First full restoration project.. 1980 P200E
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Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Thu Apr 30, 2020 5:07 pm quote
With those parts mentioned in my previous post, I started looking at what type of port timings I should be targeting for economical touring on stock P200 gearing. I found a similar thread by ginch where jack suggested two possible targets for touring results on a P200.. piston below deck @TDC target of 3mm below deck, and/or a squish of 0.8mm.

http://modernvespa.com/forum/post2309694#2309694

So I measured my stock P200 barrel and came up with these numbers (no measurements for the Rotary Valve yet as nothing is mounted in case).

Stock P200 Port Timings

Exhaust: 39mm
Transfer: 47.8mm
Stroke: 60mm
Conrod: 110mm

My default port times if set to zero deck are as follows:

Exhaust: 161
Transfer: 122
Blowdown: 20


Now if I wanted to get to same exact port timing I have on my stella 177 kit, then I would have to set everything to these numbers:

Piston below deck: -0.8
Exhaust (grind up 5.5mm): 33.5mm
Transfer: 47.8mm

with the MMW 0 deck head this gives me the target 0.8mm squish jack mentioned on Ginch's thread for touring, but my port timings become exactly what they are on my stella kit: 185/125 with 30 blowdown.

If I wanted to meet (or get close to) his other target instead... piston at 3mm below deck then my port timings become much higher. This would put my numbers square in the target timings for the viper exhaust I am looking at. Those numbers are as follows:

Exhaust (grind up 6mm): 33mm
Transfer: 47.8mm
Piston Below Deck: -2.5mm

which give the timings of 194/134 with 30 blowdown (this is in the middle upper range of the viper exhaust targets SIP suggests).

So my question is, for touring/torque/fuel economy.. is it better to hit the tighter squish, with the lower port timings having the piston higher in the barrel? Or is it better to have the larger squish, with much higher port timings and the piston lower in the barrel? Obviously the second option of 194/134 would have too large of a squish at 2.5mm so would require some work to the head to get the squish down.

Any suggestions? I'm trying to more completely understand the torque/fuel economy effect of piston height and squish. My personal thought is that higher port timings equal higher RPM equal lower fuel economy and torque, but I feel like I have read that having the piston lower in the barrel equals more torque, so I am confused as to which priority is important in a circumstance like this, given my lower piston numbers equal much higher port times as measured currently. I am leaning towards the higher port timing targets of jack and sip viper exhaust because that gives me a lower piston in the barrel, then possibly adding 2.5mm head gaskets to lower those port times, along with the max rpms. This would then require a considerable amount of machine work on the head to counter-sink it enough (approx 4-5mm) to reduce the squish to usable range.

Im also probably way wrong in thinking the placement of the piston inside the barrel is so important, and over complicating things for myself, and rather the only really important thing is port times., Which my -0.8mm below deck and 185/125 would get at much simpler and easier.

And this is all on a Grand Sport piston.

P200_stock_default60mmtiming.jpg
stock measurements with zero deck

P200_stock_tightersquish_lowertimings.jpg
0.8mm squish by default, 185/125 timings

P200_stock_jack+viperexhaust-targets.jpg
Jack and SIP Viper exhaust target timings, much larger squish.

Ossessionato
1979 P150X, 1983 P200E, 1988 T5, 1995 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 2070
Location: Veria, Greece
Fri May 01, 2020 4:48 am quote
Personally, I would go for the new Polini crank instead of the Mazzi. Definitely my next purchase...

https://www.sip-scootershop.com/en/products/long+stroke+crankshaft+polini+_45121000
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1557
Location: UK (South East)
Fri May 01, 2020 4:59 am quote
I would definitely go 185/125 to meet your objectives, and I would forego the Viper for a Polini box or a Road 3.0. Those higher timing are getting you into serious MHR territory, but with all the limitations of the P2 iron cylinder. All my opinion of course

What piston do you have in mind? Grand Sport?
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1557
Location: UK (South East)
Fri May 01, 2020 5:00 am quote
SaFiS wrote:
Personally, I would go for the new Polini crank instead of the Mazzi. Definitely my next purchase...

https://www.sip-scootershop.com/en/products/long+stroke+crankshaft+polini+_45121000
The machining quality on that Polini crank does look good....
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Fri May 01, 2020 5:59 am quote
swa45 wrote:
I would definitely go 185/125 to meet your objectives, and I would forego the Viper for a Polini box or a Road 3.0. Those higher timing are getting you into serious MHR territory, but with all the limitations of the P2 iron cylinder. All my opinion of course

What piston do you have in mind? Grand Sport?
Yes a Grand sport piston.
https://sip-scootershop.com/en/products/piston+grandsport+200+cc+_12090000

My other option I figured was a better choice was the sip road 3, so we are in agreement. I just really want to try the viper but its not for this build.

