Modpx, This must be your third barrel this year! Or is there more than one scooter? I haven't tried the new 210 yet but from what I have seen they look pretty impressive. Just like a Malossi version of a Polossi You want me to work out the base packer thickness for that gearing you have?
Hi everybody, i resume this post cause i'm having a similar problem (actually identical) with my new Malossi 210 2013 sport. I bought it cause i thought it was easier to set up with a 57mm crank due to his renewed port timings apparently more touristic but i was wrong. At the moment i run a drt 3 petals reed valve intake system for SI carburettors, 23/65 with short fourth 36 teeth, a worb 5 flowed 57mm crankshaft and a sip road kind-of pipe. Ah... and.. i don't pull the fourth!!!! at the moment i have a Malossi standard base gasket (the one that comes in with the kit) and 0.5mm head gasket, squish 1.3mm. I see that pxguru is suggesting to pack 1mm down and leave a very tight squish to keep up the power AND the torque in order to pull the fourth. hinders: have you ever tried that? Hows your Malox doing now? Still riding?
On other forums i was suggested to do other way round: skim the cylinder base to lower the transfer ports and get more torque... but i'm not convinced about that solution...
right, i could finally made a few tests and the 1.5mm at the base w/o head gaskets i have to say was the best! with 1mm down and 1 up it was de-compressed, not revving so fast and not much torque either (the worse) with 0.5mm down and 1mm up huge torque at the middle high ranges but dead at the lower and not much fast at revving too. With 1.5mm and the 0.8 standard Malossi squish w/o head gasket instead has a great torque but revs much faster than with any other set up! A real beast! Havent tryed the top speed yet but easily gets over 100/105 in third gear! And it doesnt scream! It just loves to rev! Thanks Guru for the tips, now i just have to keep t cool and for once being able to finish the running in properly without seizing it!
Main transfer-top of the barrel: 47mm Exhaust-top of the barrel 34mm squish approx: 0.75, lets say between 0.7 and 0.8
the piston measure with 0,.5 at the base is Zero, i mean he upper piston ring is still inside the barrel at the very edge of it. i think i cant pack less than that or it'll come out of the barrel. but i havent tryed. Let me know.
i forgot to mention that the on/off vespa result was before all the works ive done on the malossi. it was pretty much plug and play at that time so it's not so relevant as a test. But still..
alright next i'm going to center the piston with the cylinder in order to match the ports perfectly (i enlightened the piston so i cut between the two little ports of the Malossi piston to make one out of them, plus other little works) then i'll take care of the packing. So you say 1.5mm at the base, like is normally suggested for longstrokes. Hmm ok... I tryed 0.5 down and 1 up and the result was a on/off Vespa: dead down and super torquey and revvy at the middle high range. If i could pull the gears a little more in the lower ranges i'll be satisfyed. But even like this is another Vespa compared to how it was before! Malox is another league. ;D I guess you're going to tell me the correct engine timing by using millimeters instead of grades, that will help as i dont have a protractor and i havent done that yet.
i didnt touch the inside of the barrel i just opened the transfer in the cylinder part that goes into the case and the corresponding transfer above so hopefully no rings will be eaten? The case is ported with all the enlarged transfers.
Yeah i ported the cases by myself and i opened those ports like in the pic taken from SIP worb 5 cylinder approx 2mm each side and upwards. I asked if someone has ever done the same job but i got no answer.
What im asking now is what is the perfect packing for a 221 since i have a 210 cylinder. I can try all the combinations by myself of course but asking to someone who has had that cyinder before would help. You surely know Malossi suffers the lower ranges so by packing the head or the base is possible to adjust that. We had more or less the same conversation for Pinasco but in a completely different context. Malossi has made a head called HTSR (High Squish Tubulence Rating, the one with the o-ring) with a squish of approx 0.7/0.85mm calculated appositely on their piston head. That's the head i have in my kit. If you or others dont have experience with the same kit or cylinder head then nevermind.
I quit the Pinasco cause it just stops revving too early, and it starts screming on 4rth gear. The set up wasnt too bad after all, but Pinasco doesnt give much choises cause is pretty much like a standard Piaggio with just one port bigger and the head is calculated to have that super squish over 2mm. Either with central spark plug or the standard the music is always the same. Ok at the lower ranges gives you a great kick but that's all. Boring.
I guess you (guru) have experience with Malossi 221, have you ever tryed the Malossi head htsr, the one calculated by Malossi with the 0.85 squish? just one question: whats ur fav set up, 1.5mm at the base or 1mm base + 0.5 head or 0.5mm/1mm or 1mm/1mm etc..?
