ooops

[Warkton Tornado No.1]

Post by a-teamlambretta » Wed Dec 28, 2016 3:50 pm

50.25mm on the piston . from little end centre to crown is 27mm. gudgeon pin is 12mm diameter. will have a look to see if any other pistons will fit. was running and sounding nice prior to the ring escaping , just needed carb setting up cant remeber what the rod is from length ect. had 1.2mm squish with a standard head gasket . no base gaskets where used. if i had then the top ring might have made a bid for freedom aswell lol. cheers simon

Post by a-teamlambretta » Wed Dec 28, 2016 9:49 pm

When using the tzr piston you need to use a j125 cylinder and starstream crank if you want to keep on a 4 speed box. I opted for what I had, a vega 75cc cylinder and reedvalved that. I'm expecting 12/13bhp from this once running again lol

Sorry if I’ve caused confusion earlier, but I’m confused as well!

Is the piston Ø50 mm & from a TZR, somehow? If so, excuse my ignorance.

It would be interesting to know, not that I have any small frame engine components or experience whatever!

[a-teamlambretta]

Tzr 150 Asian market bike. Piston is used with a j125 cylinder and crank. Rod has to be changed to a yam dt125/175 to get you onto the right sized little end to suit the tzr piston. Piston has windows in and one has to be welded up if not going reedvalve. I have a set up like this aswell. I think the piston is 57mm or 59mm can't remember. I decided to use the vega cylinder and over bore to suit the piston leaving some scope for rebores. The tzr/j cylinder conversions leave the cylinder thin and cylinders are very rare. I have some even more madcap conversions, a vespa small frame parmakit 135 reedvalve kit grafted onto a j125 starstream engine.

[a-teamlambretta]

The crank for the parmakit conversion is a sunny crank with a slight mod to the drive sleeve with vespa drt eccentric +/- 2mm big end pin and a drt vespa t5 105mm rod. I think I invented the sunny crank conversion a few years ago lol.

[mickey c]

Thanks for the tip on the exhaust, cut & shut a sporty series 3 pipe hadn't occurred to me.
I'm hoping for similar BHP on 140 starstream conversion but doubt my modified standard exhaust will assist.
It'll be good to catch up on vibration reducing techniques which the posted thread mentions & I'm worried about, I'll hopefully know and still have my fillings in a few weeks!

[Warkton Tornado No.1]

Post by a-teamlambretta » Wed Dec 28, 2016 3:50 pm

50.25mm on the piston . from little end centre to crown is 27mm. gudgeon pin is 12mm diameter. will have a look to see if any other pistons will fit. was running and sounding nice prior to the ring escaping , just needed carb setting up cant remeber what the rod is from length ect. had 1.2mm squish with a standard head gasket . no base gaskets where used. if i had then the top ring might have made a bid for freedom aswell lol. cheers simon

Post by a-teamlambretta » Wed Dec 28, 2016 11:21 pm

Tzr 150 Asian market bike. Piston is used with a j125 cylinder and crank. Rod has to be changed to a yam dt125/175 to get you onto the right sized little end to suit the tzr piston. Piston has windows in and one has to be welded up if not going reedvalve. I have a set up like this aswell. I think the piston is 57mm or 59mm can't remember. I decided to use the vega cylinder and over bore to suit the piston leaving some scope for rebores. The tzr/j cylinder conversions leave the cylinder thin and cylinders are very rare. I have some even more madcap conversions, a vespa small frame parmakit 135 reedvalve kit grafted onto a j125 starstream engine.

Looks like there was a typo then.

TZR150 is a nominal Ø59 mm bore.

Now I'm beginning to understand. Phew!

There's a lot of pistons @ around Ø56/57 mm then nothing up to about Ø60 mm as I'm sure you know.

[a-teamlambretta]

Standard vega 75cc cylinder is around 46mm diameter I think?, I used a piston from a small motocross bike think it was for an 80cc but not sure what make of bike, diameter of 50cc and as said the vega cylinder has plenty of meat left after being taken out to 50mm. Just a slight miscalculation regarding the ring peg position and the porting lol.

[a-teamlambretta]

There was a couple of other conversions, kawasaki kh500 triple piston and a series 1 tv175 piston. Have seen a kawasaki kh conversion but not seen the tv 1 done. Probably some others aswell.

[a-teamlambretta]

I was hoping that the casa 75cc ally/nicasil kit was going to be an improvement but it's identical just about to the original, if making them why not go a bit bigger on cc and better port layout. I should be in charge of product development at casa, prating around with that 250, I'd would have gone to at least 500cc. Same with tino satchi, varitronic for an ld 125/150 why??. 4stroke top end for series 3 why??. Did he do the ally/nicasil cylinder for the ld's aswell why??. The best thing from him is the imola kit for the 125 cases brilliant, great kit no need for a 200 case anymore. I should be in charge of product development for tino aswell. These are just my opinions. Where is my 5 speed gearbox for my vega??? Lol. For starters if I was in charge all new cylinder kits developed by me for 125/ 200 cases would be water cooled, not just the head either if the vespa small frame men can do it why can't us lambretta men do it?? , they never go wrong either lol

[a-teamlambretta]

right , back to the coal face. this pojcet has been on going for a coulple of years and the cylinder had been tuned years ago before me owning it . it came as a complete engine and when stripped by me and digger he spotted that the ports had been built up with some kind of epoxy resin and he said it had been over done porting wise and the epoxy was to replace the metal that was removed . i cleaned the barrel up and used it as it was for a coulpe of years without issue until the crank big end started to go. i stripped the motor and thought now was a good time for some tuning and to go reedvalve. the tuning and reedvalve conversion was done and it was noted that on the dry build a year ago that the bottom ring should not be fitted as it was going to drop into the inlet. several months later i fitted the reed block , then over christmas i decided to finish the engine and completley forgot about the bottom ring not being needed , if id of left the reed block off i might of noticed and questioned the use of the ring or even remebered not to use it. a lesson to learn here, rebuild your engine no later than one month after stripping should be up and running tomorrow . cheers simon.
ps what was tino thinking when he did the targa twin ?? could have gone 225 reedvalve on each cylinder and have a nice round 450cc ?? the mind boggles or is it just me

[a-teamlambretta]

back up and running , just fine tuning the timing and carb set up. holly shit, when it gets on pipe it screams . hope it lasts .going on a rolling road next week with a bit of luck

[Adam_Winstone]

^... great, please keep us informed?