3 into 1 pipe

[diablo]

sounds good

[tz375]

Thanks. It's interesting that noise isn't so much higher because you can actually see straight through from the tailpipe to the headers and the tailpipe is over 28mm bore.

I agree that the slightly sharper tone sounds "better" than teh muffled flat tone before and as for stock - well it's stock so can't really complain, but it's flat and quiet. The real test is a dyno though and when it's running I'll try to grab another video to compare to the others.

Unfortunately my sound meter is dead and a replacement doesn't fit into this week's budget - I have dyno time and another pipe to pay for and not in that order! I had better get back to work and make some money....

[diablo]

i hear ya lol , no pun intended, looking foward to the numbers and the video, cheers

[Craig380]

@ TZ - for what it's worth, the Piper 3-1 I had for my 380 had the same internal baffle design as you have now.

Large diameter outer tube, with a 12" long, perforated straight-through baffle tube that could be wrapped with wadding. The inner end of the baffle tube mated with an internal collar where the end of the 'chamber' section met the tailpipe.

At the other end, the Piper's headers just went into an expansion section. No other obstructions / baffle plates etc anywhere in the pipe.

[tz375]

Thanks Craig.

That's the most common two stroke muffler design on aftermarket pipes. It's not the quietest, but it works. The "internal stinger" reference means that I allowed part of the straight pipe (non perforated) go inside the rear cone.

When i looked at piper design it seems to be three headers into a flat collector. That collector is basically an open pipe with cross sectional area of more than all three pipes, and the pulses see that as a big open box. Anything from there back doesn't really work much like a chamber because the pulse energy is already dissipated by the collector.

The most interesting 3 into 1 design is by JollyMoto. It has what appear to be long tapered headers and a very clean collector followed by a large body chamber. Their chamber looks like the angles are mild but follow conventional design ideas. The open question is how well does it work and how do the long headers work. In theory the returning waves are split into all 3 pipes and they lose amplitude i.e. they are weaker than in a single pipe.

Parallel pipes dampen those waves but tapered headers are an improvement. So 10/10 for the design but how did they get the long headers to work without losing all the pipe energy. If I win the lottery soon I'll buy one and test it, but since I don't buy tickets very often, that's probably not happening any time soon.

If anyone here has a JollyMoto pipe or knows of someone with one, I'd love to see the dyno chart.

[Craig380]

Yep, the Piper design was for looks and weight saving only, rather than any power gains, I believe ...

Intriguingly, a 2-1 pipe on a 180-degree twin could actually work if the exhaust port timing wasn't too aggressive. The Koenig flat 4s had only two chambers, which were appara fully functional (or at least, the gain from having 4 separate pipes wasn't worth the extra hassle of finding room on the bike)

[tz375]

The Konig was, and still is, and interesting engine. It's still available and it has a 2 into 1 system with very short manifolds so there is no header problem to work around. As a 180 degree flat 4, the pulses from one cylinder really don't effect its partner in the way that they do on a triple.

That's why a guy in the UK changed his triple to two together into one pipe and 1 single pipe.

[ja-moo]

Yep, the Piper design was for looks and weight saving only, rather than any power gains, I believe ...

Intriguingly, a 2-1 pipe on a 180-degree twin could actually work if the exhaust port timing wasn't too aggressive. The Koenig flat 4s had only two chambers, which were appara fully functional (or at least, the gain from having 4 separate pipes wasn't worth the extra hassle of finding room on the bike)

From what I have read, the 2 opposing cylinders move in and out together, so act like one cylinder.

[tz375]

There are several different pictures of the crank on the Konig site that could lead one astray. I assumed from the photo of the cranks that the cylinders sharing a pipe were 180 degrees apart, but that does not appear to be the case from pictures of a konig race bike.

It's a flat 4 motor with two forward and two facing to the rear. On the left pair one is at TDC as the other is at BDC as JaMoo mentions, but it would appear that the forward facing pair fire together and then the rear pair. In this case they are basically working like a twin with two pipes.

I checked a picture with the pipes off and on that motor it's easy to see both pistons close to TDC on cylinders that share a pipe.



In that layout, there are no interfering pulses.

There's a bunch of pictures here http://www.flickr.com/photos/teamherons ... 365286593/

[diablo]

that is a very cool power plant. sad story about the driver passing

[ja-moo]

It looks like they all come to TDC at the same time.......

[Suzukidave]

http://www.youtube.com/watch?v=iImhHZQY_7Y" onclick="window.open(this.href);return false;

[tz375]

Now this is getting interesting. That video shows the crank the way that the parts list has it and the other picture has them two up two down. And it's a much later manufactured engine with different castings and drive belts.

So it looks like some versions of the motor (early ?) were a twingle doubled up and others were two boxers 180 degrees apart. And as Jamoo pointed out, a 180 degree crank in a boxer has all 4 at TDC at the same time! In either case a siamesed exhaust will work.

[ja-moo]

It is after all, a boat engine, and has been around for a long time. There are probably a few iterations.......

[Craig380]

Wow, I thought those motors fired in diagonal pairs, like in the Youtube clip above! I guess only some of them do

Live and learn