Doesnt that give more power? I've done that already ;D i'll test it later this week,with lightened piston, Gran Sport gudgeon pin. i also ported the cases for that "new" transfer enlargement...
this type of job im talking about , im thinking of doing the same job to my cylinder , cutting the exhaust port up to the cylinder base and enlarging upwards the port right above
Hello guys, i have some questions for you. I am working on a Malossi 221. Can anyone of you tell me exactly what kind of modifications is worth to be done on the cylinder? What about enlarging the exahust port like in the worb 5 version? What does it give more? How much do you enlighten the piston exhaust port? Thanks
maybe i made it, i think it was a loose stud that was giving me problems, after trying over and over again i took one gasket off the base (now it´s approx 0.5) and i put one 0.5 head gasket i tighten the head and i did like suggested i let the motor warm up and i tight it again and at that point i discovered that loose stud. In other words i was intaking air but not cause the cylinder head was bent. Not having a socket for measuring the tightening power i had to proceed more like by trial and error. Im curious to see how the Vespa will work with this set up now, and then if the head will be reliable i will start packing and ill report my impressions! cheers everybody!
well guys i took the head to rebore today, the guy put it on a flat surface and lapped it for a few seconds and went: this is perfectly straight. Where's the "banging head against the wall" emoticon ?? cause i dont know anymore what to try or think..
Your original pictures show that the head was leaking, signs of blowby on the cylinder and head, and I did say that quite early on.
Lapping the head in can take quite some time, ages if the head is warped badly, but does work.
Start off with quite rough wet & dry (600 grit,) and colour the head sealing face with black marker pen, after a few seconds of lapping have a look at the sealing face and where the marker has been rubbed off is a high point and where it's still coloured is a low point.
Lap in a figure 8 motion to ensure it laps evenly.
Once all of the marker colour starts to disappear after only a few seconds you can move down a grade on the wet & dry finally ending up on a 1200. You don't really want to go any finer.
Once it's all nice and flat make sure you torque tighten the nuts using equal and opposite and do each one a bit at a time. Once the head is correctly tightened let the motor warm up on a high tickover for 20 minutes or so and then retorque the nuts.
I generally torque head nuts to 20lb/ft, not sure what it is in newtons, so do each nut to say 16lb/ft (or metric equivalent,) then do each one to 17 etc.
Personally I think doing the head properly will cure all your problems.
Ok i'll try again but as you seem to know Pinasco, which head would you pick between MMW central plug and Pinasco VHR central plug for my cylinder? Do you have any experience or know anyone who has had those heads? And is there big difference between the central plug and the side plug? Cause now i have the side plug. This question is for everyone who has some knowledge about these heads and wants to help.
Don't use any sealant kid............. lap it in properly on wet & dry sprayed with WD40 as was explained in the other thread.......... it'll take a while but it'll be worth it. I did say on the other thread that a leaking head was your problem
Hi joey,i tryed that already i bought a sheet of glass appositely for that purpose but the result is even worse! Now it doesnt even start. How long should i lap it for and how? and should i lap the cylinder as awell? I dont know if the head crooked because i made some mistake while taking it on and off the cylinder (like leaving the head hanging from the studs from one side only) or cause the first time i lapped it with wd 40 to get rid of the blue sealant i didnt use a perfect flat surface..this might have caused some gaps in the head surface. I dont think the head was leaking before the seizure cause i had no major signals like accelerated idle and so on...
i thnk i know what it is, must be that the head is crooked and now it has to be grinded.. alternatively i could try to use some sealants to see if it works... or put the Piaggio cyinder back.
The problem sounds like a crank seal. You shouldn't start it again until you have fixed it. If the cluch seal is spinning in the casing it could really damage your engine!!
This is what happens, at evry kickstart you see a "cloud" fuming out the cylinder head!! :
1.7mm on the base calculates as correct for what you need. The piston ring may be 1mm past the port at BDC this is not important when the port is fully open.
Sounds like you may have a problem with a crank seal. Check your gear oil level and read the thread on "air leak test". You need to fix this problem before going any further. Your wife might not be so happy about this!
Good to know, i'll fix the head and then i'll try the different set ups. Im thinking of putting back the original piaggio cylinder+head to make a long stroke 208 Piaggio packing 1.5mm the base for the long stroke also to verify if the problem is in the head or somewhere else. i'll keep you posted.
That is always the big question. What is "the perfect set up". The perfect set up is like the perfect girlfriend! There isn't one! So pick a few factors that you insist on and compromise on the rest! ;D
If i keep seizing in the snow, spending tons of euros in spare parts and especially spending all my spare time in the garage i will soon not have a wife anymore! ;D I have like the feeling i was more mature when i was 15 riding my Piaggio Ciao!
For yours you need to achieve at least 7 to 7500 rpm in gear, pull like a train and not blow up, all with a 24mm carb. This is possible.
To get there as easily as possible with what you have, you need to raise the barrel by another 0.9 mm that will be 1.7 mm in total. The piston should then be 1.3mm from the top of the barrel at TDC.
but if i pack 1,7 mm the base then the transfer ports wont be anymore completely open cause now theyre only 0.5mm or so distant from the piston ring..is that ok?
