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05-14-2006, 08:53 PM
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Valve Spring Question
I just started disassembling a pair of 781 heads that are fresh but I wanted to do a little porting and polishing, plus they have been sitting up for 3 years so I probably need to replace the seals anyway. My question concerns the valve springs. Upon removing the first valve I found that there are actually 3 springs per valve, and they are incredibly stiff. Is this common? They are going on a 454 with an xtreme energy 274h cam. It seems that these springs are going to be a little stout for break in, but I'm a newbie so whats an educated opinion?
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05-14-2006, 09:05 PM
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im not too much on heads and valve springs. not really my specialty, but seems like whoever built the heads intended them for high reving. if your uncomfortable with the stifness of springs on breakin try to find a set with lower seat pressures to use on break in then change them afterwards. hope this helps....
-Matt
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05-14-2006, 09:24 PM
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If I pull the seals off of the valves are they shot?
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05-15-2006, 06:27 AM
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Depends on the type of seal,, The white teflon seals are usually destroyed on removal. The black/blue umbrella type seals, if removed carefully, can be reused. Same goes for the positive (metal band type) seals. Be careful taking them off and they are usually OK.
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05-15-2006, 08:31 AM
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Are you sure it's not a dual spring with damper? I don't know why anyone would run a triple spring on that head.
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05-15-2006, 12:05 PM
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well there were two springs that find of look like coiled flat steel at an angle, and the smallest inner spring was a regular coil type spring
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05-16-2006, 10:44 AM
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Sounds like a single spring with 2 dampers or a dual spring with single damper.
Dual springs look like regular coil springs, one outside, inside, with a flat wound damper in the middle. Triple springs don't usaully have dampers to save space.
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05-16-2006, 10:46 AM
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Huhhh...
To answer you question, I would remove the inner spring for break in or use breakin rockers. More work but less expensive than a cam repair.
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05-17-2006, 12:32 AM
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after further inspection, actually I just looked at them again to make sure, the outer spring is a coil, the inner spring is the flat steel type, and the inner is a coil spring. Just as the previous post described. So would you guys suggest removing the inner / smallest spring for break in? Im everybit of 6' 225#s and it took everything I had to compress the springs with a pry bar type spring compressor to get the springs compressed far enough to remove the retainers. They just seem kind of stout to me, but then again maybe I'm just a puss. lol. thanks for the help
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05-17-2006, 06:05 AM
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I would install the springs that are reccomended for that cam, last thing you want is to assemble then a thousand miles later have no lobes left on the cam.
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05-17-2006, 10:11 AM
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Quote:
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05-17-2006, 10:21 AM
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I would take the heads and do the porting that you want to do. Then take the heads to a good shop and have the springs installed, take the cam card with you. You might have roller springs there an it will ruin a cam real quick. Do it right the first time and it will be a lot cheaper and it will last.
Your in Memphis, take them to Racing Head Service. It won't get any better than that.
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05-17-2006, 05:49 PM
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One thing that has to be checked is the proper installed height for the spring. It is possible that those heads have an installed height of 1.800" instead of the normal 1.875" for BBC heads. If your heads have the exhaust spring pockets cut for rotators, you have the heads with the 1.800 installed height.
If you springs are for 1.875" installed height, oops! tom
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05-17-2006, 05:55 PM
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there is a rotator on the intake spring and just a shim on the exhaust, or maybe its the other way around. Is this correct?
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