Hello from Spain

[santacama]

Hello everyone:

First I want to tell you that I would like to speak German, but other than Spanish I only speak a little English. I've been looking at your forum and translating with Google what I have found that contained data (impossible to understand almost nothing) and I want to compliment the superb level of the forum.

After some Polini engines for PX 200 I decided to finally make a real engine: Malossi 221 in the range of 25 to 30 HP for everyday use.

I have almost all the components I need, but I have yet to determine exactly what changes to make the cylinder to properly install the 60 mm crank (Undi). From the English forum Scooterotica (http://scooterotica.org/forum/viewforum.php?f=8) I have the following links:

htm http://vintagescooters.free.fr/tuning/malossi_210/210Malossi.

http://i234.photobucket.com/albums/ee97/w5a/auslass_malossi221_road.jpg

Mods to the piston are Obvious .... no problem. But When we come to the issue of timing is another matter.

It appears that the proposed exhaust port in the German forum, is Designed to use a gasket under the cylinder of 1.5 mm. In this way I would not have to touch the original exhaust port at the top, because if we respect the 32 mm (Original Malossi 210) to the top of the barrel, the exhaust timing is about 188 degrees (60mm crank). Also in this way the line crossing the top of the intake ports will match with the its measures.

My questions:

I guess that I will have to enlarge the exhaust port in the lower part 3mm (and to the sides) to match it with the piston crown at BDC, right?

What about the intake ports, Do I Have to make them match the piston crown at BDC?

What squish and compression do you recommend me? Squish 1.2 -1.4 mm and compression around 11:1? Where could I buy a SCK head?

Can you explain the following?, Google Translator does not translate them:

Steuerzeiten: 128 Überströmer

Vorauslass 31 Grad

Exhaust port with BDC lines 57 mm stroke and 60 mm stroke with 1,5 mm basegasket:

My measurements of the: 210 Malossi

Thanks

Bearbeitet 13. September 2010 von santacama

[Das _O]

Steuerzeiten: 128 Überströmer (128° transfer open) - about 1mm gasket at cyl.foot.

Vorauslass 31 Grad (° of exhaust open before transfer open)

e.g. exhaust 190° - transfer 130° /2 = 30° "vorauslass"

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dont touch the transferports unless u got the rigth tools and exactly know what u are doing. (u might loose the right angle, velocity of the incoming gas)

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u dont have to lower the exhaust to the bdc.

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edit:

Timing Calculator

Bearbeitet 13. September 2010 von Das _O

[santacama]

Thanks for the info.

Yes I have the right tools and this is not my first trasnformación of a cylinder.

The most important thing for me now is knowing what to do with the intake and exhaust ports. The 60 mm crankshaft gets the piston crown 1.5 mm lower than the 57 mm, that joined with the 1.5 mm basegasket, causes the piston crown to be 3 mm below the lower line of the intake and exhaust ports: as you can seen in the previous picture: what do you do with those 3 mm?

Ultimately what modifications are needed to do to the intake and exhaust ports? Is the one in de pic OK:

Finally, How would the behavior of the engine be with a timing of 190/30?

Thanks to all.

[Tobi - MS]

Your Outtake timing will be OK but it depends on your exhaust.

For Intake you will find nice works here in the GSF

Ask Basti LINK to MRP

Sorry for my english

[santacama]

I have two exhaust pipes: a Malossi and JL R Hand

Bearbeitet 14. September 2010 von santacama

[Tobi - MS]

I have two exhaust pipes: a Malossi and JL R Hand

JL R-Hand the old one with the small belly or the good one like this (Example by LTH)

If it is the second one it will be the right exhaust for your project. If you have got the one with the small belly you should sell it and buy another exhaust.

Malossi exhaust....I think its not the first choice.

[santacama]

Ja, ja, ja

Yes it is the new one...