Novarossi engines thread
#3451
Tech Elite
iTrader: (19)
Hey Pattojnr,
You are right regarding the timing. I would be interested exactly what did you do and how did you know how much to change the ports in the sleeve?
Regarding the Crank I wouldn’t touch it, because the last action in the production process is balancing. So if you modifying it you can ruin the balance of the crank. The result can be shorter life time of the bearings or worse breaking of the bearings.
But anyway always when you tune an engine (assuming you are doing it right) you shorten its life time because you expose it to greater stress.
The power of engines in these days is way over what materials can handle! In the future the manufacturers don’t have many options to get more power. If they increase power with existing materials the life times of engines will be shorter and shorter. So the main point is to focus on stronger materials that are able to withstand more stress. But this will mean more costly engines for us.
By
You are right regarding the timing. I would be interested exactly what did you do and how did you know how much to change the ports in the sleeve?
Regarding the Crank I wouldn’t touch it, because the last action in the production process is balancing. So if you modifying it you can ruin the balance of the crank. The result can be shorter life time of the bearings or worse breaking of the bearings.
But anyway always when you tune an engine (assuming you are doing it right) you shorten its life time because you expose it to greater stress.
The power of engines in these days is way over what materials can handle! In the future the manufacturers don’t have many options to get more power. If they increase power with existing materials the life times of engines will be shorter and shorter. So the main point is to focus on stronger materials that are able to withstand more stress. But this will mean more costly engines for us.
By
#3452
Tech Elite
iTrader: (19)
Gerberit, i dont change sleeve port timings. all timing changes i make are the crank open close timings. this is the best way to get easy reliable quick power.
all the R & D in sleeve design remains the same with what i do. but cranks are very conservative from the box.
all the R & D in sleeve design remains the same with what i do. but cranks are very conservative from the box.
#3453
Can you explain this in any scientific or engineering way?
If you have less material you have only les rotational mass and smaller inertial forces! But less material can handle less stress. Look, on witch branch can you sit on 20inch/cm diameter or 0.5inch/cm diameter. The power of a 2.11ccm engine is enormous regarding its displacement.
If this was so simple why didn’t the manufacturers come up with that idea!?
By
If you have less material you have only les rotational mass and smaller inertial forces! But less material can handle less stress. Look, on witch branch can you sit on 20inch/cm diameter or 0.5inch/cm diameter. The power of a 2.11ccm engine is enormous regarding its displacement.
If this was so simple why didn’t the manufacturers come up with that idea!?
By
#3454
Tech Elite
iTrader: (19)
Can you explain this in any scientific or engineering way?
If you have less material you have only les rotational mass and smaller inertial forces! But less material can handle less stress. Look, on witch branch can you sit on 20inch/cm diameter or 0.5inch/cm diameter. The power of a 2.11ccm engine is enormous regarding its displacement.
If this was so simple why didn’t the manufacturers come up with that idea!?
By
If you have less material you have only les rotational mass and smaller inertial forces! But less material can handle less stress. Look, on witch branch can you sit on 20inch/cm diameter or 0.5inch/cm diameter. The power of a 2.11ccm engine is enormous regarding its displacement.
If this was so simple why didn’t the manufacturers come up with that idea!?
By
#3455
Gerberit, i dont change sleeve port timings. all timing changes i make are the crank open close timings. this is the best way to get easy reliable quick power.
all the R & D in sleeve design remains the same with what i do. but cranks are very conservative from the box.
all the R & D in sleeve design remains the same with what i do. but cranks are very conservative from the box.
Tell me, what would you recommend when I buy a new engine. Should I tune it right away or should I run it in first and then tune?
Cheers
#3456
Tech Elite
iTrader: (19)
I know what you mean with the crank timing. And I see you have many experiences with the engines. I didn’t try to modify any engine yet but I’m considering buying a cheep one and giving it a try.
Tell me, what would you recommend when I buy a new engine. Should I tune it right away or should I run it in first and then tune?
Cheers
Tell me, what would you recommend when I buy a new engine. Should I tune it right away or should I run it in first and then tune?
Cheers
#3457
I hope we can chat about these things in the future.
Regards
#3458
I did even outperform a Mega ZX21 DSII (tuned) with a Nova Basic N21-3T just by copying all dimensions from a JP RX21 Kangaroo Teamspec 2003 and added a tiny bit more cranktiming.
As for messuring the timings I have a new toy:
As for messuring the timings I have a new toy:
#3460
I've got it here: http://www.roeispul.nl/pitchmeter.php
But if you take a search on Ebay to a digital agle level meter you will find this model as well.
It is also handy for messuring camber if you have straight setup wheels.
But if you take a search on Ebay to a digital agle level meter you will find this model as well.
It is also handy for messuring camber if you have straight setup wheels.
#3461
Tech Elite
iTrader: (19)
I've got it here: http://www.roeispul.nl/pitchmeter.php
But if you take a search on Ebay to a digital agle level meter you will find this model as well.
It is also handy for messuring camber if you have straight setup wheels.
But if you take a search on Ebay to a digital agle level meter you will find this model as well.
It is also handy for messuring camber if you have straight setup wheels.
#3462
Tech Master
iTrader: (2)
Can you explain this in any scientific or engineering way?
