Umbrella Seal Clearance inside Valve Spring - Hot Rod Forum : Hotrodders Bulletin Board -- 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
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 08-20-2007, 08:22 PM
dirtydave's Avatar
Join Date: Oct 2003
Location: so. cal
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Umbrella Seal Clearance inside Valve Spring

working on a SBC and was just wondering what kind of clearance I need between the inside diameter of my inner valve spring and the outside diameter of my umbrella seal. thank you!

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 08-21-2007, 06:03 AM
F&J F&J is offline
Registered User

Last journal entry: 32 Ford cabriolet conversion/windshield
Last photo:
Join Date: Mar 2007
Location: Connecticut
Age: 65
Posts: 1,571
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
There was a thread on that a few months back here. I think it was Tom ? that runs a engine machine shop; said to use "studebaker V-8" valve seals so you don't have to machine the heads for clearance.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-28-2007, 01:55 PM
dirtydave's Avatar
Join Date: Oct 2003
Location: so. cal
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for your reply F&J

Let me elaborate a little more on my setup. My guides are already machined to accept a small diameter positive valve stem seal. My valve springs fit over these nicely as well. The problem lies with the exhaust valves since I am going to run rubber umbrella seals on them to allow some oil down the stem. Intakes are gonna have the positive seals on them.

The problem is, I can't find any umbrella seals that will fit inside my valve springs without rubbing on the inner spring. I would think that they would come apart pretty quick from the friction if I installed them like this.

So I was thinking of using a positive style seal with a smaller outside diameter that will fit inside the spring, but I'll remove the metal rings from the seal so it can't grip the guide. I would imagine if I did this, the seal with travel up the valve and stay in that position to act as a normal umbrella seal. What do you guys think?

Thanks a bunch
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-28-2007, 06:17 PM
techinspector1's Avatar
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Zephyrhills, Florida, USA
Age: 75
Posts: 15,329
Wiki Edits: 326

Thanks: 1,500
Thanked 2,019 Times in 1,559 Posts
Never had this problem because I don't use umbrellas. If I did, I'd machine the spring pockets and use a larger diameter spring for clearance.

With positive seals, I use a very small, fine tooth triangular file and make a shallow cut on the inner diameter at one or two places to allow a little oil down the valve to lube the stem and guide.

I'd say that in a perfect world, your idea of using a positive seal without the guide boss clamp would work. But it's an imperfect world and I can see the valve angling around enough to catch the edge of the seal on the guide boss and push it up on the valve, where it will stay for the remainder of its tenure.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


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
Valve Spring Tester W/o Taking The Springs Off? tiresmoke55 Garage - Tools 1 09-09-2006 06:02 AM
Rocker to Spring Clearance AFR Springs DTL504 Engine 2 06-02-2004 12:38 PM
Broken valve spring??? Miligav383 Engine 6 05-16-2004 09:40 PM
small block valve seal question, o-rings? propaniac Engine 2 11-23-2003 01:39 PM
broken valve spring dampner nastynova Engine 18 07-04-2003 09:28 PM

All times are GMT -6. The time now is 01:45 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.