Quote:
Originally Posted by John in Santa Cruz
the earlier spitfires were quite a bit lighter, I think it was the final Mk IV version that tipped the scales at 1800 lbs.
|
True, that was a 1976 and up (1500, the version after Mark IV) spec. I found a 1971 Mark IV spec: 1750 pounds. For a Mark III I only found a dry weight: 1568 pounds. It's possible that there was some Spitfire in ancient times that was under 1600 pounds wet.
Even the largest Spit engine only weighs 100 kg (220 pounds) complete internally but without manifolds - having carried around the housings, rotors, and mainshaft of a 13B (individually), I wouldn't expect it to be much lighter, and various online sources report 70 kg similarly without manifolds. Since the exhaust manifold, cooling system, and external oil cooler of rotary are all heavier than stock Spitfire parts, my guess is that the rotary conversion saves no weight at all. Then a typical swap upgrades (to stronger but heavier components) the transmission, final drive, suspension, and brakes.
Quote:
Originally Posted by John in Santa Cruz
... that Mazda engine wasn't even a foot long from the bell housing, it barely stuck out past the firewall of the TriAzda.
|
But photos of multiple Spitfire swaps show the engine reaching to close to the front crossmember, and the rotaries I worked on were not that short, either. There's a rear end housing, two rotor housings, the intermediate housing, a front end housing, and a substantial front cover. The length depends on the rotor width (and so the 10A with 60 mm rotors is shortest and the 13B that almost everyone uses in swaps with its 80 mm rotors is the longest), from 15" to 16.75" from bellhousing face to the front pulley (ignoring the fan, which sticks out further). That's about the same as the stock Spitfire engine.
As usual, the reality is not quite as impressive as the initial impression.