it would be useful to understand more about the button shimming and also the back plate mods that you can buy and how they make a difference to performance.
Button shimming is about changing the compression ratio of the engine in order to optimize it for the Nitro percentage of the fuel you are using. The more Nitro in your fuel, the less compression the engine must have, or the ignition timing will be too early and the engine can run into detonation issues. Compression, along with Nitro %, and glow plug temperature, is what controls the ignition timing in these engines. Back plate mods? A back plate for a starter box, with no pull start or "roto start" will make for a faster reving and responding engine. The one way bearing and extra starter shaft required for the use of a pull start or roto start adds quite a bit of weight to the rotating assembly of the engine, AND creates a bit of drag on the crankshaft. Removing those items and installing a standard bump-box backplate will give a noticeable gain in engine power and response. As far as grinding on a back plate goes, the purpose is ti create more airflow inside the bottom half of the engine by removing material that the piston skirt "blocks" when it comes down to the bottom of it's stroke. It ALSO changes the volume of space in the crank case which affects how much air can be brought in during the compression stroke when the piston rises. These types of mods should be left for a professional engine modder that is radically altering the entire engine and it's induction system. It's more of a fine tuning tool. For the average R/C guy that wants a little more power from his engine, getting rid of the pull start/roto start back plate, one way bearing, and any extra shafts associated with it, WILL give him much more of a noticeable gain than trying to grind and modify a back plate for airflow.
tall one looks like ed bridges insert, is the inside not have the machining marks cleaned up? like concentric rings? 7mm. its supposed to flow as much as an 8mm insert i never noticed a difference just more surface area for the airfilter elbow to grip against
Nice video! I was just talking about this subject with my buddy like 2 days ago haha, yea triton has the plastic duo carb with the 2 slots. I have it still gotta try it out. I’m curious to see what tools you use for your measurements etc. some do there’s in different ways with there own tools. Ha yea someone commented on one of my videos saying I say yea to much haha
Yeah, the rubber hair bands don't last. What I use is, cheap bicycle tube. Cut your own rings out of it. One can easily change the rubber ring stiffness by changing it's width. Lasts wayyy longer than the usual rubber bands.
Have you ever tried a Venturi that create a vortex? I tried to make one I wasn't too happy with the way it came out but even that seem to make a difference. I tried another one where it would try to go counter-clockwise that one didn't work so well. If you know someone who makes one please let me know or if you would custom make one let me know if you're interested buying one. Just getting into the a 1/8 scale buggy racing I have a Triton dual Venturi that I haven't had a chance to try out yet but I think a venturi that was clockwise vortex made right so I didn't have to worry about anyting coming off of going into the engine what do better. I got the idea from my mustang my cold air intake came with a piece like a Venturi that creates a vortex and I get better fuel economy, so when I tried it my RC I got more power and that was with one not made properly.
To put it this way.... The old "Tornado" throttle spacer that was designed like that for full size cars, and was supposed to give you, "Increased fuel economy, and more power!" NEVER lived up to it's name, and went down in history as a farce with everyone laughing at someone who bought into it, I would say NO... 🤔
I've always wondered if there was any testing done on performance gains/losses from a velocity stack in these little nitro engines. Kind of thinking about turning a few and testing the acceleration in my bashers.
A velocity stack is going to benefit an engine at only one certain RPM in it's power band.... And especially in conjunction with a tuned pipe that is set up for that same RPM also. A guy used to see velocity stacks used with throttle-less pylon racing airplane engines that were setup for max rpms, and had finely tuned pipes on them. In my opinion, they wouldn't work well for a throttled engine with a wide RPM range.
I love your videos don't stop! So knowledgeable and interesting.
Wish you were still here bro! RIP 🙏
I just notice your the famous RWmods I've heard a lot of good things brother... Braaaaaap
it would be useful to understand more about the button shimming and also the back plate mods that you can buy and how they make a difference to performance.
Button shimming is about changing the compression ratio of the engine in order to optimize it for the Nitro percentage of the fuel you are using. The more Nitro in your fuel, the less compression the engine must have, or the ignition timing will be too early and the engine can run into detonation issues.
Compression, along with Nitro %, and glow plug temperature, is what controls the ignition timing in these engines.
