Login  /  Register  
  Home  -  Forum  -  Classifieds  -  Photos  -  Links     

 Return to Index  

Thanks Kris - top 2 428cj road test MPH were both early 68

February 11 2018 at 8:07 PM

WerbyFord  (Login werbyford)

Response to Re: Kris I dont follow some of this

I don't think I had heard about the c8oe-a intake vs the c8oe-c.

But of all the almost 40 428cj road tests I have, the fastest two MPH are both early-1968 cars,
106.64 and 13.56 from the Hot Rod super-light Mustang 4spd article

More impressively:
105.10 and 13.52 from the Feb 68 SuperStock test in a big c6 Torino.

I thought maybe the "C" cam got slipped into these, otherwise it made no sense - why would the early cars be the fastest?
Maybe this pair had that rare "A" intake????

You can see the difference in the 428cj-"C" vs 428pi intakes from the photos in Jay's book - the PI has bigger runners. And sure enough, Jay lists the volume as 4250cc for the PI intake, but only 4050cc for the CJ intake. Indeed it looks from Jay's curves that the big advantage of the iron 428cj is in the midrange, maybe 10hp from 3500-5000. Of course, half of that will be lost with the extra 50lb of weight. But Jay shows no comparison to the mysterious 428cj-"A" intake.

Jay discusses and tests the "1" and "2" intakes, gets the same results, but both these are c8oe-c. He does not refer to the "A" intake.
I think this early pair of cars, for whatever reason, had about 10 ponies more than later 428cj cars from running the Gonkulator on all these tests. Maybe that was the "A" intake difference.

This message has been edited by werbyford on Feb 11, 2018 8:42 PM

 Respond to this message