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11/7/03
QUESTION 1
I have a 327-275 hp small block Chevy and bought
the Edelbrock package 7102 cam 60899 g4cc aluminum
heads and ram air gap 7501. Edelbrock claims
420 hp with a 350, so with a 327 I thought I
would get at least 375 hp, but it only dynode
285 at the wheels. So, I figured about 330 hp
ran a 14.00 sec. e.t. I ran that before I did
all this upgrade...any suggestions? Thanks.
P.S. It is a '67 Nova
Dear '67 Nova,
Here are my thoughts on your
combo:
The 7102 cam has a 112 degree
lobe separation with a 107 degree intake centerline,
which I feel is a little wide for a 327 engine.
This would be fine for a larger engine or a
four-speed, high rpm combo. Something around
108 degree l/s and 104 degree c/l would be better.
Your cylinder heads are good
and your intake manifold would benefit from
a 2" spacer. Next I would look at carburetion.
A 650 double pumper would work well.
Thanks,
Scott
QUESTION 2
Hi, I just read some Q & A on Drag Racing Online.
We race the traditional style Pontiac engines
(455's) and getting peak hp to move up in rpm
just doesn't seem to work. These engines make
some pretty amazing torque numbers also. Do
you have any theory on where 4.350 bore 4.000
stroke vs. 4...350/4.350 and 4.350/4.500 stroke
engines with a deck ht of 10.230 will make peak
hp, and if a short deck block was make would
it run rpm then? I'm at the point where I am
putting more cubes together and moving rpm down
even more with the big stroker combinations
just because they will get me to 900 hp.
Also, does anybody make an overdrive transmission
that can handle big power? I've been thinking
about or tire rpm vs. the comp guys who will
spin their engines 9800 rpm and more. We've
hit peak hp in our best rpm engine at 7800 (499cid
4.100 stroke 920 hp) 2000 rpm short of their
tire speed. We can grunt gears pretty good;
we would just like to find some more speed.
-Rob
Rob,
Here are some things that I
have found on the dyno and at the track:
- Big stroke and bore engines
make a lot of torque and hp and do not require
a lot of rpm.
- Short stroke and big bore
engines make a lot of hp and higher rpm, but
torque suffers.
- Tall deck is beneficial
because a longer rod is required, which keeps
the piston straighter in the bore, making
more hp and torque.
- Any combo will have high
rpm with lots of spring psi and good valve
train.
- The comp guys rev their
engines to the moon to keep momentum because
they are pounds per cu. in. racers.
- As far as trans., call Mike's.
Thanks,
Scott
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