LCGB Forums

For more on the story, read this http://www.scooterlab.uk/reviving-lambretta-siluro-record-breaker-video/

Would like to Sticky but not been able to log on to SLUK all day - is there a problem with your server?

I'd love to see that run in the flesh. Well done to the Rimini lads to get it going again.

The megaphone exhaust is interesting, I think. The Vespa race scoots have them as well. They were the performance exhaust of the time.

Then someone decided to quieten the exhaust down by adding a smaller pipe on the end of the megaphone, effectively adding a second cone and accidentally inventing the expansion exhaust.

Imagine the conversation: "Yeah, it's quieter, but it goes like the bloody clappers".

I wonder if an expansion on this would have made a significant difference?

I'm not having a problem with the SLUK site, by the way.

Ranburetta wrote:Would like to Sticky but not been able to log on to SLUK all day - is there a problem with your server?

We have swapped servers recently. Is it working for you now Ranburetta?

Sticky wrote:

Ranburetta wrote:Would like to Sticky but not been able to log on to SLUK all day - is there a problem with your server?

We have swapped servers recently. Is it working for you now Ranburetta?

Yes thanks, was able to log in the following day.

Bit like owning an Alfa,

Enter the tunnel, wind down the window (actually I find opening the sun roof more satisfying) and drop down a cog.

Aural sex!

EddieStone wrote:I'd love to see that run in the flesh. Well done to the Rimini lads to get it going again.

The megaphone exhaust is interesting, I think. The Vespa race scoots have them as well. They were the performance exhaust of the time.

Then someone decided to quieten the exhaust down by adding a smaller pipe on the end of the megaphone, effectively adding a second cone and accidentally inventing the expansion exhaust.

Imagine the conversation: "Yeah, it's quieter, but it goes like the bloody clappers".

I wonder if an expansion on this would have made a significant difference?

1951 was probably the first year expansion chambers were seen in the racing world introduced by ze germans, but they were very much at the head scratching stage until Walter Kaaden came along. This guy revolutionised 2 stroke exhaust dynamics from 1954 right up until 1976. Much of his work was an iron curtain secret until it was revealed in 1961, I think, and that's when Suzuki got involved.
The Suluro used brute force supplied by a Supercharger to fill its little combustion chamber with highly volatile fuel......Exhaust dynamics didn't matter really.
It would be interesting to see what a custom designed chamber would do for it now with the right carb though?

I'm not 100% sure how supercharging works on two strokes without losing most of the charge out of the exhaust.

The exhaust of this and bikes of this era seem to be designed to get the gases out into the atmosphere as quickly and easily as possible.

Fast n Furious wrote:

EddieStone wrote:I'd love to see that run in the flesh. Well done to the Rimini lads to get it going again.

The megaphone exhaust is interesting, I think. The Vespa race scoots have them as well. They were the performance exhaust of the time.

Then someone decided to quieten the exhaust down by adding a smaller pipe on the end of the megaphone, effectively adding a second cone and accidentally inventing the expansion exhaust.

Imagine the conversation: "Yeah, it's quieter, but it goes like the bloody clappers".

I wonder if an expansion on this would have made a significant difference?

1951 was probably the first year expansion chambers were seen in the racing world introduced by ze germans, but they were very much at the head scratching stage until Walter Kaaden came along. This guy revolutionised 2 stroke exhaust dynamics from 1954 right up until 1976. Much of his work was an iron curtain secret until it was revealed in 1961, I think, and that's when Suzuki got involved.
The Suluro used brute force supplied by a Supercharger to fill its little combustion chamber with highly volatile fuel......Exhaust dynamics didn't matter really.
It would be interesting to see what a custom designed chamber would do for it now with the right carb though?

Very interesting story MZ i.e. Walter Kaaden /Ernst Degner his defection made Suzuki and the whole Japenees bike industry what it is today.
MZ were years ahead in terms of development it makes me laugh when people sneer at the humble MZ.

check out this link

https://www.facebook.com/Lambrettaclubi ... 269207100/

Having seen this iconic Lambretta in various photographs throughout my scootering years, I was bowled over to see it in the flesh at last years Bridlington custom show.
Congratulations to the lads at Rimini, I bet they were eager to get it running again, and doesn't it sound well for a model A engine, albeit a beefed up version.
I look forward to see it running but I hope Matteo is going to put some air into the front tyre before he tries!!

Frank.

In reply to EddieStone's question about supercharging, I agree with him that some of the pressurised charge would be lost through the exhaust port before it closes, but obviously not all. I would imagine that Lambretta's R & D department did some extensive testing before deciding to use the supercharger for the record runs. The open megaphone exhaust is acting in the same way to pull the fresh charge from the crankcase as the exhaust pulse rapidly de-pressurises. The only thing they didn't understand was by fitting a reverse cone the returning pulse would have stopped the charge from exiting the exhaust port and there would have been no need for a supercharger. Does anyone know if other bike manufacturers used this idea in the early 1950's?
The Siluro and it's sister are fitted with very special Model A looky likey engines, but that's were the similarity ends! Just about everything else is unique to the Siluro's and the 6 monotubo racers they built (4 raced in Europe and 2 in Australia which still survive). I find it quite amazing that the company, just three years old at the time, could put so much effort and expense into this project.....and make it the success it was!
I have been interested in this for many years, unfortunately information is very scarce simply because it was such a long time ago. Last year I had the chance to talk to Vittorio who is probably the only person who has lots of info on this wonderful machine and the others like it.

I got some video of it starting at Goodwood Yesterday , it needs to be caught by the pit guy's at the other end as he can't put his feet down.

https://youtu.be/2U-mZq30owA

Brilliant. Thanks for posting that.

Thanks to HartleyHare for posting the video. Just great to see it running again......and doesn't it look and sound well??
Any idea who the lucky rider was?

I believe it was Matteo Panini

Thanks Sticky...........he is a lucky lad, and I'm pleased to see that he did put some air in the front tyre!!
All I can say is Ferri must have been a tiny guy to fit into it!

Thanks again
Frank.