LCGB Forums

Hi all, the first 4 pictures are of the original cylinder that came fitted to my 59 Tv175. You may notice that it has been bored out to suit the 65mm pistons that were available as a '200' conversion way back. (i have a couple of oversizes knocking about). Dont panic,the pictures were taken pre cleaning!. As i have a tidy Tv crankshaft assembly, already enlarged cylinder head,and the next oversize piston standing idle,i thought i would put together a spare Tv 175/200 engine for something to do (while im awaiting parts for my knackered RT195 to arrive).
Well it is Frday the 13th........i knocked the Tv cylinder off the work bench and put a dent in the cylinder skirt (see pictures)....Can this be repaired without too much expense or am i going to have to go to plan 'B' (see below)
IMG_20220513_164315 by Kevin Payne, on Flickr
IMG_20220513_164329 by Kevin Payne, on Flickr
IMG_20220513_164334 by Kevin Payne, on Flickr
IMG_20220513_164414 by Kevin Payne, on Flickr
PLAN 'B' is the use of the cylinder below which i believe is a 'Motoristica Milano' pattern item to suit a Tv175 series 3 as the transfer ports are larger!
IMG_20220513_164505 by Kevin Payne, on Flickr
IMG_20220513_164521 by Kevin Payne, on Flickr
IMG_20220513_164538 by Kevin Payne, on Flickr
IMG_20220513_164545 by Kevin Payne, on Flickr

Despite the ding, the TV 175 II cylinder is by no means scrap. No doubt, a sympathetic engineer could tease it back into shape with heat & specific tooling, braze into enlarged contours following the crack, but I would just remove that piece & go even larger to a symmetrical cut out in the skirt. I drastically slotted the skirt of a 'wrecked' TS cylinder that had thrown a rod & that resulted in easily the most powerful engine I've tuned because I thought 'WTF' & threw all of my pet theories into the mix. But that's another story....

Think Max Quattrini MQ 210 (NO spigot) & you'll not be far wrong

I would advise a light hone after any modifications followed by port deburring.

Yep I'd personally lop off the damaged segment, clean it up and run it as is. Years ago I had a Small Frame Vespa Polini cylinder with a damaged spigot and I just tidied up the knackered part and it ran fine. Paul

Thank you all for your input,all info taken on board