SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: 88CARRERA on February 14, 2012, 06:47:27 PM
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So I installed a set off roller rockers ( ford racing bolt down) and one cylinder is giving me problems it's max torqued or bolt is bottomed out before the rocker gets to 20 ft lbs. all are fine but 1 cylinder do I need longer push rods. Anyone else have the issue?
Chris
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Can u be more specific Sir?. Re- check your valve train geometry :)
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I re checked it twice. Tried shimming and it did the opposite.
At 20 lbs of torque intake and exhaust are still looser than the rest.
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Run a tap down the threads and make sure there is nothing in the hole to stop it from torquing correctly.
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Are these pedistal style or stud? If one is that far off I would check the lifter or cam. If pedistal if all is ok shiming should do the trick.
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Run a tap down the threads and make sure there is nothing in the hole to stop it from torquing correctly.
I will try this! good idea, do you know the thread size/pitch?
Are these pedistal style or stud? If one is that far off I would check the lifter or cam. If pedistal if all is ok shiming should do the trick.
these are pedastal mount, bolt down.
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So I installed a set off roller rockers ( ford racing bolt down) and one cylinder is giving me problems it's max torqued or bolt is bottomed out before the rocker gets to 20 ft lbs. all are fine but 1 cylinder do I need longer push rods. Anyone else have the issue?
Chris
When you say that the "bolt bottoms out before the rocker gets to 20 ft lbs," do you mean that the pushrod has not yet depressed the lifter plunger? Or do you mean that the pedestal stand of the rocker arm is not seated against the cylinder head pedestal before the bolt bottoms out in the head? If it's the former, then you need to play with pedestal shims and/or pushrod lengths. If it's the latter, then you need to either play with the thread depth in the cylinder head or it's possible that a pedestal shim will be required anyway and it will make up for the short thread length in that particular pedestal.
Although your style of valve train is referred to as a "non-adjustable" valve train, it does in fact have limited adjustability.
LO
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LO,
basically i get to 0 lash by hand and its almost totaly tight. put the torque wrench on it at 12o'clock and i can only move the TW to 1o'clock before it stops. There is actually only 1rocker that is doing it. it was on exhuast on # 5 and I moved to intake on #6 and it does the same thing. and 5 is now fine. FFrp thinks there may be an issue with the rocker. they want me to take some photos.
the bolts are all the same length. i have the shim kit and it did nothing.
again this is only on 1 the rest are installed and perfect
and yes they are pedestal mount with the little saddle set up that fits in the pedestal
chris
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LO,
basically i get to 0 lash by hand and its almost totaly tight. put the torque wrench on it at 12o'clock and i can only move the TW to 1o'clock before it stops. There is actually only 1rocker that is doing it. it was on exhuast on # 5 and I moved to intake on #6 and it does the same thing. and 5 is now fine. FFrp thinks there may be an issue with the rocker. they want me to take some photos.
the bolts are all the same length. i have the shim kit and it did nothing.
again this is only on 1 the rest are installed and perfect
and yes they are pedestal mount with the little saddle set up that fits in the pedestal
chris
Chris, I'm still having difficulty understanding what the exact issue is. After reading your latest post and then re-reading the entire thread, all I can determine is that you have observed that the #5 exhaust section of the valve train is somehow behaving differently than the rest of the valve train...but I don't see what about its behavior is unusual or unacceptable. ???
When you say, "it was on exhaust #5 and I moved to intake on #6 and it does the same thing..and now #5 is fine," could that be because you just rotated the engine/are not installing the rocker arms with their respective lifters at the base circle of the cam? Some lifters hold theiier preload on a non-running engine longer than others.
Or did you mean that you moved the rocker arm from #5 to #6 and the problem disappears?
If you want to call me directly and explain it over the phone, maybe I can help.
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Could this be a valve stem height issue, sure sounds possible.
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Chris, I'm still having difficulty understanding what the exact issue is. After reading your latest post and then re-reading the entire thread, all I can determine is that you have observed that the #5 exhaust section of the valve train is somehow behaving differently than the rest of the valve train...but I don't see what about its behavior is unusual or unacceptable. ???
When you say, "it was on exhaust #5 and I moved to intake on #6 and it does the same thing..and now #5 is fine," could that be because you just rotated the engine/are not installing the rocker arms with their respective lifters at the base circle of the cam? Some lifters hold theiier preload on a non-running engine longer than others.
Or did you mean that you moved the rocker arm from #5 to #6 and the problem disappears?
If you want to call me directly and explain it over the phone, maybe I can help.
Sorry for the confusion
I couldn't figure out the problem on 5 so I removed that one and swapped with another cylinder (6)and the problem followed and 5 is fine.
All were installed correctly on base circle of cam. Again 15 others are perfect
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LO,
basically i get to 0 lash by hand and its almost totaly tight. put the torque wrench on it at 12o'clock and i can only move the TW to 1o'clock before it stops. There is actually only 1rocker that is doing it. it was on exhuast on # 5 and I moved to intake on #6 and it does the same thing. and 5 is now fine. FFrp thinks there may be an issue with the rocker. they want me to take some photos.
the bolts are all the same length. i have the shim kit and it did nothing.
again this is only on 1 the rest are installed and perfect
and yes they are pedestal mount with the little saddle set up that fits in the pedestal
chris
I was gonna suggest that also, just swap the rockers aound and see if the issue follows the rocker. if it doesn't, try the pushrods. You already did that, and my conclusion would be the same, bad, bent, or damaged rocker(s). Are these the same rockers you showed me a long time ago?
Ray
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IR
yep,
I got them from simidan in trade.
to my knowledge there was nothing wrong with them. i sent him a pm no answer yet just to see if he had an issue.
i just dont want to chase my tail. if i have to buy 1 to replace it its fine i just want some info.
i havent put 2 side by side yet i will do it this weekend.
thanks for all the help!
chris