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Old 09-15-2011, 04:17 PM
saltshaker saltshaker is offline
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Join Date: Sep 2007
Location: Marlboro, NJ
Cobra Make, Engine: Contemporary Cobra
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Quote:
Originally Posted by ERA427 View Post
So… surely someone will have good guess. I just got ERA #434. I’m trying to determine (through its specs), how much HP and torque it has.

I've found all the casting numbers.

It has: 1966 428 FE block
- 1968 Cobra Jet heads
- 1966 aluminum police interceptor intake manifold
- New Holly 750 4bbl
- Stainless side pipes from ERA
- Mallory ignition
- Tremec TKO







I spoke to the guy who rebuilt the engine in 1995 when the car was built. He told me that it was a stock rebuild. In other words, it’s not a custom cam, bored, etc.









Q

My calculations are as follows. With CJ heads, I think I should be getting all the power of a stock Cobra Jet 428, which most people seem to agree is 410hp by the old measurement standards
(yes I know it was rated at 335hp by Ford). So 410 seems like the starting place.




Then it has the PI intake, which according to the old ratings, added 15hp over a stock 428FE for 1966 (a PI 428 was rated at 360hp, compared to 345 of a stock 428). So I’m adding 15hp for that, and that would bring me to 425hp. I’d assume that a new Holly 750 must get me something more than the original 735cfm 4bbl that came on a 428 cobra jet. Not sure my ignition buys me anything. Anyway, I’m tempted to go with about 440hp and 450torque.

Thoughts?
With a stock cam you really have a CJ motor...the 735 cfm carb is a great carb and switching to a 750 isn't going to add anything. The PI intake is the same as the CJ ...just aluminum so you save weight. Original Cobras that had PI 428 motors with a 427 cam were rated at 390 hp. Together to 440 hp you need ported heads and a cam like a comp 282s and then you would be close if your CR is at least 10/1
Jon






Jon
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