Regarding the Polini crank, any reason you both prefer it? Just because it looks machined better? They are practically same price so it makes no difference to me.
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1557
Location: UK (South East)
Fri May 01, 2020 9:03 am quote
I've not personally had any issues with Mazz cranks, so I won't knock them. My favourite is the 60mm Tameni that's in my PX225, simply because it's served me very well for seven years and many thousands of miles. The Polini does look shiny and well made

I've also been itching to try the Viper since I read about the prototype in a bake-off, but I bought the BBS cause I need something last November. I just think that you'll not get the bang for the buck if you're after a fast 'o' tuned tourer.
Ossessionato
1979 P150X, 1983 P200E, 1988 T5, 1995 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 2070
Location: Veria, Greece
Fri May 01, 2020 10:19 am quote
Build quality, finish and a better conrod (CNC milled), plus I've seen a few Mazzis failing lately...
Member
1965 Vespa VBB
Joined: 20 Apr 2020
Posts: 26
Location: NYC
Fri May 01, 2020 10:51 am quote
If you're looking to clean up that cylinder while minimizing material loss on clean steel, a SUPER effective way is to use "The Works" toilet bowl cleaner. It's a more potent acid than vinegar alone, but once you've used it, you can just flush it.

Rig up an old paint can and wire hanger holder to grab the cylinder, than put in the cylinder and pour in The Works. Avoid the off-gassing which is an irritant, and check it every 5 minutes.

I've cleaned at least 25 gas tanks this way, and it's fabulous. Turned my lambretta tank spotless in about 12 minutes of swishing.

IN between dunks, feel free to hit it with the hose/dunk it in a bucket of water and scrape.

When it's done. give it a good rinse with a a baking soda/water dilution to neutralize any remaining acid, and spray it down with some light machine oil just to avoid flash.

That cylinder is perfectly fine looking as well, I would expect a light hone and some fresh rings would do it just right.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Fri May 01, 2020 6:21 pm quote
Dirty30Dillon wrote:
If you're looking to clean up that cylinder while minimizing material loss on clean steel, a SUPER effective way is to use "The Works" toilet bowl cleaner. It's a more potent acid than vinegar alone, but once you've used it, you can just flush it.

Rig up an old paint can and wire hanger holder to grab the cylinder, than put in the cylinder and pour in The Works. Avoid the off-gassing which is an irritant, and check it every 5 minutes.

I've cleaned at least 25 gas tanks this way, and it's fabulous. Turned my lambretta tank spotless in about 12 minutes of swishing.

IN between dunks, feel free to hit it with the hose/dunk it in a bucket of water and scrape.

When it's done. give it a good rinse with a a baking soda/water dilution to neutralize any remaining acid, and spray it down with some light machine oil just to avoid flash.

That cylinder is perfectly fine looking as well, I would expect a light hone and some fresh rings would do it just right.
You are talking about cleaning up the crud on the outer ribs of the cylinder by doing this paint bucket dunk?


Yeah i will give that a try, I was trying to figure out how to clean all that crap off. I can't tell but it seems like its not rust, but is some sort of bee hive or insect nesting material that has solidified between the ribs. Your dunk method won't damage the bore?
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Fri May 01, 2020 8:39 pm quote
swa and safis, thanks for the suggestions! I have modified my order for the polini crank and other sip exhaust. Still trying to decide how much I want to pack into this order for parts to complete this engine assembly before I place it.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Tue Jun 09, 2020 5:08 pm quote
Now that my stella is back on track and jetting is close, I am looking to finally purchase my order of parts to start assembling this p200 engine finally.

