Kawasaki 240cc Conversion

[martints1]

...what skirt-lenght do the Kawasaki-H2-Wiseco-piston have ?

[shocky]

good thread its been a while since i did a jap piston conversion(15yrs) so i wanna check a few things out measurment wise i wanna do a 230/240 conversion heres what i have
71mm bored barrel from taffspeed
standard stroke crank yet to be rodded
and a choice of pistons either h2 or the weisco one
if i use the tv116 rod i need a 2mm packer plate ?
heres my calcs ;piston is 7mm shorted at crown than a standard type one the 116 rod is 9 mm longer that means a differance of 2mm
will this give me a 228cc barell with standard port timings which i could run just as an overbored cc conversion to start with
i wanna go the weisco piston as it doesnt need the ring pegs moving
is there a better rod than the tv one perhaps a yamaha 115 rod and then make the packer 1.5mm thick
i have a 58 stroke crank so i wanna use that to start also i want to start standardish with the timings so i can build up what works and what doesnt if im way out with any of the above id welcolme some tips but i want to learn why things need doing to get the correct measurments cheers

[J1MS]

68mm is the standard length, I am running mine with nothing cut from the inlet skirt at the moment due to the engine not having the correct stroke that i tuned it for, with the correct stroke I have a H2 with 4mm cut off the inlet skirt, this gives me 170 deg inlet timing. Skirt length depends on your tune and what in let timing you are looking for.info on my  Kwak 240/250 (depending on stroke used) engine is here http://www.lambretta-images.com/display ... =60&pos=18 if anyone is interested.The info above is updated from time to time as I try new things and when things fail.

 Done a couple of these conversions in the past, early 80's, The crank in the past (on mine) was always the weak link, but these are alot better now...I never ran mine with an inlet timing as big as 170 degrees....where does the power start coming in.. at what sort of revs....I would expect it to fly when it gets on power... Back in the 80's this was one of the most expensive conversions to do and there were never that many about but they are good fun to ride..... I put a mates together about 1984 he had a load of bits off MB ... it was a water cooled barrel... Mark Broadhurst did three that I knew of... I put the electrics together for all three of them and built one of the engines and helped with the other one....In there day they were pretty radical a frame filled with water a water pump radiator, electronic stator supplying the dc power....Brings back good memories...

[byron]

...piston is 7mm shorted at crown than a standard type one the 116 rod is 9 mm longer that means a differance of 2mm
will this give me a 228cc barell with standard port timings which i could run just as an overbored cc conversion to start with
i wanna go the weisco piston as it doesnt need the ring pegs moving
is there a better rod than the tv one perhaps a yamaha 115 rod and then make the packer 1.5mm thick
i have a 58 stroke crank so i wanna use that ...

71mm bore with a 58mm stroke gives 230cc
I am using an RD400 rod on a 60mm crank.
got my rod kit from yam-bits - £31
the rod is 115mm, has 22mm big end and takes the 16mm gudgeon pin from the wiseco 71.5mm piston I am using. I'm just hoping the Rapido 225 barrel can take the overbore... the spigot will be thin, so will radius the corners to relieve any stress.
I haven't got as far as working out the port timings or thickness of any packing plates yet.
I am expecting to have to cut a groove in the casing for the end of the rod to fit, this end of the rod is bigger than the one originally fitted.

[DMC]

wiesco doesnt need repegging for piston ported engine

presume you outbid me on ebay last night for that piston

sounds like payback to me David, you've done me in the last minute on two TS barrels on flea bay, you must have a right collection now I ended up wininng a rapido barrel and thats been a right pain in the arse to weld.

I don’t think you can get genuine H2 750 piston rings anymore. I know Ralf Saxelbys got some new H2 pistons and was struggling to get rings for them, even through the trade. I also use Wiseco and think it is the way to go but the German lads seem to praise Wossner and Athena forged pistons saying they are just as good.

[mawso]

Have a look on U.S Ebay for the rings, Ebay.com basically as opposed to .co.uk and you'll come across H2 rings standard and oversizes.

[fishi]

hi mawso,

can you please post some photos of your barrel and piston?


fishi

[mawso]

Fishi, I can but don't hold your breath...it's packed away in a lock up now. I'll dig it out soon and put some pics up.

After speaking to Ian at Taffspeed I've found out it isn't one of theirs and it's not engraved anywhere to identify who tuned it.

[davidblythe]

wiesco doesnt need repegging for piston ported engine

presume you outbid me on ebay last night for that piston

sounds like payback to me David, you've done me in the last minute on two TS barrels on flea bay, you must have a right collection now I ended up wininng a rapido barrel and thats been a right pain in the arse to weld.

I don’t think you can get genuine H2 750 piston rings anymore. I know Ralf Saxelbys got some new H2 pistons and was struggling to get rings for them, even through the trade. I also use Wiseco and think it is the way to go but the German lads seem to praise Wossner and Athena forged pistons saying they are just as good.

but in my defence have a few projects on the go, looking to use Wossner KX250 pistons and TS250 pistons as they are readily available and very cheap in comparison

[J1MS]

but in my defence have a few projects on the go, looking to use Wossner KX250 pistons and TS250 pistons as they are readily available and very cheap in comparison

TS 250 pistons are very good... Ive been trying to get a Genuine Suzuki (ART) TS250 piston kit for one of mine, but no joy yet... ...