Back plate mods? A back plate for a starter box, with no pull start or "roto start" will make for a faster reving and responding engine. The one way bearing and extra starter shaft required for the use of a pull start or roto start adds quite a bit of weight to the rotating assembly of the engine, AND creates a bit of drag on the crankshaft. Removing those items and installing a standard bump-box backplate will give a noticeable gain in engine power and response.
As far as grinding on a back plate goes, the purpose is ti create more airflow inside the bottom half of the engine by removing material that the piston skirt "blocks" when it comes down to the bottom of it's stroke.
It ALSO changes the volume of space in the crank case which affects how much air can be brought in during the compression stroke when the piston rises. These types of mods should be left for a professional engine modder that is radically altering the entire engine and it's induction system. It's more of a fine tuning tool.
For the average R/C guy that wants a little more power from his engine, getting rid of the pull start/roto start back plate, one way bearing, and any extra shafts associated with it, WILL give him much more of a noticeable gain than trying to grind and modify a back plate for airflow.
Great content Rex, I need all the tips for track I can get. And I can't wait for tomorrow so I can try rolling on power to see if it's faster for me.
I love these, please don't stop.
He passed
tall one looks like ed bridges insert, is the inside not have the machining marks cleaned up? like concentric rings? 7mm. its supposed to flow as much as an 8mm insert i never noticed a difference just more surface area for the airfilter elbow to grip against
Rex could you do a video on how to tune a long low end needle vs a short low end needle engine tuning?
Did you watch the tuning video? I talked about the long vs short but maybe not in detail.
@@TheRwmods i did but i will go check again if i have a question i will hit you back up
Great vid.
Nice video! I was just talking about this subject with my buddy like 2 days ago haha, yea triton has the plastic duo carb with the 2 slots. I have it still gotta try it out. I’m curious to see what tools you use for your measurements etc. some do there’s in different ways with there own tools. Ha yea someone commented on one of my videos saying I say yea to much haha
instablaster
Those exhaust port restrictors (with the shoulder on), have you made any for the OS Spec2??
Yeah, the rubber hair bands don't last. What I use is, cheap bicycle tube. Cut your own rings out of it. One can easily change the rubber ring stiffness by changing it's width. Lasts wayyy longer than the usual rubber bands.
Great video 👍So the bigger venturi, the easier to tune the engine?
I would say 6.5mm-8mm tune good, under 6.5 it can be harder to tune when racing.
@@TheRwmods I just bought the fx 301 engine. It should hold a tune pretty well
Have you ever tried a Venturi that create a vortex? I tried to make one I wasn't too happy with the way it came out but even that seem to make a difference. I tried another one where it would try to go counter-clockwise that one didn't work so well. If you know someone who makes one please let me know or if you would custom make one let me know if you're interested buying one. Just getting into the a 1/8 scale buggy racing I have a Triton dual Venturi that I haven't had a chance to try out yet but I think a venturi that was clockwise vortex made right so I didn't have to worry about anyting coming off of going into the engine what do better. I got the idea from my mustang my cold air intake came with a piece like a Venturi that creates a vortex and I get better fuel economy, so when I tried it my RC I got more power and that was with one not made properly.
Sorry I brought up Triton.
I did attempt to make some dremel cuts in a venturi. I was trying to get the air to spin but I never got it the way I wanted.
To put it this way.... The old "Tornado" throttle spacer that was designed like that for full size cars, and was supposed to give you, "Increased fuel economy, and more power!" NEVER lived up to it's name, and went down in history as a farce with everyone laughing at someone who bought into it, I would say NO... 🤔
What Venturi would you recommend for breaking in a Novarossi Paloma or Mito 4?
For break in it doesn't matter, when you go to tune the engine after break in use the one you paln to use.
do car setups expand your scope and help us learn thank you
I do know setups ok but usually ask my son for advice. haha
I've always wondered if there was any testing done on performance gains/losses from a velocity stack in these little nitro engines. Kind of thinking about turning a few and testing the acceleration in my bashers.
A velocity stack is going to benefit an engine at only one certain RPM in it's power band.... And especially in conjunction with a tuned pipe that is set up for that same RPM also.
A guy used to see velocity stacks used with throttle-less pylon racing airplane engines that were setup for max rpms, and had finely tuned pipes on them.
In my opinion, they wouldn't work well for a throttled engine with a wide RPM range.
@@davelowets interesting, thank you for the reply!
I need a 5.5mm restrictor.
You know very little about venturies😂😂😂