Reusing the stock barrel with a new piston, head and long stroke crank. Goal is to get a solid touring scoot with fuel economy and keep the autolube.

https://www.sip-scootershop.com/en/products/piston+grandsport+200+cc+_12090000

https://www.sip-scootershop.com/en/products/cylinder+head+mmw+px200+for_13013935

https://www.sip-scootershop.com/en/products/long+stroke+crankshaft+polini+_45121000
as suggested by SaFis.

Timings I am thinking of are 177/125 25.5 blowdown to try to target just over 8000 RPM max, which with a T5 4th gear should be theoretically 85mph max.. but real world anywhere around 70-75mph max is fine for what I want.

One lingering question I have before I order is, should I keep the 20/20 carb, should I upgrade to 24/24 carb same as the one on my stella malossi 177, or what about going to a 26/26 autolube carb? Does going larger affect fuel economy? Similarly, would a 26/26 carb work better on my malossi 177 since that is much higher performance/rpms?

I'm leaning towards just upgrading to same 24/24 carb I have on the stella, but the 26/26 I am curious if there are any benefits to it. I will say that I am setting this engine up with long stroke crank in the event that I ever decide keeping the stock barrel is not doing it for me, I can more easily go higher tuning kits with it.

Carb options I'm mulling over:
1.) stock 20/20 carb
2.) 24/24 E autolube carb https://www.sip-scootershop.com/en/products/carburettor+dellortospaco+by_285204t7
3.) 26/26 G autolube carb https://www.sip-scootershop.com/en/products/carburettor+dellortospaco+by_40016000

Once I sort this decision out I will place an order for these parts and a bunch of other random stuff I need for the scoot so I can start on the engine finally.

For exhaust, I am thinking either one of two options.. both PipeDesigns:

S-Box Torque 220 (target timings 168-178/116-124)
S-Box Torque 220 II Plus (target timings 168-178/116-123)

Both of these exhausts appear to give peak torque at 5600-6200 rpm and peak rpm around 7500 which provides peak torque at the right cruising speed on highway (approx 45-67mph) and target max speed of about 75mph that I am happy with.
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Tue Jun 09, 2020 11:04 pm quote
That stock cylinder doesn't have the transfer ports for higher power but if you get them as high as you can for a tight squish, then that will do. Before buying that expensive piston you might want to think about a cheap kit. This will give more options.

If you get a 26/26 for the Stella, then the 24/24 can go on the 200.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Wed Jun 10, 2020 2:44 am quote
Yes that was my thought.. Stella 26/26 and moving the 24 to this. But question still remains, is there a benefit for the Stella to doing that or am i just swapping parts for the fun of it?
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Jun 10, 2020 3:08 am quote
By the time the 26/26 arrives the Stella will be set up. Put the 26/26 on, set that up and see what the difference is.
26/26 is not too big for the Stella, so should accelerate quicker (easy to test by video gps comparison) and maybe 1mph faster.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Wed Jun 10, 2020 3:14 am quote
What cheap kit would you suggest for this goal instead of the stock barrel? Right now I'm at about $200 to reuse the stock with these parts. So not much more than that is my goal. And something that won't drink gas but it's best suited to mild increase over stock that gives serious torque at 6000rpm
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Jun 10, 2020 3:25 am quote
Any 200 kit. I always liked the iron Polini. Set up well they run forever. Set up wrong they blow up instantly.
What kit can you get used? Same as I said to Fatbear. Someone here must have an old kit.

The serie pro was only $215
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Wed Jun 10, 2020 4:13 am quote
Jack221 wrote:
Any 200 kit. I always liked the iron Polini. Set up well they run forever. Set up wrong they blow up instantly.
What kit can you get used? Same as I said to Fatbear. Someone here must have an old kit.

The serie pro was only $215
This is an interesting option. I see that the serie pro is a brand new px200 barrel with some stuff done to it. If I go this option I still have to buy a head which brings the price up another 100 or so. Not opposed to it, but I just found an old post of yours which mentions some things you can do to a stock barrel to improve it slightly. Before I go the serie pro route, I am wondering what is involved to achieve what you mentioned in this post:
Jack221 wrote:
If you want to go a bit further there are some fairly easy things that can be done to the iron 200 barrel to add quite a bit more power. If you are leaning towards a touring kit then having a crack at your iron barrel first might be enough.
http://modernvespa.com/forum/post2206567#2206567

I'm assuming you were implying doing these simple things to what is the equivalent to the serie pro barrel because its the same as this guys later model px200? Not my P200 barrel. Would these same things apply on the older barrel?

