Inverted V engine vs. V engine

stona · Jun 25, 2011

B-17engineer said:
But if the Germans were such good engineers why did they stick with it?

Just curious, if from an engineering standpoint its 'the wrong way' what are the disadvantages?

They stuck with it because it worked which makes the second question a moot point. There is no right and wrong way. Just because the earliest engines were built piston up doesn't make it the correct way. If engineers thought like that your car would still have an engine something like Otto's original in it!
To say the piston engine was not designed to run upside down is,politely,a daft statement. All the inverted engines mentioned already were obviously designed to run that way up.
Steve

Kryten · Jun 25, 2011

davebender said:
Radial aircraft engines would have a similiar problem for half the pistons.

well obviously, but this does not address how it is achieved, which it obviously was, which is what I asked!

DonL · Jun 25, 2011

well obviously, but this does not address how it is achieved, which it obviously was, which is what I asked!

It was achieved with a dry sump lubrication and 3 Oilpumps.
2 pumps draw out the oil of the crankcase and one was pumping in.

Edit:

An other very popular inverted vee V12 aero engine was the Liberty 12-A, also named as Packard V-1650.
This statement is no crap, the Liberty 12-A inverted vee was the first aero engine that was produced by Packard till 1926 and named Packard V-1650.

Kryten · Jun 25, 2011

Hi Don,
I am aware how the dry sump works, I have one on my race car, what I am curious is to how you prevent oil from collecting in the piston skirts?, the oil fed to the crank drillings will evacuate out past the bearings and have only one way to go, down, on shutdown the engine will drain the oil on the rods, crank piston walls etc down into the cylinders, unless of course there is a system to divert this?
otherwise how do you prevent oil collecting in the piston and getting past the rings on start up?

Shortround6 · Jun 25, 2011

When the engine is running it is not much of a problem. Even at idle the piston speed should be enough to throw the oil back into the crankcase. Even shutting down the engine shouldn't be that much of a problem, with the oil pups stopped the only oil left is what is cling to the walls and other surfaces. The bigger problem is when the oil seeps past the piston rings and collects in a cylinder with closed valves on the compression stroke. If the engine is started without turning it through a few times you can wind up with hydraulic lock and break things. But since this was known, proper staring procedures prevented almost all major problems.

Mustang nut · Jun 25, 2011

Kryten said:
Hi Don,
I am aware how the dry sump works, I have one on my race car, what I am curious is to how you prevent oil from collecting in the piston skirts?, the oil fed to the crank drillings will evacuate out past the bearings and have only one way to go, down, on shutdown the engine will drain the oil on the rods, crank piston walls etc down into the cylinders, unless of course there is a system to divert this?
otherwise how do you prevent oil collecting in the piston and getting past the rings on start up?

Kryten I dont think you do. When the engine is running the piston itself will throw the oil out from the skirt. When the engine is still some may get past the rings. Radial engines smoke like a magic dragon on start up I presume this is oil getting past the rings on the lower cylinders. In any case I think these engines burnt oil as a matter of course, certainly the Merlin used a lot even from new.

Shortround6 · Jun 25, 2011

Kryten said:
Hi Don,
I am aware how the dry sump works, I have one on my race car, what I am curious is to how you prevent oil from collecting in the piston skirts?, the oil fed to the crank drillings will evacuate out past the bearings and have only one way to go, down, on shutdown the engine will drain the oil on the rods, crank piston walls etc down into the cylinders, unless of course there is a system to divert this?
otherwise how do you prevent oil collecting in the piston and getting past the rings on start up?

I believe there would be, for want of a better word, shelves at the side of the crankcase near the cylinder openings that would either route most of the oil to a pick up point or to drains that would lead to the camshaft/rocker arm area in the heads (now at the bottom of the engine) to be picked up there.

tyrodtom · Jun 25, 2011

Inverted aircraft engines was not a rarity in the 30's, it was more of the norm. Most of the civilian light aircraft engines were inverted, the Ranger line of engines 6 and v-12 were inverted, Manasco, Argus, Hirth, De Havilland , and more, all made inverted engines, for the civilian and military market.

