HarleyTechTalk

Technical Forums => Twin Cam => Topic started by: Chippitt68 on May 27, 2019, 08:44:16 AM

Title: 2000-2500 rpm
Post by: Chippitt68 on May 27, 2019, 08:44:16 AM
Why does the most valvetrain noise happen in this rpm range? What is the inherent issue in twin cams that makes them noisy at these rpm. Why are some noisy and some not?
Title: Re: 2000-2500 rpm
Post by: Deye76 on May 27, 2019, 08:48:56 AM
On my 2014 RK, at that very rpm range mine sounds like valve train, but it's only in 3rd gear, the other gears in that range it's quiet. So I think its from the trans.
Title: Re: 2000-2500 rpm
Post by: smoserx1 on May 27, 2019, 10:46:11 AM
I have heard some people believe it is just harmonics and resonance.  Mine has sounded like a jackhammer in that range from day 1.
Title: Re: 2000-2500 rpm
Post by: tomboyjr on May 27, 2019, 01:52:00 PM
Or its because over 2500, most of our exhausts get louder and we just can't hear the drivetrain-lol
Title: Re: 2000-2500 rpm
Post by: kd on May 27, 2019, 03:48:37 PM
Rocker shaft clicking on the mounting fasteners is responsible for most of them.  Check with this vendor after reading some of the posts.  Search the site for more info using the name.

https://harleytechtalk.com/htt/index.php?board=96.0
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on May 27, 2019, 04:58:42 PM
I have them installed. Once you install them, you cannot pull the plate towards pushrods to provide clearance to the tubes. 😖. Same question, why don't the bolts move above or below the rpm mentioned?
Title: Re: 2000-2500 rpm
Post by: kd on May 27, 2019, 05:58:15 PM
Quote from: Chippitt68 on May 27, 2019, 04:58:42 PM
I have them installed. Once you install them, you cannot pull the plate towards pushrods to provide clearance to the tubes. 😖. Same question, why don't the bolts move above or below the rpm mentioned?


I agree.  It may be more important with High lift cams than OEM range cams.  Some of the members here (myself included) chose to "pin" the shafts to the rocker stands back when the discussion first started on here a few years ago.  I used double locked grub screws.  At about that time a member here was experimenting using 30 cal bullet casings with good success and began manufacturing them for sale.  They may not be for everyone but all reports are they work for most.  The other options are to pin them which means a level of skill is required or a machinist expense, or get used to it. 
Title: Re: 2000-2500 rpm
Post by: klammer76 on May 28, 2019, 03:15:39 AM
Quote from: kd on May 27, 2019, 05:58:15 PM
Quote from: Chippitt68 on May 27, 2019, 04:58:42 PM
I have them installed. Once you install them, you cannot pull the plate towards pushrods to provide clearance to the tubes. 😖. Same question, why don't the bolts move above or below the rpm mentioned?


I agree.  It may be more important with High lift cams than OEM range cams.  Some of the members here (myself included) chose to "pin" the shafts to the rocker stands back when the discussion first started on here a few years ago.  I used double locked grub screws.  At about that time a member here was experimenting using 30 cal bullet casings with good success and began manufacturing them for sale.  They may not be for everyone but all reports are they work for most.  The other options are to pin them which means a level of skill is required or a machinist expense, or get used to it.
I installed a set of Rockout Rocker Lockers this spring. I was in there so decided to try them. My bike has never been this quiet. Always had the annoying tap/click/tick through different sets of lifters etc over 18 years. I will add that I also installed new rocker arms & shafts also due to were on original oem rocker arms but I do think the Rockouts work well for me also.
Title: Re: 2000-2500 rpm
Post by: Rockout Rocker Products on May 28, 2019, 08:42:16 AM
Quote from: klammer76 on May 28, 2019, 03:15:39 AM

I installed a set of Rockout Rocker Lockers this spring. I was in there so decided to try them. My bike has never been this quiet. Always had the annoying tap/click/tick through different sets of lifters etc over 18 years. I will add that I also installed new rocker arms & shafts also due to were on original oem rocker arms but I do think the Rockouts work well for me also.

