Modern Vespa

Thanks CM.
Helpful.
Makes sense.
So while we are here:
- What is the best method of install for the crank sleeve ?
- Haven't I seen some Vespa engine case that has some kind of retaining "ears" on the clutch side that holds the bearing in place? (as opposed to a circlip)

I'll either do the ol' freeze the crank and heat the ring like a bearing install. I've also used my crank puller to press it on when that only halfway worked.

My Sprint motor has the tabs on it. I'll dig out a picture when I get home it you can dig through my Sprint rebuild thread, which might have one.

I could never understand why Malossi went with the stock P series bearing on the fly side of the V-One casing. The T5 bearing is clearly the way to go for an uprated motor, yet they only designed it into the VR-One casing for some reason

Love all the extra stuff I'm getting up to speed on as I ramble through the brush.

SWA - hadn't caught that. Weird. Agreed.

CM. Sprint? Hahaha. Ik I had seen it somewhere…. My garage…. Thanks.

The tabs hold the clutch seal in place, not the bearing.

Ok.
That pic explains more for me.
There's not a lot of force trying to drive the bearing or seal out toward the clutch.

I'd also imagine that since that seal is steel inside - the bearing can't really escape outwardly even if it wanted.

Mostly - I wondered if there had been a retained bearing used on some case at some point - for the inward direction- but it appears not.

I'm doing some clean up and preliminary thinking on how I might solve for my motor. Have a simple plan for the fly side - will share with some photos perhaps tomorrow.

The usual method is heat/cool, but the easiest method that also allows for fine adjustment is a spacer/sleeve pushing the inner race into position using the thread on the crank.

I have no idea what your plans are, but maybe this item could give you some ideas? Take a very close look in the picture and note that the holes don't quite line up with the threaded studs! Both SC and SIP sell that part.

https://www.scooter-center.com/en/locking-ring-drive-side-bearing-td-customs-vespa-p-bolt-on-type-7670877

Thanks Ginch.
That's helpful.
I can create a little press as you describe.
Like.

Whodat - Nice!
was just typing an update.
Appreciate everyone continuing to throw in knowledge and ideas through the day.

That element you are showing is along the lines of what I plan.
See image below - its a flat shim about 1.75mm thick.
I plan to drill/countersink flat head retaining bolts around it just outside the bronze bearing seat.
It will overlap the opening and serve to keep the bearing from moving inboard.

Cases are stripped/ cleaned/ inspected.
Patch where I burned through near the primary looks like I have a crack.
Not sure its worth/possible to repair - but I will have a closer look and determine options if any.
These cases probably have limited life in them.
Worth using to test the retaining if I can get them to hold tighter long enough.
Probably the last time I will put back together tho - facing diminishing returns.

Lets see how the retainer ring works.
Go from there.


I will modify this shim to create a retaining ring

Do you guys all know about these Roloc Bristle thingys? I use them to clean the gasket surface - soft enough not to damage the aluminum - tough enough to strip the gasket.

The after - really clean it up quick. Love em - no gouges like with razor - 10x faster - more thorough.

The ring will be fine as long as there is approx 1mm between it and the crank. Any closer and there will be some element of power robbing drag.

What I would do in preference, is to half depth recess the casing to accept two ears about 15mm wide and slightly cut into the bearing for the overlap. Counter sunk screws and loctite and nothing is moving.

There are a number of geometries I am trying to satisfy.
Primary gear - clearance to main seal holder
Main seal to crank shoulder
Main crank web to cases
Then the whole other side of the crank at the fly side...
Your point on drag and option on milling the bearing are good ones.
Will keep those in my belt.
I had already planned to counter sink the retaining ring - once I figure out the usable space as per the geometry notes above.

But first - I had to try and repair this rolling fill rod of a set of cases I have.
The crack that formed was nasty.
Went back in to the main bearing through a large air pocket in the original casting.
Truly felt I was just going to toss the cases away more than once this afternoon.
Managed to get the voids to fill - and welded up the crack on the inside.

If you think I'm approaching the boarder of diminishing returns - I would just like to say in my defense - I am no where near the boarder.
I passed it months ago.
🙂

Retaining rings arrive tomorrow.
For your viewing pleasure below today.


Cracked here. Meant I would have to attack from both sides to get it well healed.

The crack went through to here. I ground off the epoxy I had sealing this area and roughed up the surface for prep

Was tough to get the welding head in at the right angle - and it's not very pretty - but it seemed more effective than I thought it would be in the end.

From the other side - I came back and put a bead along the crack. (ancient bearing inserted as heat sink)

Ha ha! If you ever need to know where the line in the sand is, just take a look behind you...

wow it's like the six million dollar man, we can rebuild him. Inside weld bead looks great if they all could look like that it seems good.

