Witness marks on valve stem is not clean... Thoughts ? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-19-2014, 09:19 PM
awsomeears's Avatar
Registered User
 
Last photo:
Join Date: Mar 2014
Location: Wisconsin
Posts: 72
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Witness marks on valve stem is not clean... Thoughts ?

Ive done this before on my old set of heads and it turned out perfect, but this go around its not as clean straight line.

All NEW Parts List I'm working with :

Profiler 176 series SBC
Scorpion 1.5 roller rockers
5/16 8.150 length smith brothers push rods
Solid Flat tappet
Cam 570/.590 http://www.summitracing.com/parts/cca-12-517-5

Last week I used the adjustable push-rod checker and came up with 8.150 and had a really nice witness mark and placed my order, that was on a set of Crane 1.5 Golds.

Now I ordered a new set of pushrods and decided to buy a New set of Scorpion 1.5 as I just wanted New everything.

Could the geomotry from my crane golds and scorpions even tho they are stated 1.5 be different ?


My process was exhaust open - Adjust zero lash intake
Intake almost closed - Adjust Exhaust zero lash



This picture shows both intake and exhaust, I did a total of 10 revolutions and I would think it would be enough ?




    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-20-2014, 05:57 AM
spinn's Avatar
Bubbles is the girl next door
 

Last journal entry: This makes a huge difference
Last photo:
Join Date: Oct 2004
Location: Midnight
Posts: 2,495
Wiki Edits: 0

Thanks: 13
Thanked 82 Times in 80 Posts
This looks like some invention of yours. How do you feel it turned out, cause I have no clue.

What I do is paint the roller with a sharpie and wipe it on the stem at base circle . If it lands in the middle but on the intake side you should be good.

Last edited by spinn; 08-20-2014 at 06:05 AM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-20-2014, 06:17 AM
TBARTA's Avatar
the five stroke engine
 

Last journal entry: Last Year Pics
Join Date: Dec 2010
Location: Lot 16, Prince Edward Island
Age: 47
Posts: 44
Wiki Edits: 0

Thanks: 7
Thanked 4 Times in 4 Posts
Yes there can be slight differences in rockers. This is why pushrods are one of, if not THE last things to get for your engine. Get out your adjustable pushrod length checker and set it so that the witness mark is as close to center as you can get it. This should also give you the narrowest mark. You will probably have to get new pushrods if staying with the scorpion rockers. Also the one on the left doesn't look to be tracking evenly. Could a slightly off valve tip or rocker stud not quite true. Hope this helped.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-20-2014, 07:06 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,064
Wiki Edits: 0

Thanks: 17
Thanked 325 Times in 305 Posts
Quote:
Originally Posted by TBARTA View Post
set it so that the witness mark is as close to center as you can get it. This should also give you the narrowest mark.
If the centered pattern gives the narrowest mark then he should buy a lottery ticket- while it is possible for that to happen (and it is supposed to) it almost is never the same length for the centered and the narrowest pattern. Go with the one that produces the narrowest pattern.

And yes your rocker arms are likely slightly different, I'm not sure why you bought the rockers after the p-rods.

Your wear pattern on the right doesn't look too terrible to be honest though, i've seen a lot worse. The one on the left does look odd that only half showed a witness mark but I'd clean the tip and try again before I'd rush to conclusions.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-20-2014, 07:47 AM
1971BB427's Avatar
Registered User
 

Last journal entry: Latest changes
Last photo:
Join Date: Dec 2010
Location: Portland
Posts: 1,659
Wiki Edits: 0

Thanks: 14
Thanked 272 Times in 237 Posts
The one on the left looks like the rocker was not sitting straight, or the end of the valve stem is not flat. I'd try it again making sure the rocker is situated correctly, and see what pattern it shows. Could be an issue with the guide plate pushing it to one side.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-20-2014, 09:21 AM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,805
Wiki Edits: 0

Thanks: 4
Thanked 443 Times in 380 Posts
Quote:
Originally Posted by awsomeears View Post
Ive done this before on my old set of heads and it turned out perfect, but this go around its not as clean straight line.