:beer: :beer:
Title: Re: 2000-2500 rpm
Post by: chaos901 on May 28, 2019, 02:32:42 PM
I've installed the "other brand" (shall remain nameless) on a couple of my bikes with good results.  FWIW, I picked them because they are made close by in MS and I did not know about the Rockouts. 
Title: Re: 2000-2500 rpm
Post by: Moparnut72 on May 28, 2019, 06:12:52 PM
After owning my Slim for a year I was ready to trade it for Triumph or a Moto Guzzi. I was getting to hate all the clicking and clacking coming from the engine. When hot it was so loud it was embarrassing to pull into a parking lot with people around. So before I did that I thought I would try to do something to get rid of the noise. I put Rockouts in it first. It was better but still wasn't good. I had read that the stock lifters weren't very good but his is the part I still don't understand. It is said everywhere to let the lifters bleed down before you go to the other cylinder. My stock lifters wouldn't bleed down. I took them apart to release the pressure and put them back in. No better. I took them back out and all of them seemed to be "hydro" locked. No matter what I did they wouldn't bleed down. I even put them in a vise and put pressure on them. They didn't budge. I don't get it but anyway I installed Johnson HyLift lifters. I can't believe how quiet the top end is now. Also I used the stock push rods. I know more work but to me worth it.

The bike is pretty quiet now, the main mechanical noises come from the lower end. Probably mostly from all the chains the B engines have. I have done a few other things to make my bike what it should have been from day one. I am happy with it now. I would put Rockouts and lifters in yours to get rid of the racket. My 2 cents.
kk
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on May 28, 2019, 06:41:42 PM
I have the rock outs installed and the same lifters you are running. Have had the bores measured and they are about .002 larger than the lifters. Pretty much the same as most I'm told. It runs really well, 96 hp and 115 tq. No clatter on start up. It's been noisy since the 48's went in when it was a 96". I don't think it's hurting anything. just returned from a 1000 mile ride and it didn't blow up and I don't believe it will. It just bugs the shite outta me.
Title: Re: 2000-2500 rpm
Post by: BVHOG on May 28, 2019, 07:49:45 PM
I think when you answer this question with complete certainty there will be a nobel prize awaiting you. 
Title: Re: 2000-2500 rpm
Post by: Hossamania on May 28, 2019, 07:51:28 PM
Try running gear drives with 100,000 miles on a thoroughly thrashed motor. Your motors are quiet as church mice compared to mine. And I'm ok with that. I just own it as I pull into a group standing around. They forget about the noise when they see the 2" wide puddle from a drip that gathers under it after 10 minutes.
"It's not a leak, it's a drip."
Title: Re: 2000-2500 rpm
Post by: Scotty on May 28, 2019, 07:53:53 PM
I have put in a few sets of rocker lockers and/or rockouts depending on what people bought and S&S premium lifters and left them with stock pushrods and they are all quiet now and everyone is happy.
Title: Re: 2000-2500 rpm
Post by: Teardrop on May 28, 2019, 08:06:46 PM
I have the RockOuts, S&S Premium lifters and adjustable lifters and although it is better the tick isn't totally gone either. I have just learned to live with it.
Title: Re: 2000-2500 rpm
Post by: Rockout Rocker Products on May 28, 2019, 09:29:01 PM
To all with some lingering top end noise... Spectro 25-60 NON SYNTHETIC oil.
You'll thank me.
Really.
Title: Re: 2000-2500 rpm
Post by: Armin on May 29, 2019, 02:28:11 AM
Quote from: Moparnut72 on May 28, 2019, 06:12:52 PM

..... I don't get it but anyway I installed Johnson HyLift lifters. I can't believe how quiet the top end is now. Also I used the stock push rods. I know more work but to me worth it.

The bike is pretty quiet now, the main mechanical noises come from the lower end. Probably mostly from all the chains the B engines have. I have done a few other things to make my bike what it should have been from day one. I am happy with it now. I would put Rockouts and lifters in yours to get rid of the racket. My 2 cents.
kk

Hi, how much preload did you use with the Hylift lifters?

