A roller cam might help, but you still need a balanced system. Sorry, but the Hemi Lope from John Force's funny car sounds cool, but at a great price. With a flat tappet cam, don't think you will find one that has torque and will go 6500 rpm +. You need to determine what you want first, an economical cruiser for use at less than 5000 rpm or an engine that starts pulling at 2500 and doesn't quit until 7000 or so. Also, couldn't get into the usable range of the cam as I needed new heavy valve springs, along with the correct breathing of the intake, carb, exhaust, transmission ratios, and rear gear ratio. A couple of broke valve springs, broken rocker arms, etc. Until I figured out the push rods were bending because I didn't have the long slot rockers. But man did it sound cool when you could keep it running. 500 lift cam in a stock 350, it wouldn't pull the hat off of an old man sitting in a rocking chair with no breeze. Lost all of the torque for launch when I buried the throttle.Īlso later stuffed the big ticket. Barely idled, but sounded mean like a hot cam. Put out so much black smoke at idle the neighbors complained about having to washer their cars daily while I was changing spark plugs daily. I remember the day, (not proud of it) took a stock 283 back in the days of primitive drag racers, stuffed a 650 double pumper and a single plane intake on it to make it run. Would I be better to go ahead and pull the cam out and go with something else? If so which cam?Īny opinion or advice would be greatly appreciated. I really want a nice sounding cam that has a lot of torque in the lower RPM range (<3800). Is there a way to tune these cams without the exhaust being so rich? If so, how do I do it? I don't have power accessories or an automatic transmission so vacuum (for accessories) isn't a big deal to me right now. I have a spring kit and an adjustable vaccum advance, but have not installed them.Ĭurrently I have 30 degrees initial timing and have taken a break from running the engine because I cant get it tuned, and the front end is being rebuilt so I cant pull it out of the garage yet. I am having a really hard time tuning the engine. Since I pulled the carb back down and trimmed the spring it is not running as rich, but still bad enough that I cant stay in the garage while its running (and the idle adjustment screws are out 1/2-3/4 of a turn). The cam makes very little vacuum (7-9") and the APT was opening up all the way causing it to run extremely rich. I am trying to stay as close to stock as possible (externally) so I kept the Quadrajet and rebuilt/modified it by doing the following: increased the down idle tubes, replaced the secondary butterfly bushings, put the lightest APT spring in it an at this point trimmed it. Since I've installed it its been a nightmare to tune. The cam that was recommended to me was a Mutha Thumpr Cam. Distributor, carb, intake, and exhaust manifolds are also stock.
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The heads are 1.94/1.5 "double hump, the pistons are flat top, and the cylinders have been bored. Start the engine and bring to break-in rpm.I have a 68 327, 4-speed, with a 12 bolt 3.08 rearend that is basically stock.
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Slow idle speeds may result in severe cam and lifter wear. Do not allow the engine to run under 2000 rpm for the first 1/2 hour. Coat cam lobes and bottoms of each lifter with MoS2 lube (supplied) to prevent cam lobe and lifter wear from occurring during initial start-up. Oil/additive must contain Zinc designed for use with flat tappet camshafts. Do not use rotator type valve springs or retainers for this application. Recommended Valve Springs for OEM heads: Edelbrock part #5712 Use only stock ratio rocker arms Adjustable valvetrain required In order for this Performer RPM cam and lifter kit to be covered under ANY WARRANTY you MUST use the correct Edelbrock Sure Seat Valve Springs or equivalent.For more information, visit Installation Notes WARNING: This product can expose you to Chromium, which is known to the State of California to cause cancer or birth defects or other reproductive harm.