You need to do something with your cylinder head. Can you measure the the gap indicated in the photo? Should be about 1.5 mm
yeah the measure is 1.5mm, im worryed cause today it happened again : detonations, air and oil on the piston and the cyloinder head and then it didn't start anymore.
Yes, put the washer on the spark plug. You don't want to see any thread showing inside.
Are you sure that measurement is 49.0 mm from the transfer to the top of the barrel? I prefered it when it was 48.0 mm
The piston looks like its 0.5mm from the top of the barrel at TDC. Do you agree?
The head was really leaking. You are going to have to fix that!
Spark plug is ok now, the measurement is approx 49 yes a bit less, maybe 48,80, it's hard to tell exaclty i couldnt use the micrometer for that. the piston is 0.5mm i agree, maybe slightly less 0,4. How to fix the head? Where is it leaking from exaclty? Are you making all the calculations with the squish and all the rest? Whats the response for the perfect set up? (cool video your polossi btw )
Edit: the distances are: 49 and 38. The spacers i used to pack the base are 3 standard base gaskets one on top of the other so they are a bit less than 1mm approx 80mm. The oil spread all over the piston head/cylinder head could be caused by the fact that i didnt empty the carburator before i started to work on the cylinder. It's good rule switch off the gas tap and keep the motor on until the carburator is empty but i only switched off the gas.
@kru yes i asked cause Pinasco gives a washer with the kit, before the seizure i drove all the time without it, now i put it back.
Twist together a few stands of solder wire to about 3mm thick and 150mm long. Take out your spark plug. Move the piston to 10mm from the top. push the twisted solder down the spark plug hole until you feel it touches the barrel wall. Turn the flywheel to squash the solder. Measure the squashed end. easy....lol ;D
Alrite then: 1) The squish is 2.92mm, 2) here are some pictures: imageshack.us/g/1/9977548/ in the first three you can see in which condition i found the cylinder/piston/head: drawned into oil That must have been when i firstly started the vespa, i saw a mixture of air and oil bubbling out from somewhere (carburator?) then it immediately stopped but the marks are still there. The other pix are about the transfer ports/piston BDC and the piston at the TDC. There's also a pic of the spark plug, do you think it goes too deep into the head? 3) The distances between transfer ports/head and exhaust port/ head are: are 37,15 and 48 approx
me: for what i know spacing the base gives more torque and spacing the head gives more revs... (correct?)
guru: As a general rule packing the base gives more torque until you go 0.1mm too far then you start to lose power. Packing the base lowers compression which also loses torque.
joey: Packing the base increases revs, top end peak hp slightly but you end up with a narrower power band and less torque. Packing the head raises compression (extra volume between top of exhaust port and head "corrected compression ratio") and increases torque with a slight loss on top end
Let's just keep it on the torque and revs level for now. What gives what?
the squish is the distance between the piston at the TDC and the head. but the head is attached to the cylinder so if you pack the cylinder the distance between the piston (that stays where it is) and the head (that moved 1mm upper) cant be the same! Or i'm missing something?!
I think you are getting the hang of this now From the measurements you sent me the transfer port open time with this 1mm gasket is much nearer ideal for the torque you want from this kit.
As a general rule packing the base gives more torque until you go 0.1mm too far then you start to lose power. Packing the base lowers compression which also loses torque.
Do you want to try to measure the squish clearance (space between piston edge and head) again?
I think you meant packing the head (not the base) lowers compression which also loses torque? I havent measure the squish yet or..let's say no squish has come out from my measurements yet! Do you think the squish is now bigger due to the base-packing? Tomorrow i will try if i can get a 3 or 4 mm stober strand and try again. What squish would be perfect on this set up? Another question about the exhaust pipe. JL is super torquey, i think is perfect for this kit, but it limits the top end a little to early. Ok the short fourth gear doesnt help to have a massive top end either especially not on a torquey cylinder like Pinasco BUT if i use a high rev pipe good on a Malossi kit, will i get abetter top end even though i lose a bit of power at the lower range? Which pipe do you have on your Polini? I know Polini is pretty torquey too. (btw videos are always welcomed)
Hello everybody, today i finally put my PX 225 Pinasco back on the road after the seizure i treated in the post "seizing on the 1st day of the year". Just a little ride around the block, cause it's too cold and icy to go anywhere these days (though the new IRC snow freshly arrived from SIP are really great!). The main jet is now 140, the cylinder has been cleaned and polished and the piston is brand new. I ordered a new part for the carburator (not arrived yet) www.sip-scootershop.com/en/products/float+chamber+cover+dellorto_128295t7 this shoud solve the problem of gas flowing at full throttle, i have the feeling that a SI 24 with that much of hp and torque might not be enough..(?). IF anyone had ever tested it let me know. I also spaced 1mm under the cylinder base, that's cause i noticed that there was still 1mm space left between the piston at its BDC and the transfer ports, i thought: if there's space why not to fill it? ;D Now: for what i know spacing the base gives more torque and spacing the head gives more revs... (correct?) Should i adjust the ignition or i can leave it where it is?