Thanks, Armin.
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on May 29, 2019, 02:49:19 AM
.140. I asked Larry and that was his recommendation
Title: Re: 2000-2500 rpm
Post by: Hossamania on May 29, 2019, 04:37:52 AM
Quote from: Rockout Rocker Products on May 28, 2019, 09:29:01 PM
To all with some lingering top end noise... Spectro 25-60 NON SYNTHETIC oil.
You'll thank me.
Really.

I should try it, but I tend to not change oil overly often, and ride in winter when temps get down to 20° or so, I don't think my starter would care for it.
Title: Re: 2000-2500 rpm
Post by: Rockout Rocker Products on May 29, 2019, 05:43:35 AM
Quote from: Hossamania on May 29, 2019, 04:37:52 AM
Quote from: Rockout Rocker Products on May 28, 2019, 09:29:01 PM
To all with some lingering top end noise... Spectro 25-60 NON SYNTHETIC oil.
You'll thank me.
Really.

I should try it, but I tend to not change oil overly often, and ride in winter when temps get down to 20° or so, I don't think my starter would care for it.

I'm guessing you're running 20-50 now? That extra 5 gonna kill ya?  :wink:
Title: Re: 2000-2500 rpm
Post by: shindig on May 29, 2019, 06:15:41 AM
Quote from: Chippitt68 on May 27, 2019, 08:44:16 AM
Why does the most valvetrain noise happen in this rpm range? What is the inherent issue in twin cams that makes them noisy at these rpm. Why are some noisy and some not?

You are lugging the motor at those rpms....  You should cruise close to 3k rpm.
Title: Re: 2000-2500 rpm
Post by: chaos901 on May 29, 2019, 06:22:30 AM
QuoteYou are lugging the motor at those rpms....  You should cruise close to 3k rpm.


I did not read it that he was cruising at this RPM, if that is the case then I agree with the above response.  Plus my gas mileage really sucks at 2000 rpm.
Title: Re: 2000-2500 rpm
Post by: harpwrench on May 29, 2019, 08:51:19 AM
Quote from: Chippitt68 on May 29, 2019, 02:49:19 AM
.140. I asked Larry and that was his recommendation
Mine is noisy when set that deep. .090" is the sweet spot on mine, you might try it  :beer:
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on May 29, 2019, 09:01:31 AM
Quote from: shindig on May 29, 2019, 06:15:41 AM
Quote from: Chippitt68 on May 27, 2019, 08:44:16 AM
Why does the most valvetrain noise happen in this rpm range? What is the inherent issue in twin cams that makes them noisy at these rpm. Why are some noisy and some not?

You are lugging the motor at those rpms....  You should cruise close to 3k rpm.
I don't cruise in that range. I do however occasionally run through that range on my way to 3000rpm.
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on May 29, 2019, 09:06:30 AM
Quote from: harpwrench on May 29, 2019, 08:51:19 AM
Quote from: Chippitt68 on May 29, 2019, 02:49:19 AM
.140. I asked Larry and that was his recommendation
Mine is noisy when set that deep. .090" is the sweet spot on mine, you might try it  :beer:
I'll give it a try. Thanks.
Title: Re: 2000-2500 rpm
Post by: Hossamania on May 29, 2019, 10:20:11 AM
Quote from: Rockout Rocker Products on May 29, 2019, 05:43:35 AM
Quote from: Hossamania on May 29, 2019, 04:37:52 AM
Quote from: Rockout Rocker Products on May 28, 2019, 09:29:01 PM
To all with some lingering top end noise... Spectro 25-60 NON SYNTHETIC oil.
You'll thank me.
Really.

I should try it, but I tend to not change oil overly often, and ride in winter when temps get down to 20° or so, I don't think my starter would care for it.

I'm guessing you're running 20-50 now? That extra 5 gonna kill ya?  :wink:

I'm thinking more the difference in flow rates at that temp between dino and syn. That dino gets thick and syrupy, the syn at least pours out of the container.
Title: Re: 2000-2500 rpm
Post by: shindig on May 31, 2019, 05:55:02 AM
Quote from: Chippitt68 on May 29, 2019, 09:01:31 AM
Quote from: shindig on May 29, 2019, 06:15:41 AM
Quote from: Chippitt68 on May 27, 2019, 08:44:16 AM
Why does the most valvetrain noise happen in this rpm range? What is the inherent issue in twin cams that makes them noisy at these rpm. Why are some noisy and some not?

