ss90 barrel id

[oldscooterbloke]

How can i ID a barrel to check if its SS90 specs, thanks

[jbcollier]

This old post may help:

vespasmallframeforum.proboards.com/thread/22625/v90-ss90

[henri]

having measured a 90SS barrel nxt to a v90 barrel , theres no damm difference at all . but the link jb put up shows the differences in the 90ss in the first 500 made . the only 90ss that came in "super sprint" format from factory , metal fuel tank,spare wheel holder with covers etc . after the 500 they were just v90 engines with a better exhaust basically .H

[tzsteve]

I have come across 90 cylinders with and without a third transfer but never knew what model they came from

[henri]

Jun 5, 2022 11:12:27 GMT tzsteve said:

I have come across 90 cylinders with and without a third transfer but never knew what model they came from

are you sure they were 90SS barrels tho , as v100s an v100sports had 3 transfers , an i have been told ,havent we all . that piaggio did a batch of underbored v100 barrels that were 90cc .but have also been told by a "ex-spurt" the v100 barrel is a overbored SS90 barrel ,but that cant be true . a 90/125 cowl will fit a 90 or 125 an even 130cc or bigger . the 100 barrels take a dedicated cowl ive found , i think the 90 an 125 2 port barrels are from same blanks ,the 100 barrels are a different fin shape an blank .
its a mystery ,not helped by piaggio's fanciful record keeping ,an the mystique thats grown up around 90SS's , an the investors wishing to maintain values .
all i know is the 90SS barrels i measured came from ian T at taffspeed ,one stock an one "worked on" , an the 90 barrel i compared too was def piaggio .but never having being privileged to do a "first 500" engine ,i cant comment on the 3rd transfer . 

last 90SS that came through "mid-lash motors" was a engine built by ian T, one of the last he did .owner asked if we should change seals an check this an that , i blankly refused to touch a screw on it . in the scooter an fuelled , an 3rd kick it roared , an sounded sweet . H 

[tzsteve]

Fanciful record keeping sounds about right, I think sometimes its whatever is close at hand gets used. I also suspect some of the early work was farmed out to many other parts makers even now some of the indian stuff seems to be much the same as the earlier parts crank webs and gear pinions as an example

[jbcollier]

There have been so many change-ups and substitutions, and owners messing about, that it can be hard to pin things down for certain. I have an original SS90 that is low miles and 98% unmessed with -- no, I'm not going to strip the engine for your pleasure. I also have an NOS SS90 cylinder kit (150737) and a used SS90 cylinder. Some comments:

The most obvious difference is that an SS90 (and SS50) cylinder has M8 exhaust studs while V9A1, V5A1, V5SA1 and VMA1 cylinders have 6mm exhaust studs.

I have seen side by side photos (can't find them, damn) and the SS90 exhaust port is noticeably wider than on a V9A1.

I took some rough measurements off my two cylinders:

top of exhaust port to top of cylinder = 37.8mm
floor of exhaust port to top of cylinder = 54.6mm
exhaust port width = 37.8mm

[jbcollier]

First I have heard of the first 500 SS90s being special. Dunno myself. I would suspect that, if such a thing is true, then it would make more sense that the V90 got the SS90 cylinder porting rather than the other way round. Though that is pure speculation on my part.

[oldscooterbloke]

Hi, i have two barrels ss90 and both match the measurements you just posted. and both have m8 studs. and two heads one has ss90 underside the other does not, both look identical to each other.
both pistons are the same size, and style and 15mm wrist pins.
both were from ss90 bikes just trying to see if there was an easy way to check.
as one barrel piston and head came with the bike (SS90 ) and the other purchased later on as a spare.
ss90 crank is different i believe , what about the stator ?

[oldscooterbloke]

I think the stator should be normal v90 type, and the crank possibly has different inlet timing i would guess, don't want to take it all apart to check .

[jbcollier]

V9A1 has a bushing small end. V9SS has a needle bearing small end. I do not know if the inlet timing is different. You can fit the later rod to the earlier crank.

Stator, flywheel, etc all have different part numbers. Don't the early V9A1s have their high-ten coil on the stator?