All NEW Parts List I'm working with :

Profiler 176 series SBC
Scorpion 1.5 roller rockers
5/16 8.150 length smith brothers push rods
Solid Flat tappet
Cam 570/.590 http://www.summitracing.com/parts/cca-12-517-5

Last week I used the adjustable push-rod checker and came up with 8.150 and had a really nice witness mark and placed my order, that was on a set of Crane 1.5 Golds.

Now I ordered a new set of pushrods and decided to buy a New set of Scorpion 1.5 as I just wanted New everything.

Could the geomotry from my crane golds and scorpions even tho they are stated 1.5 be different ?


My process was exhaust open - Adjust zero lash intake
Intake almost closed - Adjust Exhaust zero lash



This picture shows both intake and exhaust, I did a total of 10 revolutions and I would think it would be enough ?



Yes different rockers may require changes in the push rod length as different brands do have dimensional variations in the realtionship of lines drawn between the push rod cup, trunion, and the tip. The ratio only describes the distance between the trunion and the tip divided by the distance between the trunion and the push rod cup.

The partial contact pattern is typical of rockers with a roller trunion as they are not able to roll side to side as does a ball trunion. So if the stud and the valve are not in the same 3D alignment the contact patch on the stem will be off to one side or the other. A similar thing happens on the push rod side but we tend not to check this contact so it goes unknown and un-noticed. The valve train runs just fine inspite of these inaccuracies.

In operation the valves rotate slowly as a result of the spring wind causing a rotational motion as the spring is compressed and released. So even without the valve rotators that Chevy is so fond of this rotation occurs, so eventually the stem tip wear surface will spread across the entire tip.

Bogie
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-20-2014, 10:32 AM
engineczar's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Sep 2002
Location: In Flowbench nirvana
Age: 52
Posts: 1,650
Wiki Edits: 0

Thanks: 5
Thanked 47 Times in 43 Posts
One thing that jumps out to me is the pushrod length. 8.150 just seems pretty long to me for a SBC. Considering stock is 7.800 and even though those heads run a longer +.100 valves an extra .350 just doesn't add up. The cam you list isn't a small base circle either. Not questioning your numbers but it raises my eyebrows a bit.
__________________
BSE Racing Engines
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-20-2014, 10:47 AM
awsomeears's Avatar
Registered User
 
Last photo:
Join Date: Mar 2014
Location: Wisconsin
Posts: 72
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
I'm guilty of buying new rockers after the fact I checked in with my old rockers.

After work I'm going to remove the guide plates and check it again with my adjustable pushrod and start over...

I also thought 8.150 was long. My old edelbrock heads with a .480 cam used stock length
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-20-2014, 12:43 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,064
Wiki Edits: 0

Thanks: 17
Thanked 325 Times in 305 Posts
when you check the marks are you using a solid lifter, or a hydraulic lifter that has somehow been made solid?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-20-2014, 04:01 PM
spinn's Avatar
Bubbles is the girl next door
 

Last journal entry: This makes a huge difference
Last photo:
Join Date: Oct 2004
Location: Midnight
Posts: 2,495
Wiki Edits: 0

Thanks: 13
Thanked 82 Times in 80 Posts
This is what I think about the one on the left, the black packman looking stem top.

The reason only part of it is contacting / wiping, is because it is wobbling. You do not have the lock nut on the square base(circled in red) of the fulcrum piece. The square is what is held up against the rocker nut. You are probably on the round part and not stable.

This is a total guess. It could be.

Picture.
Attached Thumbnails
Click image for larger version

Name:	23578.jpg
Views:	61
Size:	120.0 KB
ID:	168050  
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-20-2014, 04:47 PM
4 Jaw Chuck's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Mar 2002
Location: Manitoba, Canada
Age: 46
Posts: 4,973
Wiki Edits: 0

Thanks: 2
Thanked 89 Times in 72 Posts
The slight alignment issue is likely a rocker stud out a bit, a quick tap with a soft face hammer can straighten that up.
__________________
Outlawed tunes from outlawed pipes
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-20-2014, 11:45 PM
awsomeears's Avatar
Registered User
 
Last photo:
Join Date: Mar 2014
Location: Wisconsin
Posts: 72
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Thanks for all the help...