You are lugging the motor at those rpms....  You should cruise close to 3k rpm.
I don't cruise in that range. I do however occasionally run through that range on my way to 3000rpm.

Sure.....in 1st gear only.....after that you shouldn't go below around 3k...
Title: Re: 2000-2500 rpm
Post by: rigidthumper on May 31, 2019, 06:34:35 AM
Quote from: shindig on May 31, 2019, 05:55:02 AM
Quote from: Chippitt68 on May 29, 2019, 09:01:31 AM
Quote from: shindig on May 29, 2019, 06:15:41 AM
Quote from: Chippitt68 on May 27, 2019, 08:44:16 AM
Why does the most valvetrain noise happen in this rpm range? What is the inherent issue in twin cams that makes them noisy at these rpm. Why are some noisy and some not?

You are lugging the motor at those rpms....  You should cruise close to 3k rpm.
I don't cruise in that range. I do however occasionally run through that range on my way to 3000rpm.

Sure.....in 1st gear only.....after that you shouldn't go below around 3k...
Do you collect speeding tickets?
3000 RPM on my 2010 in first gear was 25 MPH and the local PD frown upon that in a 5 MPH school zone  :hyst:


Seriously, if they make a product that is supposed to operate from 1 to 10, and then say " Only use from 3-7", that sounds like a sales tactic to avoid warranty issues, or a design flaw.
Title: Re: 2000-2500 rpm
Post by: PoorUB on May 31, 2019, 10:20:19 AM
Quote from: shindig on May 31, 2019, 05:55:02 AM
Quote from: Chippitt68 on May 29, 2019, 09:01:31 AM
Quote from: shindig on May 29, 2019, 06:15:41 AM
Quote from: Chippitt68 on May 27, 2019, 08:44:16 AM
Why does the most valvetrain noise happen in this rpm range? What is the inherent issue in twin cams that makes them noisy at these rpm. Why are some noisy and some not?

You are lugging the motor at those rpms....  You should cruise close to 3k rpm.
I don't cruise in that range. I do however occasionally run through that range on my way to 3000rpm.

Sure.....in 1st gear only.....after that you shouldn't go below around 3k...

So you ride in first gear in town?

Nothing wrong with riding in 3rd gear at 2,000 RPM if just riding easy. On the highway keep it above 2,500 RPM.
Title: Re: 2000-2500 rpm
Post by: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.
Title: Re: 2000-2500 rpm
Post by: szunker on June 09, 2019, 07:43:42 PM
Quote from: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.

Mine does the same thing , I think its the pushrods hitting the top of the pushrod tube.
Im thinking about trying the .030 offset rocker arm support to move the rocker arm over to center of the pushrod tube.  See: http://protwin.com/highperformancebilletrockerarmsupports.aspx
Title: Re: 2000-2500 rpm
Post by: szunker on June 09, 2019, 07:46:42 PM
Quote from: szunker on June 09, 2019, 07:43:42 PM
Quote from: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.

Mine does the same thing , I think its the pushrods hitting the top of the pushrod tube.
Im thinking about trying the .030 offset rocker arm support to move the rocker arm over to center of the pushrod tube.  See: http://protwin.com/highperformancebilletrockerarmsupports.aspx

or this one also: https://www.woodcarbs.com/rocker.htm
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on June 10, 2019, 02:50:58 AM
It's definately possible. I've checked mine and I don't see signs of contact. I'm not sure how much contact would need to be present to cause a rattle? I have a set of tubes that have been clearanced and when I get them in, I'll let you know if it helps. I'm beginning to think it's a combo of things. Lifter bore clearance, oil aeration and and rocker arm bushings.
Title: Re: 2000-2500 rpm
Post by: Kllongbrake on June 10, 2019, 04:45:41 AM
Quote from: szunker on June 09, 2019, 07:46:42 PM
Quote from: szunker on June 09, 2019, 07:43:42 PM
Quote from: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.

