valve floating
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Road Captain
Joined: Dec 2009
Posts: 512
Likes: 6
From: Minnesota
valve floating
Ok I have the Crane 570 cams installed and love them but, a couple times when winding it up and shifting to the next gear it would fall flat on its face. I think it is called valve floating
. Is there a stronger valve spring that I would need to put in to solve that problem? If so how hard is it to do the job? Thanks in advance.
. Is there a stronger valve spring that I would need to put in to solve that problem? If so how hard is it to do the job? Thanks in advance.
Sponsor
Joined: Dec 2007
Posts: 12,084
Likes: 829
A weak spring, that would cause a un-controlled valve event, would usually result in valve/valve contact, and once that occured, the engine would operate in a very poor fashion.
I would be much more inclined to believe that it is a fuel issue, pipe(s) are pinching the peak delivery, or you are running out of cylinder head flow.
Scott
I would be much more inclined to believe that it is a fuel issue, pipe(s) are pinching the peak delivery, or you are running out of cylinder head flow.
Scott
Cruiser
Joined: Feb 2012
Posts: 123
Likes: 1
From: Ontario, Canada
It is strongly suggested that you use roller rockers and 175lb base springs on a 570 lift cam. While the valves may not be trully "floating", they can bounce off the valve seat with insufficient spring tension. This won't go on for long before you have cylinder leak down/ valve guide issues.
The other thing that comes to mind is the Rev limiter, stock is about 5700rpm, SE ups that to 6200 for most applications. Could it be possible your bouncing off the limiter with your newfound power?
Just some thoughts to ponder. Fastrider124
The other thing that comes to mind is the Rev limiter, stock is about 5700rpm, SE ups that to 6200 for most applications. Could it be possible your bouncing off the limiter with your newfound power?
Just some thoughts to ponder. Fastrider124
Thread Starter
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Road Captain
Joined: Dec 2009
Posts: 512
Likes: 6
From: Minnesota
It is strongly suggested that you use roller rockers and 175lb base springs on a 570 lift cam. While the valves may not be trully "floating", they can bounce off the valve seat with insufficient spring tension. This won't go on for long before you have cylinder leak down/ valve guide issues.
The other thing that comes to mind is the Rev limiter, stock is about 5700rpm, SE ups that to 6200 for most applications. Could it be possible your bouncing off the limiter with your newfound power?
Just some thoughts to ponder. Fastrider124
The other thing that comes to mind is the Rev limiter, stock is about 5700rpm, SE ups that to 6200 for most applications. Could it be possible your bouncing off the limiter with your newfound power?
Just some thoughts to ponder. Fastrider124
Mine does same thing at times.
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Seasoned HDF Member
Joined: Sep 2018
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From: Kalifornia
The original post was from 2012, so I doubt you will get an answer.
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