I'm really into this idea of keeping essentially the stock barrel and improving it just enough with some basic dremel and gasket work with the only big upgrade being a long stroke crank and larger carb than the 20/20 included in the USA. Its a challenge to try instead of just buying a better kit and throwing it on. Although the serie pro px200 kit is not entirely breaking my own rules as that was an improvement in the stock lineup Piaggio did themselves!

Specifically, Now that I know how my Stella runs and feels, I don't really want this P200 to run the same. Slower acceleration is fine as long as I get massive torque, broad power and solid fuel economy. The stella 177 is for when I just gotta get to work as fast as possible so I'm not wasting half my day commuting public transportation. This P200 is for when I just want to go for a drive.. and maybe that drive takes me out of state for a day or two or 10!
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Wed Jun 10, 2020 6:14 am quote
I guess to clarify my question.. not including the heads, is there a difference in the PX200 cylinder vs the original P200 cylinder that would necessitate purchasing the serie pro kit and benefit vs keeping the original? Cause if they are essentially the same this is just putting a new cylinder on with the same piston I plan on purchasing.

EDIT: The only info I can find on differences is from wikipedia PX article that says the old P200 cylinder is 10HP and the new PX200 cylinder is 12HP. So I guess that is enough of a performance update and hopefully can handle the timings im targeting.
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Jun 10, 2020 6:24 am quote
If you need a rebore and a GS piston the serie pro is an easy way to avoid the fuss of doing it yourself. For cheap there are often kits on eBay. Brought a few myself over the years, for tuning projects (ie. breaking stuff for fun).

Your options are used kit or the pro. You could use the stock head but squish would be big. Although a Polini is only $240
https://www.sip-scootershop.com/en/products/racing+cylinder+polini+208+cc+_14000820

For a bone stock 200 there are a few cylinder changes that make more power. A 60 crank in stock will up it a few bhp with no effort.

Leave the gearing as it is and we'll just make it high torque.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Wed Jun 10, 2020 6:29 am quote
I didn't realize until just looking at these kits now, the exhaust stub is removable/replaceable. I'm guessing the stub is the same regardless of p200 or px200 cylinder? So I can just remove the one off my p200 and stick it on the px2 and save a few bucks there.

I've also decided I'll keep the 24/24 on the stella and just get another 24/24 for this as neither a slightly improved acceleration low down or an extra mile up top isn't needed. No sense in messing with it when its dialed in for minor increases.
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Jun 10, 2020 6:36 am quote
I'd like to see you get the Polini. Like the grown up version of the CM Polini.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Wed Jun 10, 2020 6:48 am quote
This budget keeps creeping up. I guess its only like $25 more which is not terrible, but I am trying to drive decisions on this one not by desires, but by whats best for long term stability and fuel economy within my usage goals.

I can be sold on this upgrade.. if it will still be north of 55mpg and not involve worrying as much about maintenance as the stella. I would like to drive this thing across country, both down south to visit family and west to see some parts I haven't seen before.

I've driven the east coast over 20 times with at least 5 of them solo in under 20 hrs in a car/truck, but I would really love to up that challenge to a scooter over a little more time with my analog photo camera. Same out west. I am not sure the stella could do that, but this if set up right I would have much more confidence in.

My two year plan for this is to finish building it in first year with a couple longer rides to test the waters with a 250 mi one way drive to visit family where I grew up in RI. If it can handle the 500 mi round trip, then I'll try a 1400 mile trip to my immediate family in Florida. Then if it can handle that 2800 miles round, maybe I'll take a chance the next year at doing east to west through the north for 2 weeks, rent a storage unit or find a place to park it for a month in LA while I fly back to NY to work for a few weeks then fly back and make the return trip west to east through the south. 4,000+ miles each way over a couple weeks each leg.
Ossessionato
1963 VBB2T
Joined: 07 Nov 2012
Posts: 2289

