HarleyTechTalk

Technical Forums => Twin Cam => Topic started by: misfitJason on February 04, 2019, 06:10:31 PM

Title: Is this witness marks from contact?
Post by: misfitJason on February 04, 2019, 06:10:31 PM
I removed my upper rocker box to check on something and saw these marks by the valve springs. Are they witness marks or just casting imperfections? Both front and rear boxes have them one the exhausts. There are no marks on the rocker and I would think that the valve springs don't get that high up. Thanks
Title: Re: Is this witness marks from contact?
Post by: Ohio HD on February 04, 2019, 06:13:48 PM
Can't really tell. But what I do is use clay (clean all of the oil off) bolt the cover on, roll the motor over, take the cover off and look.
Title: Re: Is this witness marks from contact?
Post by: koko3052 on February 04, 2019, 08:19:25 PM
Another way of doing it is put your top cover on but leave the fasteners backed off a full turn, fire it up & put your hand on the cover......you'll feel if it's touching.
Title: Re: Is this witness marks from contact?
Post by: prodrag1320 on February 05, 2019, 04:26:37 AM
I cant even see what your talking about,circle it on the pic
Title: Re: Is this witness marks from contact?
Post by: Norton Commando on February 05, 2019, 04:50:56 AM
Looks like casting marks to me.

Jason
Title: Re: Is this witness marks from contact?
Post by: Hillside Motorcycle on February 05, 2019, 06:38:40 AM
No marks evident from here either.
Title: Re: Is this witness marks from contact?
Post by: misfitJason on February 05, 2019, 06:44:10 AM
Here it is zoomed in. It's still blurry but it's the best I can do without taking her all back apart
Title: Re: Is this witness marks from contact?
Post by: PoorUB on February 05, 2019, 07:19:10 AM
Can you circle or point to what you are concerned about?  I don't see it either!
Title: Re: Is this witness marks from contact?
Post by: wolf_59 on February 05, 2019, 07:23:34 AM
while you have it down that far go ahead and remove the rocker assemblies and check the clearance with feeler gauge.
I ran into this the last time I freshened up the topend on my 06 ultra checking for anything that might stop the noise, it was pretty tight so I ended up clearancing the rocker box for peace of mind, installed rockouts and drilled out the upper pushrod tubes, installed new lifters
Title: Re: Is this witness marks from contact?
Post by: misfitJason on February 05, 2019, 09:11:41 AM
Wolf it's  not tore down at the moment.
Title: Re: Is this witness marks from contact?
Post by: PoorUB on February 05, 2019, 09:32:16 AM
Nothing there from normal operation. Your valves and springs are not getting over there!
Title: Re: Is this witness marks from contact?
Post by: Armin on February 05, 2019, 09:44:05 AM
Is the valve on the photo in the fully open position then consider the valve lift to determine if the spring collar might touch the rocker box, if the valve is closed just use a feeler gauge to ascertain that you have good clearance.

Armin.
Title: Re: Is this witness marks from contact?
Post by: jsachs1 on February 05, 2019, 02:15:37 PM
Never seen an exhaust retainer get close to the rocker box area you're concerned about. The intake on the other hand sometimes gets extremely close with aftermarket dual springs.  :wink:
John
Title: Re: Is this witness marks from contact?
Post by: misfitJason on February 05, 2019, 03:48:03 PM
The valve was fully open in the phot. I finally got my photos to load so here is a much better pic
Title: Re: Is this witness marks from contact?
Post by: Ajayrk on February 05, 2019, 03:56:13 PM
I see it now.  Let the valve close and check the clearance.  You may only need to slightly move the lower box for clearance.
Title: Re: Is this witness marks from contact?
Post by: misfitJason on February 05, 2019, 05:01:45 PM
 :oops:sorry I meant closed