No cowlings

[a-teamlambretta]

Anyone running a tuned motor say TS1 or RB with a mammoth or MB head but not using any cowls or a fan for that matter?

Cheers Simon

[dickie]

I've often thought about that because there are so many bikes like that. But...

They have totally open frames. Vertical cylinders. And they tend to by models that are in a low state of tune.

I think you'd need a scoop to direct air from below over the fins.

[Warkton Tornado No.1]

Race bikes get away with scoop cooling because they - obviously - travel fast, though another major factor is the use of Avgas which runs cooler than petrol. Although a tad more expensive, with a shelf life of around four years, it’s worth considering the investment as petrol will be lucky to survive three months.

Racing Lambrettas will also have an adequately sized exhaust bleed which contributes to avoiding overheating.

[lozmondo]

a mate has a TS1 with an MB head in a series 2 and its done over 6000 miles with no issues

[Vega125s]

Hello
I have been running an Avanti 225 with an old MB head ,no cowlings and fins on the flywheel for about 6 years and no overheating issues.How ever I do have open body work , no panels etc.
On the way to the Belgium euro a mates rb230’s flywheel broke up , the only spare we had was a finless flywheel, took all the cowlings off and there wasn’t really any overheating issues for the rest of the trip there and back , full panel GP (well except the fuel tank splitting ! but that’s another story !)

[a-teamlambretta]

Thanks for the replies and knowledge...no cowls or fan it is ...motor is going to be an RB225 home tune ...

Cheers Simon.

[Warkton Tornado No.1]

My perception is that an alloy cylinder without a fan cooling it is fine for an engine built for the purpose of producing maximum power for short bursts. We must surely all be aware that sprinters tend to dispense with the fan, though one of the most successful utilises the inherent cooling of methanol.

If the fact that an alloy cylinder is unlikely to seize - as might not be the case with iron - you need to consider why that is.

What occurs when the alloy cylinder gets too hot, is that it expands resulting in excess clearance to the piston & a drop in power. Long term, such a scenario will result in piston slap & ultimately breakage.

So, although some may claim many trouble free miles without fan cooling, the fact that no seizures came about is not the only factor to take into consideration…..