Wed Jun 10, 2020 7:47 am quote
Swiss I've often wondered what makes a reliable high mileage vintage scooter. I've rented one in Sicily for a week ,if you're not familiar with vehicles in Italy a dent free vehicle is not seen often. The rental scooters are much the same , scraped dinged but of course newer. We had a really great time my wife on the back, travelling all kinds of mountain roads , along the coast including visiting Taormina . Making a long trip along the coast on your vintage would be a blast. I was going to go to the Canadian East coast here in July on my street bike but whats going on in Quebec is turning me off and I will probably make the 3 day ride out to Calgary instead , less populated.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Tue Jun 16, 2020 5:16 pm quote
Jack221 wrote:
I'd like to see you get the Polini. Like the grown up version of the CM Polini.
Ok I think I am going to go with this Polini instead of reusing the stock 200. I'm gonna trust your gut on this as the Stella rebuild turned out better than expected. Also its got the added benefit to compare with CM's 177 version which I know he was curious about upgrading to P2. This will be interesting to see how the two engines differ with ideally similar setups. Gonna order the parts over the next month or so to spread it out and not dump all the cash out at once.

Lynn, I am very interested in trying to keep this P2 as close to stock as possible in terms of not being overly powerful but keeping with the torque and fuel economy. The stella project is a bit of work to ride as it is much faster and while its not crazy peaky compared to some of these scoots i'm sure Jack and others have built, it is a bit more racy for me to see touring for days on. So a P2 near stock but with slight improvements keeping it in its less peaky but strong touring riding style is much more appealing to me for multi-day drives. Driving in city traffic with the stella is fun but you gotta pay attention and constantly shift around to keep from racing too fast or keep it from wanting to drift the wheel off the road at red lights. That type of riding is perfectly suited for my 45 minute commute to work where I am just trying to get there as fast as possible and am racing off the line at red lights in manhattan to get past all the cabbies. Doing 3-4 hrs like that is a little exhausting.

Sure it will not be stock, but I hope it will be have similar characteristics to stock with some improvement that won't affect fuel economy or reliability. We will see how it goes.

EDIT: Given my recent soft seize on the stella.. I am all for keeping this P2 as cool and stock as possible with only case matching and some slight o tuning to keep it running more reliably. I need to have more confidence this one wont be so finicky at speed. So I am going to try to clean up the current barrel rust to see if I can get away with hone only with new GS piston, crankshaft and head. If it required a bore, then I will upgrade to the 12HP stock cylinder with GS piston. I can't be dumping money into two scooters that seize regularly! I don't have sponsorship
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Thu Nov 05, 2020 4:42 pm quote
Update: Just ordered the 12ps Stock Piaggio Cylinder with the GS Piston and MMW 0 squish head. Also a Polini 60mm crankshaft.

I'll be working on this for the next few months finally! Need a straightforward stock (ish) rebuild so I'm not getting so wrapped up in tuning crap I don't have full handle on yet. Keeping it as close to stock as possible with the only real upgrade being the long stroke crank. Probably should have done this one first.
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Fri Nov 06, 2020 4:36 pm quote
Will still need custom jetting. Very tunable with the 60 crank and thin ring piston. Will be nice to get it running first though. Should be an easy win.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Thu Nov 12, 2020 5:37 pm quote
Ok first major parts arrived. I might start working on it this week! Maybe a little cylinder cleanup.. chamfer the ports and polish the exhaust port? The malossi cylinder was more finished than this piaggio. Ports are rough and jagged.

I took some basic measurements to get a sense of the port timings. Don't have the crank installed in case yet to measure the rotary values, but plugged the numbers into calculator as if it was a reed valve engine.

Haven't worked on a p200 engine yet, but I immediately noticed the gs piston boost and transfer ports don't line up straight perpendicular to the cudgeon pin. Can't remember when I took the original cylinder off, but this makes me think that the cylinder doesn't sit exactly perpendicular to the engine, but is slightly rotated off axis. The transfer ports are also like that.

Port measurements..

Exhaust: 39.14mm
Transfer: 48.43mm

Port timings of 160/118 with 21 degree blowdown at 0pbt.

I would like to leave this cylinder minimally touched.. only polishing the exhaust and chamfer ports, but set it up at ideal port timings and squish as is. Will get the rotary valve measurements once I get the crank installed into case and can mock things up to take those measurements.

