LCGB Forums

Looking for a 66mm piston for TS1, what are my best options?

Thanks in advance.

You should be mindful of any size ''grading' that might apply to pistons running in plated bores. 'A', 'B', 'C' etc. because there are varying opinions as to the ideal clearance. Saying that, my opinion is that running unfiltered air after going to the n'th degree to achieve such an ideal may defeat the object, what with the proximity of the intake. By comparison, motorcycles & karts may not have filtered air, but they have an air box, or plenum, that is fed fresh air from some place not so likely to contain cr@p. These were the considerations that I made with the last TS built. The bore was fine but had thrown a rod, so the slots in the spigot became ports! I gambled on using a very inexpensive good pattern DT250 piston, re-pegged, piston & the results are so good, that I would do the same again.

Unless there is now a better piston for 66 mm TS1's, my choice would be IT175, depending on stroke, rod length & packer.

I hope that helps

I've had a lot of PM replies thanks, all very helpful. The 66mm wossner seems well thought of with a standard crank.

I had a Taffspeed TS1 20 odd years ago using a DT 175 piston and 115 Yamaha rod, it was a very smooth engine.

The cylinder is being re-plated so they'll match it to suit.

I have a TS1/200 which uses a re-pegged 2mm oversize Yamaha Banshee Piston on a 110 yammy rod (36mm comp height) which now has near 7000 trouble free miles on it and no ring changes yet.
Re-pegging pistons is quite feasible if its done right.

John Deeley wrote:I've had a lot of PM replies thanks, all very helpful. The 66mm wossner seems well thought of with a standard crank.

I had a Taffspeed TS1 20 odd years ago using a DT 175 piston and 115 Yamaha rod, it was a very smooth engine.

The cylinder is being re-plated so they'll match it to suit.

Ron Moss sells decent pistons to suit TS1' I bought one from him a few years ago, Matica I think which gave good service. I notice he's got them on sale at the moment

coaster wrote:

John Deeley wrote:I've had a lot of PM replies thanks, all very helpful. The 66mm wossner seems well thought of with a standard crank.

I had a Taffspeed TS1 20 odd years ago using a DT 175 piston and 115 Yamaha rod, it was a very smooth engine.

The cylinder is being re-plated so they'll match it to suit.

Ron Moss sells decent pistons to suit TS1' I bought one from him a few years ago, Matica I think which gave good service. I notice he's got them on sale at the moment

Is that not for the 225 kit Coaster?
Fella looking for 200 66mm version

Fast n Furious wrote:I have a TS1/200 which uses a re-pegged 2mm oversize Yamaha Banshee Piston on a 110 yammy rod (36mm comp height) which now has near 7000 trouble free miles on it and no ring changes yet.
Re-pegging pistons is quite feasible if its done right.

I agree that re-pegging is fine. I fit a sliver of alloy, tapered to fit the ring groove in the area that I want the new peg to be prior to drilling. For pegs, often a needle from a bearing will suit. The only pegs I've had fail were the brass type in the OEM Honda pistons.

The filing down of the original peg then takes an age. If only spark eroders were cheaply available....

ULC Soulagent wrote:

coaster wrote:

John Deeley wrote:I've had a lot of PM replies thanks, all very helpful. The 66mm wossner seems well thought of with a standard crank.

I had a Taffspeed TS1 20 odd years ago using a DT 175 piston and 115 Yamaha rod, it was a very smooth engine.

The cylinder is being re-plated so they'll match it to suit.

Ron Moss sells decent pistons to suit TS1' I bought one from him a few years ago, Matica I think which gave good service. I notice he's got them on sale at the moment

Is that not for the 225 kit Coaster?
Fella looking for 200 66mm version

OOps, missed that

Warkton Tornado No.1 wrote:

Fast n Furious wrote:I have a TS1/200 which uses a re-pegged 2mm oversize Yamaha Banshee Piston on a 110 yammy rod (36mm comp height) which now has near 7000 trouble free miles on it and no ring changes yet.
Re-pegging pistons is quite feasible if its done right.

I agree that re-pegging is fine. I fit a sliver of alloy, tapered to fit the ring groove in the area that I want the new peg to be prior to drilling. For pegs, often a needle from a bearing will suit. The only pegs I've had fail were the brass type in the OEM Honda pistons.

The filing down of the original peg then takes an age. If only spark eroders were cheaply available....

Yep... that's how I do it. Needle rollers are perfect.
I actually use an end mill bit to drill the new peg hole on a milling machine to discount the possibilities of drilling off-centre. Then, very carefully grind out he old pin with my trusty Dremmel.

