ACTUAL Horsepower of Cotton Owens #6 RACE Daytonas

[odcics2]

First scan shows the top of the stack of dyno runs from 1970 and 1971, done by Cotton Owens at his shop in Spartanburg, SC..
Second scan is the important one. Note best HP of 588 for a speedway engine without a restrictor plate. This engine was used at MIS, June 1970.

Note that Larry Rathgeb mentioned in the 'Supercars" book the the Chrysler Engineering Daytona ran 200 with a 585 HP engine, built at Highland Park Engineering. (like every engine in the car was...) This coincides closely with Cotton's 588 hp number on his own dyno.  

Now, around 200 mph, it takes 17 hp to increase 1 mph.  The #88 ran 200.447 with side glass on March 24th, 1970.
The #88 ran 197.5 without side glass on March 25th. 1970, testing for Nascar at Talladega to see how much it would slow the cars down.

So, for Cotton's Daytona to run 200 without side glass in April 1970, it would take about 639 hp. That is clearly beyond what
a hemi could do.  It's documented that the best speed #6 ever ran was a bit over 198.  And, that was done, IN THE DRAFT, at the April 1970 Talladega race.  (the draft was good for 3-5 mph)

Having actual HP numbers puts it all into perspective.  

[tan top]

 this is interesting stuff  , thanks for sharing   

[warmpancakes]

thats some pretty cool paper work,   

[moparnation74]

Thanks for sharing, that is great historical information.  It  proves your point on actual top speed of CO's car.  The highest horsepower was done with champion's 57r's.

[Indygenerallee]

Very cool stuff!

[1RareBird]

I'm with Warmpancakes.  Between the cool jacket and now this paperwork, you must know some impressive people to acquire all this stuff.

[warmpancakes]

I'm with Warmpancakes.  Between the cool jacket and now this paperwork, you must know some impressive people to acquire all this stuff.

wonder if he got any cool stickers ?

[Ghoste]

I'm with Warmpancakes.  Between the cool jacket and now this paperwork, you must know some impressive people to acquire all this stuff.

He does. 

[Aero426]

What the real world dyno results prove is the HP disadvantage the seven year sold Hemi gave away to the Boss 429.

[odcics2]

What the real world dyno results prove is the HP disadvantage the seven year sold Hemi gave away to the Boss 429.

Have any real dyno results for the 429 semi hemi ?

[Aero426]

From Charlie Gray's files.   This was probably early as they tried it with the 1968 legal 2 x 4 bbl setup.

[Aero426]

Boss 429 track test showing calculated corrected HP with and without tail pipes running out to the end of the back bumper.

[Aero426]

Page 2.

[moparnation74]

Aero, that is some great info, thanks for sharing.  I had no  idea the 426 was that much less in horsepower than the 429.  I would have thought they would have been closer to each other, if not more than.

[hemigeno]

Dumb question here... wouldn't the COG dyno results Greg posted be comparable to the "Test #1" criteria listed below, with a single 4v carburetor prepped for Grand National racing?  If that's the case, then the two manufacturers' engines may have been pretty comparable -- depending on which shop put the engine together, of course.

[Aero426]

A good question.   It does not "appear" that the Ford engine is yet in final evolution with the higher CFM 4500 Dominator carb as raced.    The Hemi ran with restrictor rings in the Dominator slightly choked down for optimum performance.     That particular carb was essentially tailored for Ford for that engine.    As you can see by test 2, the Boss engine liked the extra air and fuel.    One thing the Boss 429 had was extra potential on tap.  By 1970, the Hemi as configured was close to maxed out.

There is another notation in 1970 that a performance objective for the Boss was to work on low speed response.  They felt they were at a disadvantage to the Hemi on the generally shorter tracks in USAC stock car racing.   The caveat to the discussion here being that one dyno sheet does not fit all applications.  

[odcics2]

And it's easy to see why aero improvement was needed by the MoPar camp.
You have an old hemi vs the latest & greatest from Ford!! 
The bottom line is hp required on the track, either raw power or less drag!   

Good info Doug!!