Comments by "EarthSurferUSA" (@EarthSurferUSA) on "Repairman22" channel.

  1. If the environment were a legitimate concern, then why over the last 45 years of giving our free enterprise and production to communism in china, has there never been our (western culture) EPA regulations added to the trade agreements? communism gets a free ride, while we, who created free enterprise in the first place, are punished.
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  2. For the tuned pipe, it is not the change in pressure through the pipe that causes the "reverse wave", but a sonic wave, (sound), that bounces off the reverse cones. The expanding gasses in the pipe create the vacuum that help draw out free gas from the transfers, into the cylinder and some out the exhaust port. It is the sonic wave that pushes that fresh charge back in the cylinder for a super charging effect, which is why tuned pipe make much more peak power (but not in the total range of usable rpm's, as it relies on piston speed match to a tuned pipe.). Maybe the creators of this bot channel should have consulted with me, to be more accurate, (less false information).
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  3. I bet neither mode works as well as they do in separate engines.
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  4.  @MichaelLyons-h4i  Yep, in racing form. After the EPA forced the 4-stroke on the motocross industry, neighbors near the tracks started complaining about the noise. Also, for the smoke of a 2-stroke, that is caused by the rich stock jetting on carbed engines. Tune the jetting well and they run much more clean, (no un-burnt dark drool from the exhaust), make more power, and smoke is pretty much eliminated sans starting a cold engine.
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  5. KTM (appeasing expensive EPA force), found out in their testing that direct injection into the head, had to fight the rising compression, and became complicated and even more expensive to make, (prices are very high today because of the EPA, and market share is dwindling in the off road motorcycle industry). So they are injecting the fuel in the transfer ports or the intake with no oil, and still may have problems with the oil injection systems used for fuel injection for the 2-stroke engine. Expensive KTM dirt bike engines today, are not a model for top reliability. But they are the most expensive. Thank the EPA.
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  6. But the reed valve is of little use, if there are no reed transfer ports to increase time area of the transfers, so we can increase the time area of the exhaust port to match. I have only seen one piston port MX bike engine (an old Montessa), that was able to use a 5th transfer. It was the only time I saw that unusual casting configuration, but there may be more.
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  7. Nope, the bot did not explain the pipe well. It may be the most naive explanation I ever heard. I have made a living modifying 2-stroke engines for the last 2 decades. I see a brain dead bot here reading from a ill educated HS research paper. :)
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  8. I think I did learn something about 2-stroke gas engines here,---but the vid is half EPA propaganda, with some poor technical information. They call this "progress" in our schools.
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  9. 7:00 Another ill educated bot error. Pressure does not cause the reverse wave in a tuned pipe. Sound does.
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  10. How do you know? I do. :)
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  11. It all depends on the size of the engine. little 2-stroke nitro engines rev to over 30,000 rpms, (and can not use a piston ring because of it). And I build 30cc gas 2-stroke engines for a living, that probably rev higher than anything with a ring, staying together at 21,000 rpm. How much rpm it can take, pretty much primarily depends on the size and weight of the parts. How would you like a screaming, 5lb little 21,000 two stroke engine for a noise maker at the bike races? They have a sound---all their own. :)
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  12. I found several technical mistakes in this vid., coupled with EPA propaganda.
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  13. For a "smokey" 2-stroke engine (carbed). The jetting is too rich. A well jetted 2-stroke engine does not smoke much at all, runs cleaner, and makes more power. Factories have to sell them jetted rich to not seize in different air quality around the world. But any 2-stroke stock, with a carb,---will benefit from leaner jetting.
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  14. You are talking about supercharging the intake. But on the 2-stroke, when the transfer ports are open, filling the cylinder, so is the exhaust port. So it all blows out the exhaust. I am sure the flowing action would clear out the burnt exhaust gasses better in the head and cylinder area, and maybe find a bit more power because of that purity of fresh fuel/air. But you will be blowing a huge amount of fresh gas/air out of the exhaust port at the same time. Until communism in china has to deal with an EPA,---I have to consider their arguments against gas engines, coal electric generation, etc., a load of crap.
