Modern Vespa

Thanks 👍🏻 If you need something modelled for your scoot, let me know, happy to support.

Actually, if anyone here on NSM needs stuff modelled, happy to help. Free of charge, and within limits of my abilities and time. 😁

Re the monster truck effect, you've got a point. I hope that GS style body kit (front mudguard) will sit nicely over the wheel, but if not, maybe I'll reduce the choice to 12". Don't like available designs in 12" 5x86 size though.

+1
On the impressive modelling.

Are you having this machined?

Thanks G 👍🏻

Yes, eventually.

I was looking at local shops, however didn't get satisfactory price/quality ratio. In other words, they asked too much for time on the machine and used material of insufficient spec.

So it'll be a far-eastern manufacturer most likely.

Twiddles moustache like a cartoon villain and starts plotting 😉

Like the late, great, Sean Lock in "carrot in the box" against Jon Richardson 😁😁😁

Happy to report that the order is finally in, for the seals, brown that is. Also some other bits as well, of which a few are pictured below.

Edit: So this happened again, attachments got lost. Now I have to retype all the smart-ass comments under the photos. 😂 Can someone tag in a forum person responsible for bugs, please? 😁

Only one main jet?

Yep, that looks like it. No one ever seems to believe me that the self-regulating works, but I swear it does.

To begin with. I do have a set of jet gauges and a reamer, so technically I just need one... 😂

This is very valuable to know, I'm hoping for it. Makes installation easier 😁

Ive had that one for the last 20 years 😀

I still run it with a return loop for belts and braces as it came that way when I had the shop install it

Its a good pump... I remember one time forgetting to connect it back togetjer properly and nearly had a face full of petrol when I was kicking it over

Great to see this moving along!

Cheers mate 👍🏻

I'm trying to push this, but there are delays everywhere. Shouldn't be surprised really, with the holiday season and all. I'm currently facing a delay with the welder and with the freight forwarder. And couple of things going on at home at the same time means I'm not doing much on the Vespa itself. Looks like I'm gonna miss the February '26. first engine start goal. 🤔

I've had it with the welder today, so I "fired" him. 😂 That meant I had to flip the script and turn to my backup option, which was the popular welder in the city, but at a cost. Well, what to do, other than to see him. I went just a few hours ago.

Looks like it was in the cards, as it seemed he's looking for simpler jobs lately. I could read the atmosphere. 😁 He first wanted to see what I needed done, before he gave me any information. And luckily, not only that he accepted, but he quoted me 75USD for it. I am in awe. His welding is top shelf, but I won't be able to document his work, until it's complete.

So, what does 75$ get me:
- welding the cylinder base to match the Explorer
- plug the old stud holes
- lengthen the intake port (a.k.a. replicate the long sealing surface)
- reinforce the input layshaft bore

If anyone's got anything to add, I've got time until 10th Jan. That's when he booked me in for.

I did a small mod on my input shaft landing. It's somewhere around page 75-85 I think. I also out a full plate inside so it's not apples to apples - but the results have been good/ it's very solid.

One thing to consider: The cases get quite hot when welding. They will shape shift.
When ever possible, I would bolt them together and torque before doing any work.

Thanks CM, that's great to know.

If you're talking about the SaFiS mod, I found it on page 68. Good work.
What thickness was that plate in the end?

Vintage vespa with sidecar (**Now In Technicolor ! **) (Post 2499390)

Oh well that's sounding very good! Hopefully we can get some pics of his process!?

I think the axle would count as the output shaft, and the xmas tree as the input shaft. The area I think CM is talking about is one we've discussed before, the one where the xmas tree layshaft exits near the clutch. It's an area that is known to crack under extremes (green line) and if that could be made a little stiffer then that would be a good thing I think.

Having said that the plate probably helps to stiffen it anyway.

Pics made me chuckle.
Brings back steep learning curve memories.

I started to weld it in trying to "stack dimes" and make it all pretty - but it kept cracking.
Finally sorted out that the cases needed to cool more slowly - and be fully heat soaked - so they didn't contract too much.

I was using 5356 filler rod - which is quite strong but has less magnisium (I think) than the vespa cases. There are some 4000 series rods that more closely match the cases chemistry and probably would have made it easier.

I eventually got to a process where I was doing a first welding - that would crack, and then going back over it and "washing" it with my torch, without any additional filler rod. This second pass had the advantage of the heat from the first pass. It wasn't very pretty, but it was really effective.
Those welds remain rock solid.

Thickness of the plate - I will check for you. I attempted to roughly match the case thickness ~1/4 - 3/8" if memory serves.

Still waiting for the Holiday's holidays to pass, so I'm prepping for the mods to the crankcase.

Crankcase halves have been washed very well, not to approval of my wife, as I did it in the tub. Too cold outside, and I don't have heating in either of the two garages. 😁 So it's ready for welding. Pics to follow.

On another note, I have made the adapter plate design, based on a combination of my own measurements of the Explorer cylinder base (and the cut template) and the PX1xx stud pattern measured by oopsclunkthud. Cheers bud. I did this purely for marking new holes, I don't plan to use it as a drill template. But, one could use the file to cut it out of metal.

