TV Cylinder

[Littlewheels]

Just bought a TV cylinder.

I have another which came off a spare engine I bought a long time ago which I believe is original.

Comparing the two they appear slightly different - new one has a stub with No 9 on it and although the opening of the inlet manifold is the same shape the opening inside the cylinder is smaller and flows at a slightly different angle?? 2nd fin from the top on the exhaust side has a sticky out bit on the old barrel but not on this new one? The transfer ports are maybe 2mm smaller on new one also but everything else is the same.

Question is - Which one is the genuine barrel or are they both genuine barrels but made by different manufacturers from different factories?

Many thanks in advance!

[Knowledge]

Or could one be from a series 2 and the other from a series 3?

I don’t know if there is a difference, but it is an alternative explanation.

Alternatively, are you certain that you haven’t acquired a bored-out 150 barrel, perhaps an SX or GP barrel?

[hullygully]

Stickeys book gives you dimensions & how many fins to each port whilst identifying barrels

[Fast n Furious]

All to often TV175 cylinders are advertised incorrectly. Just because the bore is 62mm is no guarantee that it is a genuine TV175 cylinder.
Use a pair of dividers to measure the diameter of the casting between the 3rd and 4th fins from the top.It should measure 80mm.
If it measures 70mm then it's a bored out 150 cylinder.

[Littlewheels]

Thanks for the replies.

It measures 77mm using external callipers & the other original cylinder looks about 78mm.

There is also a small notch in the spigot on one half? Maybe to help identify?

I get the feeling it's a Lambro cylinder? Anyone know how to tell the difference? Looked online but there isn't any info.

Thanks.

[Fast n Furious]

You might have more luck if you can post a picture?

[MickYork]

Did the Spanish do a TV ? might be a reason for the discrepancies

[alex_hughes]

Does it have an almost circular inlet port? Italian Series 3 do have this shaped port - not oval. It's unusual and model specific.

Does it have a stamp on the head gasket face? Typically o or - or + These are normally factory stamps for piston fit.

[Littlewheels]

Thanks for all the replies. Yes it has a round shaped inlet and has a No stamped on the top gasket face so I'm pretty confident it's original. Maybe just differences between castings?