Author Topic: 482 cube Cobra Engine with LeMans bowls and Aviad pan - - 556HP  (Read 3778 times)

Barry_R

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482 cube Cobra Engine with LeMans bowls and Aviad pan - - 556HP
« Reply #1 on: February 18, 2015, 04:37:23 AM »
I have not posted any of these for quite a while.

This one just got some coverage by EngineLabs - so I figured I could give it a double up with a little more info here and a link to Jason's write-up for video & more pics.

the engine is built for a Cobra project.  The design intent was to be plenty powerful, but still very smooth & linear so that the car would be still be pleasurable to drive on the street or on a road course.  A secondary concern was the desire for vintage cosmetics - it need to have a strong passing resemblance to something that would have been in a Cobra back in the proverbial day.

It started out as a "normal" 482 build (hard to consider a stroked 427 as normal...), capped off with a pair of "as cast" Survival heads and a Blue Thunder dual plane intake.  Compression is pump gas oriented middle 10s, oil pan is an Aviad.  Distributor is a vintage Accel procured from Faron by the customer.  Carb is a customer supplied custom piece with modern innards and a pair of LeMans bowls.  The cam is a hydraulic roller - specs are 242/248, .643/.637 on 113 LSA

Ended up being a really nice package.  Tuning around the LeMans bowls was interesting to say the least.  They would not tolerate very much fuel pressure before getting overwhelmed.  They also had a rather small 1/8NPT inlet which limited flow into the bowls.  I would get to a point where adding jet would not deliver a corresponding increase in air/fuel mixture.  You could look at the A/F numbers and see where it started out nice & linear, but on the lean side & then add jet & watch them go rich at the bottom and return to the leaner ranges as the bowls dried up at high RPM.  Really does not mean much in the car - how often are you going to experience a 14 second long high gear pull in a Cobra?  But illustrates why they went to the cathedral bowl design.

Engine made really cool torque - look at the curve - 497lbs at 3000 and 503 at 5800 - peak was 559 pounds at 4600.  Horsepower peak was 556 at 5700 RPM, but it had nearly 500 way down at 4700....

Charts, pics, and a link:
Pics will follow as soon as I can get that worthless Photobucket site to work worth a damn.

http://www.enginelabs.com/news/video-survival-motorsports-and-482-cubic-inches-of-fe-fury/