CycloneFE |
09-10-2012 03:09 PM |
Re: The damage recently done
Quote:
Originally Posted by 69Cobra
(Post 345707)
If I'm thinking right. The PI intake is the same casting as the CJ intake except it is aluminum instead of cast iron. Basically the only advantage is the difference in weight between the iron and aluminum. It's not going to make any more power than the CJ intake. But I'm sure the difference in weight is worth .20 :rolleyes:
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Kris, you are correct. Here is some more history on the PI.
The aluminum PI intake is the same as a later-design of the 427MR intake. Early MR intakes had different throttle mount bosses and did not have the machined-in features that allowed fitting the three-fingered rocker oil control baffles used in all FEs (except the 427MR) from 1958-66, so to fit the 427MR intake to a non-427MR engine six extra cutouts at the pushrod holes needed to be machined into the aluminum intake. Note that all FEs would inherit the simpler 427MR rocker oil control baffles from 1967-76. By the time the 428PI was developed in 1966, the 427MR intake machining protocol added the extra counterbores to the intake, and also modified the throttle linkage bosses so the intake would work in both 427MR and 428PI applications. As for the penny-pinching part, the PI did not earn a special intake casting, but 1966 was the first year of both the of the Chrysler 440 and Ford 428, so it was clear some free breathing was in order. It made sense to install the MR aluminum intake onto the 428PI to keep competitive with the 440, even though the intake was not cheap to cast. It wasn't until the 428CJ was born that the accounting department saw a cost-benefit to designing a low-cost iron alternative to the MR intake, so about a month or so after the iron intake was being installed onto 428CJ engines, the 428PI engine lost the aluminum and gained the CJ iron intake, thus making the Ford a more profitable police vehicle.
Seems funny to me that in 1968 the CJ was slotted into the C/SA catagory and you will find it STILL there today. Sounds to me like there are little or no improvements other than just keeping up with the rest of the pack.
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