keuk

No no these are all the dimensions I took on the cylinder, exhaust hight, laterals hight, and cylinder hight, I deduced the squich with these values and the theorical "64" "64,5"... Next week I'll know the truth. By the way, is it better/easier to machine the cylinder head or the cylinder to adapt the squich ?

Das ist sehr richtig.

I have checked the timings of my Polini EVO cylinder on solidworks. I'm not really close of the timings in the Polini assembly instructions notice... There are two versions, one with 64mm between the crankshaft axis and the base of the cylinder and one with 64,5... I don't know yet how much I have on my engine but in both case I haven't use the gasket (I have added 0,1mm for the Dirko / Loctite for the gaskets). I think in any case I will have to use the 0,5mm copper gasket because there is no clearance between the matting surface of the cylinder head and the top of the cylinder... So the squich will be 0,3/0,5mm higher.. Well, it just a simulation, it will be probably different once I will put it on the engine casing. But the squich is very very secure.

Thanks !

Sure, I'll take more or less this measure and adjust it to find the same timings annouced by the manufacturer, (here the 126/178° of the Polini EVO) then I will check how many millimeters I have to increase the exhaust port to have 30° blowout. (that's just a simulation I'll take the correct timings once I have access to my engine). I think it should be 1/1,5mm. Thank you ! So when the manufacturers annouce the timings of their cylinder it will differ on each engine casing right ?

Meine winterprojekte: Before: Jetzt: I have added spot weldings to the clutch basket to fit the DRT clutch without having to bend the last cork discs... But maybe the fitting of the clutch will be harder. We'll see. More coming soon.

I would like to work on my cylinders' timings on solidworks. There is one dimension I don't have. Any one knows the distance between the crankshaft axis and the original upper surface of the engine casing ? Thanx. Antoine

Eine neue frage: Now that I have both cylinders.... M1 and Polini EVO, is the M1 a good choice to replace my old full machined Polini iron cylinder on my racer ? I have to choose between a upper size for my GS piston or something else...so maybe the M1 should be a possibility.

Alles klar, danke !

One more question, I just took a look on the official manual, the Polini EVO has the same timings than the M1, 178/126, is there a big difference between both cylinders ? Of course the price, but for the performances ?

Thanks for the advises guys ! So it will be a Polini evo to stay in the Polini family with my racer ! I will try to get rid of the M1 then...

So it would fit like that ? (That's a Photoshop)

Really ? Ooooh damned !! that's why they made this little edge inside the transfert port !! I thought the transferts were like a modified Quattrini but in fact their are more tight ?

Because the transfert ports are too big on the Polini EVO and i don't want to weld the engine casings.

Hello, I'm working on a new engine for a daily scooter. The idea is to use the engine casing without weelding it. Here are the parts I already have. Short 4th DRT Clutch DRT 8 springs Koso 28 Polini reedvalve manifold with a fitted 28mm intake 2,86 with repair kit Mazzu anticipated ET3 ignition with 1,8kg Sip flywheel PM40 exhaust or maybe Sip Road I would like to use a cylinder without touching it too much, maybe the exhaust port but that's all. So I think I could use: - Polini 133 Iron - Parmakit Aluminium touring (not the SP09 but the one with small transferts) - M1 I saw on another M1 post that the timings of the M1 are lower than on a Polini... but i think i remember than the PM40 need 185° to work well at the exhaust port.... so what's the best choice for a punchy scooter ? The thing is that I have already ordered the M1 on Sip, and I'm a bit disapointed now that I have seen the other post... What do you think ? Thanx Antoine

Ok thanx ! And the next one... For the bottom of the exaust port...

Ok, so the blue one can be even less and the bigger corner is how you call the red one right.

Hello, I'm going to update my Polini cylinder to 58mm because I had a small problem with the piston. The engine still work with 20hp but there are small marks inside... I will then rework the exhaust port to reach the 70% with the new GS piston and I need your advise. My old exhaust port use to look like the B model, but I saw that the Dittmar's one (http://www.vespa-hamburg.de/pages/index.php) is a bit different and more straight on the sides. What is the best shape for the exhaust ? Is there document that shows the construction of the shape with minimal radius, etc ? Thanx

Anyone knows what is this seat ?

Hello, I did the modification on the polini reed valve to use it with a Keihin 33 but I think I have cut the midle part a little bit too low... What do you think ?

Hello, Sorry to change the subject, I saw this intake on this thread, where can i find one ?

Mad Max !!!

Hello, When machining the bottom of the engine casing, can we use the side of the engine as a reference ? When the machinist did it on my engine casing he told me that it was probably the reference used by piaggo to make all the mahining operation on the casing (drilling, bearing surfaces...). Right or wrong ?

Things have a bit changed since last year... I have updated the diagrams to 192/127,put a 3.00 primary ratio, reworked / optimised the exhaust, i use the DRT clutch, a frantz exhaust, the piston clearance is far away from 7/100 but it seems to work well

Hi, i'm looking for the shockabsorber plate of the following picture, the model B. I don't excatly know what is the model of Vespa equipped with this model. Cheers