[Amc-list] 195.6 and 58-63 American hop-ups
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[Amc-list] 195.6 and 58-63 American hop-ups
- From: Frank Swygert <farna@xxxxxxx>
- Date: Wed, 05 Sep 2007 11:54:09 -0400
I ran a 63 American 440 sedan for 14 years, and it would *almost* make a
rally car! Splitting the exhaust is tough because there are only three
ports -- one for each pair of cylinders. Dual carbs don't work well
because there are four inlet ports -- one for each end cylinder and two
siamesed port for the center four. The intake ports are angled for best
flow from the center. The carbs need to be right at the point where the
center ports start, so the flow from the closest carb has to take a 130
degree or so bend. I ran dual Carter YF carbs, which had much more flow
potential than the ~200 cfm WCD 2V carb (factory). They didn't run any
better, so I switched back to a WCD.
I had a camshaft reground with 0.10" more lift and 20 degrees more
duration. That was the single most impressive thing I did to the engine!
It didn't help low end power one bit (but didn't hurt it). What it did
do was give it about 20 hp in the mid range. Just keep the car running
over 40 mph and it had good power and throttle response, fall to 40 and
it took a few seconds to get back up to speed. I also ran a 2" exhaust
all the way to the back. The factory head pipe is 1-7/8", which fits
perfectly inside a piece of 2" exhaust pipe -- I used the factory head
pipe and cut it just as it leveled under the floor, running it 2" the
rest of the way through a turbo muffler. The only other mod was to the
air breather. The factory breather had a little 2" snorkel on it. I
removed that and opened the hole up so I could take a 4" can and squash
it to an oval. When I cut the bigger opening I cut two tabs that could
be bent out to rivet the can to. Then I just trimmed the end of the can
to fit the curve of the breather, and used paintable silicone caulk to
seal around the opening. After painting factory semi-gloss black it
looked factory due to the nice rolled edge of the can. Add factory
stickers and no one noticed, but the engine sure did! It idled much
smoother after opening up that breather.
All told I figured it had 170-175 hp (gross), compared to the stock 135
hp (2V model). A friend punched it all in Desktop Dyno and got 175, so
that should be about right. It's also about as much as you can do
without major machine work. The intake design and port layout just
doesn't lend itself well to modifications -- and machine work would be
troublesome and laborious, making any possible benefit very costly. A
small turbo with 4-6 psi boost would be the best bet if you just had to
have more power, but you'd still have poor throttle response under 40
mph. The problem is the long stroke and small bore -- it just takes time
to get moving! There's plenty of low speed torque. I had to keep my foot
on the brake with an auto and 3.31 gears (the factory "performance"
gearing), even on a slight incline! If not it would creep out into the
intersection. A stick shift model is the only stick my ex wife could
drive! She'd jerk my old four speed Chevette badly, sometimes even on a
level road! The old Rambler just chugged a bit and slowly took off, even
on an incline. She just couldn't coordinate the gas and clutch, but the
Rambler didn't mind no gas when the clutch was let out.
Handling is the big surprise in these cars! I had front springs wound
15% stiffer than stock. I also modified a 79 Spirit sway bar to fit (had
to straighten the arms in a hydraulic press -- never use heat on a sway
bar!). The sway bar really didn't help at all except at high speeds. The
spring-on-top-of-upper-arm setup is inherently roll resistant, that's
why most Ramblers didn't use a bar, and even the V-8s only used a small
bar. The stiffer springs kept the car on an even keel more than anything
else! I stiffened the rear ones by using bolt on half leaves, the ones
that bolt to the long part of the spring behind the axle. All I needed
was aluminum (or poly) bushings in the front of the leaf springs. Even
with the old rubber bushings that thing would corner like a roller skate
on rails! I just never dropped below 45 mph on the back roads all around
Warner Robins, GA! A 30 mph marked curve was a piece of cake at 45 with
the suspension mods. It held the road as good or better than a friend's
Trans-Am! It almost always surprised him, he'd suddenly hang on when I
hit a 30 mph or so curve without slowing much! I told him once that he
should know the car by now, that it holds the road great. His reply:
"but it's not supposed to!" I also ran 7" cast aluminum slot wheels with
195/65R15 tires (usually Bridgestones). Got used ones. People would burn
the rubber down on one then get a new set all the way around, with over
1/2 the rubber left on the other three. Since I only put 5-7K a year on
it I didn't mind, and the tires were never more than three years old
when I got them. I got four for the price of two easily, and didn't mind
changing every 2-3 years.
--
Frank Swygert
Publisher, "American Motors Cars"
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)
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