2 Stroke Pipe Performance Tips and Tricks.

Hi, welcome back everyone. Thanks for joining me again. So, a bit different, I'm going to do a bit of an update today. So I'm going to be looking at something that was pointed out in the last video and how that could be causing issues for the power figures. I'm also going to be looking at a new challenger that's come and finally I'm just going to go over a brief overview of how I'm going to go about the new bike that I'm going to build for this challenge. So, the challenge, the original bike was lent to Practical Sports Bikes by a guy called Phil Holm, who's Mr. AR. He does a lot of restoration work and it is absolutely spot on. He lent them the original bike when the project came to an end. He had the bike back and he's still got the engine and he's got the original pipe as well. So, he, I'm obviously a member of his Facebook group, the AR Owners Group on Facebook. I'll leave a link in the description. He's dug out the motor, dug out the pipe and they're going to have a go at it themselves actually. So, it's quite interesting, a bit of a challenge. He's going to push everything on, so I'm really looking forward to that. You're in the video now, Will. Come say something. Right, where was I? So, that was Will. Elder son, doesn't like the camera quite as much. So, he's scuttled off back to his room on his Xbox because I still feel it needed maybe another one or two horsepower or maybe the power band. It might have been just enough horsepower but the power band wasn't quite wide enough. That's all I'm going to put out there now. Given to me, this guy I've been chatting to, Paul. He's been giving me quite a bit of information, ideas, bits and bobs. So, thanks again, Paul. He was telling me about a time a guy worked with doing a slippy pipe. So, a slippy pipe is where this bit, which I'm not going to force on there because it's a really tight fit, allows you to adjust the tune length by one bit sliding inside the other. However, this is an option. It will change the tune length, make it longer, so it goes longer. When I drop down the gears, it gives me a bit more torque at the bottom end and allows me to get back up. And as the RPM rises, the pipe shortens itself. A few people have done it before. I've seen it. There's pictures about it. You can do it on a header as well, but that's really, really difficult to do. Other things, you could have water injection. That's been used. Other ways are like an ATAC chamber, so it increases the volume of the pipe at low RPM. And obviously, you've got the power valve, which is probably the most effective way of broadening the two-stroke power band. But I'm not going to do power valve. Probably not ATAC chamber. Water injection, possibly. But I'd quite like to look at this. It could be quite an interesting side project, regardless of whether it's needed or not. I guess a few guys watch two-stroke stuffing. At the minute, he's having issues trying to get it up onto the pipe. Potentially something there. Get it up on the pipe, then the pipe reduces length. So, through the comments of the previous video, eagle-eyed viewer, TheDarkKnight1971, spotted that the back tyre was starting to catch, or looked like it was catching, on the bottom of the dyno. And after some investigation, it appears he is 100% correct. And I need to do something about that. I had originally identified it wasn't sitting correct. I bought a wheel chock. I was going to fit it, and I never got around to it. So I took the wheel chock that I've had about two or three months, and mocked it up. I'm going to do some modifications, and then I'm going to retrofit it to the dyno. So that should then place the wheel in the correct position, and we'll have no more issues like this. As a bonus, I don't know, let me know in the comments, if you think I'm going to get a great deal more horsepower. OK, so finally, I'm going to talk about making the pipe itself. So, as I said before, you can see here, I'm going to put it up on the B-roll, the dimensions. This is the original Shallings pipe. It was a bit of a fluke, if I'm honest. I developed it for an AM6. I was given a lot of help by a guy called Graeme Coker, who's a really good pipe builder. I gave it to Chris, and I think it was about 7 or 8 horsepower up on a Micron pipe. So my plan is to recreate this pipe. So these are my slip rolls. They're a bit rusty. I'm going to give them a bit of a polish, and then I'm going to put these back into action. So basically, cut out a template out of sheet steel. I use 0.8. And then, this is what I did earlier. I don't know why that was off. Perfect. Put your roller in here, then weld it up. Then, you make those bits absolutely perfectly, perfectly, perfectly, and I can't say this enough, perfectly flat. And I spin that in my drill, and I make those flat. So everything fits together. And then you can just fusion weld all the sections together. And you shouldn't have too many holes, because as soon as you start banging filler in there, then it seeps through, and then you get boogers that restrict the gas flow. So, for me, these things are why I spent a lot of time researching, spent time on forums, obsessively spending hours, and I mean hundreds of hours, playing with a sim, motor to start off with, and then I progressed on to Engine Mod 2T, trying to make these, trying to design these, and then making them, and then testing them. And they don't always work. Sometimes they do work as well. And that's when it's great, when you can pick up a couple of horsepowder, just for some sheet metal. It all starts life as a piece of sheet metal. Here's the templates for the last pipe I did. Put it on there, trace around it, cut it out. With trusty tin snips, these have cut every single section, apart from a couple I've got laser cut, of every pipe I've done so far. So, this is one of the last pipes I did. Features of it, from my X7 racer. I've got an adapter on here, so I can put an EGT probe in there. You'll also notice a design feature, something I'll try and do. This first section of the pipe is straight, from the exhaust, but you want it straight. You don't want to go straight into a bend. So keep it straight for as long as you can, with the design limit of the vehicle itself, that you design it around. And then as you can see, there's quite a lot of sections in here, and I've hand beaten all this as well, to try and get it as smooth as possible. Other options, hydroforming, or bad hydroforming. That's one of my first goes. I did get a little bit better on the set of pipes. I'll put it up. This is an RD250 pipe, I did for a mate's design. So yeah, hydroform headers, because you can control the dimensional tolerances quite well. But, when it comes to the main body, unless you're a guy called Howard Gifford, then it's very difficult. In fact, Graham Coker's very good, he does a lot of hydroform stuff as well. And it looks absolutely beautiful. However, I ain't that good. So I stick to using the templates, using the slip rolls, because if you measure this correct, and this is correct, then you can get very accurate results. So another design feature, which caused me to seize my engine, is inside here, there is a restrictor. And I'll just hold it in with springs. I can take that out, and I can vary the diameter in here, through a little Venturi. And that will, and it has been shown with dyno, I picked about a horsepower, a horsepower and a half. But I got greedy with the ignition advance, I got greedy with the restriction, and I went to a longer circuit, that's at sea level, and it self, so there you go. But you can use this to tune the pressure in the pipe. More pressure, the more effective, but it gets to a point it builds up too much heat, and it will kill. I imagine I'm not going to have a particularly tight stinger on this project, just because it's going to be, the heat, heat, heat, is my biggest Achilles heel on this. It's air cooled, and just trying to, Achilles heel for any two stroke, but you've got to get rid of the heat. If you can't get rid of the heat, it starts melting stuff, then it stops working. That's a little bit on the pipes. Have I waffled on enough? Don't mind. And I'm going to start cutting out bits of metal, and rolling them up. I'm going to fix the dyno, that's how it might actually read a bit more accurately. And we'll go from there, so thanks for everyone who's subscribed. Thanks most importantly, actually, for all the guys that are really interactive with me, and giving me advice, and putting stuff up, and it's all stuff, all little ideas that help, that open your eyes, that I hadn't thought of this, hadn't thought of that, so it's really appreciated. Thanks.