71mm?

[dirtyhandslopez]

Been following the Rapido 225 thread. I am gathering that a Rapido classic can be taken out to 71mm with no worries? I've got a RD rodded crank so that ends not a problem. bore is at 68.5 right now.
Thanks

[Lui]

yes

[Knowledge]

DHL,

What piston do you fancy?

Martin

[cezeta]

what oversises are there beyond 71mm?

the rapido does wear using crome rings so is 71mm the end. i tried to get my rapido ceramic lined last week, it can be done but they would not do a single barrel batches only which is a shame.

[byron]

what oversises are there beyond 71mm?

71.5mm, 72.0mm & 72.5mm

i tried to get my rapido ceramic lined last week, it can be done but they would not do a single barrel batches only which is a shame.

hmmm... how many needed for a batch ? I've got a Rapido 225 barrel and first oversize wiseco piston. but I'm probably a little way off needing the top end finishing off on that particular motor

[shocky]

what oversises are there beyond 71mm?

the rapido does wear using crome rings so is 71mm the end. i tried to get my rapido ceramic lined last week, it can be done but they would not do a single barrel batches only which is a shame.

i think a liner is the best option when you get to this size maybe a stepped oversize one , the spigot looks thick enought for 72mm but near the top of the barrel its very thin there i friend is building a 244 with 72 mm piston and 60mm crank ports arnt massive 30mm carb sx 200 box 48mm rev con clubman prob only have 17-18 hp but plenty of grunt and a lowish revver he,s using a rapido classic cylinder but not relined so far the kit has cost 300 quid and that includes the new 60mm crank with reroded 18mm small end ,piston rebore and head reprofile plenty of oversizes here

[lofty]

i seem to remember the OEM H2 pistons needing repegging as one of the ring ends coincided with a transfer poert.. is this the case with the wossner and wiseco ones?

[byron]

i seem to remember the OEM H2 pistons needing repegging as one of the ring ends coincided with a transfer poert.. is this the case with the wossner and wiseco ones?

not with the wiseco, don't know about the wossner

[shocky]

not that im aware of altho i havent looked myself i dont think terry would have bought the woss one if that were the case i think he got it from a ktm dealer and looked a spec book for piston dimentions

[dirtyhandslopez]

my money's on a wiseco

However did you guess?
According to a recent purchase, apaprently the Wiseco H2 piston is the same as the Jetski 440 piston, just bigger. Although it did appear to me holding them side by side the skirt on the H2 was a few mm longer. Eden, show 'em the box
So you can literally go form 68mm all the way to 71mm on the same Rapido classic cylinder, using oversize Wiseco pistons, which is nice. I was concerned the spigot was going to get a bit thin at 71mm.