TV175 barrels

[DigDug]

apologies I thought that I had said but to be fair all i was asking for was for someone to tell me which 175cc cylinders were small block spacing and which were big block spacing .

Anyway what I am aiming for is to build a TV175 engine

If I had just wanted to have a 175cc upgrade I would buy a 175 small block conversion kit for £100 and save myself all this grief.
Now I bet someone is going to ask me why I should want to build a TV175 long stroke engine to put on my Li150 series 3

If they do then you'll know they've never ridden a TV175...

[blimeyolriley]

I'm a bit puzzled with what you're hoping to achieve. If you have an Li150 and want to increase the capacity (in order to increase the power) then you would bore out the barrel, fit a conversion piston, modify the head, maybe do a bit of porting and you would get an increase in power.

If you fit a TV175 barrel, you would need to replace the crank (or at least the conrod), modify the head and fit a normal TV/GT175 piston.

Both achieve pretty much the same thing but the first one is a lot easier and cheaper.

if your using a tv175 barrel on an li or other small block you can simply use a conversion piston so you dont have to change the crank, but you would need the head

I'm getting more confused by the minute with this.
So as I understand it the Li , SX, and TV cylinders have ports that are at the same height (more or less ) and it is the piston on the TV175 that compensates for the additional length of conrod so that the piston has the same alignment with the ports that a SX or LI piston would have used with a 106mm conrod ....

IMy initial intention was to rebuild a spare Li150 series 3 crankcase but swop the crank cylinder piston and head for TV175 parts so effectively I'd end up with a TV175 (with Li150 gearing of course)

So... I ordered a TV175 piston kit . I also ordered a 175cc Cylinder from a well known ebay shop, which I was assured fitted a small block crankcase and wasn't one of those Lamby lambro 3x wheeler jobbies. The cylinder was the reason for this post.

I already had a line on a TV175 crank and I have a 175 head so I thought great ...job done !

In the meantime yesterday the crank purchase fell through and the cylinder arrived an hour ago clearly labeled 'LAMBY'
I phoned the shop and the owner assured me that he had been told the cylinder was a SX150 rebored to 175 (not what I was originally told when I ordered it on the phone)...

On inspection the cylinder is clearly not a TV175 cylinder nor is it a rebored SX or Li series 3 cylinder. The inlet port is so small I cannot get my little finger into the port ! However in all other respects the cylinder does appear to resemble a SX150 cylinder as all the ports are the same height and placement save the inlet which is much narrower .

The Cylinder was advertised as a 175cc 62mm cylinder with no other information so i suppose I should have guessed it would be too good to be true. i just hope nobody else is silly enough to buy one and gets a Lamby like I did

So now I'm back to square one with no crank and no cylinder .

[EddieStone]

A genuine TV175 barrel has much bigger transfer ports than an Li/SX/GP barrel. Just to add another layer of complexity.

This thread does explain how I come to own a 175 head with 200 large block stud spacing though. It's off a bluddy three wheeler. It was around the time I found this out that I vowed never to buy anything critical off eBay. There are too many people selling too much crap.

As for the crank, I would call a reputable tuner and ask him to make you one. I don't know how much your crank kit was going to cost you, but it probably wasn't much less than what I was quoted for a crank. It's a whole lot less grief as well.

[joespeed]

i have a 175 cast cylinder with new piston just been rebored £100

[Scooterdude]

i have a 175 cast cylinder with new piston just been rebored £100

He doesent want a cast 175, he wants a genuine TV 175 cylinder (I think) I'm getting confused now!

[blimeyolriley]

i have a 175 cast cylinder with new piston just been rebored £100

thanks joespeed but its a bit over my budget as I already have bought a piston kit so was hoping to just buy a cylinder . I'd prefer a TV175 naturally but any series 3 175cc would do .
I can get one of my 150cc cylinders bored to 175 for £83 but by the time I factor in vat and delivery/collection I might just as well buy an Indian 175 long rod kit .

[blimeyolriley]

There are too many people selling too much crap. you're right there

As for the crank, I would call a reputable tuner and ask him to make you one. I don't know how much your crank kit was going to cost you, but it probably wasn't much less than what I was quoted for a crank. It's a whole lot less grief as well.

this might be my best option. i have a couple of donor cranks and I could buy an Indian rod kit but I reckon the engineering work would make it unviable.
I think I saw a new 175 crank somewhere for around £100

These prices are ridiculous !.... you can buy a brand new Ve**a crank for £25.00 quid

[Chris in Margate]

Good luck with your venture. I would read as much Lambretta.literature as possible before spending more money.
BTW:
The TV 175 Series 3 was never referred to as the GT 175. You are confusing that with the TV200 often referred to as the GT 200.

[blimeyolriley]

apologies I thought that I had said but to be fair all i was asking for was for someone to tell me which 175cc cylinders were small block spacing and which were big block spacing .

Anyway what I am aiming for is to build a TV175 engine

If I had just wanted to have a 175cc upgrade I would buy a 175 small block conversion kit for £100 and save myself all this grief.
Now I bet someone is going to ask me why I should want to build a TV175 long stroke engine to put on my Li150 series 3

If they do then you'll know they've never ridden a TV175...

hey digdug have you got a Tv175 / or ridden one ?
What are they like in camparison with a typical series 3 Li150 . I'm dying to know what they are really like to ride
the gearing ratios are quite a bit different . Does that give the TV175 a slower acceleration but less gear changing ie longer in each gear and a lower RPM to MPH .

[Scooterdude]

There are too many people selling too much crap. you're right there

As for the crank, I would call a reputable tuner and ask him to make you one. I don't know how much your crank kit was going to cost you, but it probably wasn't much less than what I was quoted for a crank. It's a whole lot less grief as well.

These prices are ridiculous !.... you can buy a brand new Ve**a crank for £25.00 quid

Welcome to the wonderful world of Lambretta's, the rich mans playground.....NOTHING IS CHEAP HERE! if you want cheap don't buy a Lambretta!