Cam question
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Cruiser
Joined: Dec 2007
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Cam question
I'm currently running a way too noisy for me engine that gets bad gas mileage (For example I get around 30 cruising between 75 and 80). Tried the lifter adjustment and heavy oil route but little luck. I also would like to improve the overall performance, especially the torque numbers (currently have 111hp and 117 torque). I am interested in a cam with no more than a .600 lift. I ride pretty hard on the highway and am not a bar hopper. I would like some solid torque from about 2500 up. My current build, given the components I'm using, is a slouch on top of being noisy. So I am starting to look into cams that perform but do not have a constant tapping noise that increases with rpm. I am having the heads removed to check everything and hope there's an easy fix. Any suggestions? Am I dreaming about a getting a quiet cam that will improve my noise, performance, and mileage issues?
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Joined: May 2008
Posts: 2,543
Likes: 19
From: Ashland Ohio
I would call Scott and talk about it.
But here is something you may wish to investigate if you haven't already done so....
It's some of the components in your heads that may need attention.
Specifically the rocker arms, the rocker arm shafts, and some say the shaft supports.
Pull your rocker arm covers and check rocker arm side play with a feeler gauge. The more play... the more noise. This can be corrected pretty cheap with rocker arm shims used on shovels. Do NOT quote or use this, and please look in the SM, but I'm thinking anything over like .003 induces noise.
Also, you may wish to go further... check the diameter of the shafts for the rocker arms. They worn? Undersized in any way? Then look at the bushings inside the rocker arms. They worn? Oversized in any way?
If each piece is just a few thousandths of an inch the wrong way... combine the math from each piece and then you can see that there could be 8-10 thousandths of 'slop' right there. Everybody calls this added math equation 'valvetrain stack'. This is something that the lifters cannot smooth out... it can be like a moving target for the lifters.
I hope that this explains this good enough for you to see what I am trying to explain. I'm just a duma$$. But, if you like the Woods... there IS a reason that a few can be quiet, and others cannot. Also, if the stack and side play are outta whack.. buying new cams wont take out as much noise as you may think.
Crappy gas mileage is more of a PC III thing. A decent tune, NOT A CANNED MAP, can help that immensely.
But here is something you may wish to investigate if you haven't already done so....
It's some of the components in your heads that may need attention.
Specifically the rocker arms, the rocker arm shafts, and some say the shaft supports.
Pull your rocker arm covers and check rocker arm side play with a feeler gauge. The more play... the more noise. This can be corrected pretty cheap with rocker arm shims used on shovels. Do NOT quote or use this, and please look in the SM, but I'm thinking anything over like .003 induces noise.
Also, you may wish to go further... check the diameter of the shafts for the rocker arms. They worn? Undersized in any way? Then look at the bushings inside the rocker arms. They worn? Oversized in any way?
If each piece is just a few thousandths of an inch the wrong way... combine the math from each piece and then you can see that there could be 8-10 thousandths of 'slop' right there. Everybody calls this added math equation 'valvetrain stack'. This is something that the lifters cannot smooth out... it can be like a moving target for the lifters.
I hope that this explains this good enough for you to see what I am trying to explain. I'm just a duma$$. But, if you like the Woods... there IS a reason that a few can be quiet, and others cannot. Also, if the stack and side play are outta whack.. buying new cams wont take out as much noise as you may think.
Crappy gas mileage is more of a PC III thing. A decent tune, NOT A CANNED MAP, can help that immensely.
Last edited by wurk_truk; Aug 4, 2009 at 11:52 AM. Reason: stoopid
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Cruiser
Joined: Dec 2007
Posts: 127
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Thanks Truk. I'll be sure to double check on the rocker arm assemblies and all the stuff that connects to them. I've had this engine on several dynos with two highly regarded tuners - I am definitely not running a canned map. My guess is that to get the performance I have that the last tuner had to make some compromises - he spent 4 hours on it. My break in map got close to 40 mpg and after these tunes I got a much stronger motor and poor mileage. My guess is that it has to run rich to put out decent numbers, but I am not an expert here and am only guessing.
Outstanding HDF Member
Joined: Oct 2007
Posts: 2,018
Likes: 6
From: Edmond, Ok
I'm currently running a way too noisy for me engine that gets bad gas mileage (For example I get around 30 cruising between 75 and 80). Tried the lifter adjustment and heavy oil route but little luck. I also would like to improve the overall performance, especially the torque numbers (currently have 111hp and 117 torque). I am interested in a cam with no more than a .600 lift. I ride pretty hard on the highway and am not a bar hopper. I would like some solid torque from about 2500 up. My current build, given the components I'm using, is a slouch on top of being noisy. So I am starting to look into cams that perform but do not have a constant tapping noise that increases with rpm. I am having the heads removed to check everything and hope there's an easy fix. Any suggestions? Am I dreaming about a getting a quiet cam that will improve my noise, performance, and mileage issues?
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