Profiler uses such Cheap JUNK guide plates, there not even exactly flat and on all of them near the corners theres extra metal, I was able to flip them over but I still don't trust them.

So what I did is I grabbed a washer to take place of my guide plate thickness, re-measured at they started to all turn out much better.

I'm finding 8.200 ( 8 revolutions on adjustable push rod ) is much cleaner, and that 9 revolutions 8.25 Length is slightly thinner but is getting away from the center a decent amount towards the exhaust port.

I called Profiler for Stud torque recommendations ( before I even started to work on the motor tonight ) and then breifly discussed my odd results. While talking with him he said

" Yea those guide plates are pretty chincey "

Well ya wouldn't say

I'm calling them tomorrow and letting them know this is bull ****, not only that my 1st set of heads had TWO spark plug threads garffed up.

I went with Profiler as there smaller a smaller company and also simply to not follow the heard of AFR or Edelbrock and now I'm questioning why I did so.

I'll update this as we go

Any recommendations on Quality guide plates ?





Quote:
Originally Posted by ap72 View Post
when you check the marks are you using a solid lifter, or a hydraulic lifter that has somehow been made solid?
Yes solid lifter @ Zero lash then rotate a bunch of times...
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-21-2014, 12:17 AM
awsomeears's Avatar
Registered User
 
Last photo:
Join Date: Mar 2014
Location: Wisconsin
Posts: 72
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
I should also add getting these rockers straight over my valve steam would be one hell of a chore, so the adjustable guideplates should work. But is that common to have a full set of 8 needed ?

Thanks again...

http://www.summitracing.com/parts/cc...make/chevrolet
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-21-2014, 12:20 AM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 9,388
Wiki Edits: 0

Thanks: 29
Thanked 468 Times in 425 Posts
I've always liked Milodon guideplates, the raised versions. Erson and Isky make good flat style, Isky makes an adjustable spacing version for perfect tip alignment.

Dart also uses a pretty cheap guideplate, and studs are cheap looking too,..... it just doesn't inspire confidence when you see this in a new set of heads though, does it??!!.

Seems like nobody completely does a quality job anymore in the $1100 or under arena. Last I saw personally was ProTopline/ProAction, before they sold out to RHS.

I had hoped Profiler wouldn't let their quality fall off from their initial offerings....

Last edited by ericnova72; 08-21-2014 at 12:25 AM. Reason: Milodon, in place of Moroso.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-21-2014, 12:36 AM
awsomeears's Avatar
Registered User
 
Last photo:
Join Date: Mar 2014
Location: Wisconsin
Posts: 72
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by ericnova72 View Post
I've always liked Milodon guideplates, the raised versions. Erson and Isky make good flat style, Isky makes an adjustable spacing version for perfect tip alignment.

Dart also uses a pretty cheap guideplate, and studs are cheap looking too,..... it just doesn't inspire confidence when you see this in a new set of heads though, does it??!!.

Seems like nobody completely does a quality job anymore in the $1100 or under arena. Last I saw personally was ProTopline/ProAction, before they sold out to RHS.

I had hoped Profiler wouldn't let their quality fall off from their initial offerings....
Yea its been a big headache really, and what sucks is that I wasn't focused on the $$$ just a good product. You get what you pay for and I'm feeling shorted here. I will ask them to ship me a set of guide plates and see what they say...

I'm worried that if I get another NON adjustable set that they won't line up.

Whats the difference between the raised and flat, clearly they look different but ?

Summit has milodon but only the 10750 model and I don't see adjustables.
http://www.summitracing.com/parts/mil-10750/overview/
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 7 (2 members and 5 guests)
engineczar, BuzzLOL
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Valve Stem Seals mightycarlo10 Engine 5 05-16-2009 08:38 PM
Valve Stem size hallamwillis Engine 2 04-09-2007 08:19 PM
Valve stem seals atlantis Engine 3 03-26-2006 04:31 PM
valve stem size? Turbo Terror Engine 1 02-06-2006 09:25 AM
valve stem seals HQ Pete Engine 2 04-02-2002 12:04 AM


All times are GMT -6. The time now is 06:52 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.