Kryten · Jun 25, 2011

Mustang nut said:
Kryten I dont think you do. When the engine is running the piston itself will throw the oil out from the skirt. When the engine is still some may get past the rings. Radial engines smoke like a magic dragon on start up I presume this is oil getting past the rings on the lower cylinders. In any case I think these engines burnt oil as a matter of course, certainly the Merlin used a lot even from new.

No I assure you I am fully conversant with dry sumps, its as I mentioned on shutdown I see the problem, the internal volume of the crank case on an engine that large would contain a considerable amount of oil on its components, this would require some method of channeling otherwise you could end up with a piston bore full of oil next time you start up, I cant see engineers of that caliber not integrating drillings or as mentioned above a "shelf" or duct to prevent that problem!
whilst all engines use oil the last thing you want is oil fouled plugs when trying to start up!

Shortround6 · Jun 25, 2011

That is one reason aircraft engines are "pulled through" for several revolutions before actually switching on the ignition or engaging the starter. To check for excessive oil or other problems.

Mustang nut · Jun 25, 2011

Kryten said:
No I assure you I am fully conversant with dry sumps, its as I mentioned on shutdown I see the problem, the internal volume of the crank case on an engine that large would contain a considerable amount of oil on its components, this would require some method of channeling otherwise you could end up with a piston bore full of oil next time you start up, I cant see engineers of that caliber not integrating drillings or as mentioned above a "shelf" or duct to prevent that problem!
whilst all engines use oil the last thing you want is oil fouled plugs when trying to start up!

Many of the pistons I have seen have holes drilled in the recesses for the oil scraper ring. The germans wernt mugs and so they must have designed some labyrinth to solve the problem. It is a similar problem to lubricating valves cams and rockers only in reverse. Engine oil doesnt flow past a ring at any great speed, neither does petrol. I know this because a friends motorcycle had a faulty fuel ****, overnight petrol seeped through the carbs into one of the cylinders when he hit the starter he bent a connecting rod

Readie · Jun 25, 2011

DonL said:
LOL!

And an boxer is not designed to run on the west and the east/ or on the left and right side?
To my opinion this statement is absurd, because a Jumo 213 could manage 3250 rpm as normal piston speed. I don't see any oil control problems!
Or could you tell me why on earth a late DB 605 could manage 1.8 ata and the Jumo 213 E was equal/could match with any RR Merlin or Griffon ever produce in the same timeline?

Very easy germany lost the war!
Or do you know any other invert piston engine state of the art?

Edit:

The only advantage was in the availability of special alloys and high performance fuel (150 octane), but nothing else!
There was no technology advantage of the Allies piston engines by comparison to german invert inline engines!

I'm not talking about a Boxer engine, I'm referring to the unnecessary complications of inverting a V12 aeroengine.
The Griffon had a very long life , retiring in 1991 so, that in my book makes it superior to your Jumo.
The RR Merlin is widely acknowledged as one , if not the most, successful aeroengine ever made.
It was the 'right' way up.
Does that not tell you something?

Regarding you edit comment.
LOL...you are having a turkish !

Cheers
John

Marcel · Jun 25, 2011

Readie said:
The Griffon had a very long life , retiring in 1991 so, that in my book makes it superior to your Jumo.

Wrong argument. Germany lost, their factories bombed to pieces, how do you know what the Jumo would have been if this had not been the case?

Readie said:
The RR Merlin is widely acknowledged as one , if not the most, successful aeroengine ever made.
It was the 'right' way up.
Does that not tell you something?

Again a bad way of argumenting. The DB series and the Jumo series engines were also used in a wide variety of aircraft and was even used in the most numerous build fighter of the war. So where was the RR more succesfull?

You might be right or you might be wrong, don't know about that. I'm not an engineer. But your reasoning is false. You'll have to do better than that if you want to convince someone. At this moment it just looks like biased posts to me.

fastmongrel · Jun 25, 2011

Can I just say that Readie makes me laugh. Probably you have to be British to appreciate it but he is a top class internet fisherman he baits his hook casts it into the waters and reels you all in.

