GN and T-Type Performance Enthusiasts (GNTTYPE) Forums GN and T-Type Performance Enthusiasts (GNTTYPE) Forums
This is a general site search and does not include list archives.

Go Back   GN and T-Type Performance Enthusiasts (GNTTYPE) Forums > Technical Topics > Engine Mechanical

Reply
 
Thread Tools Display Modes
  #1  
Old 09-12-2007, 10:21 PM
jcawley3's Avatar
jcawley3 jcawley3 is offline
Senior Member
 
Join Date: Feb 2007
Location: South Carolina
Posts: 150
jcawley3 is on a distinguished road
Default Valve Springs

would someone give me a quick lesson on valve springs......I read a lot of people upgrading to the 100lb springs....is there a big differance or just a maintance thing, there only $55. or is it hell putting them on? is something I should get?


ps. sorry if this is the wrong topic for this thread was not sure where to put it......
Reply With Quote
  #2  
Old 09-13-2007, 09:50 AM
kenmosher's Avatar
kenmosher kenmosher is offline
Whoosh
 
Join Date: Aug 2004
Location: CO
Posts: 3,984
kenmosher is on a distinguished road
Default Re: Valve Springs

The stock springs fatigue pretty quickly and are 80# when new. After 10-20K miles I've seen them test as low as 50# (which is too low when running 20# of boost pressure pushing on the valve).

IF you are going to replace the cam with a more aggressive, fast ramp cam, then you need more spring pressure (like the 100# springs). If you are running the stock cam, then stick with the Comp Cams 80# replacement springs (CC980??)

In either case, modern oil formulations have removed a LOT of the ZDPP (Zinc) to protect catalytic converters. Unfortunately, it seems to be leading to a lot of wiped cam lobes in flat tappet cam applications like ours (most modern engines are roller cams). It is recommended that flat tappet cam users (especially if going with higher pressure springs) use a engine oil supplement with Zinc and Phosphate in it ... Crane Cams makes one, Redline's synthetic oils have it in it, the diesel oils have it, and GM makes an EOS.

This has come about with the latest round of API specifications ...
__________________
Ken Mosher
1987 GN original owner 650+ HP Black
2015 BMW 328xi XDrive wagon
2012 Volkswagen Tiguan (the Tig!) Night Blue Met (sold)
2006 Trailblazer SS Red Jewel Tint 395 HP AWD (sold)
2014 Silverado LTZ Crew 4WD
2012 Honda VFR 1200F Tahitian Blue (sold)
2015 BMW S1000R Racing Red
2013 Honda CBR500R Red (wife's bike)
2014 Triumph Bonneville T100
2003 Harley Davidson V Rod Anniversary Edition
Reply With Quote
  #3  
Old 09-13-2007, 11:45 AM
PaCemkr86's Avatar
PaCemkr86 PaCemkr86 is offline
Tech Support
 
Join Date: Jan 2005
Location: Texas
Posts: 4,817
PaCemkr86 is on a distinguished road
Send a message via AIM to PaCemkr86
Default Re: Valve Springs

If you are running the stock cam, then stick with the Comp Cams 80# replacement springs (CC980??)

ive installed these on many high mileage TR's and there is a huge difference when done...

Are you going to do this yourself?

Its not hard, just takes some time
__________________
Phil Underwood

My Turbo Buick
Reply With Quote
  #4  
Old 09-13-2007, 01:05 PM
Electrajim Electrajim is offline
Senior Member
 
Join Date: Sep 2004
Location: Missouri
Posts: 143
Electrajim is on a distinguished road
Send a message via AIM to Electrajim Send a message via Yahoo to Electrajim
Default Re: Valve Springs

You'll need a few special tools too.
Air compressor, fitting to connect it to the spark plug hole, and a valve spring compressor tool.

Back ones are a little tight and a PITA.
Sometimes the valve keepers stick, requiring a shot of penetration oil on them, and a quick "rap of a hammer" to free them from the retainer/valve. I used a socket on the end of an extension.

