Alternate Cooling Method.... Worth it or not?  By  mopojo (Read 2,078 times)

How a Two Stroke Expansion Chamber works.

Friends, all I can say is that it works well for me, and has for a half-century.  I'm beginning to wish I'd have not bothered re-posting these old 150 "how-to" tricks, and am glad I moved up to a larger-displacement ride that doesn't require more wrenching than riding...  If it didn't work well, I wouldn't have wasted my time taking pix and making the post...

While chamber pipes are not common or popular on 4-strokes, they are a proven success...  A few years back, even top Alcohol dragsters were experimenting with chamber pipes on their engines with promising results. For over fifty years, I've run numerous chamber pipes on small 4-strokes with noticeable improvement in overall performance over stock-type mufflers and straight-pipes.  I'm well aware of how a chamber pipe works on a 2-stroke...

A 4-stroke is totally different scenario with a much simpler "exhaust impulse" than a hot 2-T.  What it is in effect, is simply an "enhanced straight-pipe" with a slight improvement in performance and a big improvement in ease of tuning and good all around running.  It is not rocket-science... just a very good "muffler" for a 4-stroke... End of story.

Back in the 1960's when we had numerous chamber pipes laying around from experiments with Mac's, West Bends, Power Products and Homelite kart motors, we adapted them to Briggs, Tecumseh and other old-school 4-strokes on pit-bikes with great success.

As I mentioned, some Vento Chinese 150 GY6's came factory-equipped with them, and I even have a NOS Vento chamber pipe laying around.

The reason I did this conversion is simple... IT WORKS. Maybe on paper it isn't supposed to, but in my experience it works VERY well.

Everybody is entitled to his/her opinion.

I raced Mac-powered karts some, but was better in the pit than in the driver's seat... Just too big... LOL!

I never did drag Harleys except for my own chopper... At Oswego Drag Strip"Old Blue" would run in the high tens/low elevens, at 130+ in street trim in 1962... (My 4'6" 76-pound gal friend could crank off a mid tens at 145+).  I won enough street racing to pay the obscene cost of building that motor... You build 'em your way, and I'll build 'em mine and we'll both be happy...

Ride safe,

Leo (some zip) in Texas

PS: That's a nice exhaust setup on your red scoot.  You found the same garbage fabrication on your stock pipe as I did.  A full-sized header is one MAJOR improvement over the stock setup.

This is a friend Pat Dakin out of Dayton Oho, Top Fuel or Top Alky know one is or has wasted there time with a Two Stroke Expansion Chamber on one of these cars.


Local to me now Roy Hills Hemi Alky Pro-mod.

Pistonguy,

I don't know how this got so off-subject. All I did was re-post my chamber-pipe how-to in response to your questioning the exhaust on my old GY6.  I've been nothing but friendly and complimentary to you, and you have chosen to be a "right-fighter" determined to belittle me and call what I did successfully "impossible".

Let me reiterate: IT WORKS GREAT!!!!!!!!! The chamber-pipe is VERY free-breathing ON a 4-STROKE. And easy to tune. And I don't appreciate your cock-sure attitude calling me a liar, and my posting false info for the members.

For your edification, here are some pix of FACTORY STOCK GY6 150 4-strokes equipped FROM THE DAMNED FACTORY WITH CHAMBER PIPES... And, ONE example of a professional custom Honda Ruckus which the builder chose to equip with a chamber-pipe.  Hmmm... I guess the engineers and custom builder represented here are "zips" too.  Problem is: They run GREAT.


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Of course there are NO chamber piped Briggs karts. I said we did that on our pit-bikes to test the theory AND IT WORKED GREAT THEN, AND STILL WORKS GREAT TODAY.  And I'm sorry I don't still have my time slips from Oswego Dragway from 1963.  You wouldn't believe them anyway.  I don't still have the chopper, OR the gal from 50 years ago either... LO not so L.

