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Old 08-17-2004, 09:01 AM
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Push Rod Length? Rockers?

I am building a 9.5 in deck height 351 Windsor with GT40 heads, w/ my stock length push rods (7.56) the tip of my roller rockers sits just to the exhaust side of center on the valve stem, and when the valve gets opened it rolls further to the exhaust side. when of course it should sit just to the intake side and roll to the exhaust side. so i re measured and came up with 7 5/16~7.300....however 7.3" pushrods are $150 from ford, $ 85 from summit...well summit had 7.290 pushrods for $29, i bought them 'cause what would 1/100 of inch difference make? well 7.290 is too short and so will 7.300. my valves appear to be the same hight as stock (not shorter which would cause the stock size goodies to be placed where they are....the only thing i can think of is my roller rockers are 1.7:1 not 1.6:1.....everything works fine w/ the 7.56 pushrods except where the tip sits should i just assemble the motor w/ my 7.56 pushrods, or should i wait and have a professional look at my set up and buy even more parts just to get the roller tip to sit 1/16 or 1/32 of ian inch more to the intake side?

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Old 08-17-2004, 09:22 AM
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at jegs you can buy an ajustable pushrod for installing only for the purpose of checking your pushrod length.itis in the pushrod section under crane cams $25.99 part # 270-99727-2
install it and run the engine while watching it.adjust until it runs true and measure it and get the right length pushrods.

p.s.
they are not to be used on the road.
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Old 08-17-2004, 09:35 AM
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pushrods

Try this, clean all the oil off of the tip of the valve tip. Take a black sharpie and color the tip. (i do it twice) then assemble the rockers with the 7.290 push rod and rotate the motor a few times. Repete this with the 7.56 push rods. Lets us know how wide the make is and where it's located in respect to the center of the valve stem.

Keith
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Old 08-17-2004, 10:25 AM
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Dont waste your time marking things yet, your numbers are way off.

Either you have the wrong rocker arms or your measuring wrong.
A 351w should be somewhere around 8.150" +/- .200 so normal should be 7.9 to 8.3 depending on heads, deck milling, head gaskets. Sometimes with retro fitting roller cams you will run as small as 7.700" but 7.3" is almost 1/2" difference. If the 7.3" rods are even close to working I would say you have the wrong rocker arms, probably cleveland rocker arms not windsor, but either way dont run it untill you get your geometry correct or you will be replacing guides and valves with in the first 1000 miles.


Where did you buy these rocker arms? Have you used them before? Are you sure they are 351w rocker arms, or did you buy them used or off e-bay. People are always selling ford parts wrong as "C" or "W" and dont know it.


Ben

Last edited by brainsboy; 08-17-2004 at 10:40 AM.
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Old 08-23-2004, 03:55 PM
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I used the adjustable length checker and came up with 7.45'' The roller tip of the rocker arm sits where it should and as i turn the motor over it rolls all the way to the exhaust side almost to the edge. I'm running 302 heads on a 351 block so that would be the biggest factors, its a 95 block with factory roller tappets. The stock pushrod length on the block is 7.567''

I got the roller rockers from summit, so I would hope they would know the difference. I'm using them with 7/16 screw in studs with guide plates.

The sharpie trick didn't really work but i'm pretty sure that the rocker travels a third of the distance across of the valve stem.

Also, what should the gap be between the rocker arm and valve stem?
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Old 09-07-2004, 12:12 PM
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try ajusting it in small increments til it rides in the center of the stem.don't force it if it won't spin around.
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