taught me that the old guys were right on every count. "If you want to fly, buy."

Dan
 
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Autodidact

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The V-12 I remember reading about was an engine very closely related to the Merlin, adapted many years ago for larger boats, and apparently had considerable commonality among the parts. Would be interesting to know if my memory is right or if senility is setting in.
I think you may be refering to the Meteor. Designed by Rolls-Royce based on the Merlin for tanks and then built by Rover in large numbers. Used in the Centurian tank among others. It is available, has been used in tractor pulls and I believe I've seen them in reproductions of those old mahogany speed boats from the thirties. Basically a Merlin with no supercharger or PSRU, 550 - 600 hp or so.
Another interesting tank engine is the all alloy 60°, flat plane crank, 1100 ci, DOHC v8 made by ford during WWII for the Sherman tank. This was a modification of a 60° v12 Ford was developing to compete with the Merlin that wasn't used because the Merlin was already there as well as being excellent. Apparently, this engine can also be found (single plug heads, but with a dual distributor ignition):speechles:
 

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Autodidact

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Here's another engine possibility. All alloy BPM V-12 marine engine, 730 ci 60° V-12, 630 hp @ around 4500 rpm. Take the transmission, water cooled exhaust manifolds, multi carb intake (fuel injection stacks?), and other equipment off and it might be light enough:
 

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flywulf

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There is a Spitfire prototype replica in England that used a Jaguar V12.
Had a landing accident and to my knowledge never flew again.
Have a look, not a very serious crash but I imagine it was none the less expensive to fix.

[video=youtube;gWSvKT6h3ro]http://www.youtube.com/watch?v=gWSvKT6h3ro[/video]

Also Here is a picture of the Astec V12 being developed in the Phoenix area. It has not flown, to the best of my knowledge. I believe it is based on the Jaguar engine.


cheers,

Ed
 

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Autodidact

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Also Here is a picture of the Astec V12 being developed in the Phoenix area. It has not flown, to the best of my knowledge. I believe it is based on the Jaguar engine.
That is definitely based on the Jaguar engine. But if you look closely at it, you can see that the starter is still mounted in its original mounting boss on the transmission mounting flange, which is now the accessory drive end of the engine. The cylinder heads have been flipped around backwards and the supercharger/accessory drive is mounted to the trans mount flange! If you look closely at the accessory drive just under the distributors (mags?), you can see holes for the shaft drives that will now drive the camshafts instead of the chain that used to be on the other end of the engine! This is not "mildly" modified, but very similar to George Morss' modification of the Buick/Rover and LS-1 v8s.

I don't know if they have flipped the crankshaft as well, but this mod makes the Jag almost identical in configuration to the Merlins and Allisons of the WWII era. Amazing!
 

litespeed

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How about using the BMW V12- light alloy, very reliable, cheap to get and great low rev power?
 

autoreply

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How about using the BMW V12- light alloy, very reliable, cheap to get and great low rev power?
Are you referring to the N73/74 ?

750 NM between 1500-5000 rpm doesn't sounds bad, that's 270 hp @ 2500 rpm and about 330 @ 3000 rpm. Any idea about the weight of the engine less transmission? The "half" version looks to weight around 250 kg, so that would put this one around 500 kg (1100lbs), probably including transmission.
 

litespeed

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No I was actually thinking the earlier 5.4L V12 motor which is much more compact and only a little heavier than the old 3.8l cast block 6.

But that one is nice as well.
 
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