Engine tuning

[rustynuts]

Hello all. I've had my IP2 for about a year now. My workshop dreams are running wild (although they will probably stay just as dreams!). I've been pondering separating the cooling from the induction system to liberate a modest power increase and have a couple of questions that some of you rotary gurus may be able to answer:When using an extractor exhaust, the lubricating oil does its business on the bearings and rotor sides and then is burnt in the exhaust. Is any additional oil then requierd in the fuel to lubricate the rotor tips or can they happily function without it?Crighton uses an elecric fan to ventilate the innards of his new machine. Wouldn't this spray a nice oil mist over anyone behind him or does he use a device to separate out the oil mist before it is expelled?Has anyone tried fuel injecting their bike. Looks like it would be fairly easy and cheap to do using a Microsquirt controller and pump and injectors e.t.c. sourced from ebay or a breakers. Does anyone know a friendly doctor who can sign me off work for a few weeks while I build it?

[Richard Negus]

Hi 'rustynuts',

When using an extractor exhaust, the lubricating oil does its business on the bearings and rotor sides and then is burnt in the exhaust. Is any additional oil then requierd in the fuel to lubricate the rotor tips or can they happily function without it?As you note, additional oil is required in the fuel to lubricate the tip seals - or you could get a four outlet oil pump and direct the two minor feeds into the inductionsCrighton uses an elecric fan to ventilate the innards of his new machine. Wouldn't this spray a nice oil mist over anyone behind him or does he use a device to separate out the oil mist before it is expelled?This may be the reason the current spec racer has an under-seat exhaust with what appears might be an silenced ejector. The early air-cooled racers were criticized by following riders for the oil mist.Mid West Engines had an oil separator on their fan-cooled twin-rotor aero engines but, with a recovery of around 30%, the fuselage had an oil slick along it after every flight. They developed a cyclone oil separator on the test bed but even then it was only slightly more efficient and was too big to fit under the engine cowlings.Those twin engines, fitted with a simple injection system, produced 110bhp at an electronically-limited 7,500rpm. Silencing wasn't really a problem as the propeller made as much noise as the engine.Has anyone tried fuel injecting their bike. Looks like it would be fairly easy and cheap to do using a Microsquirt controller and pump and injectors e.t.c. sourced from ebay or a breakers. The challenge isn't the injection hardware, but arriving at optimum fuelling for acceptable driveability. Give it a try !

The down-side of extracting more power from the engine is the probability of reducing gear box life ; the gears/ shafts were originally designed for the Triumph T140V (46bhp?) and weren't capable of handing 130bhp even with better materials and heat treatments. The later RCW588 racers had a completely different gearbox with bigger gears and wider shaft centres to cope with their alleged 140bhp.R.

[dave perry]

Hi Rustynuts, the other way to get more speed is to lose weight and make better use of the power the engine has to offer. My take on this is to (so do the opposite) is to try one of Geoff's lightweight exhausts. I am not sure how many more BHP are liberated, probably not too many. What is for sure is a lot less weight and more ground clearance. This would get me round Cadwell in grand style, Yee Haa - life in the old dog yet !(GM, I have a very busy couple of weeks coming up - will be in touch end of month)

[rustynuts]

Thanks for the replies chaps. I had always thought the gearbox felt like the weak link in the bike. I sometimes get a false neutral or have trouble finding the real one. It would be nice to have that sweet AMC gearbox feel rather than the notchy uncertain feel that exists. Looks like I will have to add producing a casting to take a modern gear cluster to my list of workshop fantasies. How much of an improvement does the NML improved gear cluster make?I had noticed how heavy the silencers are, so maybe replacemet is the way to go if I can get something to withstand the heat and keep to a reasonable noise level.