Excessive rocker box noise after top end rebuild

Snapping lifter adj bolts for pushrods

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PanHunter
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Excessive rocker box noise after top end rebuild

#1

Post by PanHunter » Sun Nov 04, 2018 4:14 am

Hey everyone, just wanted to see if anyone had an idea what I can do to solve this problem. Just did a top end freshen up on my 49’ pan w 56 heads. Left the old Pistons, put new rings new valve seats and guides new tappet block gasket head gasket and rocker gaskets and re honed the barrels. When pulled apart I noticed both the intake valve oilers were in the front head so I relocated one back to the rear Intake as it should be. Did a lifter inspection as well and they seem smooth and even. Put it all back together and now I’ve got a loud tick from the rocker boxes. I had a previous problem of the valve spring cups hitting the rocker boxes so figured that was happening again but just disassembled and have no running whatsoever. The other problem I had today is it snapped one of the push rod adjustments bolts on the front exhaust lifter. I did the push rod adjustment to spec. Let it sit and then checked it again. Any help on this would be great. Trying to have a decently quiet running engine. Thank you.



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Re: Excessive rocker box noise after top end rebuild

#2

Post by RooDog » Sun Nov 04, 2018 1:45 pm

A 1949 Panhead originally had adjustable lifters with hydraulic pushrods, the hydraulic units were at the top of the PRs, and the adjustment procedure was totally different from the later engines with hydraulic lifters. Your engines cases will not support hydraulic lifters. So, what exactly do you have? RooDog

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Re: Excessive rocker box noise after top end rebuild

#3

Post by Andygears » Sun Nov 04, 2018 2:08 pm

Since you snapped a lifter adjuster, you must have solid lifters with adjuster in the lifter, correct? So, new seats and guides will change the non-adjustable pushrods fit in the pushrod covers. And many times the valve noise is the large diameter aftermarket pushrods hitting the pushrod covers. Examine the pushrods for evidence of this. I like the solid lifters with adjuster but they move the pivot point of misalignment up above the lifter block and can cause the interference. And the adjustment should be done COLD, very cold, like not having run that day at all, to where they can just spin. One more "flat" (1/6 of a turn) should tighten the pushrod so they bind from turning.

My two cents
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Re: Excessive rocker box noise after top end rebuild

#4

Post by PanHunter » Tue Nov 06, 2018 4:45 am

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Just wanted to attach a few pics of what I am working with. I checked the pushrod tubes for evidence of rubbing and didn't see any marks. Seemed to me like most the noise was coming from the top of the rocker box so I thought possibly a roller on a lifter was going bad so I pulled them out to inspect and everything seems to be In decent shape. Also inspected the cam for wear.

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Re: Excessive rocker box noise after top end rebuild

#5

Post by RooDog » Tue Nov 06, 2018 5:38 am

Lifter rollers are kinda bitch to change but if you feel ANY up & play it is too much and the roller should be replaced.

Also on my 1950 Panny Project, just a few months ago, I discovered that the splined pinion gear was loose on the pinion shaft by about .003-.006" backlash. The way a camshaft imposes alternating pressure and release pulses on that driving gear the whole engine sounded like a beer can with .022 Cal brass rattling around inside. I discovered that Harley offered a "close fitting" pinion gear in 1951 or '53 and I luckily found one, installed it with a little hammer persuasion, and all my unwanted noises went away. That gear has no identifying marking. I said all that to say what? Check your cam case gear train for slop and backlash on all the gears especially the pinion to cam interface..... RooDog

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Re: Excessive rocker box noise after top end rebuild

#6

Post by RooDog » Tue Nov 06, 2018 5:41 am

BTW: Those are the correct style solid lifters for your '49 engine, Do your push rods have hydraulic units up top? RD

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Re: Excessive rocker box noise after top end rebuild

#7

Post by PanHunter » Tue Nov 06, 2018 6:07 am

RooDog wrote:
Tue Nov 06, 2018 5:38 am
Lifter rollers are kinda bitch to change but if you feel ANY up & play it is too much and the roller should be replaced.

Also on my 1950 Panny Project, just a few months ago, I discovered that the splined pinion gear was loose on the pinion shaft by about .003-.006" backlash. The way a camshaft imposes alternating pressure and release pulses on that driving gear the whole engine sounded like a beer can with .022 Cal brass rattling around inside. I discovered that Harley offered a "close fitting" pinion gear in 1951 or '53 and I luckily found one, installed it with a little hammer persuasion, and all my unwanted noises went away. That gear has no identifying marking. I said all that to say what? Check your cam case gear train for slop and backlash on all the gears especially the pinion to cam interface..... RooDog
Awesome, thank you for the advice I will crack into checking that on Thursday when I get some time again! My pushrod tubes are solid, weird thing is someone put one slightly longer pushrod In it at some point. Has worked fine though for the last 6000 miles I put on her this summer. Also is there any way of telling what cam is installed? Checked for markings but didn't see anything.

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Re: Excessive rocker box noise after top end rebuild

#8

Post by Bosheff » Tue Nov 06, 2018 12:12 pm

The front cylinder, exhaust pushrod is in fact longer by design....bosheff

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Re: Excessive rocker box noise after top end rebuild

#9

Post by RooDog » Tue Nov 06, 2018 3:53 pm

Most aftermarket cams are marked with maker's info on the end of the shaft and not on the gear as they are generally removable. You could measure the lobe lift and search the makers' catalogs to try and match up that figure, or multiply X 1.5 for the valve lift. A degree wheel can help getting the timing events and duration figures too..... Really simple, eh? RooDog
BTW: I made the mistake of buying a set of V-Twin's rockers trying to chase down my noises. They did not fit well and I sold them at a loss on eBay, but now I know that rocker end play is not as bad a thing as I imagined it to be. Taiwan Tedd's V-Twin has some good stuff but not their Panhead rockers, don't go there.....

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Re: Excessive rocker box noise after top end rebuild

#10

Post by PanHunter » Fri Nov 09, 2018 7:53 am

Just posting an update here, so I found the problem. I took my heads to a very reputable shop when I got them re done. Turns out the guy left the valve guides way too long and when the valves would open it was hitting the top washer on my valve springs right down on top of it. It was hitting so hard it managed to crack my rocker arm. Pretty disappointed. I cut them down to give proper clearance and put a new rocker arm now time to re assemble.

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Re: Excessive rocker box noise after top end rebuild

#11

Post by Larry » Fri Nov 09, 2018 2:19 pm

New seats? Hot rod cam?

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Re: Excessive rocker box noise after top end rebuild

#12

Post by RooDog » Fri Nov 09, 2018 3:23 pm

I have been screwed by just enough "reputable" service providers that I don't trust most of them. I try not to have them do any work unless I can not do it my self, like boring cylinders, But I minimize what they are allowed to do for me. I always check what they have done, and do my own assembly work so what happened to you does not happen again. Last time I cammed a Panny I went through all the procedures assuring I had enough clearances for my spec'd valve lift + a little more in case I want a bigger cam at a later date. As Ronald Reagan said: Trust but verify. This is a very important concept to live by especially when dealing with our old Harleys.....
RooDog

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