The crankshaft has valve timings of 138/5.
https://old.sip-scootershop.com/en/products/long+stroke+crankshaft+polini+_45121000

And finally, I gotta figure out how to remove the exhaust stub from the old cylinder to install on new.. forgot that is a separate part which doesn't come with the cylinder. I see there is a tool specifically for removing this, but everywhere I see it listed seems out of stock. I might just try using a wrench at the right thickness to the slot in the end of the stub, and tapping it with a mallet until it comes loose.

PXL_20201113_003915132.jpg
New Piaggio 12ps on left. Old Piaggio 10ps on right.

PXL_20201113_003924840.jpg
brand new piaggio 12ps 200 cylinder.

PXL_20201113_003945468.jpg
maybe polish this exhaust port up cause its jagged and rough.

PXL_20201113_004401904.jpg
GS Piston

PXL_20201113_003741741.jpg
MMW head with no squish. so i'll be raising the cylinder to get my desired squish.

PXL_20201113_003627067.jpg
Polini 60mm crank.

PXL_20201113_003644298.jpg

12psPiaggio200cc_untouched.png

Molto Verboso
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 1844
Location: california
Thu Nov 12, 2020 9:16 pm quote
Popcorn eating emoji.
Love the shinny new parts.
Forgot you had this one on the go as well.
Good to see you back tinkering.
Hope you are getting some enjoyment outa it.
-CM
Ossessionato
Joined: 26 Oct 2015
Posts: 2795

Thu Nov 12, 2020 10:16 pm quote
A Crapsman socket was donated...

06605A73-201D-403C-B225-D476DD9CE283.jpeg

Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Fri Nov 13, 2020 5:04 am quote
Genius whodat!
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Fri Nov 13, 2020 8:59 am quote
Going to be non standard jetting anyway, so might as well clean up the exhaust port and widen a bit. Should take 60% with those rings. Good idea to lower the exhaust port for 60mm BDC. Squish target would be 1.2 but no wider. Could possibly pull a stock gearbox with 24 tooth clutch cog. You got a clutch already?
Not an iron Polini but will go well and keep going. Definitely in the bulletproof class.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Fri Nov 13, 2020 9:21 am quote
Jack221 wrote:
Good idea to lower the exhaust port for 60mm BDC.
This you mean lowering the bottom edge of exhaust to 60mm below deck.. in the same way that I did with my malossi cylinder in order to get the exhaust to open just before the piston top at BDC? and I will leave the top edge (closest to deck) of the exhaust at same height so not to tune this thing for higher rpm.
Quote:
Squish target would be 1.2 but no wider.
The sip descriptor for mmw 0 deck head says a 1mm base gasket on stock cylinder equals 1.3mm squish with this head I have when using a 60mm crank. So with your suggestion of 1.2 max, I would need a 0.9mm base gasket to get 1.2mm squish. Plugging the 0.9mm base gasket into the timing calculator, I get timings of 164/123 with 21 blowdown.
Quote:
Could possibly pull a stock gearbox with 24 tooth clutch cog. You got a clutch already?
I have not bought a clutch yet, but am looking at the SIP Ultrastrong clutch with CR80 plates for this build. I also already have a DRT short 4th gear for this engine if it is better. "Gear Cog 36 teeth, 4th gear"
Quote:
Not an iron Polini but will go well and keep going. Definitely in the bulletproof class.
This is my goal for this one. bulletproof. long distance touring. minimal tweaking.