Fast n Furious wrote:
Yep... that's how I do it. Needle rollers are perfect.
I actually use an end mill bit to drill the new peg hole on a milling machine to discount the possibilities of drilling off-centre. Then, very carefully grind out he old pin with my trusty Dremmel.

I've got die grinders & a Dremelish tool with flexible shaft drive & an angled hand piece, but I dare not try & remove the pin as you do!

It's probably due to my lack of alcohol.....

Could someone say what the process of turning an old bearing race pin into a ring peg is, please?

My instinct says

drill a hole
Insert peg

But I suspect I missed a couple of things...

rossclark wrote:Could someone say what the process of turning an old bearing race pin into a ring peg is, please?

My instinct says

drill a hole
Insert peg

But I suspect I missed a couple of things...

I can only speak for myself, in that I attempt to replicate the original pegs as closely as possible but in an area of the ring land that suits a build better. I prefer to relocate pegs rather than have three fingers, say, in the example of making/modifying boost ports.

Dependent on the ring ends, the peg will require to have the same geometry. It may be central in the ring slot, half & half, recessed etc.

As said previously, I 'fit' a piece of alloy into the slot where the peg needs to be. Then very carefully drill a smaller hole of less than the depth required. Gradually, the size of hole is increased in diameter & depth to suit the new peg, often an ex bearing needle, which should be finished nicely in it's length with polished ends & the slightest chamfer.

With a satisfactory hole achieved to ensure correct depth & a transition fit, the new peg can be gently knocked in. Too long is preferable to too short as the end can always be dressed if necessary.

Once all of the process above has been completed, 'removal' of the original can be achieved. I only 'dare' remove what is necessary via needle files. I've attempted heating the piston & giving it a knock to try & dislodge an unwanted peg (as suggested on some sites) but it's never worked for me.

Re-pegging was essential in the 70's when some Japanese pistons were first used. Done properly, there will not be any issues, despite what some Legends-in-their-own-Lunchtimes may claim. In, fact, those that proclaim themselves to be such excellent engineers yet cannot repeg a piston reliably should surely be a bit doubtful as to the rest of their 'first to do this' & 'first to do that' statements & products. Obviously, I think so

Re-pegging means that an excellent Japenese type piston can be utilised @ a fraction of the cost of specialist pistons. After all, how many Kawasaki H2 pistons were blasting about in 240's for many miles having been re-pegged? It was THE top conversion prior to the advent of TS1's etc & I still retain a Webbo version. Under the bench, mind you.....

Hmmmmm yes.
What the lunchtime legends conveniently forget, or don't realise, is that some of us were doing some of these mods back in the days when many City's had their fair share of precision engineering workshops unlike today.
We had no internet to shout out publicly about it back then and only a few of us were prepared to pay for it cos we was very young and constantly skint. There was also some kudos in having something better than everybody else and so you kept quiet about it. Some of us were lucky and worked for such prestigious companies, or had a mate who did. (Anyone who's worked in aerospace will know what I mean ) The old boys used to rule those workshops like they owned them and knew exactly what to do and how to do it. Meanwhile, the Lunch legends back then were still trying to figure out how to zip up their pants.

Guys what kind of clearance is required from peg to outlet?
Cheers Shane.

Not sure what you mean there Shane. Please clarify.

Sorry for the confusion exhaust port and inlet, 5 mm clearance from peg to ports?
Cheers Shane.

The minimum gap from peg to port depends upon which port & the width.

The rings only traverse transfers & the exhaust port(s) & the widest by far, will be the exhaust port. Ideally, ring pegs will be on the inlet side of the cylinder where the environment is not so harsh & any ports will be transfers/boosts where the duration will be far less.

If there is a very wide exhaust port & the gap from the side to the peg is 5 mm, theoretically that will be fine, but it will not have an easy life. The ring will spring outwards as it crosses the port & be sprung back in as it is above the port. That will increase the wear on the port edges, the ring itself & the peg. In fact, that was so often the reason that the Honda pistons with brass pegs wore out.

That is why repegging can work out to an advantage, as it can be positioned centrally between ports & allow any boost ports to be single, rather than 'three fingers' as so many tuners adopt to avoid moving the ring pegs.

ideally, the pins should be diametrically opposite the exhaust port center-line. This then minimises the lateral ring thrust forces generated by the action of the ring passing over a wide exhaust port, from consistently bashing the ring peg until it fails.
To aid ring seal, there needs to be a little angular offset only. Top ring slightly left of centre and the bottom slight right.
Some cylinders are better than others with re-pegged piston options. Some designs have the boost port right where you want the ring pegs to be.

To th O. P QUESTION
AF did/do a wossner 66mm piston that they will put the cut outs in for a reasonable fee.
So straight fit no need for head or Crank alterations.
Very happy with mine