Polini 177 timing

[morbin]

Hi all,

I'm collecting some information about modifications for my Polini 177.

It is gonna be a valve inlet engine, standard stroke, 20mm cut crank, casing lightly adjusted, probably GS piston, GSF Kopf and modified exhaust...

I found this file, I know what inlet valve duration is, but I have difficulties understanding German.

How does this engine behave?

Could anyone tell me which is a good inlet valve duration for my setup?

I read around that I should not exceed 60°-65° nOT (I think I better keep closer to 60°), what can you tell me about the vOT side?

I'd like it for sport-touring with balanced low end power and high power and rather cheap on gas...

Carb will be a 24 SI (would ovalizing it be any good?) and standard exhaust.

Gruss

Matt

index.pdf

index.pdf

[Johnny13]

Hi Matt!

Finally found a link. http://www.germanscooterforum.de/index.php...dpost&p=1155047

[morbin]

Thank Niko!

Anyone with suggestions for nOT-vOT?

[morbin]

up

[morbin]

Do you all go with 19mm cut on the crank and 4+4 millimeters on the valve?

[maxpower]

Do you all go with 19mm cut on the crank and 4+4 millimeters on the valve?

hello, i have tryed this a view years ago. it works very well a long time. i have also tried it with a 24:24si

and also with a 28php.

but a better setup is with membran and an worb5 crank called schaliwelle

sorry for my englisch

[morbin]

hello, i have tryed this a view years ago. it works very well a long time. i have also tried it with a 24:24si

and also with a 28php.

but a better setup is with membran and an worb5 crank called schaliwelle

sorry for my englisch

Thanks a lot Max.

Good suggestion I used to run a Polini 177 with worb5 crank and RZ Right but it was too noisy! It run excellent but expecially overhere in Italy, where it is not possible to make it streetlegal, I felt too much out of the low...

And so now I decided to go back to the valve.

Did you prefer the 24SI or the 28? How was it on fuel consumption? Which had better low end torque?

Gruss,

Matt

[morbin]

up

[maxpower]

Thanks a lot Max.

Good suggestion I used to run a Polini 177 with worb5 crank and RZ Right but it was too noisy! It run excellent but expecially overhere in Italy, where it is not possible to make it streetlegal, I felt too much out of the low...

And so now I decided to go back to the valve.

Did you prefer the 24SI or the 28? How was it on fuel consumption? Which had better low end torque?

Gruss,

Matt

hi there,

i have also a vespa witch ist working with the valve. but only with an 177dr. this machine works real good with the 24si and sito+, :grins:

i think with the 24si it is not so loud vs 28 or 30.

how ever, you run out of the law with both versions, valve or not valve.

the problem to run out of law is the 177 polini.

if only noise is your problem try another exhaust such as sito+ or t5-original,

then the police will not hear your 177,maybie

[morbin]

Oh yes, I'd be out of law anyway, but at least they would not hear me so clearly! and Polini cylinder is not different from the standard cylinder to an unexperienced eye...

Ok so 28 makes more noise than 24, and then I'll go for the 24. And already thought about standard Sito, with this one Polini should sound a little more ...

Did you work the valve on your DR? 4+4?

Does the Sito + give something more than Standard Sito?