Also need a suggestion for best box exhaust for this setup? I've been leaning towards the p200 version of my road xl..the new sip viper exhaust:
https://old.sip-scootershop.com/en/products/racing+exhaust+sip+road+xl_24164000
although their suggested timings don't line up in any way.. so it might be a waste:
Quote:
The 'Viper Box' functions optimally when the port timings of the cylinder are adjusted to suit its elaborate layout. We recommend a transfer port timing of: 130-136, exhaust port timing of: 190-196 and a blow down timing of 30-32.
Molto Verboso
79 P200E, 62 Allstate, 2008 Stella
Joined: 11 Jan 2006
Posts: 1819
Location: Florence, OR
Fri Nov 13, 2020 11:17 am quote
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Fri Nov 13, 2020 3:04 pm quote
swiss1939 wrote:
Jack221 wrote:
Good idea to lower the exhaust port for 60mm BDC.
This you mean lowering the bottom edge of exhaust to 60mm below deck.. in the same way that I did with my malossi cylinder in order to get the exhaust to open just before the piston top at BDC? and I will leave the top edge (closest to deck) of the exhaust at same height so not to tune this thing for higher rpm.
Quote:
Squish target would be 1.2 but no wider.
The sip descriptor for mmw 0 deck head says a 1mm base gasket on stock cylinder equals 1.3mm squish with this head I have when using a 60mm crank. So with your suggestion of 1.2 max, I would need a 0.9mm base gasket to get 1.2mm squish. Plugging the 0.9mm base gasket into the timing calculator, I get timings of 164/123 with 21 blowdown.
Quote:
Could possibly pull a stock gearbox with 24 tooth clutch cog. You got a clutch already?
I have not bought a clutch yet, but am looking at the SIP Ultrastrong clutch with CR80 plates for this build. I also already have a DRT short 4th gear for this engine if it is better. "Gear Cog 36 teeth, 4th gear"
Quote:
Not an iron Polini but will go well and keep going. Definitely in the bulletproof class.
This is my goal for this one. bulletproof. long distance touring. minimal tweaking.

Also need a suggestion for best box exhaust for this setup? I've been leaning towards the p200 version of my road xl..the new sip viper exhaust:
https://old.sip-scootershop.com/en/products/racing+exhaust+sip+road+xl_24164000
although their suggested timings don't line up in any way.. so it might be a waste:
Quote:
The 'Viper Box' functions optimally when the port timings of the cylinder are adjusted to suit its elaborate layout. We recommend a transfer port timing of: 130-136, exhaust port timing of: 190-196 and a blow down timing of 30-32.
1mm base is probably 0.95 anyway. Just use that. Transfer timing doesn't matter so much on this cylinder. However, wouldn't want it any less than 123. Exhaust nearer 175 would go better. Need to check everything lines up. Inlet opened to suit crank. All fits well.

That viperbox is not suited to this. Road 3 or Polini better.

Gearing will need 35 tooth and 24 cog. Will pull it ok.
Sip ultrastrong complete is surprisingly cheap but 24 cog is not so and extra. Is worth it. The sip CR80 are better than the real CR80 plates.

Plenty to do. Better get started.
Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Sat Nov 14, 2020 9:26 am quote
whodatschrome wrote:
A Crapsman socket was donated...
Even more crude, but worked!

Quarter inch piece of steel held in place by hand with long end towards the loosen direction, then just hit the end of the long end of steel with a hammer until it came loose and slowly worked it out until it would spin by hand.

PXL_20201114_171425138.jpg

PXL_20201114_173431500.jpg

Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Sat Nov 14, 2020 10:49 am quote
...and for Jack/anyone else interested in the port mapping of the stock piaggio 200 cylinder.

More accurate measurements taken from the trace:

Exhaust - 38.77mm
Transfers - 47.98mm
Exhaust Arc Width - 40.98mm

As you can see from the exact trace of the ports, they are extremely rough shaped from factory. Jagged edges everywhere.

Updated port timings with 1mm base gasket:

Exhaust - 166
Transfers - 126
Blowdown - 20

Trying to remind myself of the exhaust width target... 60% of the Bore diameter... 68mm? Which would be 40.8mm. So I am fractionally wider than 60% with my measured arc. So no more widening.

p200_ports.jpg

p200_port_stock_measurements.jpg

p200 stock port timing_fromtrace.jpg

Molto Verboso
2007 Stella 150
Joined: 02 Nov 2019
Posts: 1258
Location: Rochester, Minnesota
Sat Nov 14, 2020 12:46 pm quote
I got as close as I wanted to get to holes for the exhaust studs before I got to wide, keep an eye on them. I was told it depends on rings for width and the new fangled 1mm steel can go to 70% percent. Not sure what you're piston has for rings.

You can see in the picture that the exhaust stud on the left is being over lapped by the port in front. I just cleaned mine up and was as close as I wanted to be.

