Re: Valvetrain noise, with vid.
[Re: jung]
#2543076
08/29/18 03:38 PM
08/29/18 03:38 PM
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Joined: Jan 2003
Posts: 14,539 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
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So. Burlington, Vt.
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Looks like “rust” on those valve tips to me. Try cleaning it up with some scotchbright.
The “usual” place for contact is right at the top of the pushrod tunnel, at the edge of the flat pad that’s cast there.
This would be when the valves are closed. The pushrod will move away from that side of the hole, towards the valve cover as the valve opens. I’ve seen a few occasions where there was contact on the valve cover side of the tunnel at full lift, but it’s not as common, and usually only affects one or two.
All of this is just on the intakes. I’ve never seen the exhaust have any issues.
It looks like someone did something minor with a sanding roll in that tunnel. The sanded finish is easier to see the witness marks in compared to the shiny machined finish. Hard to see from the pic if those dark spots are from contact, or if they just never got hit by the sanding roll. Might try the scotchbright there to see if it leaves more of a mat finish for future observations.
When the rockers are bolted down, much much side to side play is there, per pair? My preference is to have at least .010, but less than .030.
If you don’t find evidence of contact, I’d put it back together and run it some. The XE lobes are usually a bit noisy....... might just be that’s what you’re going to get.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Valvetrain noise, with vid.
[Re: fast68plymouth]
#2543175
08/29/18 06:42 PM
08/29/18 06:42 PM
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Joined: Aug 2018
Posts: 22 CA
jung
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member
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OP
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Joined: Aug 2018
Posts: 22
CA
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That's incredibly helpful thanks. The 'rust' stuff just wipes off with a finger so no worries there... I'll pop it back together and take a very close look where you described, if it's at the top, I should be able to see it. Will measure the side play on the rockers too - I haven't done that except just to feel there was some. Will let you know how it goes, hopefully smoothly. I'm well overdue turning a wheel or two in anger. I'd settle for mild annoyance at this point....
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Re: Valvetrain noise, with vid.
[Re: dart9ss]
#2543621
08/30/18 11:03 PM
08/30/18 11:03 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Most guys will think they have a lifter noise when its a small exhaust leak.. believe me it can happen to all of us.. happened to me and I worked in the exhaust lab at Chrysler for 35 year and building headers.. it doesnt take much for a leak.. also make sure your shafts are on the right way.. there is a UP and front on them
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Re: Valvetrain noise, with vid.
[Re: jung]
#2543937
08/31/18 06:13 PM
08/31/18 06:13 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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There is a notch at one end of each shaft.. that notch has a direction that it should be pointed.. and the holes are pointed down
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Re: Valvetrain noise, with vid.
[Re: jung]
#2543960
08/31/18 07:11 PM
08/31/18 07:11 PM
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Joined: Jan 2003
Posts: 14,539 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,539
So. Burlington, Vt.
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The HS shafts are symmetrical. There is no up or down, or front or back.
When you put it back together, start it up and let it idle for a couple minutes.
If you see a trail of oil running along the head out by the valve cover rail toward the back of the motor, and starting to fill in the area in that rear corner....... and then start to crest(or almost crest) the valve cover rail....... then the oil flow is fine imo. When there isn’t enough up top, the first thing that happens is the pushrods/adjusters run dry and burn up. Oil typically doesn’t come spraying out of those rockers when you have the factory “through the cam” oiling.
As I mentioned earlier, the only oil hole is at the underside by the adjuster screw.
With any other rocker I can think of, you’d have more oil flying around since they would have another set of holes either on top of the rocker, or feeding the roller.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Valvetrain noise, with vid.
[Re: jung]
#2544272
09/01/18 02:23 PM
09/01/18 02:23 PM
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Joined: Aug 2003
Posts: 43,744 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,744
Bend,OR USA
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Harland Sharp recommends and wants .015 minimum side play at room temps, use a feeler gauge that is accurate to measure yours I use from 1/8 to a max of 1/2 turn preload on any Mopar hydraulic lifters at room temps A lot of folks on here forget that the adjuster is on the lifter side of the rocker arm and the ratio of the rocker arms changes how much preload the valve sees Most adjustable rocker arms use a 3/8x24 thread per inch adjuster screw, which equals .04166 per revolution for that size adjuster screw. The larger 7/16x20 adjuster screw equals .050 per thread revolution If you do the math on either one 1/4 turn equals either .0105 on the 3/8 size adjuster screw and .0125 on the 7/16 adjuster. Most of the instructions I've read about hydraulic lifter preload says to use from .030 to .000 preload on the Hi Po high rev hydraulics lifter
Last edited by Cab_Burge; 09/01/18 02:24 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Valvetrain noise, with vid.
[Re: jung]
#2544440
09/01/18 11:06 PM
09/01/18 11:06 PM
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Joined: Jan 2003
Posts: 14,539 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,539
So. Burlington, Vt.
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As long as there is at least “some” side to side free play between the rocker pairs when the motor is at operating temp you’ll be fine.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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