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#1
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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...... |
#2
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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 |
#3
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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 |
#4
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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 |
#5
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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
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Scott Keller - GNTTYPE Founder & Moderator
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#6
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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 |
#7
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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
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#8
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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?
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#9
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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 |
#10
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Re: Valve Springs
So it is agreed that we leave the cup off when using the 980's?
Please chime in. thanks |
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