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  15. How do you know? You don't.
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  16. Funny a bit. 9:58, on the dirt bike with a go-pro on his helmet: "Do I take this line down the hill, or this line?" He choose the easy one. :)
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  17. As a 2-stroke engine builder myself, I would have to disagree with #3 a bit. I would say the rotary valve intake offers the best performance, then reeds, then piston port. The reason is the difference way they fill the crank cases. Reeds offer a wider power curve, (and usually more power, as piston ports rarely have a 5th transfer), over a piston port, and it flows based on different pressures and not piston location, and can have an open duration of the intake to a full 360 degrees, allowing fuel to flow when ever pressure differences let it happen. But, the reed valve is an obstruction. Rotary valve, similar to the piston port as the flow is controlled by mechanical means instead of different pressures, has the ability to tune the intake duration at closing, and opening, where the piston port is symmetrical, but is more expensive to build. Obviously, the MX factories went with reeds starting in the 70's, because they are out performing the piston ports. But I think the rotary valve has the best potential because of that intake control, and no obstruction like a reed valve. I will listen to this vid, (which is probably a bot vid, just repeating what it learned, correct or incorrect), and I bet I could find other discrepancies also. :)
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  18. "The transfer port and the exhaust ports are the ones open at the same time." Nope. The exhaust opens much earlier then the transfers. The cylinder pressure has to "blow down" to about zero pressure, so the transfers can flow into the cylinder. The measured number of degrees of crank rotation between the exhaust opening up, and the transfers opening up, is called "The blow down phase". It would not run if they opened at the same time. "Loop Scavenging" is the correct term. I would like to build a rotary valve engine from scratch. I think I can get the most power form them.
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  19. I see problems with false information all the time. If we "lighten up", well, I am old and more wise today and I have seen the devolution of our thinking over the last 4 decades, (started before I realized it too), . We don't even know any math anymore to figure stuff out. The amount we "lighten up" is the amount of our decline. It is your future, not mine. Bottom line son. I hate the communism that has pretty much taken over the USA, with the destruction of our individual liberty and the theft of our free enterprise that free people in the USA created in the first place. I have been studying for 16 years, our decline, from the perspective out human freedom. Not many people have done that, (I don't know anybody), and I do understand our decline, the decline of mankind, just about as well as the communism sabotaging us. Son, I have hated communism for 52 years now, since I was 8 years old. This not a bad vid for overall understanding, (leaves out "loop scavenging" for some reason, showing one transfer port pointing at the exhaust port, and would be very dirty. And the smoke of a 2 stroke that could be pretty much eliminated with good jetting), so there is a bit of propaganda in there. "Lighten up", and we will be run over. I am sick of the bullying. I say it is "our turn". :) Doug in Michigan PS: I port and stroke these little engines for a living, started with Go-Ped scooters 20 years ago, but the RC cars using the same engine a bit later made my business,--the most popular in the world today in the RC/Scooter industry (the ones using the Zenoah engine anyway). I have come to learn that we get taken advantage of, if we "lighten up", during a national transformation of our society. 52 years, I have hated communism. I am figuring it out well. I was motivated by it.
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  20.  @ct1762  He is talking about the normal maintenance that he is too lazy to do. Factories usually don't sell new engines in those worn out conditions. :) Pretty sure this guy hates shoe laces. Too complex, and he does not have time.
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  21. Well, you can add a supercharger to a 4-stroke, not a 2-stroke, and make any 4-stroke engine with increased flow capacity.
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  22. Excluding the force of the EPA, probably the longevity of the engine. A tame 4-stroke ( not a racing engine), will go a lot longer than a 2-stroke with out a top end rebuild, but costs much more to rebuild it.
