Scooterotica

What are peoples views on using Vespa cylinder studs on a TS1 build

I used them on a imola build without problem but when we tried tbem in a oiltek converted casing(small to large block) they felt tight when starting to screw them in and so didnt use them for fear of a nice crack appearing . Standard studs went in no problem though.

I have heard that because they are thinner it allows the cylinder to expand more and so reducing the chance of a 4 point seize

alanscottj wrote:I have heard that because they are thinner it allows the cylinder to expand more and so reducing the chance of a 4 point seize

I think there is something in this thought. I've used them on my TS1, and other engines, and never had any issues.

There's also the issue that the genuine Piaggio studs are threaded rather than rolled, so they have a natural 'stop' at the end of the thread that prevents then being over screwed into the casing.

rolled threads on thin barrel studs; tapped threads on thick barrel studs

alanscottj wrote:I have heard that because they are thinner it allows the cylinder to expand more and so reducing the chance of a 4 point seize

Proporting passed a long series drill through my iron barrel for that very reason think it was a 9mm one I used "gold" mec studs that were 10mm longer than standard as I had a longer rod fitted to my crank

I have had two seizes on my TS1, both four point seizes, so I am looking at all probabilities and my mate spoke to Andy Francis who recommended that I swap to Vespa studs