Modern Vespa

Wow great job maybe you can take your hands off the handle bars now and it will steer straight!

🤣 I hope so!

Got a chance to finish painting the last of my black parts. Just need to finish working on the frame then that'll be the grand finale of the painting.

Took a couple photos of the base coat and what they look like after the clear goes on. The base coat is thin and shows sand scratches and looks bad till the clear is applied. Night and day with the clear.

Looks great Baja black chrome is on the spectrum of silver.

Gorgeous paint!

That clearcoated black looks amazeballs.

Clearcoat brings a gloss that single stage never will, but you still have to know what the hell you're doing to get results like that.

The camera on my phone makes it look even better!😁 The lighting in our booth is terrible so I shoot with a flashlight in my other hand. Once the first coat of base is on its really hard to see what you're doing.

The principle of leverage right there!

So what's the tolerance for a bent fork? Idk
My VNA fork is slightly bent towards the rear (bubble level). No issues can't feel anything.

Thanks Ray. That helps alot. I have no experience in this department. Sunday was the first time I've ever ridden a Vespa thanks to Hibbert. I've had this scoot a long time but it's never been rideable. Would be hard for me to tell if a fork is bent enough to make a difference. Now I can sleep through the night without worrying about twitchy steering!

Black paint is unforgiving, but you make it look easy.

Yeah! It looks really great

Thank you orwell84 and GeekLion. I do get nervous every time I'm going to paint. Using the same brand of paint and knowing it's characteristics helps a great deal. The clear is really amazing from House of Kolor too. It goes on pretty smooth. Doesn't take much color sanding before buffing either and gives a nice deep glossy finish.

Wow - looks amazing!

I made a tool to install the engine mount bushings. Wish I made it sooner. Tried to use the press at work first without stellar results. It's fastened now but I think I need a better staking tool. 🤨

Cool. I used the threaded rod technique. It was fairly difficult.

You always come to mind when I'm painting. Some things I've discovered recently in my painting adventures:

High build primer. I've known about it for a long time but have always used an epoxy primer that can be used for sealing or build depending on how much reducer used.

High build primer works way better. It fills tons of imperfections and transitions between filler and bare metal. It's way easier to sand and there is a lot less chance of breaking through it. The primer I used before required more rounds of application and sanding. It works, but I will never deprive myself of high build again. It's also way easier to spray. I gunned it on after 2 coats of regular epoxy.

The other revelation: Twiddling the knobs on the paint gun. It can be fine tuned a lot on the fly to adjust to how you paint and the surface you are painting. Turned down the fan and pressure to do slim edges, opened it all up for big surfaces on the same piece. Less overspray, mess and paint in the air.

It's like plinking away on a guitar for years, until the day you can play a song. Sorry, just had to share.

Totally true and glad you shared! We use the same type of primer at work. For the pieces that are smaller and already have a nice finish, I use the primer as a sealer and just shoot right over it with paint after the primer gasses off. Really versatile stuff. Only way to go for me. I use a 1.8 tip for primer. You can get a really fine finish with a 1.4 tip shooting it as a sealer though.

Did a little reconstructive surgery from the augmentation removal. Just needs a little more sanding. Now she's whole again. Thank you hibbert for letting me use yours for the template!

Looks great like it never happened. Black chrome is next.

Impressive! Great job

Huge progress for me today. Buttoned up the cases. Had everything laid out nice and neat. After the case halves went together I realized the new bougie bolts I bought were too short. Made a mad dash to find the originals, clean them and put them in. SIP claimed they were the correct size but my mistake for not double checking 😟. At least the loose rollers didn't drop out on assembly. Gick's crank seal spreader for the crank made installation a breeze. Tomorrow I'll detail and fit the cylinder. Going to figure out the timings and squish before putting it on and doing a leak check.

Here's a pic of the new exhaust compared to the original.

Here's the cylinder map and squish using solder.

Can't wait to see this finished. Looking great so far.

Billet head looking cool.

What's the PBT, stroke and Conrod? With these the port timing can be calculated. The carb inlet is difficult to calculate correctly but for this a degree wheel duration will help. And calculation needs the bottom edge of the piston window to crown measurement.

57 stroke
105 rod
Bottom edge of window to crown 57.8

I measured the squish of the head and the PBT and can't find where I wrote it down. 😡 I did manage to measure some degrees with the wheel. The cylinder is all buttoned down with zero leaks and a measured squish of 1.6.

TDC to top of intake transfer 124.2°
TDC to top of exhaust 109°
TDC to BDC 178.5°

I tried to convert the degrees to mm but wasn't successful. 😂

Really need the PBT to calculate. Can you guess?

Your degree wheel exhaust duration is 142. If correct will be high torque and run like a generator engine.

I'll going to pop the head off and check. Got so excited I didn't remember to check the numbers with the stock head! Amateur move there.

Do it even if you don't change anything good to have the measurements. Probably won't disrupt the case/cylinder sealing.

Add a photo of the inside of the head.

Donatella My 1961 GS Experience(augmentation removed) (Post 2677891)

That head is more like a high power head. Smaller squish area and big bowl. Will still work but a larger squish area would be preferred.
Looks like most of the squish clearance is in the head.

Here are the numbers;

PBT .3
Squish new head 1.6
Squish original head 1.75

The blue SIP gasket is .45 so if I used it the squish would be .35 more.

These numbers come out like a model aircraft engine.
143 Ex 115 Tfr 14 Bd
And the exhaust port is about 10% narrower than what would be very conservative.

This is very low port timing. The Exhaust duration does confirm your degree disc estimate. It's going to have a lot of torque and not rev very high. The max rpm will probably be the same revs as the max power.

Need your piston length, on the inlet side to work out the inlet duration. It will be opening/closing on when the skirt clears the window.

Plenty to modify. I think right now 40mph will be a struggle. Going to be a beautiful scooter; people will have plenty of time to admire it, as it crawls past them.

That's interesting as the stock GS150 setup is a 55 mph bike with room into the 60's. Yes, not a high rev engine.

Need your piston length, on the inlet side to work out the inlet duration. It will be opening/closing on when the skirt clears the window.

Plenty to modify. I think right now 40mph will be a struggle. Going to be a beautiful scooter; people will have plenty of time to admire it, as it crawls past them.
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There goes my dreams of setting new records at Bonneville! 🤭

Skirt to crown 64.16
Intake side to crown 60.78

Using the inlet side measurement, the duration comes out at 91 degrees. This is short. Often these are 110 degrees. Can be a bit more but go to far and they easily flood, ending up with Lambtetta type issues.

It's not going to be fast but it will be saved and back on the road.

It may well get there eventually. Head down, wide open, small hill. With the 2 port technology of 1961, they had to be blowdown restricted to have any power. Which means the exhaust pipe gets hot when into overrun rpm. And then it needs loads of extra oil to keep it reliable. Hence the 6% mix. Fun for sure.

It's not going to be fast but it will be saved and back on the road.
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Thanks Jack! I'm going to run this cylinder with the newer pipe and see how she goes. After SIP releases the new cylinder kit (December, yeah right!) I plan on trying that out and comparing the two. Maybe I'll be able to keep up with hibbert on the longer rides with the new kit.

This looks pretty good.

That's interesting as i ride these bikes all the time owning 5 of them. Not head down, wide open, with a hill.....55 mph. it's simply not like that, not a struggle, but certainly not a modern cylinder.

i think somewhere the measurements, math, or formulas are not ending up in reality.

The extra oil is to help with the bronze bushing in the small end and help with the crank bearings. the being said, new cranks come with a needle bearing and many users now run 2% .