[updated:LAST EDITED ON 15-01-03 AT 01:23 AM (GMT)]Early radial engines had one row of 7-9 cylinders. WWII radial engined fighters usually had 16 or 14 cylinders arranged in two rows. The most sophisticated radial engine was probably the Pratt&Whitney R-4360, which had 28 cylinders in four rows generating an awesome 3,500 horses. Was there any THREE row radials?
By: Christer - 17th January 2003 at 00:49
RE: What about multi-row radial engines?
Hi Keith!
This is an engine layout that I´ve never seen before. Very interesting and my sorry excuse for a brain hurts when I try to figure out how it works.
I think we can forget about the conventional radial thinking, e.g. the ignition sequence of a radial requires the number of cylinders in each row to be uneven.
The X-layout Rolls-Royce Vulture was not considered to be a radial engine but a multi bank engine, four banks of six cylinders with 90° between the banks. The 90° between the banks and the number of cylinders in each bank was what gave good mass balance without dynamic balancing and a reasonable firing order.
Is it possible that we are looking at an engine that really is four 90°V or maybe four horisontally opposed, four cylinder engines, fitted to the same crankcase?
How was it developed from the Octagon?
Maybe I ought to try to understand that one first ……
Christer
By: keithmac - 16th January 2003 at 21:05
RE: What about multi-row radial engines?
I’ve just found this – It’s Hawker Harrier J8325 with the Hydra installed at Filton in 1933!
KeithMac
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By: keithmac - 16th January 2003 at 20:45
RE: What about multi-row radial engines?
Hi Christer, The Hydra is one of those engines which defies convention. I’ve not got too much info on it, but it appears to have 8 “double” cylinders, that is 8 outer casings with a double sleeve inside each! Even more unusual is that it is a row of 8 Cylinders, as far as I know, totally unique!! Anyway there’s a picture below. You’ll be as confused as I am. By the way, it’s not a faked or doctored picture, the engine is on display in the “Power for Flight” display at Bristol Docks on the same Quay as the SS “Great Britain”
KeithMac
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By: Christer - 16th January 2003 at 11:14
RE: What about multi-row radial engines?
Hi Keith!
I´ve tried to find more information on the web about the Octagon and the Hydra but I couldn´t find anything.
Do You have more information on layout and such, possibly even pictures?
As I understand it, the Octagon was a single row 8 cylinder engine and the Hydra was a double row 16 cylinder engine.
The designs can´t have been radial-ish, at least not in terms of ignition sequence.
Please, help me to regain my sleep, if not at night so at least at work!
Christer :'(
By: keithmac - 15th January 2003 at 18:25
RE: What about multi-row radial engines?
[updated:LAST EDITED ON 15-01-03 AT 06:29 PM (GMT)]Hi Multirole, There were 18 and 14 cylinder 2 row radials, you can’t really have a 16 because that would mean an even number of cylinders on a single row and that don’t work too well. You can have a single row or 2 rows or multiples of 2 rows, but not a 3 row without horrendous difficulties in balancing the crankshaft. The Bristol engine company tried to produce a “double Octagon” (16 cylinder) engine called the “Hydra” back in the 1933, it produced 870 HP, it was test flown in the Hawker Harrier (the original version), but they never put it into production. So it’s not impossible to have a 16, or a 3 row, but it’s never been a road that was successful. If you look back at some of my earlier posts on radial engines you’ll pick up some more info.
KeithMac
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January 15, 2003 at 1:18 am