Mine does the same thing , I think its the pushrods hitting the top of the pushrod tube.
Im thinking about trying the .030 offset rocker arm support to move the rocker arm over to center of the pushrod tube.  See: http://protwin.com/highperformancebilletrockerarmsupports.aspx

or this one also: https://www.woodcarbs.com/rocker.htm
What's the plan to clearance the rocker shafts for the .030 offset? Does your lift or valve stem protrusion warrant the investment? I'm going to try some known good used (S&S premium)lifters this evening. See if maybe one has a problem. Everything else seems to be okay. Tubes are bored to 5/8" top to bottom. Originally I'd only went half way. There appeared to still be some contact so finished them off. Still rattles though. Sounds more solid then a pushrod tube anyway. I'd swear something was rattling on the pipe heat shield....but it's not. Gets worse at full temp too.
Title: Re: 2000-2500 rpm
Post by: kd on June 10, 2019, 05:10:14 AM
Quote from: Kllongbrake on June 10, 2019, 04:45:41 AM
Quote from: szunker on June 09, 2019, 07:46:42 PM
Quote from: szunker on June 09, 2019, 07:43:42 PM
Quote from: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.

Mine does the same thing , I think its the pushrods hitting the top of the pushrod tube.
Im thinking about trying the .030 offset rocker arm support to move the rocker arm over to center of the pushrod tube.  See: http://protwin.com/highperformancebilletrockerarmsupports.aspx

or this one also: https://www.woodcarbs.com/rocker.htm
What's the plan to clearance the rocker shafts for the .030 offset? Does your lift or valve stem protrusion warrant the investment? I'm going to try some known good used (S&S premium)lifters this evening. See if maybe one has a problem. Everything else seems to be okay. Tubes are bored to 5/8" top to bottom. Originally I'd only went half way. There appeared to still be some contact so finished them off. Still rattles though. Sounds more solid then a pushrod tube anyway. I'd swear something was rattling on the pipe heat shield....but it's not. Gets worse at full temp too.


You haven't said what lift or rockers you are using.  When you take the rocker covers off check "real close" for contact signs on the rocker tip or in the cover.  If it's just a click and not a heavy CLACK it may not leave a mark.  If it's OK cold and gets worse as it heats up especially.  Before you pull the rocker stands and pushrods clay the rocker tips and reassemble to check.  The covers or boxes may only need a little clearanceing. 
Title: Re: 2000-2500 rpm
Post by: Kllongbrake on June 10, 2019, 02:47:40 PM
Quote from: kd on June 10, 2019, 05:10:14 AM
Quote from: Kllongbrake on June 10, 2019, 04:45:41 AM
Quote from: szunker on June 09, 2019, 07:46:42 PM
Quote from: szunker on June 09, 2019, 07:43:42 PM
Quote from: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.

Mine does the same thing , I think its the pushrods hitting the top of the pushrod tube.
Im thinking about trying the .030 offset rocker arm support to move the rocker arm over to center of the pushrod tube.  See: http://protwin.com/highperformancebilletrockerarmsupports.aspx

or this one also: https://www.woodcarbs.com/rocker.htm
What's the plan to clearance the rocker shafts for the .030 offset? Does your lift or valve stem protrusion warrant the investment? I'm going to try some known good used (S&S premium)lifters this evening. See if maybe one has a problem. Everything else seems to be okay. Tubes are bored to 5/8" top to bottom. Originally I'd only went half way. There appeared to still be some contact so finished them off. Still rattles though. Sounds more solid then a pushrod tube anyway. I'd swear something was rattling on the pipe heat shield....but it's not. Gets worse at full temp too.


