Twin Cam Warm idle Knock
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Joined: Mar 2010
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From: Poolville
As already suggested, install an oil pressure gauge... However, No one ever mentioned preload on the adjustable pushrods.. was it originally at least .125"?
Last edited by 98hotrodfatboy; Sep 21, 2019 at 10:21 AM.
HDF Community Team
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From: san antonio
The noise started immediately after the cam plate upgrade and has not changed. I will look up at the bottom of the rocker arm when I take out the pushrods and open the cam chest. I will put a pressure gauge on it this week and likely try a Baisly spring to see if it makes any difference. Clearly an oil change is coming too.
It seems to me that oil is not getting to that exhaust lifter and my understanding is that is the last in line for oil. So, perhaps a sticky or leaky bypass valve?
It seems to me that oil is not getting to that exhaust lifter and my understanding is that is the last in line for oil. So, perhaps a sticky or leaky bypass valve?
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Novice
Joined: Jul 2019
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From: Richfield Springs, NY
Oil pressure light only comes on when I turn the ignition. As soon as the bike starts the light goes out.
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Novice
Joined: Jul 2019
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From: Richfield Springs, NY
You may be right about the exhaust lifter but until you check oil pressure and pull the rocker box covers to visually check oil flow to the rocker arms, you are flying blind. First things first. The Baisley spring will only help idle oil pressure and you really don't need it with the high capacity pump; forget that for now. However, it is worth the effort to remove the pressure relief valve piston, polish it up and replace. Also still think the oil pump assembly should be disassembled and checked.
Garage results:
Cold Start 40psi - after 2 minutes of idle I twisted the throttle and the raised it to a steady 60psi
Ride Results:
Steady cruising - 52-55psi
Hot idle: 18psi
That seems like the oil pressure is good.
On another note: The last two test rides, I have noticed some oil on the exhaust tube and the transmission that leaked from somewhere. I thought it was leaking from the tappet cover, but this time I am pretty sure it belched out of the top of the pushrod tube. Perhaps I did not get the o-ring seated properly. Not sure that this has anything to do with my problem since it has only shown up since the lifters were changed.
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From: Honah Lee
Obviously, that is a lot of pressure for a Harley. Stock bypass is set at 35. Idle should be below 15 or so to keep the TC oil injectors from working at idle to prevent oil cookings at stops. Probably for up North I guess.
Road Master
Joined: Aug 2019
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From: wv
Cold start 40lbs should be normal pressure. Prob 65F and garage kept (like mine lol)
Your raise to 60 to me means the oil is still cold. Again, mine will do that unless I let it idle too long.
Your 55lbs at cruise is pretty high. Looking like a high pressure pump in there.
Hot idle at 18 is a huge drop from 55. Im guessing its a liquid filled gauge and the liquid is now pretty warm. (been there done that one).
Your raise to 60 to me means the oil is still cold. Again, mine will do that unless I let it idle too long.
Your 55lbs at cruise is pretty high. Looking like a high pressure pump in there.
Hot idle at 18 is a huge drop from 55. Im guessing its a liquid filled gauge and the liquid is now pretty warm. (been there done that one).
Road Master
Joined: Aug 2019
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From: wv
Just a though.
I've heard that a weak valve spring makes a lifter pump up. I think I had that going on one time but all the noise was up top, not at the lifter block on that engine.
How many miles are on this engine anyway?
I've heard that a weak valve spring makes a lifter pump up. I think I had that going on one time but all the noise was up top, not at the lifter block on that engine.
How many miles are on this engine anyway?
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From: Honah Lee
Lifters have a leak down rate. They are designed in theory that that when pumped up to no clearance, the leak down is strong enough to not loose valve opening distance thru the opening cycle. The actual rate of leak down is overrode by valve spring strength. If the valve spring was that weak, it would pump up past zero clearance holding valve open. If valve spring was that weak, it would idle terrable and you would be lucky if it would idle if it was an intake.
Road Master
Joined: Aug 2019
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From: wv
Listening to your videos again it sounds like its up top to me.
I think I can hear it in the cold engine too at the end where you're on the left side.
Noise transmits through metal making it hard to find it.
Its noisy the whole valve train in these speakers.
Nice looking bike.
I think I can hear it in the cold engine too at the end where you're on the left side.
Noise transmits through metal making it hard to find it.
Its noisy the whole valve train in these speakers.
Nice looking bike.