Our LML motors didn't have that issue.
swiss1939 wrote:
...and for Jack/anyone else interested in the port mapping of the stock piaggio 200 cylinder.

More accurate measurements taken from the trace:

Exhaust - 38.77mm
Transfers - 47.98mm
Exhaust Arc Width - 40.98mm

As you can see from the exact trace of the ports, they are extremely rough shaped from factory. Jagged edges everywhere.

Updated port timings with 1mm base gasket:

Exhaust - 166
Transfers - 126
Blowdown - 20

Trying to remind myself of the exhaust width target... 60% of the Bore diameter... 68mm? Which would be 40.8mm. So I am fractionally wider than 60% with my measured arc. So no more widening.


pxl_20201113_003924840_19564.jpg
You can see in the picture that the exhaust stud on the left is close to being over lapped be the port in front. I just cleaned mine up and was as close as I wanted to be.

Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2340
Location: Staten Island, NY
Sat Nov 14, 2020 5:16 pm quote
Forgot to mention, the exhaust port bottom center is already 62.77mm below the deck. Measured with caliper in barrel and confirmed using the tracing.

And here are the clutch I am planning on picking up.. along with the 24 tooth cog Jack suggests. Just want to make sure I can leave the primary stock with this 24 tooth cog cause the sip descriptor suggests primary gear needs changing, but the drt description says it works with standard 65 tooth P200 primary.

https://old.sip-scootershop.com/en/products/clutch+gear+cog+24+teeth+_87478000

https://old.sip-scootershop.com/en/products/clutch+sip+cosa+2+ultrastrong+_93445300

Looks like using this gearing calc.. http://gearingcalc.free.fr/ going from stock 23 cog to 24 cog gives you an extra 3mph theoretical at the top. Again, going off theoreticals from these calculators... Comparing my stella gearing/max rpm to this P200 gearing/max rpm they are going to be nearly identical in terms of theoretical top speed for each gear. But the stella wants to do wheelies and race like hell, whereas hopefully the p200 will be a more gradual rise to those speeds and be more torquey, and hence, way more fuel conservative!
Molto Verboso
2007 Stella 150
Joined: 02 Nov 2019
Posts: 1258
Location: Rochester, Minnesota
Sat Nov 14, 2020 5:53 pm quote
I just looked up my order this is the one that I have installed. Looks like the same part number.

https://old.sip-scootershop.com/en/products/clutch+gear+cog+24+teeth+_87478000
swiss1939 wrote:
Forgot to mention, the exhaust port bottom center is already 62.77mm below the deck. Measured with caliper in barrel and confirmed using the tracing.

And here are the clutch I am planning on picking up.. along with the 24 tooth cog Jack suggests. Just want to make sure I can leave the primary stock with this 24 tooth cog cause the sip descriptor suggests primary gear needs changing, but the drt description says it works with standard 65 tooth P200 primary.

https://old.sip-scootershop.com/en/products/clutch+gear+cog+24+teeth+_87478000

https://old.sip-scootershop.com/en/products/clutch+sip+cosa+2+ultrastrong+_93445300

Looks like using this gearing calc.. http://gearingcalc.free.fr/ going from stock 23 cog to 24 cog gives you an extra 3mph theoretical at the top. Again, going off theoreticals from these calculators... Comparing my stella gearing/max rpm to this P200 gearing/max rpm they are going to be nearly identical in terms of theoretical top speed for each gear. But the stella wants to do wheelies and race like hell, whereas hopefully the p200 will be a more gradual rise to those speeds and be more torquey, and hence, way more fuel conservative!
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Sun Nov 15, 2020 5:01 am quote
If sip won't sell you a whole clutch with the 24 cog in already just go with the 23 for now. Can easy add it later.

I ran my tourer with a 24 for a while but got bored with it. 4th still pulled hard, although less rapid acceleration over 70mph.

If your rings are 2mm then 42mm is probably enough. If 1.5mm then could go to 45mm. Not worth risking it to the limit. Stock cylinder has large stud holes, making it quite difficult to get really wide. Get it more square with tight corners. 126 transfer is not quite accurate as the ports are slanted. Is 126 for blowdown but not for performance flow. You're going to need more than 20 degrees blowdown though.
28 degrees is nice for what you want.
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