20Likes2017 OS Speed R2103 3.5cc Nitro On Road Engine
08-16-2017 | 07:26 AM
#46
Tech Fanatic
Joined: Dec 2010
Posts: 805
How further the crankpin is located from the center the more force you can create on the output w/o needing more combustion power. I also believe the larger movement of the piston will make the pump to suck up the mixture a little bit better.
More torque is not only about the stroke, it is more about the height and width of the exhaust port together with how much fuel you can burn. The longer the combustion stroke is before the exhaust opens the more power it has. The same is with the barrel of a gun.
Looking at F1, more power comes from more combustions per seccond, to reach that a short stroke engine is needed due the physical speed limitations of the pistons and lubrication.
As Picco has succes with their extra long stroke engines Novarossi did not do well with their xtra long stroke Keep-on and Mito models as their current topmodel is the normal long stroke 35WC.
Longer strokes do not have to be better als also with the amount of ports. It is more about timings, dimensions and materials to make a good engine.
More torque is not only about the stroke, it is more about the height and width of the exhaust port together with how much fuel you can burn. The longer the combustion stroke is before the exhaust opens the more power it has. The same is with the barrel of a gun.
Looking at F1, more power comes from more combustions per seccond, to reach that a short stroke engine is needed due the physical speed limitations of the pistons and lubrication.
As Picco has succes with their extra long stroke engines Novarossi did not do well with their xtra long stroke Keep-on and Mito models as their current topmodel is the normal long stroke 35WC.
Longer strokes do not have to be better als also with the amount of ports. It is more about timings, dimensions and materials to make a good engine.
It is however possible that there is small gains in decreasing the radial burn distance as the rpm goes up.
But as you mention, there is so many more things that influence the outcome that looking at just a couple of things isn't giving the whole picture.
08-16-2017 | 07:34 AM
#47
First of all, do not rely on the written specs, mostly they are made out of nothing. And because Novarossi is producing several engines from cheap up to expensive they would never alow a cheaper motor running faster (in real and on specs). As I have mentioned several times that I have made 5 port engines run as fast as many top range models by just changing some timings. Timings is making the engine, not the amount of ports.
08-16-2017 | 11:22 PM
#48
but how we going to find a heavier flywheel? roelof what solution could u come up with to make a flywheel heavier?
08-17-2017 | 12:55 AM
#49
Tech Lord
Joined: Aug 2007
Posts: 14,052
From: Holland
Make one or use an older version, but to be honest I do not think it is needed, I still think many people will replace the steel bearing for a ceramic w/o issues (and w/o any gain 
)
Also Rody did mis understood your sugestion. adding tiny screws in the flyweights is done but that is to change the way the clutch reacts.
)Also Rody did mis understood your sugestion. adding tiny screws in the flyweights is done but that is to change the way the clutch reacts.
08-17-2017 | 01:08 AM
#50
R/C Tech Elite Member
Joined: Jun 2014
Posts: 265
From: Carces FRANCE
Make one or use an older version, but to be honest I do not think it is needed, I still think many people will replace the steel bearing for a ceramic w/o issues (and w/o any gain )
Also Rody did mis understood your sugestion. adding tiny screws in the flyweights is done but that is to change the way the clutch reacts.
)Also Rody did mis understood your sugestion. adding tiny screws in the flyweights is done but that is to change the way the clutch reacts.
08-17-2017 | 04:20 PM
#51
Very interesting discussion. Thank you for the info. Roelof, regarding crankpin and stroke length, Is it safe to say longer stroke engine has larger diameter of crankshaft then? I had to look up definition of crankpin and nitro engines don't really seem to have the "obvious" crank pin in the crankshaft. correct me if I'm wrong.
08-18-2017 | 01:01 AM
#52
R/C Tech Elite Member
Joined: Jun 2014
Posts: 265
From: Carces FRANCE
Very interesting discussion. Thank you for the info. Roelof, regarding crankpin and stroke length, Is it safe to say longer stroke engine has larger diameter of crankshaft then? I had to look up definition of crankpin and nitro engines don't really seem to have the "obvious" crank pin in the crankshaft. correct me if I'm wrong.
08-18-2017 | 03:20 AM
#53
Tech Adept
Joined: Mar 2015
Posts: 163
First of all, do not rely on the written specs, mostly they are made out of nothing. And because Novarossi is producing several engines from cheap up to expensive they would never alow a cheaper motor running faster (in real and on specs). As I have mentioned several times that I have made 5 port engines run as fast as many top range models by just changing some timings. Timings is making the engine, not the amount of ports.
08-18-2017 | 10:50 AM
#55
http://www.rctech.net/forum/onroad-n...ghlight=Legend
08-18-2017 | 08:44 PM
#60
