Modern Vespa

I don't post here often but I do stop by almost every night to see what you guys are up to.

I've had a Pinasco 177 2 port kit sitting on my shelf for a few years now. It's time to play with it.

The plan is to put it in my Allstate replacing the VNA lump.

I'll be replacing seals, bearings and the cruciform.
Gearing is to remain stock 3 speed.

Clutch: Cosa with DRT 23t gear cog for 67/68 primary

Crank: ? Should I go with a 57mm or 60mm stroke?
https://www.sip-scootershop.com/en/product/long-stroke-crankshaft-pinasco_46006100?q=Pinasco%20crank

I'm also thinking of replacing the Pinasco head with this MMW head.

https://www.sip-scootershop.com/en/product/cylinder-head-malossi-mk-iii-177-cc-by-mmw-177-pinasco-alu_38348410?q=Pinasco%20177
Has anyone played with one of these yet?

Carb: I have a 20/20
Is that enough carb or should I go with a 24/24?

I'm sure there are things I'm missing and plenty of questions I'll have to ask.

What do you think of the plan so far?

I have the Pinasco 177 2-port on my three speed VNB2 (1962 Allstate).

I went with the 57mm crank, but if I was replacing the crank today, I'd go with the 60mm.

24/24 carb was easier to get rid of the roughness at 1/4 throttle.

Jetting needs to be richer than you might think. Go with a 120 air corrector/BE4 Atomizer, and I've got a 132 main jet in mine, may be dropping down to 130mj in the future, and 45/140 idle jet. This is on a 24/24 Dellorto with drilled passage to 2.1mm

Also, running the VAPE static ignition, which makes life easy when it comes to lights.

Hope this helps...

It sure does help. Thank you.

Oh yeah the Vape ignition is in the plan too.

I read through your awesome threads 62 Allstate Cruisaire & The tale of two rebuilds.

I have a VNB4

I went with a 57 tamm crank, pinasco 177, sip rd 2,
Pinasco EI and a 20/20 carb on stock gears (3-speed).

It's a torque monster. Will hit low 60's.
Wouldn't change a thing!

Afterthought - the rad thing is 10 or 15 years ago VNBs or VBCs weren't all that fun. These days though you can kit 'em out and they are just an absolute blast to ride. Fingers crossed these glory days of aftermarket, go-fast bits and bobs keeps going.

I would go with a 60mm crankshaft for flexibility of being able to adjust timing. I would also think about a longer than factory connecting rod. Both would be to allow adjustment of timing and squish. If I had the cylinder sitting on a shelf, I would dry fit it to see what you get for squish.

Good idea.

The squish is bigger than the 2.5mm solder that I have on hand.

I twisted two strands together and got a measurement of 3.5mm.

Did I do that correctly?

3.5mm!

You want to measure it at the very edge. Looks like it didn't squish enough on the cut ends. Try a piece twice as long as the diameter that you bend in half to fit and twist that around itself. Make sure the non cut end that is bent 180 degrees is right at the edge of the piston. Then measure that end that isn't cut after squishing.

You also want to use the calipers not at the part of the arms where they have a wider notch. Looks like you are measuring on the notched sections of the caliper arms.

Measure using the flat parts of the caliper arms that contact and close completely.

If you really have a 3.5mm squish, that is obscenely large.

That's what I get for trying to rush it and get it done before dinner.

I'll give it another go.

Okay the redo measurement is 2.1

If you currently have no base gasket and a 57mm crankshaft installed, a 60mm crankshaft would allow you to get squish to 1.0mm fairly easy with a base or head gasket.

2.1mm - 1.5mm (half of extra 3mm from a 60mm crankshaft)=0.6mm

You could adjust squish with a head or base gasket to get cylinder timings closer to where you want them.

Wouldn't need head for adjusted squish band at that point.

This is also a good time to measure cylinder and intake timing on rotary valve. You can get a new crankshaft that will keep rotary open a bit longer for extra power.

I haven't measured port timings before. I found a SIP video.

Is this the proper way?

I'm not sure if I measured this correctly.

I got:
exhaust port 148d
Transfer port 114d


Intake valve duration 138g
Opens 98 BTDC
closing 40 ATDC

It's Alive