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  23. "The appearance of direct injection was good news for the 2-stroke engine." Forced by the EPA and increases the cost of the engine with less market share due to cost and complexity,--------------------is not good news. Intervention like that has damaged every industry we ever created, and your car should be about half the price it is today for the same reasons.
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  24. I build 2-stroke engines for a living, racing applications and recreation. If you have "seen" a lot of other explanation,---they were all probably just a bit worse than this one. I give this a B- for technical information, and a F for the EPA propaganda.
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  25. Nope, (to the best of my knowledge). KTM is using "transfer port injection", (because of EPA force). What they dropped is the direct injection into the cylinder during the compression stroke, (like this vid shows), because it requires much more pressure, probably making metering and reliability not as sound. The bottom end temps will be the same. But, there is the cooling factor you mention, so maybe I am wrong, and the bottom end just gets warmer with only oil injection on the bearings.
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  26. 8:40 The bot vid is comparing a corrected compression ration (7:1, the area only above the exhaust port in the stroke), to a 4-stroke method (12:1) using the full stroke of the bore. People do measure 2-stroke compression with the 4-stroke method, (which is not a good practice IMO), but the corrected method is just for 2-strokes. You will not find a 2-stroke with 12:1 compression, (measured by the corrected method), that will run on gas with out failure,---quickly.
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  27. The vid is wrong with compression ratios. it compares the 2-stroke method (about 8:1), to a full stroke 4-stroke engine (12:1). 10:1 with the 2-stroke method (only the area above the ex. port is calculated), and you probably could not run gasoline.
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  28. The catalytic converters on your modern cars, are so close to the exhaust ports of the head, to raise the temps of your engine to burn as many hydrocarbons as possible. But it also adds heat to your engine, which is why Toyota never advertises 300,000 mile from their engines as they had in the late 70's. The heat is hard on parts and the new electronics of engine management. Reliability has fallen greatly for the enteral combustion engine,---which the EPA does not want us to use. They don't care if it makes you broke, and they do make us more broke. The cost of a car is probably double with the EPA regulations,---which communist china does not have in our trade agreements with free enterprise mixed with communism. Is the EPA about saving the planer from our prosperity and freedom to produce? Or about advancing communism, stealing our free enterprise to fund their advancement?
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  29.  @liloldsnoopy4279  Less friction, but more blow by. Racing engines still use both.
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  30. 1:50 Oil burning is more blue in color. White smoke (steam) is probably a water cooing leak into the cylinder. Good crisp jetting greatly reduces that smoke you see in that example.
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  31. I do know, what this vid and you don't. When you don't know much, any information can be seen as correct information. That is why we graduate form our schools today,----------------------stupid.
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  32. Now to get more peak power, rpm's usually have to ride, (part of the equation), and it is usually true for racing or performance engines to seek more peak power, especially for racing like road racing. But, the fact is, a pipe can also be made to enhance lower rpm power, like many pipes sold for off road use in dirt bikes. The type of power can be changed for the application greatly, with pipe and porting. I can tune a pipe to peak at 8000 rpm just as easily as peak at 16,000 rpm, by changing its tuned length.
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  33. Now to get more peak power, rpm's usually have to "rise". sorry
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  34.  @RonaldDaub-v9y  " It needed a toggle switch instead of a throttle." :) Good post. But the best way to build a engine is make the porting for the application, then make the pipe to match the porting. But IMO, if they are just judged on their own (porting or pipe), pipe effects can change the power output more than just porting.
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  35. I have seen one two stroke engine start backwards. It was in the 70's on a Husky 250cc dirt bike. It was funny. I saw my buddy start up the engine, put it in gear, took off a bit and the roost hit the front tire. The culprit? The flywheel key was sheered and the timing changed enough to backfire (on the kick), and start backwards. It sounded like it was running good too. :)
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  36. Is the bot sure that t-stroke ports are just "simple holes"? Because decades of research and testing to gain the most power has proven to be quite complicated. Probably much more complicated than a valve. So, I already see "simple holes" in this vid.