I've only done this once on a V6, added 2'nd springs on a V8.

Good valve springs are important in these cars, however like Ken said, too much pressure can be fatal to the camshaft.

Stick with the 980's and leave the OEM "cup" off like I did.
Worked for me for a while w/o any problems.....then I put ported heads on.

ElectraJim
Reply With Quote
  #5  
Old 09-13-2007, 03:44 PM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,424
Keller is on a distinguished road
Lightbulb Re: Valve Springs

I used 979's with cups on. Here is a previous thread with P/N's and rates included.

http://www.gnttype.org/forums/showth...=valve+springs
__________________
Scott Keller - GNTTYPE Founder & Moderator
Reply With Quote
  #6  
Old 09-13-2007, 04:59 PM
PaCemkr86's Avatar
PaCemkr86 PaCemkr86 is offline
Tech Support
 
Join Date: Jan 2005
Location: Texas
Posts: 4,817
PaCemkr86 is on a distinguished road
Send a message via AIM to PaCemkr86
Default Re: Valve Springs

ive also found that the CC 980's work with a roller cam if you remove the cups " for correct height and seat pressures.. " with the cups installed major coil bind and causes the roller lifters to make noise.

but for what its worth, ive seen many stock cammed TR's come back to life with a fresh set of valve springs.. the performance all around is improved
__________________
Phil Underwood

My Turbo Buick
Reply With Quote
  #7  
Old 09-14-2007, 03:54 PM
jcawley3's Avatar
jcawley3 jcawley3 is offline
Senior Member
 
Join Date: Feb 2007
Location: South Carolina
Posts: 150
jcawley3 is on a distinguished road
Default Re: Valve Springs

no, I don't think I'm ready to tackle this one, I have someone do this for me....my GN has 117K, after reading some other posts I figured mine could probably use some........however I think I'm starting to get a brake issue.....pls see brake section
Reply With Quote
  #8  
Old 09-18-2007, 05:53 AM
81 elky 81 elky is offline
81 elky
 
Join Date: Mar 2007
Location: Texas
Posts: 222
81 elky is on a distinguished road
Default Re: Valve Springs

What is the correct procedure for re-installing the rocker arm shaft? A little tightening on each bolt at a time? What's the torque spec?
Reply With Quote
  #9  
Old 09-18-2007, 09:56 AM
kenmosher's Avatar
kenmosher kenmosher is offline
Whoosh
 
Join Date: Aug 2004
Location: CO
Posts: 3,984
kenmosher is on a distinguished road
Default Re: Valve Springs

Yep ... and go from the middle outwards.

As per:

http://www.gnttype.org/techarea/misc/torque.html

25 ft lbs
__________________
Ken Mosher
1987 GN original owner 650+ HP Black
2015 BMW 328xi XDrive wagon
2012 Volkswagen Tiguan (the Tig!) Night Blue Met (sold)
2006 Trailblazer SS Red Jewel Tint 395 HP AWD (sold)
2014 Silverado LTZ Crew 4WD
2012 Honda VFR 1200F Tahitian Blue (sold)
2015 BMW S1000R Racing Red
2013 Honda CBR500R Red (wife's bike)
2014 Triumph Bonneville T100
2003 Harley Davidson V Rod Anniversary Edition
Reply With Quote
  #10  
Old 09-18-2007, 12:42 PM
JRI5906 JRI5906 is offline
Member
 
Join Date: Feb 2007
Posts: 51
JRI5906 is on a distinguished road
Thumbs up Re: Valve Springs

So it is agreed that we leave the cup off when using the 980's?

Please chime in. thanks
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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
Forum Jump


All times are GMT -4. The time now is 08:03 AM.


This page maintained by: gnttype-webmaster@gnttype.org

The content, images, text and multimedia displayed and contributed by the members of the Grand National and T-Type Performance Enthusiasts Organization are Copyright ©1996-2005. No part, section, image, article or whole of this site may be reposted or redisplayed without permission of the author/contributor and/or the Grand National and T-Type Performance Enthusiasts Organization.

Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.