You obviously are skilled, and know a lot. But you don't know everything. I would NEVER post a how-to on ANYTHING that I did not do myself, and PROVE on the street that it works.

I admire your knowledge, but your attitude is wearing thin. How'd you like it if I replied to something you did successfully, and called it impossible, criticizing you for such a post?

Think about it. Think about the fact that when somebody does something that works over the long haul, they don't appreciate being called a liar, blowhard, etc. all of which you have insinuated that I am.

Please, let's keep it friendly, and PLEASE open your mind to things that may not look practical to YOU, but WORK ANYWAY...

Pardon me all to blazes for trying to be helpful by sharing my experiences... No hard feelings, but I am DONE with this subject. Period. This whole juvenile banter is making me really want to dump scooters and get back to real bikes again.  And that's a shame since I really enjoy the site, and sharing 50 years of experience with new riders.

Regards, Leo in Texas

PS:  I actually have one of those Vento GY6 chamber pipes I got from Puerto Rico to use on my GY6, before I found that sweet little stainless-steel pipe.  Pay the postage, and I'll mail the damned thing to you just to prove those pix aren't "Photoshopped"...

Thank you Wheelbender.

You said it better than I could.  Have a bone!

4-strokes and 2-strokes are "apples and oranges".  All the technical sound-wave, impulse technology which makes the chamber-pipe so good on a 2-stroke (and ONLY at the rpm tuned for) go out the window when the pipe is on a 4-stroke.

I'm not the ONLY guy or gal to discover how well a 4-stroke will run with a chamber-pipe.  It's not all that uncommon, especially on scooters both "from the factory" and custom-built.

On a 4-cycle, the initial "cone" or megaphone part helps scavenge the exhaust.  The reverse-cone then slows it ONLY slightly.  The little "stinger" is a straight-through glass-pack.  The whole assembly is a VERY low (near zero-restriction) STRAIGHT-THROUGH "muffler" with slightly better scavenging than most other systems.

On my old mostly stock GY6, that little chamber pipe (with full-inside-diameter header) probably did not increase horsepower measurably.  But, it DID noticeably increase low-end "grunt", gave better pull at mid-range rpm (especially riding 2-up, up hill and into wind) AND provided INSTANT throttle-response... It also made easy work of carb-tuning.

THAT is the truth, and is WHY I posted the "how-to" originally.  I rode it that way for two years, and the dealer I traded it to on the Kymco was astonished at how it ran.  I heard he kept it for some time as a shop errand-runner because it was just plain fun, with amazing performance for a Chinese 150.

I'm not on a crusade to put chamber-pipes on 4-strokes... I just see red when somebody tells me something I've done successfully many times won't work.

Ride safe!  And thanks for the insight into "real world" performance opposed to theory.  No, I wouldn't have posted the "how to" if it didn't work.

Leo

No reason to get your Panties in a wad over a Scooter board.
You say its works, Ok ya it starts, runs and goes down the road thats all, if ya put a clock on it or Dyno it aint gunna happen... you can see red white or blue, with a comprehensive understanding of the two its just plain silly and a no brainer.
The Scooter market are the worst maintained vehicles on the road, mostly entry level kids, and the Most Gullible customers on the market. Just because a supplier lined the pockets of a purchaser means nothing to me. ya just can't show me anywhere in the market place were anyone is adapting Chambers on a Four Stroke. the two T systems Work on Back Pressure and heat, The Singer Diameter and length builds in a certain amount of back pressure, the Sound Waves work Within a Higher Temperature medium, Non of that works with a Four Stroke.
There are a few of us elders that have been around but I find most are telling fish stories. ahh don't like it ya don't have to read or really to it, But Im calling you out after read ing for several years of your Drag race exploits with a Oompa Loompa at the helm. those are impressive numbers to throw down and they should be framed if true, convenient you have Non to post.
I call Bullhonkey and Utter Bunk.