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  1. #1

    Default Another cam question.

    Got a 82 gt orginial motor . T 5 trans , new weiand stealth intake . New holly 600 4 barrel carb . Headers, underdrive pulleys. Looking to put a new set of gt40 aluminium heads on it . Any cam suggestions? Or any other mods i can do without a total rebuild. Car is just a street cruiser,thanks

  2. #2

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    With even 58cc chambers and only a smidge over 9:1 compression, something like the Ford Motorsport A311 hydraulic camshaft (204/214 degrees @ 0.050" & 0.448"/0.472" lift & 112 degree LS... there are a number of other brand generic camshafts with these specs), or the Comp XE250 (206/212 degrees @ 0.050" & 0.459"/0.474" lift & 110 degree LS) would perk things up. The real stopper is the 600cfm carburetor, generating nearly 2"Hg of vacuum up top. A 750cfm on it alone would decrease red line vacuum to just over 1"Hg, and add approximately 10HP/TQ to it's peaks (4500rpm for TQ, and 5500-6000rpm for HP) and about 5HP/TQ to it's averages. Distributor ignition advance "recurve" is what's ALWAYS needed. I really would do a compression test (ring seal) first before doing anything, and finding out it's running oil pressure (bearing clearances), before doing anything else. Rings, bearings, gaskets, oil pump, timing chain, etc., really isn't alot of expense or hard to do yourself for the knowledge that what's in there will perform and survive for many miles with no balloon-popping surprises....
    Last edited by Walking-Tall; 12-31-2017 at 08:40 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  3. #3
    FEP Super Member gr79's Avatar
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    Torque spec cam for street.
    HP spec cam for strip

  4. #4
    FEP Super Member erratic50's Avatar
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    If you do not own those heads already do some homework. There are countless better options for the same or less money.

  5. #5
    FEP Super Member bwguardian's Avatar
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    Yes, what ^^^...erratic50 said. When I was doing the same thing a half dozen years ago I found a set and almost pulled the trigger, then decided to go with the GT40p heads after some research. I also did what Walking-Tall suggests relative to new oil pump, timing chain, etc. The heads I found were fresh out of the machine shop with good springs and oil seals so all good. I have also been happy with the cam I chose and picked up a similar Ford Racing high rise dual plane intake.
    HAD
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  6. #6
    FEP Power Member Ethyl Cat's Avatar
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    Quote Originally Posted by Walking-Tall View Post
    The real stopper is the 600cfm carburetor, generating nearly 2"Hg of vacuum up top. A 750cfm on it alone would decrease red line vacuum to just over 1"Hg, and add approximately 10HP/TQ to it's peaks (4500rpm for TQ, and 5500-6000rpm for HP) and about 5HP/TQ to it's averages..
    I am curious as to where you get the 2" vacuum data from Walking-Tall. Is that a software sim? The reason I ask is that a 302 at 100% VE (which this engine will not reach) reaches 600CFM at 6866 rpm(which those cams will not reach). The 600cfm rating is at 1.5" vacuum so that number just seems high to me.

    Not a challenge just curious.

    Thanks
    Steve
    BBD PERFORMANCE
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  7. #7

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    Quote Originally Posted by Ethyl Cat View Post
    I am curious as to where you get the 2" vacuum data from Walking-Tall. Is that a software sim? The reason I ask is that a 302 at 100% VE (which this engine will not reach) reaches 600CFM at 6866 rpm(which those cams will not reach). The 600cfm rating is at 1.5" vacuum so that number just seems high to me.

    Not a challenge just curious.

    Thanks
    Steve
    You're right, Steve, I was misreading here. Sim, yes, EA Pro, briefly but fairly closely simulating OP's combo, for 500-7000rpm. The differences (with resultant 85+% VE) are 1.5"Hg with a 600cfm VS (1-1/4" & 1-5/16" venturi) & 1.1"Hg with a 750cfm VS (1-3/8" & 1-7/16" venturi), @ 6000-6500rpm... with the additional 150cfm uncorking with a 750 on top of the intake differences actually being 20+ @ both peaks and 10+ for both averages. Illustrating the point I'm often trying to make around here, lol, that there's virtually no such thing as too big a carburetor that cannot be dialed in, and a 750cfm VS certainly isn't too much on a 302. The only dangers being making too much peak and average HP & TQ.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

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