Forum

[Tim NZ]

140 mph 500 Enfield.
90mm bore, 78mm stroke, 8500 rpm, 6 speed gbox...
http://www.bikesportnews.com/news/news- ... ield-dream

Tim
N.Z.

[PeteF]

Probably not in standard trim

[ric]

and needs super unleaded to do it

[Mark M]

I have met Steve Linsdell on several occasions, one of which was a guided tour of his bike collection including a previous incarnation of this racer, his Model K v-twin and his 800cc Series 3 Interceptor prototype among others. A very nice guy indeed, very quiet and modest and an amazing engineer and tuner.

REgards, Mark

[Rattlebattle]

An amazing achievement from a pushrods single, though probably no more RE internally than a Sometfield is a Manx Norton.

[Felix]

Would love to defrock that bike and leer at its nakedness! There must be a lifetime's creativity under wraps.

[Alan R]

Hi Guys----- and thanks TIM NZ for posting this..I'm imagining I'm in those pits and having a "Sneak-peek" at the bike...Here's some random thoughts}--- "I wonder what the all-up weight is ??---From that I could roughly calculate the BHP at the wheel needed for 140mph....Bore/stroke = 90 x 78..... Forged Slipper piston, forged H-Section steel con rod--- roller or needle bearings throughout....Lightweight internals so mass inertia is reduced as is piston linear speed compared to a "Long" stroke but at a price}--- ie Poor chamber filling so is he using 2 small diameter inlet valves activated by big overlap polydyne type cams ??...That 42mm carb tells me that fuelling at top RPM has been a problem.....I imagine the useable power-band is narrow ( Hence the 6-speed box ) but looking at that exhaust can I bet he's using some form of reverse-pulse scavenging to draw extra fuel/air mix into the chamber...A look at the final drive sprocket ratio would help .........I can't see under that fairing but I'd expect a digital electronic ignition system firing 2 or even 3 plugs ( 1 for cold start then 2 for running ) ... only 1 disc up front ? ".............. As I say, just some random thoughts....

[Adrian]

Alan,



something tells me he's not using some weird three valve head, read the article again. This from the man himself.



"The cylinder head, timing case, crankcases, gearbox casing - it’s all original old stuff.”



The 41mm Dell'Orto carb is also used (in pairs) by the CRMC BMW sidecar outfits, my friend Tim's 998cc oufit being one of many.



A.

[PeteF]

It did occur to me Allan, one disk at the front and a drum at the back?
Enough on the track I suppose but.....