Good save on the crack. Casing was close to junk.

Recessing the whole ring would need quite a bit of metal removed, might not be much left to stop the bearing cracking out the case. To block the bearing from moving requires very little metal contact. 2 ears are plenty.

I'm primarily focused on getting the crank inline with the center of the motor - and ensuring the seals and bearings line up.
Bigger puzzle than it might appear.

Question for the crowd:
Normally there is a groove cut in the cases that allows the side of the P200 crank web to sit closer to case half; its raised rib sitting down in that groove.

Does anyone know what this gap is?
Seems like it would be less than 1mm.
Not sure tho.

Craig or Safis - any idea on the Malossi cases how much gap is between the side of the crank web and the case half on the clutch side?

Outer or inner?

I have a flyside laying around somewhere but don't recall a groove on the outer. Let me go dig…

Sorry my crank terminology is no bueno


Less than a mm and doesn't go all the way around on the flyside

Inner is maybe 3.5mm…
(Using a cm ruler and converting)

Oh man.
So appreciate that.

Ok. First - mine is a Hendricks and pelegrino - w/ lime.

Second: I'm talking crank as opposed to fly side.
Looking for the gap between crank web's side and cases - once crank is installed.

I'm reacting to the point jack made on drag caused by the proximity of the crank webs side flank and the cases. It makes sense that file oil mixture will create resistance when that gap gets too small. However - I think the std gap may be smaller than 1mm.

That's what I get for (not) paying attention.

*ducks back to the bar*
(Hendricks and fever tree tonic)

<>

I mean…

do you want the critical measurements of the relationship between the flat of the crank web and case with a focus on the lip/groove for P200?

am I right? am I even close?

Greasy - yup.
How much space is left between the side of the crank web, and the case ?
Suppose that's not easy to tell - cause the lip of the crank is in the way.
May have gotten my answer tho another way.
Below a picture of a 150 performance crank.
(ignore the welding experiment...)

The lip is .5mm.
On a 150 - this would create a .5mm gap between side of web, and cases, when crank inserted.
Perhaps my answer is - I need somewhere between .5 and 1mm of gap.
Jack suggested 1mm.
For reasons this GnT are making too hard to explain - its not that simple on my design.

Think I have what I need now tho - guess I just had to process it on this page...

With a SIP crank installed in my stock 200 cases, there's at least 1.6mm gap (where I have the orange circle on the crank web). That's with trying to stuff feeler gauges in there at an angle. In real life have a feeling that it's closer to 2mm though.

Whodat!
Yup - that was the spot I was asking about.
Thank you.

Kinda interesting - and I'm gonna get myself in trouble now - but that means that the lip of the crank is not actually in the groove on your motor.
(Ik, Ik, your post was not supposed to be about your motor!)

I know there is some wiggle room on how and where you install a crank.
I've seen various videos where they give it a tap to re-center it after the cases are closed.

It would be interesting on that motor you shot the image of if you blued up the crank with some sharpie - and then used an etching tool of some kind through the intake while turning the crank - to show whether it is on center with the inlet?
Do people offset the crank on the inlet to bias it to the clutch side to allow for movement with time?

Feel free to post an unfriendly hand gesture in response - and thank you for taking the time to have a look and show.

I've never purposely centered one but I certainly give it a hairy eyeball down the inlet and a touchy-feely kinda once over. I figured that things would kind of self correct as needed and allowance for wear was that if it were veering into that territory everything would be wore out and crappy thereby making an ass ton of noise and performance would be way the F down.

-That's correct, the lip on my crank isn't actually in the groove on the engine. I didn't make any actual measurements of how much of a gap there is between the two.

-I'll try to remember to "blue up the crank" tomorrow. It would be interesting to see where the crank is at there.

-I've never been aware of anyone trying to offset a crank in a P/PX case. There's really no additional offsetting of the crank that can be done (unless you use some sort of shim between the crank and crank bearing). On a P case, the clutch side bearing is sandwiched and locked into place (it ain't goin no wheres), and then the clutch nut pulls the face of the crank tight against the face of the bearing. I figure by the time you get noticeable slop in the clutch side bearing, that means it's well past the time to replace that bearing. I'm not sure how a love tap can do anything beneficial. I will do that tap (aka "shock load") the bearings on other things, such as on automotive U-joints on axles, drivelines, and 4x steering knuckles.

Charlieman22, you are INSANE. Awesome work here. Diminishing returns for the win! Doing the lords work....or is it the Devi's, we'll know in the end

Whodat - this is probably more my ignorance / learning than anything else. I kinda figured that was the case.
So when I saw your shot - I wondered - is his crank really pulled in all the way? (don't say it).
And if yes - does that mean that the P cranks don't really use the groove?
Kinda intrigued about all that.

