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Text and Photography - C.Asaravala
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The last time reported on our resident
'67 Mustang project car it was back in 2000. That was eons ago. Heck people were
still making money on stocks, the country wasn't at war, and the car was running
11's! So where is it now?
Well some of you have been very perceptive,
and put two and two together, and were able to quickly identify our 331 Stroker
buildup as a prelude of things to come - a rejuvenation of sorts for our old Project
11.99 car. Many of you emailed us, some even called (really...not necessary) to
ask us when the car would be ready, when the new motor would be dynoed or tested
at the track. We probably gave you the standard BS answer...soon, real soon.
Well 'soon' passed several months ago. There are no track or dyno results
to report. But rest assured, we are getting close! Here is all that is going on... |
Power brakes were added to help achieve better streetability.
Look for a full write up soon. | The
'67 went through a major overhaul. Rather than being a stripped down, bare necessities,
quarter miler, we desired to have better street manners. We upgraded to a cable
clutch mechanism to alleviate the knees of severe strain. We then installed
a new
steering box to make the old '67 feel crisp and modern. Finally we installed
a power brake booster, an important modification in making vintage Detroit iron
feel like it can stop on command.
By the way, while the motor was out,
we also completely detailed the engine bay. Check
it out.
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Our 400HP 302 motor was on its last legs, evident by bearing
wear. | While we had a
blast running the 400HP 302
to 7000+ rpm in order to reach the 11's, that amount of abuse took it's toll on
the motor. A couple hundred passes was enough to wear the bearings and reduce
oil pressure to scary levels (5-8psi at idle, bouncing as low as 20psi at 6000
rpm, wide open throttle!) We even sent an oil sample to an testing lab (Oil Medic)
and the results verified the bearings were worn. The test also detected evidence
of blowby (fuel in the oil.)
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The 331 has been in between the shock towers for a couple
months now, but hasn't seen any track time due to some issues in bringing the
other systems up to par. | So
this led us to the 331
stroker idea. We want to achieve similar (or better) ET's than the high revving
302 produced, but to do it at lower rpms. There is no better way to achieve this
than with more cubic inches. We set the 331 up with the same TEA
ported World Jr. aluminum heads as were on the 302. The Victor Jr. intake
and 750cfm Jet Modified
Holley are also carry-overs.
What differs, besides the 29 additional
cubes, is the cam and compression. The 9.4:1 compression ratio of the 302 was
a short coming. The 331 sports a full point more. This alone will be a noticeable
power increase. A hydraulic roller cam replaces the solid roller. This made sense
because the engine is designed to make power between 6200- 6500 - in a range where
a solid offers no benefits, but the headaches of very stiff valve springs, periodic
lash checking, and a louder valve train. The hydraulic will aid in the streetability
goals. Overall the cams differ in only their duration. The hydraulic sports 226/232,
whereas the solid had 238/246. Accounting for lash, we drop about 6-8 degrees.
Lifts work out to be very close in the .550" range.
All said and
done we feel the motor should surprise us. It will take some time to dial in,
but assuming it holds together(fingers crossed, and proverbial wood has been knocked)
we see no reason for it to run slower than expected.
So what is the
hold up?
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As with any major project, we have been resolving
a few issues. Due to the heavy abuse the car will take while launching and buzzing
down the track, we have been very diligent about setting up a proper clutch. We
opted for a Spec Stage III. This clutch is a dipraghm style, using a carbon metallic
composite puck type disc. It is said to handle 600HP, far beyond our needs, BUT
it is a light and relatively easy to drive coupling. This is in far contrast to
the Ram 900 sintered iron clutch we ran near the end of our 400HP 302 project.
The Ram held very well, but it was a digital "on or off" engagement.
No slipping possible. This meant it hit hard and took its toll on everything in
front of and behind the clutch. It also chirped the tires in 5th gear... a little
to rough for our new streetability edict.
Stock 5.0L T5 pivot left, and Lakewood adjustable on the
right. | Setting up the new
Spec and cable operated lever has been challenging. We have a 11" flywheel
which is 3/8" thicker than a stock 5.0L flywheel. The Stage 3 pressure plate
is designed to fir the 11" bolt pattern on our flywheel (Spec does make a
Stage 3 based on the standard 5.0L equidistant pressure plate bolt pattern.) This
all adds up to an odd clutch stack height which results in the fork and throwout
bearing riding the clutch levers, and not allowing the fork to release the clutch
propely. To alleviate this we ordered a Lakewood adjustable pivot ball, to allow
moving the fork back slightly. Once this is in, and the new ET Drag slicks are
mounted, we should be ready to hit the track.
Three core and 16" parts store electric fan is just
not enough for the 331. We'll need to resolve this before we can run the car hard. |
Finally, we have cooling issues. More compression
and cubes means more heat. The three-core radiator and 16" generic electric
fan were borderline for the 302, but clearly insufficient for the 331. The three
times we've started or driven the car water temp has hit 200 deg. after a few
hard romps (editor's note: The torque is freakin' amazing! This car is downright
scary with this motor! - end note.) We'll install a four core radiator and higher
cfm fan to keep the motor cool. Look for that install article very soon.
So when should you look for results? Soon, real soon. F/M |
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