Ducati TT1, Ducati TT2 and Ducati 750 F1 Forum

my Pantah racer
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Author:  ducadini [ Fri Jan 05, 2018 7:58 pm ]
Post subject:  Re: my Pantah racer

Memo to myself : FIRST check all calculations and facts before posting an answer :oops: because when it takes too long (15 min) or someone else posts something you loose everything :lol: :lol:

So from memory :
Do they allow a +3% increase in capacity for the TT500 ? 500 + 3% gives 515 cc.

The alazzurra head has a 10.0 compression, calculated is that a 19.4 cc volume in the head BUT since the piston is domed the volume in the head must be greater. I guess your measurement of 25 cc is correct.

BUT the calculation of the compression ratio isn't ! Should be 513/2 gives 256 cc cilinder and 25 cc head and then (256+25)/25 gives 11.2.
With the cutout of the monster piston that would come down a bit but I don't know what the result will be with the flat machined piston.

Don't forget to check valve piston clearance with the 650 cams : more lift then a 350 cam.

Keep up the wrenching :D


Author:  flattop900 [ Sat Jan 06, 2018 1:47 am ]
Post subject:  Re: my Pantah racer

Hi Filippo...
I have to ask, did you calculate the compression ration before or after you machined the piston?

Author:  583 [ Sat Jan 06, 2018 1:12 pm ]
Post subject:  Re: my Pantah racer

HI Ducadini and Flattop 900, thank you for replying.

Without cecking, Tollerance on Italian TT500 is at 5%
Ducadini, you're right on compression calculation, mine is wrong, but we did that short way just to have an immediate feedback an then starting this project, if my calculation was down to 10/1 whe had give up.
And of course we need to check valve clearance.

Flattop we measured the head volume before machining pistons. without considering squish and valve clearance.

Author:  ducadini [ Wed Jan 17, 2018 5:54 pm ]
Post subject:  Re: my Pantah racer

Hey Filippo,

It's in german so You probably need the goegel trensleter :D :D


Then go to "Technikseite" and then "Verdichtungseranderung einmal anders"

Let us know if something isn't clear ;) ;)


Author:  583 [ Thu Jan 18, 2018 4:26 pm ]
Post subject:  Re: my Pantah racer

Hi Ducadini
And thank for the link. Amazing site, i will translate and read carefully that article.

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