Stuart Engine

[Lynn Eades]

Maybe the reason is in the design, in that each power stroke happens one cyl after the next, and so is more of a continuious "Push" on the big end? (does this line of thought make any sense?) (I have never seen the internals of one) Weight saving would have been one of the main reasons that moved aero engine designers to a radial.

[cantankrs]

Originally Posted by Lynn Eades

Maybe the reason is in the design, in that each power stroke happens one cyl after the next, and so is more of a continuious "Push" on the big end? (does this line of thought make any sense?) (I have never seen the internals of one) Weight saving would have been one of the main reasons that moved aero engine designers to a radial.

Hi Lynn,
Maybe - good thought - although the firing order on all radials AFAIK is odd numbered cylinders from 1 and then even numbers - 1, 3, 5 7, 2, 4, 6, 1,...
The rotary aero engine and conventional crank inline engines preceded the radial. It was the rotary that offerred the weight saving through air cooling, but large horsepower rotary's (c. 200HP) were a heavy revolving mass that dangerously affected the pilots ability to control their machine. I think that's what inspired design thought toward the radial's reversed concept of fixed engine with revolving crank.

It's been commonly written that the Sopwith Camel having the pilot, fueltank and rotary engine grouped close together was a deadly design for novice pilots, but had certain turning advantages in the hands of practiced pilots due to the gyroscopic effect of the engine.
I read an article years ago by Gene DeMarco about a Sopwith Camel replica (possibly Cole Palen's) where I think he wrote that at that time he'd never flown a loop in it because by about 3/4 the way through he was flying at right angles to the direction from which he first entered the loop. It's amazing what Gene and his crew at TVAL in New Zealand are doing for Great War aircraft. And I gather that it was amazing what Cole could do too.

Regards

Alex

[Lynn Eades]

I Knew in my gut that I was putting my foot in my mouth with that post.
You know that thing about the guy who shuts up as listens to all the fools.
Why dont I learn from him?
Your obviously quite knowledgeable about these things. I have no clue as to who Gene is, or Marco, or what TVAL is.
Are these guys tied up with Peter Jackson by any chance? Would you fill in the gaps,for me please?
Having thought about the firing order, they still fire in a circular fashion, just that its on every 2nd cylinder, as the one between the bangs is coming to the top of the exhaust/start of induction. (assuming the cylinders are numbered in a circular fashion, and there is only one bigend journal, shared by the seven conrods)

[cantankrs]

No foul Lynn.

Originally Posted by Lynn Eades

Are these guys tied up with Peter Jackson by any chance? Would you fill in the gaps,for me please?

Gene DeMarco seems to have formed The Vintage Aviator Limited (TVAL) and it is I think (not having been there) not far from the Movie Director, Peter Jackson's, aviation museum. I think Gene used to fly some of Cole Palen's WW1 airplane collection at 'Old Rhinebeck' in New York state. See http://www.oldrhinebeck.org/ or Google it. Cole's life story is entertaining, just as he was.
TVAL seem to be at the pinnacle of quality and authenticity in WW1 aircraft restoration and reproduction.

Originally Posted by Lynn Eades

Having thought about the firing order, they still fire in a circular fashion, just that its on every 2nd cylinder, as the one between the bangs is coming to the top of the exhaust/start of induction. (assuming the cylinders are numbered in a circular fashion, and there is only one bigend journal, shared by the seven conrods)

No1 cylinder, top one, has the Master Rod. The remaining cylinders have knuckle rods on pivot or wrist pins arranged around the remaining web of the Master rod big end, adjacent to the crank journal. So there's a bit of oscillation in the paths of the knuckle rods as the crank rotates. I think the Curtiss Conquerer V12 had a Master Rod for each cylinder down one bank, and a knuckle rod for each cylinder down the other bank, on each crank journal. Most V motors use either two, half and half, or in some designs tongue and fork, combining of conrod bigends on the same crank journal.

The original Rotary engine had the crankcase and pots rotating about a fixed crankshaft. So the crank was bolted to the (wooden!?) firewall or longerons, and the rear crankshaft was hollow and was the induction path for the fuel and air. No sump or dry sump meant no traditional oil capacity for lubrication so castor oil was mixed with the fuel and was a total loss lubrication system. The scarfs some of the brave dashing young men wore were said to be for wiping the oil off their goggles as well as allowing them to turn their necks in their uniform collars. Not sure which - heavy drinking (understandable) or castor oil ingestion or air sickness resulted in the most stomach contents emptied over friend and foe and maybe cows alike.

I'll try and post a pic of a master rod.

Regards

Alex

[Bob Moseley (RIP)]

Hi Tim - check your PMs.

Bob