build your own expansion chamber!! plus adjustable header design

[David Luciani]

first i posted this article as a how to build an era correct pipe circa 1967 not a make your kart faster article.

i may not have been super clear about this pipe in earlier posts.
this pipe represents early pipe when they were still pretty new.
in 1967 oil clutches  were new on the scene so e-chamber development at first reflected dry clutch performance limitations.
as with anything kart racing the evolution was very fast.
within a couple of years oil clutches were common and e-chamber design became almost a science.

so if you are looking for a fast or cheap design this isn't what you want.
and building you own e-chamber is pretty silly in view of whats still commonly available.
but if you are matching an existing pipe repairing a rare pipe or just like building things this may be for you.

the article is more about how to hand build your own e-chamber pipe.
something that without a cone roller will occupy at least four hours of your life if you are a skilled welder and metal former.
rank amateurs can expect anywhere from 8-9 hours to never as a time result.

i think building pipes is something the hobbiest should consider if they have the time skills and inclination to do it.
or just swipe elements of the article to apply to your particular build so you install on a show kart is that much cleaner and era correct.

anyway without starting a war about anything i am posting the builders reply.

Hi David,

The pipe/header unit in the photos you are posting was both reliable and very competitive back in 1967/68. So Cal enduro races were held about once per month back in that era. I raced A-open light and A-open heavy with my Hornet. I drove approximately 3 - 4 hours of on track time at each race weekend using that pipe assembly. Since I ran the open classes I was always trying new ideas and different engines in the available practice time. The track was always full with racers testing things. Our races were one hour long. I NEVER had a problem with that design causing exhaust insert or bolt  failure on my Mc91's.  There was enough flex in the system to allow movement and yet remain leak free at the ball joint. That pipe design and header length won enduro races back then. I don't remember if anyone copied my design for the slide joint. Those of us running in the lead pack always seemed to have other racers looking at our setups. That header setup was something I created for my Marauder III. Judged by the design of pipes from the 70's and later it may seem like a pipe not worth using today, but for an accurate representation of a late 60's pipe, it works well. I used to sell pipes like it to a couple of So Cal kart shops to get the funds to buy Mc91's and other parts. I feel that vintage should be having our karts be like what was being raced then, rather than how we can add newer equipment to them to make them faster, so we can win an event without weight limits or engine rules as they existed back in the day. A vintage win now is pretty close to meaningless in my opinion, but others  may not agree with me. Back in the late 60's all of us were just starting to try to learn about pipe designs that seemed to work. A lot of the pipes I saw being raced in 67/68 were home built. At that time I was still using a dry RevGrip clutch and the typical gearing for the tracks I raced on was 14-56 to 14 -58, going up to maybe 14-62 for some of the shorter and tighter tracks. A-open light raced at 260 lbs. and A-open heavy raced at 320 lbs. Pipe designs and lengths changed as effective wet clutches became common. If anyone decides to build a pipe based on the photos you've posted I hope they keep in mind that that particular pipe is vintage and NOT meant to be the ultimate pipe/header combo that can be made using info from later years.

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