In regards to the TRACO AMC Trans-am intake manifold that I use, the following information was obtained from the very helpful Pigpen.
Hello Gene, aka Pigpen,
First, I’d like to thank you for your time and efforts to share a part of your life with us on this forum. Your first hand experiences can and do lend a hand to the legendary name of Traco.
Growing up in Southern California during Traco’s Trans-am days, I can attest to not only the “street” reputation, but also of the “mystic” that surrounded anything Traco’s name was on.
I was fortunate in 2005, to acquire and restore a 1969 AMX that had been raced in the 70’s. When found, it was equipped with several Traco specific components. The unique Traco two four barrel intake manifold being the most prominent. Our forum has a brief description and history on the car and the Traco manifold. You can find it posted under entry #9 here:http://www.camaros.org/forum/index.php?topic=8069.msg66670;topicseen#msg66670
As posted, I feel fortunate to have received some great recollections from Stewart Van Dyne concerning Traco’s AMC program, and primarily the Traco intake. I hope you may be able to add to the history of this special intake manifold.
As I understand it, the intake was initially engineered for the Trans-am program. Photos of a similar intake with a single four barrel top have surfaced showing use on the Trans-am Javelins. I have not been able to find any clear photos of the Dual Four being used on the Javelins though. Do you have any recollections of this Dual Four Intake? Stewart remembered dyno times with the manifold, and believed it was tested or briefly used on a Javelin before the rule change. He also thought it may have later been tried on the Matador, but I believe he was away from Traco by then.
As stated in the forum post, it’s a terrific running manifold.
On another note, you might recall a Traco designed AMC lifter retainer. It shows typical Traco execution, beautifully formed of stainless steel. I am still using it in the AMX, and wouldn’t think of running an AMC without one.
Again Gene, thank you in advance for any tales you may have concerning my intake, but most importantly, your contributions to this forum.
Response from Pigpen:
Yes I was involved with the design and testing of that manifold along with many other people at TRACO. I'm surprised Stewart remembers it, he was up to his ears in Offys and had little time for anything else, he was TRACO's Offy expert, and later proved to be one of the foremost Offy experts in the industry.
A little background; Many of the earlier TRACO track engines were built using Weber carbs, 1 cylinder / 1 carburetor, easy to jet and tune, lots of breathing capacity.
The Chevy factory supplied TRACO with a dual in-line 4-barrel prototype manifold (not the Cross Ram) on which we spent a lot of time gluing in runners at the bottom of the plenum to equal out the flow, eventually the factory modified their pattern to match what we'd done and a number of the manifolds were produced. We also performed a similar series of tests for the Cross Ram, which Chevy used to make improvements.
From what we learned on the Chevy manifolds and our Weber experience, we designed the AMC manifold to mimic (as much as possible) a 1 cyl / 1 Carb design, but with a common plenum (rules is rules). That strange plenum design (you mentioned) was the result and worked quite well.
The 304 CID AMC Trans AM engines had been tuned to the maximum using a single 850 Holly (or was it 800), so when we attached the dual 4-B manifold, which allowed for a serious increase in breathing, we found that the added horsepower reduced the life expectancy of the engines from 1 to 2 races to about 1/4 race. They were fine for the drags, but the Cam and lifters would have to be changed for any serious track use. About that time, the rule about using 1 4-B was issued, pretty much ending the work on that project for Trans Am. The Matador, under NASCAR rules, could only have a 1 4-B set up.
What Stewart mentioned about the cam bearings was right on, the bearings were compressed and spun right out of their journals, welding themselves to the cam. We tried a few things and finally ended up using a special Aluminum Bronze alloy for the cam bearings.
I do remember the first time that manifold was dyno tested on a 304, The torque curve just kept climbing and climbing, everyone in the shop was cheering and yelling "Go Baby Go". I don't remember the exact horse output, but it easily broke the 1.7 horse per CID rule of thumb for a normally aspirated track engine.