Mondial 2665 piston crown

S

stanfordcg

Junior member
Location
Cambridge
Just got a NOS Mondial 2665 piston, however comparing it with the original the crown is different.

All the marking inside are identical and everything else look the same, just look like the top of the piston has been shaved off.

Any ideas?
 

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left piston in the photo is a high compression Jota piston
right hand piston is the run of the mill low compression piston



 
I was looking for just one 75mm Jota piston a few years ago, and I asked Wolfgang if he had a good used one because I wasn't interested in replacing all 3 and reboring at the time. He told me to measure the height of the crown above the gudgeon hole because there were 2 different Jota pistons, a highish compression one and an even higher compression "Jota Sport" one. Don't remember the different dimensions at this point, but I'm prepared to bet that there's a millimetre or so difference in height between the two you have there.  You could take the millimetre off if you have a bodgy too high compression one, but the valve reliefs would still be different. Better off trying to find the right one, or as Red suggests, just replace all 3 with modern forged ones, lighter, stronger, sexier.

Ken
 
I see from your profile that you are based in Cambridge thus buying Ross pistons does not make much sense

Wolfgang stocks Ross pistons in Canada but mainly for the twins I believe and I carry stock of them for the 500/750/1000/1200 models but we have ours custom machined to reduce weight and add other features so they are more expensive

OCT carry ASSO in Germany, supposed to be a good piston, hundreds of Laverda's are running them with no issues
Keith in Scotland stocks Omega I believe that he has made to his own specifications
No idea what Slater stock, never dealt with them
Andy Wagner stocks pistons as well in Germany

buy closer to home and save money



 
http://cochise.uia.net/pkelley2/DynamicCR.html

Need I say more about Piston Domes, Cams, Lift and Duration other then Harold Brookshire of UltraDyne and Lunati. Sincerely hope Harold is still around.

Haven't heard from him in years. Just did a search and Harold is gone ;o(

Fuck static compression dynamic compression is what's it's all about.
 
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