Detuned?

[mhsilverw]

A question I wondered and not really found the answer either on the web (i.e. places like this site or the dutch site) is how the Sport and maybe Strada?) were in terms of tune. The Brooklands test book of Morinis doesnt really make it clear here, nor does Mick Walkers book; and the Dutch site has some pics of the 'changes' or 'evolution' of the Sport (visually) but is less 'clear' in-terms of specifications.

The Sport in some road tests seems to sometimes be 42bhp and then sometimes 39bhp and the Dart around 35bhp from memory.

Did the power change (or tests get more accurate)?

I know it was said originally that the early Sports had a different cam and higher compression pistons; but assume as some publications and interviews suggst parts could be interchangeable at the factory back in the day and some bikes were fitted with what was to hand.

Did the Sport change from it's drum braked original as it went disc braked (wire wheel) to cast wheels to 'K' then 'K1' then 'K2' and Dart?

Assume the change in brakes from drum to disc (sometimes 2 then 3!), wire to cast wheel, adoption of kinked frame (what difference does this really make?) and then the adoption of stuff like the 'leccy start and non-electric tacho (from K models?), K2 seems quite different but assume these 'componant chnages' changed the weight too - although tests dont seem to show that clearly, even if engine internals were unchanged, so assume a fluctuating power to weight.

Maybe the the Dart with it's 125 origins in terms of cycle parts and frame maybe should be compared as it's so 'different' really.

Anyone clarify or flesh out how the bike changed, albeit these days maybe overtime a 'std' bike maybe more rare, as parts get/got replaced overtime.

Regards

M

[mantaray]

engines on early drumbrake and early discbrake are the same (i own both in original condition)

Later on they changed the right bearing, some people say they lost a few hp. (more friction)

[72degrees]

My 79 Sport was very different to my 75 Strada. Definitely a 'Sport' cam in that and it had to be revved through the gears in proper Morini fashion to make progress. The Strada had surprising torque at low revs. Some suggest that the early cast alloy intake stubs were a factor. The 87 K2 I had was frankly very disappointing. It seemed to be a cross between a Strada and a Sport so far as the cam was concerned. Except the anticipated Sport kick when it came on the cam never materialised. Does the Dart essentially use the K2 cam whatever that was? Paging Evguru to the cam hotline!

My current motor has been through phases as 350 Strada cam and pistons, Strada cam and Sport pistons, Strada cam and 375 pistons, 2+2 cam and 375 pistons and currently is 375 with L5 cam. Oh and 28mm carbs went on at the same time it went 375. I like it this way

[mantaray]

Does the Dart essentially use the K2 cam whatever that was?

In my Darts i have the M cams

[MarkB]

Hmm, interesting comparison with 72degrees: I have a 1975 drum-braked Strada and a '76 wire-wheel disc braked Sport. The Sport has a great deal more stomp and torque right through the rev range and a top speed nearly 10mph faster than the Strada (measured via GPS, not a Vague-liar speedometer). At Cadwell on the Strada, the engine's performance seemed very closely matched to a cast-wheel Strada in all respects.

I wouldn't complain about either of them though!

Regards, Mark.

[EVguru]

The Sport in some road tests seems to sometimes be 42bhp and then sometimes 39bhp

42bhp = SAE (Society of Automotive Engineers)
39bhp = DIN (Deutsches Institut für Normung)

The original factory dyno graphs show that the Sport produced more torque all the way through the rev range and that's certainly my general experience.

[dunk 1]

Hello- What differences do the L5 and 2 plus 2 cams make to the standard sport - are they a benefit for general road use as well as racing - thanks - Duncan