If you have less material you have only les rotational mass and smaller inertial forces! But less material can handle less stress. Look, on witch branch can you sit on 20inch/cm diameter or 0.5inch/cm diameter. The power of a 2.11ccm engine is enormous regarding its displacement.
If this was so simple why didn’t the manufacturers come up with that idea!?
By
If you have less material you have only les rotational mass and smaller inertial forces! But less material can handle less stress. Look, on witch branch can you sit on 20inch/cm diameter or 0.5inch/cm diameter. The power of a 2.11ccm engine is enormous regarding its displacement.
If this was so simple why didn’t the manufacturers come up with that idea!?
By
Adding more material doesn't automatically makes for a stronger part.
Adding material in the right spot, makes a part stronger. Sometimes you could make a part stronger by removing material, because the material doesn't add anything to the structural integrity of the part and only weakens it because of the added weight, so more stress at high rpm.
I have a JP engine which has the intake side of the piston milled away from the bottom of the piston to the bottom of the piston pin.
Makes up for a much lighter piston, but it doesn't weaken it.
As a downside, the engine is much harder to tune and was worn out quickly (5 liters) because of the huge power and high revs.
The main thing to improve, especially for 2.1cc engines, are the bearings.
With the current high tuned engines they last 2-3 liters at most in high competition.
Another important thing is crankcase rigidity. You would be amazed how much the older crankcases flexed under high load.
#3463
Your right on one part, but wrong on another part.
Adding more material doesn't automatically makes for a stronger part.
Adding material in the right spot, makes a part stronger. Sometimes you could make a part stronger by removing material, because the material doesn't add anything to the structural integrity of the part and only weakens it because of the added weight, so more stress at high rpm.
I have a JP engine which has the intake side of the piston milled away from the bottom of the piston to the bottom of the piston pin.
Makes up for a much lighter piston, but it doesn't weaken it.
As a downside, the engine is much harder to tune and was worn out quickly (5 liters) because of the huge power and high revs.
The main thing to improve, especially for 2.1cc engines, are the bearings.
With the current high tuned engines they last 2-3 liters at most in high competition.
Another important thing is crankcase rigidity. You would be amazed how much the older crankcases flexed under high load.
Adding more material doesn't automatically makes for a stronger part.
Adding material in the right spot, makes a part stronger. Sometimes you could make a part stronger by removing material, because the material doesn't add anything to the structural integrity of the part and only weakens it because of the added weight, so more stress at high rpm.
I have a JP engine which has the intake side of the piston milled away from the bottom of the piston to the bottom of the piston pin.
Makes up for a much lighter piston, but it doesn't weaken it.
As a downside, the engine is much harder to tune and was worn out quickly (5 liters) because of the huge power and high revs.
The main thing to improve, especially for 2.1cc engines, are the bearings.
With the current high tuned engines they last 2-3 liters at most in high competition.
Another important thing is crankcase rigidity. You would be amazed how much the older crankcases flexed under high load.
Regards
#3464
Tech Master
iTrader: (2)
Well basically I follow the same procedure with every engine and never had problems what so ever.
Break in, and the first race with the conrod the engine came with.
Mostly the engine is fully broken in after it's first race, at least in my case since I don't practice a lot.
After the first race I replace the conrod, and do a really good check up, clean up of the engine. With pretty much every engine I owned it wasn't needed to change the conrod a second time, because they were worn out before that point. My engines last around 10 liters after break in.
The bearings are really unpredictable, sometimes they become bad during break in already and sometimes they last 2 races.
When they start to feel different as when they were new, change them.
Don't wait until you see the (steel) balls become dull, then you have waited to long, and mostly you could see damage to the outside of your crank, it becomes hard to take it out.
When you change the bearings, put the crankcase in an oven, most of the time 45 min on 140C, then put the new ones in by using your crank to guide them in, and align them. I always immediately screw the flywheel on and rotate it. Since I have been doing it like this I feel the bearings last a little longer and the crank can spin more easily.
I wouldn't suggest using the cold-puller method, as this puts a lot of force on the components, and it's harder to properly align your bearings this way.
Break in, and the first race with the conrod the engine came with.
Mostly the engine is fully broken in after it's first race, at least in my case since I don't practice a lot.
After the first race I replace the conrod, and do a really good check up, clean up of the engine. With pretty much every engine I owned it wasn't needed to change the conrod a second time, because they were worn out before that point. My engines last around 10 liters after break in.
The bearings are really unpredictable, sometimes they become bad during break in already and sometimes they last 2 races.
When they start to feel different as when they were new, change them.
Don't wait until you see the (steel) balls become dull, then you have waited to long, and mostly you could see damage to the outside of your crank, it becomes hard to take it out.
When you change the bearings, put the crankcase in an oven, most of the time 45 min on 140C, then put the new ones in by using your crank to guide them in, and align them. I always immediately screw the flywheel on and rotate it. Since I have been doing it like this I feel the bearings last a little longer and the crank can spin more easily.
I wouldn't suggest using the cold-puller method, as this puts a lot of force on the components, and it's harder to properly align your bearings this way.
#3465
I know what you mean with the crank timing. And I see you have many experiences with the engines. I didn’t try to modify any engine yet but I’m considering buying a cheep one and giving it a try.
Tell me, what would you recommend when I buy a new engine. Should I tune it right away or should I run it in first and then tune?
Cheers
Tell me, what would you recommend when I buy a new engine. Should I tune it right away or should I run it in first and then tune?
Cheers