Modern Vespa

this pleases me greatly....

Big shout out to Mark to start. As always he has the tools, the ideas, and levels of patience for my stupid notions. Pics tell the story:


Step one (after scribing) was dremeling out the recess.

The slow and tedious... hand filing the recess down to be even to where the circlip lives.

About ready for the drill press...

My crazy dog SQRL has a crush on mark and kept nipping his ankles and trying to herd him.

Maybe this side will get his attention?!?

Drill Press action...and then tap that shit.

yep

m4 and ready to rock

A set of saved SS180 cases. A bit of a fight with the bearing and crank... but done.
Hat tip to EVERYONE that had ideas, retainers , and helped! Grtazi

That's just beautiful and an elegant solution! It took THREE of you to get it done , but it's the result that counts. One little niggle if you don't mind, can I send you a couple of these Grade 8 screws for additional insurance and beauty, please?

Just gimme the length and TIA from my OCD.

Hahaha - I am with Voodoo on all his points - including the black grade 8's.
Trust a touch of lactite was dolloped in the holes.
Damn fine solution - fitting of the cases - and arguably better than original (less slop!)
Impressed.
Take a bow on that one y'all.

Great job!!! I didn't think there would be so much "meat" there, probably the previous photos didn't help much. I'm with the Gents on the bolts and also, I think the edge will need trimming so as not to hit the primary's cog...

IDK about lactitite (look, I don't judge) but yes locktite was used… the red stuff… ya know the "*fuck the next guy" version.😸

I will look for some grade 8's thanks all for the suggestion.

(*Anonymous quote used to protect the original author.)

I am in agreement with better screws. The Philips heads are screaming out to be stripped and then you will be the fucked next guy before you know it.

Very satisfying fix.
3rd part proud.

4th part proud. I'm stoked to see these saved cases. Smart thinking, careful work; and a bit of the ol luck. Very nice work!

Good eye. We had the same concerns and kinda dry fit everything before we started dremeling. There seemed to be a good bit of clearance.

I'm ALL about rescuing old cases and I saw this pic in another thread. So I wondered if there's enough meat there to copy your case mod plan, but use these standard parts w/ suitable shoulder screws if anybody runs into the same problem? I was struck by the basic similarity, obviously more than enough here with the bigger studs to keep the bearing in place.

Buttoned up.

Closing SS cases is an interesting affair. The KS cog will not clear the main case if left on the fly side as normal. If you leave it on the primary, you cant close the cases either.
You have to leave the cog propped (preciously) on the flyside over the spring leafs. Partially close the case, and then get a dowl or long thin screw driver and push it onto the spindle. Pretty good PITA. Please post up if you have a tricks or know of an easier way.

Hope to get the top end on in the next few as time permits.

Indeed. That took me awhile to figure out. At first I thought it was an impossibility.

Welcome back to my never ending SS resto thread. Today's show is all about piston rings.
Let's get started!


Our piston is a Piaggio stamped OG 62mm. On a scale of 1 to 10, it is maybe a 7 condition wise if we are generous. Serviceable for sure. However... the ring gap is a gaping 0.90mm. Easy money would be to replace the rings... but the only rings I can find are GOL rings and they are never gonna fit. When I first received the rings and spit-balled with Greasy he assumed they were Rally rings that had been mislabeled. Seemed reasonable so I reordered. New "SS rings" arrived, but no joy... good friends these rings are meant for GOL pistons not Piaggio... and are just way too big to fit the bore sitting in the lands of the original 62mm.

"Grade B - Decent Repair" Grade F - Garbage + shipping

Can you have rings made? Is there a source? Is a gap of .90mm really too big to run? Do I scour for an original 62.00? Do I scour for the Gran Sport repop sitting on someones shelf. Do I run a GOL?

For the record - Again, all the main shops are stocking GOL rings and they DO NOT fit og pistons.

*Start Ginsu Knife Commercial Here*


This is the droid I am looking for

This is not the droid I am looking for.

R2-62

Oh, that sucks. I suspect you'll see more blowback than pissing into a gale with that gap, but if the options are that or nothing, you could always try it.

I'd try to source some rings off a dirt bike site, maybe. I googled a little bit, and unfortunately nobody lists the ID vs. OD of their rings, so find the right ones may require a little bit of picking up the phone, but 62mm 2mm rings aren't uncommon, so there's probably something out there, it'll just be a PITA to find.

the Grand-Sport Race piston is what I would use.
https://www.grand-sport.de/navi.php?a=39&lang=eng

or if just replacing the rings
https://www.grand-sport.de/index.php?a=3237&lang=eng

sadly, both seem to be out of stock, but worth contacting them

Update - I did find a NOS Borgo Piston and Rings in first oversize, 62.2
If this was a P/Sprint/etc I would be reboring w/o a second thought, but over-boring an SS unless 100% necessary makes me very uncomfortable...

