Hi all,
I've been looking for a set of high compression pistons here in the EU for some time and emailed Agostini , Omega and Pistal Racing .
Here is what Pistal answered yesterday .
Hi Angelo,
I will make some investigation from a friend dealing with Moto Guzzi since years, I did some racing piston for him few years ago, is the Moto Guzzi dealer in Parma, if I will make some pistons for your engine you will be the first to know.
Kind regards
Giorgio Casolari
Technical and Sales Manager
PISTAL RACING Srl
commerciale@pistalracing.it www.pistalracing.it
Da: Angelo Machairas Inviato: giovedì 3 aprile 2014 18:04 A: Giorgio Casolari Oggetto: Σχετ: R: Moto Guzzi V11 pistons ?
Dear Giorgio, Thank you for your swift reply. V11 was produced between 1998 and 2006 . It is a two valve per cylinder engine of 92mm piston diameter .. Although much loved by it's owners , some of them suffer from pre-ignition (knock,pinging) due to the mismatch of the stock piston top to the combustion chamber , leading to slow flame speed . Even with high octane fuel , mine pinged near 4500-5000 rpm . Adding more fuel or retarding the spark timing is not a desirable way to cure this phenomenon . I believe that , if you would make a better shaped piston top , with a mild increase of compression ratio from the stock 9.3 : 1 , you would have a winner . If you are interested , when I open the motor , I will try to send you a piston , a rubber mold of the combustion chamber and whatever measurements of interest I can take from it. I will contact you first . Best regards Angelo
My take on the matter is , we can have a hand at determining the specs for the end product .
I , for one , would like long (as the OEM) skirts and as much as possible extended squish band .
Others , more knowledgeable than me , might suggest some other desirable characteristics .
Cheers