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  37.  @paulsawczyc5019  Just the commie EPA son,--who duped those people. Properly jetted for the most power, and they actually make very little smoke. Only on start up. What I don't like is the EPA force, that drives up the cost of everything,---which is why you won't be able to afford much.
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  38. But, the back pressure will help hold in the fresh gasses from leaving the ex. port at lower rpm's, before the sound wave is in effect. We use the calculations of "sound speed" to created a proper length and geometry tuned pipe. If you build too much pressure, (a small diameter exhaust end bleed, the end of the exhaust), then the engine will get hotter at higher rpm, like the close cats on your car overheating your engine in an effort to burn every hydrocarbon. Nope, the EPA does not care how long your gas engine lasts, unless it is a shortened live span. I don't see Toyota ads today, like we did 40 years ago, bragging about 300,000 miles.
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  39. It depends on the size of the engine, and the tune (is it a race engine, and what kind of racing?). Typically, 2 stroke can be made to rev higher, because they have less reciprocating mass and no poppet valves. Now, if we go by rotations of the crank, I am seeing high revving 4-strokes. But if we go by the entire power cycle, (each spark, twice as may crank rotations for a 4-stroke to complete one cycle), than that would be half. But we measure crank rotation only. I build 30cc (approx) racing 2-strokes for a living. let me know if you can find a 30cc 4-stroke that will rev to 21,000 rpm with out breaking.
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  40. Why do we give praise and agree with people when they really don't know exactly what they are talking about? Because we don't know the difference. I do. :) Sue your schools son. They do the same thing today.
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  41. They are the same thing. Schnuerle (sp?), developed "loop scavenging". You are right though, the programmed bot missed that,--and the fact that a sound wave in the pipe, that the bot confused with only pressure.
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  42. Then I would not buy a modified engine from the bot. :)
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  43. In my estimation from years of study, I am sure the creators of this vid know what loop scavenging is. But if they come from the perspective of the EPA, (which communist, anti free enterprise china has no EPA regulation in the trade agreements), it is to show a dirty running engine as much as possible, and no production 2-stroke engine ever had that port configuration in reality. They all like to show a lot of smoke from the exhaust of un-burnt oil/gas, and all 2-stroke engines with a carb are shipped rich to be on the safe side for air quality around the world. But that smoke can be greatly eliminated, burning cleaner, improving performance and gas mileage, with good jetting (which we have to do ourselves). With those facts left out, makes this vid a piece of propaganda IMO. Doug in Michigan.
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  44. How do you know?
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  45. No bot vid in the world----knows that. :)
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  46.  @ct1762  "Loop scavenging" replaced "cross scavenging",---a long time ago. 70 years maybe?
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  47. Finally, a guy who knows what he is talking about. Kudos. Doug @ ESP (Earth Surfer Performance).
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  48.  @jan-akelofgren7547  "The aftermarket crankshaft is wrong, they have increased the stroke by 2mm but only downwards, " You better figure that one out. That is not possible. The added stroke is equally split, up and down. It can't work any other way with a rotating circle crank.
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  49.  @repairman22  Just as good of a explanation as much of your vid. What do you mean, "The piston goes under the intake port."? The poster is wrong though. "The crown of your piston, is not opening up the top of the intake port at the bottom of the piston stroke." That is what you meant to say son. Now, go research the "sonic wave" that you called "pressure" in your explanation of a tuned exhaust pipe. I am professional at this stuff, (and do it for a living, selling world wide). Not like your teachers today, who we trust soooo much. :)
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  50. 7:40 That is also not true. My dyno reads with different types of exhaust, or none at all, (as I calibrated my dyno), with these 3 different runs: 1 Tuned pipe makes the most power. 2) No exhaust at all made the 2nd most. 3) A stock exhaust can, (found on all lawn equipment for example), made the least amount of power. (Pipe almost doubles that power). On the engines I work on, the stock can makes about 18% less power than no exhaust at all.
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