Sunday, November 28, 2004
Hold that Tiger (part 2)
The engine of choice back in the 60s was known as an Oliver "Tiger". It was a 2.5cc, two stroke, diesel motor that was designed by the legendary John Oliver (JO) who lived (and still does) in Dorset, England. The Tiger was an absolutely brilliant design. Very powerful and rugged with a timeless appearance somehow reminiscent of other British classics such as an XK series Jaguar or a Supermarine Spitfire. The Mk 3 version of this motor was the best and it was the mill of choice for combat flying and team race. They are now quite rare (many had a very hard life) and sell for outrageous prices on eBay.
Back in the summer I was offered a Mk 3 Tiger for a mere $80. I bought it sight unseen and without hesitation. The motor I eventually picked up was in very sad condition. Not only was it quite clapped out and missing the correct needle valve assembly but the fins had been squared off (a team race practice, I think) and at some point it had suffered a very hard air-to-air collision with another engine: the crakncase thread was clearly and deeply imprinted on the cylinder head. I pondered for awhile as to how to restore the Tiger to its former glory and came to the conclusion that this would be better done in the land of its birth. So I emailed Clive Sharp and asked him for advice. To my utter amazement, after discussing various engine tuners, Clive offered to ask John Oliver in person if he would do the refurbishment. I wasn't aware that the great JO was still around in earthly form let alone fiddling with stinky diesel engines. Well it turns out that John, who is now in his 80s, is not only alive and well but is still as meticulous as ever and accomplishing feats of engineering genius.
I duly sent my rather sad lump of metal off to the UK (rather insensitively in a box which had once contained a modern Chinese/Australian Oliver copy known as a CS). That was back in August. Then yesterday, out of the blue, I had a message from Clive to say that the motor was finished and he enclosed the picture posted here. Not only has JO rebored it but he has fitted a lighter piston, bushed the conrod, fitted a new cylinder head, needle valve assembly and prop nut (which is anodised black). The prop driver is still the original and a bit battered and the crankcase has an epoxy repair on it. But this patination lends some character. The motor had already been tuned and with JO's touches, I'm convinced it will go like stink when it's run in. When I get it back I'll put in a Dominator and use it for fun flying: it's too valuable to expose to the rigors of open diesel combat. Overall I feel very proud to own one of these classic diesels and indeed honoured that the great JO himself has personally refurbished and tuned it for me. Thank you, John.