You haven't said what lift or rockers you are using.  When you take the rocker covers off check "real close" for contact signs on the rocker tip or in the cover.  If it's just a click and not a heavy CLACK it may not leave a mark.  If it's OK cold and gets worse as it heats up especially.  Before you pull the rocker stands and pushrods clay the rocker tips and reassemble to check.  The covers or boxes may only need a little clearanceing.
Standard HD rocker arms and 590 lift. I'm pretty certain they're not hitting the box. Would think they would have from the start. It's a definite rattle starting around2300 not a click or tick.
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on June 10, 2019, 04:04:19 PM
Quote from: kd on June 10, 2019, 05:10:14 AM
Quote from: Kllongbrake on June 10, 2019, 04:45:41 AM
Quote from: szunker on June 09, 2019, 07:46:42 PM
Quote from: szunker on June 09, 2019, 07:43:42 PM
Quote from: Kllongbrake on June 09, 2019, 07:02:02 AM
But what is the rattle actually coming from in that 2300-2800rpm range? Is it a  lifter rattling? My 124 starting rattling in this range after about 250 miles. Rockouts, S&S premium, SE Tapered PR's. I can't figure it.

Mine does the same thing , I think its the pushrods hitting the top of the pushrod tube.
Im thinking about trying the .030 offset rocker arm support to move the rocker arm over to center of the pushrod tube.  See: http://protwin.com/highperformancebilletrockerarmsupports.aspx

or this one also: https://www.woodcarbs.com/rocker.htm
What's the plan to clearance the rocker shafts for the .030 offset? Does your lift or valve stem protrusion warrant the investment? I'm going to try some known good used (S&S premium)lifters this evening. See if maybe one has a problem. Everything else seems to be okay. Tubes are bored to 5/8" top to bottom. Originally I'd only went half way. There appeared to still be some contact so finished them off. Still rattles though. Sounds more solid then a pushrod tube anyway. I'd swear something was rattling on the pipe heat shield....but it's not. Gets worse at full temp too.


You haven't said what lift or rockers you are using.  When you take the rocker covers off check "real close" for contact signs on the rocker tip or in the cover.  If it's just a click and not a heavy CLACK it may not leave a mark.  If it's OK cold and gets worse as it heats up especially.  Before you pull the rocker stands and pushrods clay the rocker tips and reassemble to check.  The covers or boxes may only need a little clearanceing.
Kd, if the rockers were making contact, wouldn't they be making contact all the time? Even if the motor has to get hot for the contact to occur, once it reaches that temp, why only in that rpm range?
Title: Re: 2000-2500 rpm
Post by: kd on June 10, 2019, 08:54:46 PM
I had a rocker cover that would warp when it heated up. The contact was not hard enough to leave a mark but after removing it a couple of times it became obvious there was a blackish smudge mark above the intake rocker.  A little touch up with a dremel on that spot (a frustration guess) fixed it.  The cover eventually began to seep at the gasket and the new one didn't make any noise so I figure it was the heat warping the top surface.
Title: Re: 2000-2500 rpm
Post by: Chippitt68 on June 11, 2019, 02:29:14 AM
Thanks
Title: Re: 2000-2500 rpm
Post by: Kllongbrake on June 11, 2019, 03:54:29 PM
I'm back in there tonight and still getting witness marks top and bottom on the pushrods even though they're bored to 5/8". Maybe that's the rattle?  :nix:
Title: Re: 2000-2500 rpm
Post by: Kllongbrake on June 12, 2019, 04:50:24 AM
Quote from: kd on June 10, 2019, 08:54:46 PM
I had a rocker cover that would warp when it heated up. The contact was not hard enough to leave a mark but after removing it a couple of times it became obvious there was a blackish smudge mark above the intake rocker.  A little touch up with a dremel on that spot (a frustration guess) fixed it.  The cover eventually began to seep at the gasket and the new one didn't make any noise so I figure it was the heat warping the top surface.
KD, when you were looking for what you found to be rocker top box contact with the arms was it a rattle that started around low 2000's and either went away in the upper range or couldn't hear it due to exhaust? Difficult to replicate on the lift table? It sounds much louder while riding then if I just rev while on the table. Maybe due to the speed at which an unloaded engine passes that range? When I stethoscope (one with a long aluminum rod) I really can't hear it when I touch the engine in various places. I can hear the valve springs as  faint tick ,much louder without the scope. They're high seat pressure. This is getting very frustrating. I'll pull the front rocker box top again tonight and clay the arms and clearance if needed.

Thanks to all for your advice. Sorry chippitt if I butted too far into your thread. It seems to be the same you're dealing with though.