Modern Vespa

Or maybe I should just go get a 12 ton hydraulic press. $169 for the Harbor Freight or Northern Tool special. But then I have to store the damn thing...

You're welding that pin before you put it back in, right?

I should've welded it before I put it in the first time, apparently.

New cases are due to arrive tomorrow and I'll talk with the folks at the machine shop about whether or not to weld it after it's pressed back into place. It's worked out about 2mm.

I'd rather wait a day/week or two and get it welded than risk having it trash your brand new shiny cases, no question. I would constantly be wondering if it was still ok.
It's moved once now, putting it back in place will definitely not improve the web's holding power!

Thats less than great, but could be worse. Remind me, is that a brand new crank?

Good the kit is safe. 11,500 rpm is really hard on the crank. Was the clutch nut still tight? Very difficult to determine the root cause. Once rubbing on the case and getting hot the cranks can come apart. Vibration and harmonics at this rpm start to matter.

If no press, could bang that crank back together with, warming, a big hammer and an anvil. Going to need fine balancing and balance factor adjusted. Quattrini piston will be lighter that what that crank is balanced to. Then welded.

Yup. Brand new expensive crank. I'm sure a local machine shop can press it back for me. I'd rather pay them a few bucks for a few seconds of their time than wind up the owner of a floor press I'd then have to store, and hammering it back would definitely not be my first choice, though I did think about it.

And, yeah, I'll be throwing a little spot weld on each side once it's back in proper shape and balance for sure this time.

are you gonna weld that crank to keep it from repeating? (after you true it)

Yep.

Amazingly, I put it on the truing stand and it's still within spec, only 0.0005" of play off true.

And there is a shortage of shops that have presses here in town, so being that I'm kind've all out of fucks to give today, I used an old water meter cover as an anvil and just hammered it back into place with a 3lb sledgehammer.

Even more amazingly, when I put it back on the truing stand after that, it was only 0.0003" out of spec!

Beating the crap out of it with a sledgehammer actually made it better. Didn't see that coming.

I'll throw a spot weld on either side before it goes into the new cases, but I'm pretty stunned that actually worked. And I didn't even have to buy (and then own/store) a hydraulic press.

Great. Hammer it some more. Get the crank to 0.0002 on the tip of the flywheel taper.
Balance at piston weight and adjust for balance factor. Drill holes in the webs to lighten, which it will need, probably not so much but it does matter.

Getting the runout tighter should be pretty easy since it's directly with the big end at vertical. A tap or two of the hammer.

I'm now going to figure out balance factor. Seems like the target should be 50-75% (FMP) and 2strokestuffing saying 55%.

balance factor higher than 50% is common on engines with vertical cylinders.

Lambretta 175 TV-SS (Post 2102177)

I just checked it and got 64%. I'm going to run with that.

This is not an exact science but on this set up, the balance factor should be 50 - 55%. With the horizontal cylinder, lighter than usual piston and 11,000rpm, any more balance factor will cause excessive wear.
Do the work, and it will notice.

I'm not gonna lie...drilling a couple of 1/2" / 12.7mm holes in a nearly new $500 crank is making me more than a little nervous, but I guess I could also fill them back in with steel plugs if it doesn't work, right?

Then, I had a thought...this is a P200 crank...and I bet Malossi designed it to work best with a Malossi 210 kit. Why not, right? So I found where scooterist provided those weights, fed them into my spreadsheet, and found that for that build, balance factor is 51% (ignoring piston ring & circlip weight, but fundamentally on the mark).

Anyways...my crank webs are 15.3mm thick, so all the way through would be just a tiny bit more than the perfect amount.

While it seems to work out amazingly well on the maths, which always makes me nervous because I feel like these things are seldom this clean in the real world, but given how well it would work if I *was* running Malossi's ideal setup, I'm going to go for it.

I'll drill toward the outer edge of the crank, because I'm not accounting for rotational momentum, but this isn't *that* accurate, so it's probably okay to skip that element.

My one risk mitigation is that I'm going to leave myself a fallback option by drilling a 1/8" pilot hole through both webs, then drilling each web from the outside so I don't have to punch all the way through. That way, if I need to plug them again later, I don't have to worry about the plugs sliding into the conn rod and resetting the explosion counter Boo-Badge style.

Showing my work...

Okay...so I fucked up...I ordered the Malossi P200 cases, not 150 cases. Which is a problem right about now, for obvious reasons.

Although I will say the new VR-1 cases arrived yesterday and they are REALLY nice build quality. Definitely a lot thicker all around, and especially at critical locations like around the primary drive shaft hole. The case mating surfaces are mostly 10mm wide, with one bit on the crankcase itself where the primary needs to clear it being 6mm. No oil suckers here.

It included crank and fly side axle bearings (strangely, no clutch side axle bearing. Go figure), which is really good since the fly side bearing is non-standard, and seals, which are standard. Plus engine buffers and all the reed goodies.

No case gasket required, just sealant. That's the same as my Quattrini smallie cases. The halves are number stamped, so clearly manufactured as a pair. Malossi recommend RTV Blue (Loctite 5926) or similar. Really thick sealing surfaces, and no lip around the crank case.

I guess I'll give Dave a call and see if he can sort me out and get me the Malossi 150 cases. If not, I guess I'll eventually be building a P200 on Malossi cases.

You could save it for a rainy day for a screaming 200+ engine. That VMC top end looks pretty sweet.

