Questions about Nitro Engines
07-27-2009, 01:04 PM
#1
Questions about Nitro Engines
Hello all,
1) How are the number of ports in an engine determined? From what I have read, the sleeve seems to be the determining factor. Can I literally take the sleeve out and immediately know the number of ports?
2) What affect does increasing or decreasing the the number of ports in an engine have on the performance?
3) I have an outside idea of what gear ratio is with real world cars, but have no idea what it is for RC cars. Don't all nitro engines have one gear?
1) How are the number of ports in an engine determined? From what I have read, the sleeve seems to be the determining factor. Can I literally take the sleeve out and immediately know the number of ports?
2) What affect does increasing or decreasing the the number of ports in an engine have on the performance?
3) I have an outside idea of what gear ratio is with real world cars, but have no idea what it is for RC cars. Don't all nitro engines have one gear?
07-27-2009, 01:26 PM
#2
1. Pull the sleeve, count the holes in it.
2.In my limited experience:
More ports = Higher Rpm, more topend, usually thirtsty. 7-9 port.
Less ports = 3-4 port. More torque, better fuel economy. A few engine types have found a way to use 4 port mills and still get plenty of topend. (ex:NR+4,Vspec.)
3. I like turtles.
2.In my limited experience:
More ports = Higher Rpm, more topend, usually thirtsty. 7-9 port.
Less ports = 3-4 port. More torque, better fuel economy. A few engine types have found a way to use 4 port mills and still get plenty of topend. (ex:NR+4,Vspec.)
3. I like turtles.
07-27-2009, 01:27 PM
#3
double click, slow connectrion
07-27-2009, 01:46 PM
#4
Hello all,
1) How are the number of ports in an engine determined? From what I have read, the sleeve seems to be the determining factor. Can I literally take the sleeve out and immediately know the number of ports?
2) What affect does increasing or decreasing the the number of ports in an engine have on the performance?
3) I have an outside idea of what gear ratio is with real world cars, but have no idea what it is for RC cars. Don't all nitro engines have one gear?
1) How are the number of ports in an engine determined? From what I have read, the sleeve seems to be the determining factor. Can I literally take the sleeve out and immediately know the number of ports?
2) What affect does increasing or decreasing the the number of ports in an engine have on the performance?
3) I have an outside idea of what gear ratio is with real world cars, but have no idea what it is for RC cars. Don't all nitro engines have one gear?
2. Like stated above, but there is more to it than that. the shape of the ports affects timing, and location of the ports affects the engine as well.
3. by saying "one gear" you mean one speed? they have a gear on the clutch bell and a center diff gear. you can change the amount of teeth on either and change your gear ratio.
07-27-2009, 01:57 PM
#5
Let me try this slightly differently. I believe that a 13T clutch bell is for use with a 13mm crankshaft, while a 14t clutch bell is for use with a 14mm crankshaft, 15t for 15mm and so on.
Clearly the notches on a clutch bell have to mesh with the notches on the center diff. Do 13t clutch bells only mesh with certain centre diffs, while 14t only mesh with different centre diffs or does the combination of 13t/14t/15t clutch bells with various center diffs make-up the gear ratio for the car?
07-27-2009, 02:32 PM
#6
the shaft diameter has nothing to do with the tooth count (ie...a 13t clutch bell will fit the same crank as a 15t clutchbell ect...) the only thing different would be the roll out on the clutchbell witch means the smaller tooth count will take less time to make one full revolution than a bell with more teeth witch translates into less top end and more bottom. you said u have an understanding of gear ratios on a full size car so to see this on that plain, take a look at a ring and pinion set from a 3.08\1 and compare it to a 4.11\1...
07-27-2009, 03:12 PM
#7
Originally Posted by Garet Jax
3) I have an outside idea of what gear ratio is with real world cars, but have no idea what it is for RC cars. Don't all nitro engines have one gear?
07-27-2009, 04:36 PM
#8
Each kit model has a selection of clutch bells.
For example an Associated RC8 comes with a 16 tooth bell. A 15 and 17 are optional. The Associated bells fit associated cars, Losi fit Losi, X-ray fit X-ray.
Generally the 15 would be for shortrt tracks, and the 17 for higher speeds. I allways run the same diff gear.
The buggy engines all have nearly the same cranks.
The clutch,flywheel,pinion gear, clutch bearings, bolt, shims, nut, etc., make up the clutch/pinion gear assembly. They come with the car kit, and work specifically for that car.
The engines are mostly universal.
For example an Associated RC8 comes with a 16 tooth bell. A 15 and 17 are optional. The Associated bells fit associated cars, Losi fit Losi, X-ray fit X-ray.
Generally the 15 would be for shortrt tracks, and the 17 for higher speeds. I allways run the same diff gear.
The buggy engines all have nearly the same cranks.
The clutch,flywheel,pinion gear, clutch bearings, bolt, shims, nut, etc., make up the clutch/pinion gear assembly. They come with the car kit, and work specifically for that car.
The engines are mostly universal.
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