Guide and spring height questions. - 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 08-06-2009, 04:21 PM
6426yy's Avatar
Member
 
Last photo:
Join Date: Nov 2003
Location: Macomb Il.
Age: 34
Posts: 536
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Guide and spring height questions.

I'm trying to finish up my BB 781 heads. I bought the guide cutter and seals, shim kit, and EV rotator eliminators.

I'm using all comp cams hardware.
Cam 4x4 extreme 270H
Springs 924-16
Locks 612-16
Retainers 714-14

Now my springs call for an installed height of 1.900"
On the Exhaust with the Spacers in place I get an installed height of 1.840"
and 1.850 on the Intakes.
All measurement are made with a spring mic.

I think the easy solution is to buy +.050 locks this would get me within about .010. Is this close enough?

Now on the seals, how far to I cut down the guides? Should I trim them off with a cut-off wheel or something first to gain additional clearance, or just let cutter cut them down?

from my rough measurements I get .540 from the seal to the bottom of the retainer which isn't enough I know. Granted I haven't cut the guide yet I just roughly measured the seal its self and subtracted that from the retainer to guide.

Sorry so long winded
Thanks in advance

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-06-2009, 04:32 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 8,925
Wiki Edits: 0

Thanks: 19
Thanked 370 Times in 339 Posts
Yes, .010" on the installed height will be close enough, but be aware that the +.050" locks might put you into a spring retainer to rocker arm body interference situation depending on what rockers you are using and the tip length of the valve.

Just use the seal cutter to cut down the guide, you need a .060" seal to retainer minimum clearance at max lift.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-06-2009, 07:13 PM
6426yy's Avatar
Member
 
Last photo:
Join Date: Nov 2003
Location: Macomb Il.
Age: 34
Posts: 536
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
ericnova72,

Thanks for the reply, so I can just use the cutter to cut the guide all the way down? .060 was what I was thinking but I figure if I decide to install larger valves and maybe a hydraulic roller someday I might as well get as much clearance as I can. Can I cut them down to the spring seat? This would be about an inch, I don't want to dull the damn thing it was kind of expensive. I was wondering if I could use a cut off wheel to shorten them first then use the cutter, would this work or should I not bother.

Thanks again.
Jesse
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-07-2009, 08:49 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,542
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 328 Posts
Do not cut the guide boss all the way down. The valve guide is what supports and cools the valve stem. Shorter guide boss ='s less valve stem support. Aftermarket seals tend to be thicker (taller) than OEM so you have to figure that into how much to shorten the guide top.
BBC's don't even get busy until you got around .600" lift at the valve so now that you are there, modify the guide boss to accept the new seals and a decent cam. say .650" cam (valve lift) +.060" clearance or .710" net clearance between the retainer and installed valve seal.
If your measurment was taken witht he new seal and retainer:
Looks like you want to shorten the guide by .200"
This more or less default .200" figure is how much I routinely shorten stock SBC head guides by.

If the new springs call for a 1.90" installed height +/-.020" should be good.

Last edited by F-BIRD'88; 08-07-2009 at 08:56 AM.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-07-2009, 10:38 AM
6426yy's Avatar
Member
 
Last photo:
Join Date: Nov 2003
Location: Macomb Il.
Age: 34
Posts: 536
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Thanks F Bird,

Do most cutters shorten the guide also? I cut down one of the Exhausts today and the cutter doesn't seem to want to cut the guide shorter. It has the third carbide that is higher that the first two.
Am I missing something?

It is a Howards cutter

HRS-92045
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-07-2009, 01:18 PM
Registered User
 
Join Date: Oct 2008
Location: Mora,MN
Posts: 414
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 6 Posts
Most of those style cutters are designed to reduce the ID
of the guide, and put a chamfer on the top of the guide. They
are not designed to cut the spring pocket, or reduce guide height.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-12-2009, 01:59 PM
6426yy's Avatar
Member
 
Last photo:
Join Date: Nov 2003
Location: Macomb Il.
Age: 34
Posts: 536
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
So, is there a cutter available to shorten the guide it's self? Or is there another way to cut it down?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-12-2009, 02:03 PM
Registered User
 
Join Date: Oct 2008
Location: Mora,MN
Posts: 414
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 6 Posts
I normally use a counter bore with appropriate pilot, but I do it in a seat and guide machine, I don't know how it would work to do that with a hand drill. Maybe if you had a drill press and could put the head at the proper angle you could get it to work.
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: 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
Checking spring installed height? nastynova Engine 15 05-09-2008 08:12 PM
Help on cam choice? 400 vortec rpm dual quads/also spring questions? Twistedwrench Engine 8 08-02-2007 05:04 PM
Valve Spring/Rocker Ratio Help 70bird Engine 6 04-14-2007 12:31 PM
what governs proper installed height? sizemoremk Engine 25 01-14-2006 07:10 AM
Valve Spring Seat Question Garbonzo Bojangles Hotrodding Basics 3 01-08-2005 12:09 PM


All times are GMT -6. The time now is 11:17 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.