crankshaft

[sjc]

is it worth fitting a 62 x 110 crank
to a standard ts1 barrel set up...........................

[Adam_Winstone]

No

[YAMLAM]

Adam,
please expand on your answer,you usually explain things so that simple souls like me can understand it.

[rosscla]

You'll need to hack it into a port timing calculator but I'm guessing the 4mm of extra stroke will screw up the durations too much.

[hendy]

For balance, Darrel Taylor was just suggesting on Facebook that this was the best route for cheap big power. Didn't go into any detail but he knows his onions.

[Norrie Bodge]

is it worth fitting a 62 x 110 crank
to a standard ts1 barrel set up...........................

Try a 60x110 crank

I run mine with a 2.5mm base packer & thick head gasket & love it
Pulls Indian GP200 box with 21x46 sprockets no problem

[Fux]

Im also running a 62x110.

milled down the piston skirt,

Flies!

Pulls high gearing fine with a ADS touring pipe and mikuni tmx30

It is, however more vibratey..

[Darrell Taylor]

if run with correct packers and a little port correction on transfers if required but not neccessary makes for good package although so does the 60mm ,, a 60mm also corrects the cylinders layout very well too as the ports positioning / casting suits 60 better

[Adam_Winstone]

Sorry, was short of time and knew that someone like DT might come along and provide more detail.

As DT has mentioned, swapping to 62mm requires additional considerations to be thought through, along with the change of rod length , which also means that you need to address certain factors.

Is it a worthy upgrade?... all depends if your knowledge of port timings, resultant power spread at various rev ranges, your ability to gear it correctly, ability to address compression ratios and/or suitable head modifications, timing and jetting requirement is up to it. If not, best left alone. Even trying to configure such a motor with a completely 'standard' TS1 barrel relies on you being able to make this assessment of these other factors that are by no means 'standard'. In light of all these other non standard factors that must be allowed for, in order to fit a standard TS1 with 62mm stroke crank and 110 rod, makes the easy answer.... No.

So, 2mm more travel at TDC and 2mm more travel at BDC... how will that be dealt with? Yes, the 3mm longer rod means that the piston will clear the casing at BDC but you now have +2mm stroke/travel at TDC and also +3mm more piston height because of the 3mm longer rod... so what are your plans to address port timings and positions in terms of allowing for this additional +5mm at TDC? You can pack at base, pack at head, recess head / rework combustion chamber / dowel to centralise to bore... or any combination of these to place the ports where you want them for the performance return that you're looking to get from the modifications.

Someone like DT deal with these issues on a daily basis, with their minds working on them when they're not in the workshop (!), but TBH understanding the implications of all of these issues, with even so much as 0.5mm of a change of port height, an extra 5 degrees duration, or the implication on geometric and corrected compression ratios, is beyond many hobby'ist engine builders.

Correctly configuring a motor with stroke and rod length changes is not simply a case of bolting it all together and hoping it works. For these reasons I believe that the correct answer for most people will be 'No', however, with the input of people like DT, the pendulum starts to swing towards..... 'maybe'.... but he would need to help most with a much greater level of detail before the answer became a viable 'Yes'.

When you consider the +5mm that you would need to find at TDC, it becomes quite easy to see why so many have also looked towards a change of piston at the same time, where a similar reduction in compression height can result in near parity and negate the need for additional packing. The great thing about this, especially in years gone by, is that you could then use Jap (or other) pistons that were far superior to traditional Lambretta offerings, however, this also meant that changes in piston crown profile usually meant that your head needed to be machined accordingly... pros & cons.

To my mind, all of these factors introduce a level of consideration that makes the standard TS1, with standard piston, with the standard 107 rod and 58mm stroke crank seem like a pretty good option, especially as it will easily meet the requirements of most. If you want a TS1 racer then mating it to the right exhaust and gear set (clutch, etc.) will result in this, even with a totally standard TS1 barrel. Then again, a standard TS1 with the right pipe and gear set can result in a near perfect touring configuration. So much can be done by setup configuration that most will not need to swap rods or increase stroke.

Don't get me wrong, I LOVE dicking about with different piston, rod and stroke configurations, with most of my motors being a mile away from standard, but there a lots and lots and lots of things to consider and to get right. Get any one of these factors wrong and you may well find yourself in a cold, wet, dark lay-by, wondering why you opted to veer away from tried and tested combos... especially when the standard TS1 does most things very well.

Anyway, sorry for the ramblings but you did ask (LOL)!

Adam

[Darrell Taylor]

For balance, Darrel Taylor was just suggesting on Facebook that this was the best route for cheap big power. Didn't go into any detail but he knows his onions.

hi hendy , the question asked was ts240 or gt 240 i just said the TS was TIME SERVED and good value for money as a kit price, power i didnt quote as it would be dependent on other components used and how its assembled.