Ford 429 CJ buildup

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Aug 26, 2005 | 01:56 PM

ivanvel

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Ford 429 CJ buildup

I am building up a ford cobra jet 429 and need some advise in selecting parts.
So far it has been sent to the machine shop for .030 over bore and head rebuild. I have ordered pistons which are Speed Pro forged aluminum with a 10.5:1 compression ratio.

I need some advise on the cam/valvetrain parts selection;

The two cams i have selected are by comp cams;

Part numbers are:

Magnum: 34-331-4 -OR- Xtreme energy 4x4 34-239-4

http://compcams.com/Technical/Curren...ML/102-109.asp

the engine will have 10.5:1 compression ratio, weiand stealth intake, holley 750cfm double pumper, full msd ignition with mechanical advance, 1-7/8" headers, 1.73 ratio roller rocker arms

thanks[B]

Aug 26, 2005 | 05:05 PM

monsterbaby

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From: iowa

go with the extreme energy cam you will like it alot better and bieng it's a dual pattern ford heads like a little more exhaust duration so it will just plain work better, and idle better but will still have a pretty lumpy idle in a 429 but it will put enough vacumn (or should) to run vac brakes were as the 280H magnum cam won't in a 429cid engine

Aug 26, 2005 | 05:23 PM

ivanvel

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I was also curious about the type of fuel i will have to run. I have heard that if i use the xtreme enegy i will have to run race gas due to the higher cylinder pressure buildup with the high compression ratio.. is that true?

also Im not sure how you are describing the idle quality of the xtreme energy versus the magnum.. smoother?

thanks

Aug 26, 2005 | 05:39 PM

monsterbaby

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From: iowa

at 10.5:1 comp your pushing it even with premium unless you want to go with alum heads, so your probably looking at at a minum octane booster or 100LL anyway.
as far as idle yes the xtreme energy cam will idle a little smoother and will pull better vacumn than the magnum cam, plus it will give you more power too so it's just a better cam.
BTW the magnum cam is a SBC grind setup on a BBF cam core if that helps you any, and too add to that it's 30+yr old technology the xtreme series of cams are a newer, and lot better lobe design