Below is a shot of my frankencranken.
Its a P200 crank - that I had the journals ground back to match a P150 crank - about 100 pages ago.
The outer rib is ~1.8mm deep.
That inner area raised area around the crank stub - that will bottom out against the bearing - is 1mm.
I unwisely asked the machinist to take it down flush there - but his grinder wouldn't reach - thankfully.
Those two large washer looking things are giant shims - one of which I will try and lathe to my desired shape.

Less words - more photos tomorrow with outcome.

FWIW, I had to do this when I rebuilt the Yellow Beast. There was ~ 1mm movement available that allowed the crank to be pulled too far into the clutch side causing it to interfere. I think it's safe to assume Piaggio's engineers did this to account for some thermal expansion of the parts at operating temperatures.

Agreed.

There is definitely a little bit of lateral float on the cranks of my VBB and Sprint, and it will bind if you pull it too far in, but so long as it's not binding, it always seems to do fine. I don't know if there's a "correct" spacing and I've just always gotten lucky, or whether it just needs to Not Bind.

The 200 crank is pulled all the way in in my picture. That lip is needed. Take a look at these pics here...

Whodat et al. Seems like in a normal Vespa motor then, there is some float to play with.
Thanks for the input gents - and appreciate the follow up pictures.

Factoid: turns out you can't cut hardened steel with a standard lathe tool.
Why is that important you ask?
Im getting there, I'm getting there.
Sit tight for a moment.

First up - I needed to create a retaining ring to hold back my bearing.
The idea is - preload the bearing against a strong ring - so that I might get long life with the crank in the same position.

But might the crank move inside the bearing?
Yeah - it might - but the one thing I have working for me is:
- the retaining compounds are best with steel on steel
- the crank is already a press fit.
We are gonna find out if those will combine to lock my crank in the bearing.

As for the bearing locked in the case - see pics below.


First up - I resurfaced the area where that crack was - to take the bead back down flush. Came out ok.

Next up I turned down the shim OD and ID

Final width is just enough to overlap bearing 2mm and leave 4mm for bolts to hold it down. 78MM OD/61MM ID

Next up was the bearing. Turns out to be too hard to cut - so instead - I ground. Started with a nice set up with my Dremel - got impatient - and pulled ou the big guns. 2mm recess around perimeter.

Then I milled a recess in the cases. same depth as locking rink (1.9mm) with 2mm overlap of bearing, and 4mm overlap of cases. Careful look - you can see the recess in the bearing

Will add screws to hold this locking ring down. Then I will flip cases and punch the bearing up against the ring - to preload it. Think the bearing will stay put. Maybe the crank will too?!?

seriously dude you are a mad genius. I dont know what to say other than, excellent work

Saw this, instantly thought of CM2's project:

Make your own bearing holder, doesn't look like it's going anywhere

Thanks GL!

108 - too funny.
The guy is doing 90% of my mods - and executes well.
Note he aligns the case halves after he does the work.
Perhaps he uses pins to hold it there.
IDK.

He also went reed - and pushed it closer to the cylinder.
And it looks like he is planning for a big cylinder - because he made the cylinder skirt area enormous.
Perhaps a motorcycle one or a 244 or 260 like Craig's quatrinni.
IDK.

Pretty fun to watch tho.
I could just have posted this guys video about 20 pages ago and been done.


His welding looks pretty good.
Very compacted.
Few voids.
And that's a pretty good sized opening...

Found prior vid.
Looks like he is doing the old Malossi 225 on sprint cases trick?
Cool.

Just goes to show that the only real difference between a large block and a small block is the amount of welding and machining you're willing to sign up for.

indeed.

Had a few hours this afternoon.
Decided to finesse it - smaller but more bolts.
Not certain that was the right thing to do - but it left more meat on the cases.
Everything is a balance.

Pics below.
8@ 3mm x 8mm bolts
Feeling was: this would be sufficient for retention of constant stress - though it might not survive a shock load (like from a sledge hammer hit).
Only time will tell.

Forced me to figure out how to use the bolt hole pattern app on my mill's DRO.
One of those features that I thought I would never learn about.
Part of the reason I am doing this.

Images below of status.


Drilled first - then chamfered.
Had to change bits.
See next image of DRO nifty tool for alignment

This was pretty cool.
Adjust to move the orange dot over the red - then fine adjust until X & Y are at 0.
Just tell it how big a circle and how many holes - and it lays it out for U

X & Y now at 0 the machine gave me - ready to chamfer at exact point you drilled.

Tapped, cleaned up, and bolted down. Might have been a better play to use 4mm bolts that were shorter. But this is what I have - I think it will work. Ugly grinding is intentional - for epoxy to bond to.

Well, that's not going to move now. Really nice looking job. Will be all different this time out.
Clarence sorted on the fly side case?