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Discussion Starter · #1 ·
My brother is trying to pick out a cam for his 72 mach1 with a 460. He has Edelbrock aluminum heads (normal port size, not CJ), Torker2 intake (hood clearance issues with anything taller than stock), demon 850 carb, ~9.5:1 comp, stock exhaust manifolds and dual 2.5" exhaust with flowmaster 40s. Oh and also, completely stock crank and rods.

First question is, with the stock bottom end in the big-block, how much RPM is 'safe'? I personally think he should definitely keep it under 6000rpm, maybe even more like 5800rpm redline. And given that, the second question would be, what cam specs should he be looking at? He wants to go with a Comp Magnum 280H or even larger, but I think that would be a little large given his max RPM, and would be giving up a lot of low-end power for not much gain up top. I was thinking more like a 270H or the 265DEH (265/275 duration) would still allow him to take it up over 5500rpm, but will also make for great torque for street duty.

I realize that since it's a big block it's already going to have more than plenty of torque, but I just see no reason to give up power in the RPM range he'll be in 95% of the time around town, just for a little more peak power and a choppier idle.

So what do you guys think?
 

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It depends upon usage and what type of exhaust system he plans to use. He will NEED a VERY free flowing exhaust with big pipes to properly vent a hotrod 460. We are talking headers and AT LEAST 2.5" pipe with all mandrel bends and good 'see through' mufflers.... Preferably 3" to avoid losing horsepower.

Remember, a cam that makes a 302 thump like crazy at idle will be MUCH more tame in an engine displacing 460 cubes. If he wants it to turn close to 6k rpm with a wide powerband, he'll end up using something with around 230 to 240 degrees @ 0.050" on the intake, and a lobe seperation of around 110-112 degrees. If he wants to get more radical, has a loose converter, steep gears and huge headers with a huge exhaust, something more radical can be put to use... maybe 240-248 @ 0.050" on the intake with a 108-110 degree lobe seperation.

More specific info on the rest of his car, including all specs and intended usage would be helpful.

Good Luck!
 

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Discussion Starter · #3 ·
Thanks Mike. Like I said he's got manifolds and dual 2.5" with Flowmaster 40s, so the exhaust is too backed that a big cam will only hurt power from the overlap and high exhaust backpressure. He's got a 2500 stall, c6 trans, 3.73 gears, and tips the scales at around 3700lbs, and is mostly street with occasional strip duty... but not a daily driver, just fair-weather fun vehicle.
 

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I didn't catch the part about him not having headers. I guess after reading the engine had aluminum heads, I ASSUMED he would have headers on it!

Small cam city! Your recommendations seem to be right in the ballpark. Oh, by the way.... TALK HIM INTO GETTING SOME HEADERS FOR THAT THING!


Good Luck!
 

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Nothing bigger then the 270H specs. Torker 2 manifold is hurting more then helping. If he can get an Edle RPM or Weiand Sleath under his hood somehow he really feel the difference. What type of Ignition does he run? I'd stay around 5500 only because of rod bolts and oiling system is Stock?
 

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Discussion Starter · #6 ·
Mike: yeah I keep hammering on him about the headers... but because they require pulling the engine and reworking the exhaust, he's put that on the back burner 'till he does a total rebuild... so in the meantime it's aluminum heads and choked down manifolds


dacofa: Right now he actually has a plain old Performer, and with a short/small aircleaner (Ford Racing 13" ) the wing nut damn near scrapes the hood... so we figured for what he wants to do the Torker2 is much less choked down than the Performer, and is probably his best option considering he can't go any taller than a stock intake. The ignition system is also getting upgraded, just not sure what yet, but hopefully something like an MSD Pro Billett.

_________________
'86 Bronco fullsize, 460, E4OD
'85 Ranger, 340hp 289, T5


<font size=-1>[ This Message was edited by: Motorhead on 4/24/06 11:38pm ]</font>
 

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Keep the performer its better than the torker 2. as far as cam is concerned his only limiting factor is the manifolds, he needs to get some headers !!! Even with the alunimum heads 460's still like split duration cams, I would stay away from the "magnum" series (they are chevy grinds) and look into some of the "Extreme" Hydraulics (Split) if you like comp cams stuff, they are more ford oriented lobes. IMO.
 

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The performer actually works very well for a mild 460.I have a dyno shootout article on 5 different intakes and the performer had the best overall torque and highest hp of them all.Intakes were the stock cast iron 4V,Weiand Stealth,an Offy single plane and two FPP high rise dual plane manifolds.This was a 9.4:1 motor with JBA shortie headers and a mild 216/[email protected] 513L camshaft....I would definetly look at getting some headers for the car though.
 

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Discussion Starter · #10 ·
frdnut: I'd love to see the article if possible, do you know if it's anywhere online, or if you could maybe scan and email it to me?
 

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270H with a Performer manifold. Headers will help allot but with the heavier car you'll want torque to do your talking. Torque convertor will have to be changed with a bigger cam and power brakes will be almost useless on the street with a big cam. Keep it fun and try and find so ideas to loose weight in the car.
 
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