Yeah, the Malossi cases include a lot of things, but strangely not others. The included hardware, bearings and complete reed set up make it a pretty good deal. I went with the VR-1 because 200 cases are getting long in the tooth and seem likely to have some rotary pad damage. As well, moving away from the si carb gives more flexibility. With a 200+, you get more power from displacement alone without having to get in deep with tuning. A big consideration for me, though not for you. I got mine from Scooterpartsco for $900 at the time.

Balls.

Pretty much. Right now, my irritation is as much with myself for having ordered the wrong part when I was all mentally set to most likely get this project done this weekend.

I've bitten yet another bullet and spent another $1,100 (including shipping) for the proper cases. Just annoyed AF I'm at this point.

Since I have a P200 motor with a 210 MHR SR3, and an EFL stack, I'm in good shape for an eventual transplant. I have all the stock parts still, too, so I can put the 200 motor back to stock and recoup my costs there if I decide to do that.

Decisions would still need to be made about if I kept the 210 or went with a different top end, but since I don't have a crank for it, that's a fairly academic discussion at this point.

TL;DR: I bought the 150 cases, now need to sell some stuff.

Find something relatively easy and simple to do on the lambretta, that should keep you going for at least the weekend.

Exactly. In addition to various Vespa stuff, I actually have a disc brake to install on it, so that'll be a thing that happens instead.

Must have been a quiet afternoon at SIP.

If I had a re-do with my VR-One engine, I'd go straight for VMC 244
https://www.sip-scootershop.com/en/product/racing-cylinder-vmc-explorer-244-cc-for-vespa-200-rally-p200e-px200-e-lusso-98-my-cosa-200_15066700

Shame it was released after I already had the Malossi 210 and crank to go with it.

That's kind've where I'm at, too, on the 200 front. Or another Quattrini. So far, I feel like I'm two-for-two with the BooBadge and the Lammy. Mostyl, I'm trying to decide if I want to afford doing that project immediately after this one.

A buddy of mine will buy the cases off me, so what I'll probably do for now is put a 60mm race crank and the 8" conversion kit on the existing P200 motor and throw that in the VBB for a bit.

I have a handshake deal to sell my SprintV to that same buddy for some cash and a project Lambretta Riverside. That'll be another bare metal teardown, so it should keep me out of trouble for a while, but also most likely do Bad Things to my wallet in the process.

My new cases are shipping out from SIP today, so I'll have them sometime next week.

Bare metal Lambretta project = 2* financial pain of vespa project, but you are already well versed in it and going in with eyes open

Yep. I know what I'm getting into. I've also already started thinking about how I'm going to get it all painted, too. Like, there's a lot more different parts you have to paint and hang up on a Lammy...like, where are those going to fit???

Still, it will be a fun project and it'll be nice to have a showy bike, rather than just a fast one.

yeah painting a Lammy is a whole different ballgame. never did it, thankfully. The one upside is the parts are small and if you jack one up - no problem, just redo. The only panel that is more like a vespa is the leg shield. the frame is mostly who cares territory except the visible hump portion.

For farming it out - nobody wants to do it. but for the home job - there are actually some advantages now that I think on it!

use serveta mats instead of leg shield runners if that part turns out poorly

New cases arrived yesterday, so I finished up the Lammy's front disc and now I'm getting ready to install the bearings.

appears to be old Scoot.RS stock?

Yep. I've already had it out on the road and it works GREAT

Small world honestly. Back around 2011 when I was living in Sai Gon, I was helping out with quality control at Scoot.RS, I knew the guy somewhat that was doing the machine work on those units. His Sister worked at Scoot.RS and helped with translations in different areas. I really knew him more through his sister than simply an employee at that factory. anyways, he was very quite individual and kept his station organized.

I got it from Lee Lux, who I assume rebuilt it since it was on his Series 2 before he sold it to me. the install of the brake itself was about as painless as such a thing can be. The SIP switch housing/mount for it, on the other hand, was kind've marginal and a huge pain to install. Better than having to weld material onto my old housing and then grind that down, though.

I ground down just a couple millimeters too far for the brake line, but it looks pretty good just the same.

Meanwhile, bearings are all installed. Every bearing except the fly side crank bearing just fell right in like it was the easiest thing in the world. Oven heating will definitely be my go-to method from now on.

The fly side crank bearing got a little crooked and I wound up putting the cases back in the over, then sorting out a puller which straightened out and let me pull it in. It never did want to just fall in, but went in ultimately just fine all the same.

Tomorrow, assembly can begin in earnest. Barring any ugly surprises, I'll be back on the road (again) with this one over the weekend.

Did you find a roller bearing for the fly side, or just going with the supplied ones?

I'm just going with the supplied one. I'll probably come to regret that decision, but if all goes well, I'll be kicking that can down the road for a couple years, at least.

It's nothing special, just a T5 one
https://www.sip-scootershop.com/en/product/bearing-crankshaft-flywheel-side-malossi-25x52x15-mm-6615990b-58800-for-vespa-t5_M6615990

Thanks, Jack. I'll worry about that when I split the cases, which hopefully won't be for a while.

I'd worry about getting them together

That's what crank pullers are for

When I got my Malossi cases, it had two roller bearings. I'm pretty sure they were both the same size, which I guess makes them 62mm?

It was no big deal pulling them together.

Oh, and while I was looking at bearing sizes, I found they now have a pre-spindled case for Uncle Tom, with spigot bored for VMC244. Nice work.

https://www.sip-scootershop.com/en/product/crankcase-sip-performance-malossi-vr-one-for-quattrini-vmc-bfa-244-for-vespa-p200e-px200-e-lusso-98-my_57172452?usrc=Crankcase%20MALOSSI%20VR-One