Maybe grab it and hoard it for a "if needed" situation?

NOS piston, he probably can ship it to you, else I can get it and send it your way…

https://automotoclassics.com/en/classic-motorcycles/piaggio-spare-parts/piaggio-vespa-ss-180-complete-piston.html

You beautiful bastard!!!

I have contacted them. We will see what happens.
Thanks so much for the link!!!

man, what a kick in the teeth. more so after all that work.

that's just wild on the construction of the ring. performance or aftermarket I get different mfgr usually means different rings. but as a basic stock replacement, that just boggles my mind.

OK... back from vacay.

Again a shout out of THANKS to Safis who found a NOS SS180 piston at a shop in Greece.

Prior to that I also found a Meteor 62mm repop at Scooterwest. All my research says that Meteor quality was respectable and certainly a step above the GOL pistons with their 3mm rings. I ordered the Meteor as a back up and for "educational purposes".

Interestingly, the NOS is stamped Piaggio, but is definitely a different manufacturer than the original piston (also stamped Piaggio.) Port transfers are slightly different and the internal supports and wrist pin mounts are different.

Most importantly though, the ring gap on the NOS is the appropriate .225mm. The Meteor measured at .250mm Both perfectly acceptable.

Thoughts on hand filing the windows on the NOS piston to match the slightly larger windows on the OG piston, or... leave well enough alone?


3 amigos.
L to R = Meteor, NOS, OG

Side by side OG on bottom has a slightly larger window.

if you open up the windows in the piston, do it to match the cylinder, not the old piston.

example of how they often don't line up:

Looks to me like someone just filed out the chamfers in the OG piston and yours would be the same size if you did likewise.

I'd go for it, but we all know I've never met a top end part I didn't want to take a Dremel to.

And IIRC Polini ships Meteor pistons with their 177 kit, though I could be wrong on that.

*Excellent* point!

I saw the same thing with my Polini, now that Patrick points it out...

wow.

Didn't figure it would be that extreme? In terms of reliability and not exploding the SS180 jug what is the best course of action?

The safest course of action is probably to touch nothing and just bolt it back together.

For safe changes, probably matching the piston windows to the cylinder and case ports as best you can, assuming your goal here is to minimize destructive changes.

Look at how the piston windows match with the case ports to start. The intersection of those defines the potential target, then figure out how much of that you think it's safe to carve out of the piston.

And then see if you need to up the jetting any.

Safest = fastest …and that's a bonus.

So win win.

you worked hard to get those unobtanium pistons, don't go carving them up - that's what I'm thinking

save that tuning shit for ordinary bikes

You have been intercepting my transmissions to/from Kajjit!!??!!

That was almost our exact text string this afternoon! (minus beisbol yammering)

well some say they've never seen Kajiit and I in the same room.

to be honest, I'm not sure that anyone has.

even the photo evidence of our meetups includes no pictures of us both at the same time....

KISS

keep. it. stock. stupid.

Im with John on this one- They ride JUST fine stock. Hot rod some other sled.

kajiit's tech department who handles all the encryption of outgoing messages is currently sunning itself in the window after drinking the tuna juice from a late lunch.

secure messaging will be back online after scritches


~end transmission~

agreed with the win-win get it back together and running.

then again...

edit: removed image, don't want to distract you. put it back together.

I couldn't agree with this more. Well, maybe I can if I suggest it x 10.

If this was a nikasil liner - I would be on the: quit your fretting and get out the Dremel Darla, bandwagon.

But its iron, and iron is unforgiving for piston expansion, and even though it might be okay MOST of the time, at some point, in a crowd of other scooterists doing some kinda ride, somewhere a little hot, somehow a little aggressive, feeling that breeze blowing your locks back, and the wonderful sound of the motor in its power band, that piston is going to experiencing some heat related distortion.

And that expansion won't happen symmetrically, affected by thicknesses and, well, holes.
Bigger holes will make it that much weirder in its new found heated shape - and that shape will not be well received by said iron cylinder.

Which is my way of saying - if you're gonna cut holes in a piston - do it with Nikasil lined cylinders - unless you like the sound of your rear tire screaming at you.

Save the whales.
-CM

Sage advice all. Many many thanks folks.
NOS piston with NOS rings have been installed as is... Stock around the block.


In other piston related news... while no one (major sources) seemed to have stock SS180 rings available I did find that Lambretta TV 175 rings are a match. 62mm by 2.5mm and the lands are spot on. Granted the ones I found are not Italian made... but they are readily available for anyone looking. FWIW.


"All you single ladies..." ...err, pistons.

Ready to go back in coach!


the long road to hamville

SWEEET

Video or it didnt happen.

The train to Hamville left long, long ago!