Novarossi engines thread
#3542
#3543

thanks.
#3544
now may anyone help me on this:
let say i wanna use this engine [N12 T1]for bigger track... how to make it as competitive, on par, with the other big expensive engine... for example the 353.
what shud i do with the clutch setting?
what about pinion/spur setup?
tire size?
thanks. think this as the budget racer tips to hang out with the pro
I just wanna leave the other equation - how to drive, as the only other variable different.
any advice is appreciated - just dont ask me to stop dreaming

let say i wanna use this engine [N12 T1]for bigger track... how to make it as competitive, on par, with the other big expensive engine... for example the 353.
what shud i do with the clutch setting?
what about pinion/spur setup?
tire size?
thanks. think this as the budget racer tips to hang out with the pro

I just wanna leave the other equation - how to drive, as the only other variable different.
any advice is appreciated - just dont ask me to stop dreaming

#3546
#3547
Tech Regular
Joined: Apr 2005
Posts: 314
@Team Kamikaze
is it fact that the cnc piston improves bottom end? Just wondering, because I run Novarossi engines since many years and they changed the manufacuring process of their pistons between cnc and microcast a couple of times. Everytime they claimed that the change is an improvement...
is it fact that the cnc piston improves bottom end? Just wondering, because I run Novarossi engines since many years and they changed the manufacuring process of their pistons between cnc and microcast a couple of times. Everytime they claimed that the change is an improvement...
#3548
Microcasting is using a mold to fill it with liquid piston aluminium but under a high pressure. The molecules will be closer to each other making the material stronger. Finally this piston will be shaped by a CNC proces.
The CNC piston is just made from a bar delivered from the supplier.
Both are just piston materials.....
Depending the other materials inside (copper, iron, silicium etc) the specs/properties is determed like friction, strength, expansion rate etc.
So for me a CNC or a Microcasted piston is just a piston and only these words say nothing about the specs than only that the Microcasted must be stronger.
The CNC piston is just made from a bar delivered from the supplier.
Both are just piston materials.....
Depending the other materials inside (copper, iron, silicium etc) the specs/properties is determed like friction, strength, expansion rate etc.
So for me a CNC or a Microcasted piston is just a piston and only these words say nothing about the specs than only that the Microcasted must be stronger.
#3549
Tech Regular
Joined: Apr 2005
Posts: 314
You made some good point here, Roelof. I think that the terms "cnc piston" and "microcasted piston" are just marketing hype. I had good success with both types of piston which leads me to believe that it makes no big difference. On the other hand I was wondering why Team Kamikaze claimed that the Flash Special has more bottom end by using a cnc piston. I never ran the Special, so I cant compare. By looking at Novarossis expoded views I can tell that the P/S set and the crank is the same between the Flash and the Special.
#3550
Some thoughts about the more bottom end:
- different timing (sounds to me the most logical)
- better expansion rate fitting the expansion of the sleeve.
- lower friction (when giving throttle the piston becomes hot and does expand faster compared to the sleeve what will create some friction)
- different timing (sounds to me the most logical)
- better expansion rate fitting the expansion of the sleeve.
- lower friction (when giving throttle the piston becomes hot and does expand faster compared to the sleeve what will create some friction)
#3551
@Team Kamikaze
is it fact that the cnc piston improves bottom end? Just wondering, because I run Novarossi engines since many years and they changed the manufacuring process of their pistons between cnc and microcast a couple of times. Everytime they claimed that the change is an improvement...
is it fact that the cnc piston improves bottom end? Just wondering, because I run Novarossi engines since many years and they changed the manufacuring process of their pistons between cnc and microcast a couple of times. Everytime they claimed that the change is an improvement...

#3552
I think based on a bar of material or Microcasted (based on the same ingredients) there is not much difference in weight.
#3553
Tech Initiate
Joined: Nov 2009
Posts: 38
Hears the actual weights of cast v cnc billet pistons on Axe Rossi pistons as an example. Cast piston = 3.9 grams, cnc billet = 3.7 grams, The cnc piston has slightly more skirt cut away + two 5 mm holes as well so given this their probably the same weight.The reason to use billet material over cast is said to be stronger + billet they can get higher silicon content. A typical cast piston has around 20-21% max silicon, Billet is up to 30% silicon. The thermal expantion on 30% is less than 20% this is why billet pistons are said to last longer than cast ( the piston expands less so dosnt wear as much in the bore). This is also possibly why theirs more bottom end / acceleration because theirs less friction on the piston in the bore because the piston is expanding less. The thermal expantion on billet 30% silicon material is 15.4, Cast 21% silicon which is the maximum that can be made in cast pistons without compromising the material is 16.3. Obviously any reduction in piston weight will make differences as well. Martin.
#3554
Hears the actual weights of cast v cnc billet pistons on Axe Rossi pistons as an example. Cast piston = 3.9 grams, cnc billet = 3.7 grams, The cnc piston has slightly more skirt cut away + two 5 mm holes as well so given this their probably the same weight.The reason to use billet material over cast is said to be stronger + billet they can get higher silicon content. A typical cast piston has around 20-21% max silicon, Billet is up to 30% silicon. The thermal expantion on 30% is less than 20% this is why billet pistons are said to last longer than cast ( the piston expands less so dosnt wear as much in the bore). This is also possibly why theirs more bottom end / acceleration because theirs less friction on the piston in the bore because the piston is expanding less. The thermal expantion on billet 30% silicon material is 15.4, Cast 21% silicon which is the maximum that can be made in cast pistons without compromising the material is 16.3. Obviously any reduction in piston weight will make differences as well. Martin.
#3555
Tech Regular
Joined: Apr 2005
Posts: 314
Very good and detailed explanation, Martin. Makes a lot of sense to me, thanks a lot for that. The only open question to me remains, why is Novarossi changing back and forth between the piston manufacturing processes and claims and improvement everytime...



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