What is the purpose of stock Oil Deflectors - 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 01-26-2011, 06:22 PM
Registered User
 
Last photo:
Join Date: Nov 2010
Location: Roselle, Illinois
Posts: 188
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
What is the purpose of stock Oil Deflectors

Small block Chevy. The stock valve springs have metal oil deflectors on top of the valve springs. What is their purpose? I have new valve springs that came with my cam, and they have new retainers and locks. I know people don't use the stock deflectors. I was under the impression they were there for oil control. Why would you not reuse the deflectors with new springs? I assume that GM designed them and spent money to put them on originally for some good reason. Just curious...

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-26-2011, 06:32 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,175
Wiki Edits: 0

Thanks: 26
Thanked 280 Times in 260 Posts
Correct. They are for oil control. On the old style heads. The ones with the little O-ring that goes under the valve keepers. The combination of the O-ring seal and the "shields" made a large umbrella over the valve.

The shield ads weight to the assembly. Weight is bad for RPM. They also have a habit of coming apart on high rpm motors and interfere with the spring on higher valve lifts.Later Chevy heads eliminated the system completely. Most people go for at least an umbrella rubber seal on high perf stuff. Positive seals are much better.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-27-2011, 12:50 AM
Registered User
 
Join Date: Jan 2011
Location: New York
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hi
It Redirects oil frm push rods to the fulcrm bals, rockrs and springz to provides maX lubrication and coolng. It Extends life of stocks valves train assembly. produced from light-weight aluminum. .
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-27-2011, 08:07 AM
Registered User
 
Last photo:
Join Date: Nov 2010
Location: Roselle, Illinois
Posts: 188
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
If that's the case, would it be recommended to use them ona street engine with stock size aftermarket springs (Comp 981-16)?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-27-2011, 09:04 AM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,954
Wiki Edits: 0

Thanks: 4
Thanked 482 Times in 412 Posts
Quote:
Originally Posted by Dougie
If that's the case, would it be recommended to use them ona street engine with stock size aftermarket springs (Comp 981-16)?
If you have a choice between shields with O rings or using a Viton stem seal, have the stem seals put on and discard the shield and O ring. This assumes the guide to stem clearance is correct, the shields do a better job of keeping oil away from the stems in the first place so when the guide to stem clearance wears beyond spec the oil consumption down the guide doesn't become too bad. With a seal, the stem and top of the guide is constantly exposed to oil with only the quality of the seal keeping oil out of the guide. If the clearance becomes excessive; the stem wanders around in the guide which prevents an oil tight fit between the seal and stem. So the stem seal is less tolerant of stem and guide wear than the shield.

But wait, there is another issue, that of using the top end oil to cool the valve springs. For a stone stock engine that doesn't work very hard cooling the valve spring isn't much of an issue. But if you're adding a hotter cam, higher spring pressure, or just like to rev the engine up, the springs get really hot and are known to break. The shield arraignment which prevents oil from being thrown on the spring in this case also works to cause the spring to run too hot.

So which way you go is dependent on how the engine will be used as much as anything.

Bogie
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-27-2011, 10:15 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by Dougie
Why would you not reuse the deflectors with new springs? I assume that GM designed them and spent money to put them on originally for some good reason. *AND* If that's the case, would it be recommended to use them on a street engine with stock size aftermarket springs (Comp 981-16)?
That spring has an ID of 0.880". It has a seat pressure of 105# @ 1.7" installed height and an open pressure of 273# @ 1.250". This tells me the cam you're running is fairly mild, and wouldn't be run at elevated RPM.

IF that's the case, the deflectors wouldn't be such a bad thing to use- especially if you were going to use an O-ring type stem 'seal'. But it has already been pointed out that they're not necessary if using positive seals.

That spring has a sufficient ID to be able to use an "umbrella" seal, if you wanted. These are often used w/o the deflectors, but they do not do as good of a job as positive seals. To use the positive seals, the valve guide boss has to be machined to a smaller OD for the seals to fit properly.

There are metal ringed stem seals that fit over the stock, unmachined guide boss, but I have no experience w/how well they work.

IF you choose to use the steel umbrellas (I don't know where the idea came from above that they are made of "light-weight aluminum" ), be sure you add their thickness to the installed height when you set up the springs.

Many times, a exhaust valve "rotator" was used in conjunction w/the steel umbrellas. Do not reuse the rotators if they were on your heads originally. Use eight retainers like what's on the intakes instead.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-27-2011, 11:26 AM
SSedan64's Avatar
Registered User
 
Last photo:
Join Date: Dec 2007
Location: Macon, GA.
Age: 50
Posts: 6,016
Wiki Edits: 0

Thanks: 0
Thanked 46 Times in 46 Posts
Cobalt, the Post above with the "Aluminum" comment is a Spammer trying to get his Post count up so members will click on His Spam links in His other Posts.
If you saw this Pic in a few Threads it was aimed at "Carrick"
Attached Thumbnails
Click image for larger version

Name:	SPAM.jpg
Views:	52
Size:	42.5 KB
ID:	51958  
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:
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: 1 (0 members and 1 guests)
 
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
what is the purpose of a fan clutch? cares Engine 7 02-11-2010 07:56 AM
Purpose of the headliner Jillopy33 Interior 5 08-27-2009 07:05 AM
Quick question: Where can you buy oil deflectors for adjusting valves on a chevrolet? loyter Hotrodders' Lounge 6 04-23-2007 11:30 PM
What's the purpose of this piece? cboy Transmission - Rearend 1 03-23-2007 08:29 PM
Introduction and Purpose mblue1013 Introduce Yourself 2 11-14-2004 12:17 PM


All times are GMT -6. The time now is 03:38 PM.


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.