| Subject: okay, LISTEN UP! Heres the facts on the stock, US spec 460 PI |
Author:
ChrisH
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Date Posted: 20:15:16 12/04/02 Wed
In reply to:
Chris
's message, "460 Interceptor" on 02:30:37 12/01/02 Sun
'74-on 460PIs had D4VE-A heads. Period. They are regular 460 passenger car heads. 96cc chambers, 8.0 CR. Nothing special.
'72-73 429/460PI heads were D2OE-AA or AB. Smaller chambers, smaller ports than CJ/SCJ. Yields 8.6 CR with 18cc dished pistons. 2.19in/1.66 ex valves, and smaller ports for better velocity. ( for better low and mid range) THESE HEADS DID NOT COME STOCK ON U.S spec '74-ON 460 PIs. The D4VEs did. The fact Chris has these heads- hey, thats great. Maybe they used them for Canadian cars only. I doubt it, though.
Let's shed some light on this motor:
Originally designed to replace the venerable 390/428, the 385 series motor was designed to push big land yachts around at low rpms and included a wedge head design for better breathing and to help with the impending emissions regulations. Stock compression for the regular 429 for 1968-1970 was 10.5:1. and it dropped like a rock starting in 1972. Everone knows the 429CJ/SCJs were no slouches and were intentionally underrated for insurance purposes. High compression, big duration/high overlap cams and big ports and valves are what made all the power right close to 6000 rpm. Most CJ/SCJ cars had 3.91 or 4.30 gears to keep the rpms up and to get off the line quick.
The 460 did not make its way into the pickup line until the late 70's when the 360/390 was finally phased out- 1977 I think. The 385 series first debuted in the medium duty truck line in 1979 and offered as 370s and 429s. Did you know that all '72-on 429/460s had timing retarded 8 degrees using a retared crank sproket? This was for emissions purposes and really restricted the motor's output. Installing a standard, non-retard timing chain "straight up" would really wake up that motor. The increase in vehicle weight, falling compression ratios, and poorly engineered smog devices really did this motor in in the 70s. In 1994,even with efi and 8.8:1, the hp never got much beyond 250hp when used in F-series trucks. Today, a 5.4L small block makes that kind of power and is only off 40 ft/lbs of torque.
My experience with 460s:
I had a '77 LTD w/ 460 in high school with 3.00 gears. What a dog. Next, I built a 460 for my '64 Galaxie. Using stock heads I ported and polished them myself, cc'd the heads (those of you who know motors know what this is) and ran successfully 9.9:1 compression on 92 octane Chevron supreme here at sea level, using a stock Duraspark ignition and a mild cam. The torque was incredible.
I currently have two late model F250s with 460 efi, and two Ford F-700 water trucks with 370s (smaller bore medium duty truck engine). The lima motors are quite stout, let me tell you and were built intentionally so.
But to compare power and torque of the 71-72 429PI with a '74-'78 460PI is apples and oranges even if the 429 is down 30 cubic inches. In heavy cars, torque rules and I know which one I'd bet on in a heads up race.
The 71/72s were definately lighter than the '74-on cars. But who really cares. All of us with restored cars don't really care about drag racing them, although maybe we would care if we were back in high school, again.
This posting started with misinformation about 429/460PI heads and digressed into a pissing match. How fast or faster one car is over another depends on the following variables: the driver, mileage of the engine, its state of tune, gear ratio, and weight. NOTHING ELSE.
Perhaps a physics lesson is in order for you, Chris, to understand that.
Maybe someone can look up the results from the MSP tests of that era and shed some light on the faster cars for 1978, to settle this once and for all.
Otherwise,Chris, try the Ford 385 series bulletin board and talk all you want about the Lima 385s which include the
370/429/460s. I'm sure you will argue with them, too.
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