Top represents the orientation in space, and also relative to crankcase.
Cutout on the left (as viewed from the top) is based on VMC design. It's parallel to crankcase split line, and I think it marks the potential interference with the flywheel.
There are also two indications to where the crankcase split line lies.

I'll add the file to the 3dp section.

Nice work!

Very nice work!

Are the holes to suit M8? If so, how do you get a good centre from them? Was thinking if they were of a size to suit a "standard" centre punch, that would make it easier to get an accurate location to start drilling.
That would be for all but the shared stud hole, which would be a snug fitting one to suit M7.

Good point. I can make small studs with a centre suitable for a punch, or reduce the holes in the design, should any of you guys need it. For myself, my punch is about 8mm in dia... 😂

The holes are 8mm and 8.6mm.

Just came across this bit of info which (hopefully) is of no use because you have plenty of meat there. This is talking about a reed case but worth a check.

https://www.facebook.com/SvgSctrs/posts/pfbid0Bdy5eQsLz2BKTtZHDTbKs7s5BzSajfR3rBKnrgmsHUh51E9nbnjBFWF8Ynua2Gj3l

Oh, wow! Thanks for looking out 👏

Hopefully this comment will come true in my case(s) 🤞😂

Couldn't just sit and hope... So here are the measurements. 😁

So you're ok there?

In the area illustrated by the FB post, absolutely. I won't be boring that deep, and if I have to manually grind for flow, I'll be observant.

Where I do lack is just under the mating surface (crankcase/cylinder). Of course, I have to take out 3.25mm of material, but that's what I'm going to have the stuff welded for. In other words, as per plan.

I've printed the adapter I posted yesterday, just need some bolts to secure it in place before I mark the new stud locations. I'll try to picture it tomorrow to show exactly how it looks.

Cheers

Looking forward to it!

Further fine tuning required...

Im liking this


I bet you will even draw the completed aluminium brace piece and upload it so anyone can. Get it cut and fit


Red Dwarf quote here.

I was gonna, tbh. Just didn't want to promise anything until it's done. 😁

Here you go guys...

Safis & Rikko

You guys are talented and generous

What thickness of aluminium sheet is recommended??

Here I will try to illustrate what I meant.

Big case half:

Smaller case half:

On the smaller side, situation is not so bleak.

Cheers G 👍🏻

I used a 100x100x5mm Aluminium coupon (alloyed with Magnesium), which I had available to me at this time. It was either that, or nothing for a while.

In essence, I don't think it needs to be thicker than case in that area, which is 4-5mm anyway. I don't believe it needs to be even that thick, given the load sharing with the case. But, as I said, 5mm is what I had... 😁

Nicely illustrated! Do you have someone lined up to mill the top after welding?

It was interesting in that FB post that 3 or 4 people commented that when they did their conversions they didn't have issues. So perhaps 150 to 200 is more common than I had assumed.

Cheers mate 👍🏻

I've got a machinist who I use for car engines, but his shop is not optimised for off-the-cuff stuff, such as the PX crankcase. I've once hired him to do machining on a Varadero engine, ended up paying for fabrication of custom tools required to hold the engine in the machine. And I didn't get to keep the tool. So I don't have anyone lined up ATM.

That being said, a friend recommended a machinist who's quite the opposite. He does almost only motorcycles, and he's versed in doing work which most shops refuse, like rebuilding the sliding surfaces for the cams. Sure, not applicable to this case, but does illustrate the machinist's capabilities. The downside is, he's away about 2hrs drive on a highway, one way. And then I'd have to go back to collect the parts... I'm still weighing my options.

On another note, I missed the welder appointment yesterday, so that's another setback. I'm curious to see if he'll take me in on Monday, or I'll have to wait for another slot...🤔

On another another note, the parts delivery is delayed, looks like by a week. Doesn't make much difference, given the above delay, but it could have if situation had been different.

To state the obvious, when machining the case, the skim, cylinder spigot recess, stud holes and threads, should all be done consecutively, without resetting the job. There is really very little room for any part being out of square. No pressure.

Other obvious, the 200 stud hole orientation angle is critical to the exhaust pipe fitting correctly. A degree out is probably a big deal.

Once this is done. Then onto the interesting work. I feel there's a lot more in an explorer.

Cheers Jack,

Given the complexity of machining, or rather, the lack of room for error, I'm more and more inclined to opting for the recommended motorcycle orientated machinist.

Re. the cylinder stud clocking, feel pretty confident. Which reminds me, need to update the file on the 3dp topic. Basically, what I've done is I used the template provided by VMC (which perfectly matches the cylinder: checked), and designed the adapter such as one originally created by Geoff. Or was it Jeff? 🤔 So I have a template which is a perfect match for the Explorer stud pattern, and a perfect match for the original px1 cylinder stud pattern. I've printed it, test fit it to both the cylinder and the crankcase, everything fits. As such, I'm expecting the exhaust to be located correctly. Well, at least hopes are high. 😁