Readie · Jun 25, 2011

Marcel said:
Wrong argument. Germany lost, their factories bombed to pieces, how do you know what the Jumo would have been if this had not been the case?

Again a bad way of argumenting. The DB series and the Jumo series engines were also used in a wide variety of aircraft and was even used in the most numerous build fighter of the war. So where was the RR more succesfull?

You might be right or you might be wrong, don't know about that. I'm not an engineer. But your reasoning is false. You'll have to do better than that if you want to convince someone. At this moment it just looks like biased posts to me.

We are all biased Marcel.Its human nature.
The Merlin's superiority is well documented. Please read the other threads that fully explore this.
What has Germany losing the war and being bombed got to do it inversion?
My reasoning is logical, why invert a petrol engine and incur more engineering problems for no obvious gain? I have never said that DB engines were intrinsically bad, weak or anything else.
Cheers
John

Readie · Jun 25, 2011

fastmongrel said:
Can I just say that Readie makes me laugh. Probably you have to be British to appreciate it but he is a top class internet fisherman he baits his hook casts it into the waters and reels you all in.

very good FM. I have been called all sorts of things in my life but, never an 'internet fisherman'...

Yes, it is an English oops, sorry British sense of humour.

Cheers
John

fastmongrel · Jun 25, 2011

Readie said:
very good FM. I have been called all sorts of things in my life but, never an 'internet fisherman'...

Yes, it is an English oops, sorry British sense of humour.

Cheers
John

Defintely British see my flags Though when it comes to 6 nations Rugby I do have conflicts being born in England of Welsh parents. Generally support the team that wins as long as its the French who are being beaten.

Readie · Jun 25, 2011

fastmongrel said:
Defintely British see my flags Though when it comes to 6 nations Rugby I do have conflicts being born in England of Welsh parents. Generally support the team that wins as long as its the French who are being beaten.

Pure English and very patriotic. The football and rugby are great competitions and I love cheering England on. If, however we are knocked out and the last British team is Welsh then I'll cheer you on as well.
I cant wait for the rugby world cup. Its a pity that NZ is so far away...
I couldn't possibly comment on la belle France in rugby or Deutschland in football other than to say that those are the sweetest victories...
lloniannau
John

Marcel · Jun 25, 2011

Readie said:
We are all biased Marcel.Its human nature.
The Merlin's superiority is well documented. Please read the other threads that fully explore this.
What has Germany losing the war and being bombed got to do it inversion?
My reasoning is logical, why invert a petrol engine and incur more engineering problems for no obvious gain? I have never said that DB engines were intrinsically bad, weak or anything else.
Cheers
John

You're technical reasoning might be logical, I cannot argue about that as I'm obviously no expert in engines. If you read my post well, you could better understand what I'm aiming at with my 'Germany lost the war'. I'll give you the quotes once more:

Readie said:
The Griffon had a very long life , retiring in 1991 so, that in my book makes it superior to your Jumo.

Readie said:
The RR Merlin is widely acknowledged as one , if not the most, successful aeroengine ever made.

Read my post again and maybe you might understand what I meant. These reasoning I quote here are not very convincing. And please try to enlighten my what you mean by 'most succesful'?
And sorry if my dutch nationality prevents me from seeing the humor that should be there.

Shortround6 · Jun 25, 2011

I will note that tooling for the Jumo 213 existed in France after WW II and a French company called Arsenal tried to market both a "standard" inverted V-12 and a H type 4 cylinder block 24 cylinder of about 4000hp. Arsenal was later merged into S.F.E.C.M.A.S and the Inverted V-12 was still on offer as late as 1953, perhaps longer. It was used in 21-23 French Flying boats, the Nord 1402.

http://www.frenchwings.net/navy/gallery/albums/userpics/10002/normal_Nord_1402_Noroit041VIDAL.jpg

I have no idea how successful it was. Wiki says last plane delivered 1956.

I don't know if it was used in anything else.

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